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Shi Z, Zhao M, Wang K, Ma S, Luo H, Han Q, Shi Y. Acidification alleviates the inhibition of hyposaline stress on physiological performance of tropical seagrass Thalassia hemprichii. MARINE POLLUTION BULLETIN 2024; 205:116642. [PMID: 38941803 DOI: 10.1016/j.marpolbul.2024.116642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 03/03/2024] [Accepted: 06/19/2024] [Indexed: 06/30/2024]
Abstract
Since the Industrial Revolution, increasing atmospheric CO2 concentrations have had a substantial negative impact influence on coastal ecosystems because of direct effects including ocean acidification and indirect effects such as extreme rainfall events. Using a two-factor crossover indoor simulation experiment, this study examined the combined effects of acidification and hyposaline stress on Thalassia hemprichii. Seawater acidification increased the photosynthetic pigment content of T. hemprichii leaves and promoted seagrass growth rate. Hyposaline stress slowed down seagrass growth and had an impact on the osmotic potential and osmoregulatory substance content of seagrass leaves. Acidification and salinity reduction had significant interaction effects on the photosynthesis rate, photosynthetic pigment content, chlorophyll fluorescence parameters, and osmotic potential of T. hemprichii, but not on the growth rate. Overall, these findings have shown that the hyposaline stress inhibitory effect on the T. hemprichii physiological performance and growth may be reduced by acidification.
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Affiliation(s)
- Zhiqiang Shi
- Yazhou Bay Innovation Institute, Hainan Tropical Ocean University, Sanya 572022, China
| | - Muqiu Zhao
- Yazhou Bay Innovation Institute, Hainan Tropical Ocean University, Sanya 572022, China; Modern Marine Ranching Engineering Research Center of Hainan, Sanya 572022, China; Key Laboratory for Coastal Marine Eco-Environment Process and Carbon Sink of Hainan, Sanya 572022, China
| | - Kang Wang
- Yazhou Bay Innovation Institute, Hainan Tropical Ocean University, Sanya 572022, China
| | - Siyang Ma
- Yazhou Bay Innovation Institute, Hainan Tropical Ocean University, Sanya 572022, China
| | - Huijue Luo
- Yazhou Bay Innovation Institute, Hainan Tropical Ocean University, Sanya 572022, China
| | - Qiuying Han
- Yazhou Bay Innovation Institute, Hainan Tropical Ocean University, Sanya 572022, China; Modern Marine Ranching Engineering Research Center of Hainan, Sanya 572022, China; Key Laboratory for Coastal Marine Eco-Environment Process and Carbon Sink of Hainan, Sanya 572022, China
| | - Yunfeng Shi
- Yazhou Bay Innovation Institute, Hainan Tropical Ocean University, Sanya 572022, China; Modern Marine Ranching Engineering Research Center of Hainan, Sanya 572022, China; Key Laboratory for Coastal Marine Eco-Environment Process and Carbon Sink of Hainan, Sanya 572022, China.
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Losciale R, Day JC, Rasheed MA, Heron SF. The vulnerability of World Heritage seagrass habitats to climate change. GLOBAL CHANGE BIOLOGY 2024; 30:e17113. [PMID: 38273578 DOI: 10.1111/gcb.17113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 10/13/2023] [Accepted: 11/28/2023] [Indexed: 01/27/2024]
Abstract
Seagrass is an important natural attribute of 28 World Heritage (WH) properties. These WH seagrass habitats provide a wide range of services to adjacent ecosystems and human communities, and are one of the largest natural carbon sinks on the planet. Climate change is considered the greatest and fastest-growing threat to natural WH properties and evidence of climate-related impacts on seagrass habitats has been growing. The main objective of this study was to assess the vulnerability of WH seagrass habitats to location-specific key climate stressors. Quantitative surveys of seagrass experts and site managers were used to assess exposure, sensitivity and adaptive capacity of WH seagrass habitats to climate stressors, following the Climate Vulnerability Index approach. Over half of WH seagrass habitats have high vulnerability to climate change, mainly from the long-term increase in sea-surface temperature and short-term marine heatwaves. Potential impacts from climate change and certainty scores associated with them were higher than reported by a similar survey-based study from 10 years prior, indicating a shift in stakeholder perspectives during the past decade. Additionally, seagrass experts' opinions on the cumulative impacts of climate and direct-anthropogenic stressors revealed that high temperature in combination with high suspended sediments, eutrophication and hypoxia is likely to provoke a synergistic cumulative (negative) impact (p < .05). A key component contributing to the high vulnerability assessments was the low adaptive capacity; however, discrepancies between adaptive capacity scores and qualitative responses suggest that managers of WH seagrass habitats might not be adequately equipped to respond to climate change impacts. This thematic assessment provides valuable information to help prioritize conservation actions, monitoring activities and research in WH seagrass habitats. It also demonstrates the utility of a systematic framework to evaluate the vulnerability of thematic groups of protected areas that share a specific attribute.
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Affiliation(s)
- Riccardo Losciale
- College of Science and Engineering, James Cook University, Townsville, Queensland, Australia
| | - Jon C Day
- College of Science and Engineering, James Cook University, Townsville, Queensland, Australia
| | - Michael A Rasheed
- Centre for Tropical Water and Aquatic Ecosystem Research, James Cook University, Cairns, Queensland, Australia
| | - Scott F Heron
- College of Science and Engineering, James Cook University, Townsville, Queensland, Australia
- Physics and Marine Geophysical Laboratory, College of Science and Engineering, James Cook University, Townsville, Queensland, Australia
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3
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Ricart AM, Honisch B, Fachon E, Hunt CW, Salisbury J, Arnold SN, Price NN. Optimizing marine macrophyte capacity to locally ameliorate ocean acidification under variable light and flow regimes: Insights from an experimental approach. PLoS One 2023; 18:e0288548. [PMID: 37819926 PMCID: PMC10566731 DOI: 10.1371/journal.pone.0288548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Accepted: 06/29/2023] [Indexed: 10/13/2023] Open
Abstract
The urgent need to remediate ocean acidification has brought attention to the ability of marine macrophytes (seagrasses and seaweeds) to take up carbon dioxide (CO2) and locally raise seawater pH via primary production. This physiological process may represent a powerful ocean acidification mitigation tool in coastal areas. However, highly variable nearshore environmental conditions pose uncertainty in the extent of the amelioration effect. We developed experiments in aquaria to address two interconnected goals. First, we explored the individual capacities of four species of marine macrophytes (Ulva lactuca, Zostera marina, Fucus vesiculosus and Saccharina latissima) to ameliorate seawater acidity in experimentally elevated pCO2. Second, we used the most responsive species (i.e., S. latissima) to assess the effects of high and low water residence time on the amelioration of seawater acidity in ambient and simulated future scenarios of climate change across a gradient of irradiance. We measured changes in dissolved oxygen, pH, and total alkalinity, and derived resultant changes to dissolved inorganic carbon (DIC) and calcium carbonate saturation state (Ω). While all species increased productivity under elevated CO2, S. latissima was able to remove DIC and alter pH and Ω more substantially as CO2 increased. Additionally, the amelioration of seawater acidity by S. latissima was optimized under high irradiance and high residence time. However, the influence of water residence time was insignificant under future scenarios. Finally, we applied predictive models as a function of macrophyte biomass, irradiance, and residence time conditions in ambient and future climatic scenarios to allow projections at the ecosystem level. This research contributes to understanding the biological and physical drivers of the coastal CO2 system.
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Affiliation(s)
- Aurora M. Ricart
- Bigelow Laboratory for Ocean Sciences, East Boothbay, Maine, United States America
| | - Brittney Honisch
- Bigelow Laboratory for Ocean Sciences, East Boothbay, Maine, United States America
| | - Evangeline Fachon
- Massachusetts Institute of Technology, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, United States of America
| | - Christopher W. Hunt
- Ocean Process Analysis Laboratory, University of New Hampshire, Durham, NH,, United States of America
| | - Joseph Salisbury
- Ocean Process Analysis Laboratory, University of New Hampshire, Durham, NH,, United States of America
| | | | - Nichole N. Price
- Bigelow Laboratory for Ocean Sciences, East Boothbay, Maine, United States America
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Pansini A, Beca-Carretero P, Berlino M, Sarà G, Stengel DB, Stipcich P, Ceccherelli G. Field development of Posidonia oceanica seedlings changes under predicted acidification conditions. MARINE ENVIRONMENTAL RESEARCH 2023; 186:105946. [PMID: 36917890 DOI: 10.1016/j.marenvres.2023.105946] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 03/06/2023] [Accepted: 03/07/2023] [Indexed: 06/18/2023]
Abstract
Ocean acidification has been consistently evidenced to have profound and lasting impacts on marine species. Observations have shown seagrasses to be highly susceptible to future increased pCO2 conditions, but the responses of early life stages as seedlings are poorly understood. This study aimed at evaluating how projected Mediterranean Sea acidification affects the survival, morphological and biochemical development of Posidonia oceanica seedlings through a long-term field experiment along a natural low pH gradient. Future ocean conditions seem to constrain the morphological development of seedlings. However, high pCO2 exposures caused an initial increase in the degree of saturation of fatty acids in leaves and then improved the fatty acid adjustment increasing unsaturation levels in leaves (but not in seeds), suggesting a nutritional compound translocation. Results also suggested a P. oceanica structural components remodelling which may counteract the effects of ocean acidification but would not enhance seagrass seedling productivity.
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Affiliation(s)
- Arianna Pansini
- Dipartimento di Architettura, Design e Urbanistica, Università degli Studi di Sassari, Via Piandanna 4, 07100, Sassari, Italy.
| | - Pedro Beca-Carretero
- Department of Oceanography, Instituto de Investigacións Mariñas (IIM-CSIC), 36208, Vigo, Spain; Botany and Plant Science, School of Natural Sciences, University of Galway, Galway, H91 TK33, Ireland
| | - Manuel Berlino
- Dipartimento di Scienze della Terra e del Mare (DISTEM), Università di Palermo, 90123, Palermo, Italy
| | - Gianluca Sarà
- Dipartimento di Scienze della Terra e del Mare (DISTEM), Università di Palermo, 90123, Palermo, Italy
| | - Dagmar B Stengel
- Botany and Plant Science, School of Natural Sciences, University of Galway, Galway, H91 TK33, Ireland
| | - Patrizia Stipcich
- Dipartimento di Architettura, Design e Urbanistica, Università degli Studi di Sassari, Via Piandanna 4, 07100, Sassari, Italy
| | - Giulia Ceccherelli
- Dipartimento di Scienze Chimiche, Fisiche, Matematiche e Naturali, Università degli Studi di Sassari, 07100, Sassari, Italy
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Celebi-Ergin B, Zimmerman RC, Hill VJ. Photorespiration in eelgrass ( Zostera marina L.): A photoprotection mechanism for survival in a CO 2-limited world. FRONTIERS IN PLANT SCIENCE 2022; 13:1025416. [PMID: 36438084 PMCID: PMC9692008 DOI: 10.3389/fpls.2022.1025416] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 10/10/2022] [Indexed: 06/16/2023]
Abstract
Photorespiration, commonly viewed as a loss in photosynthetic productivity of C3 plants, is expected to decline with increasing atmospheric CO2, even though photorespiration plays an important role in the oxidative stress responses. This study aimed to quantify the role of photorespiration and alternative photoprotection mechanisms in Zostera marina L. (eelgrass), a carbon-limited marine C3 plant, in response to ocean acidification. Plants were grown in controlled outdoor aquaria at different [CO2]aq ranging from ~55 (ambient) to ~2121 μM for 13 months and compared for differences in leaf photochemistry by simultaneous measurements of O2 flux and variable fluorescence. At ambient [CO2], photosynthesis was carbon limited and the excess photon absorption was diverted both to photorespiration and non-photochemical quenching (NPQ). The dynamic range of NPQ regulation in ambient grown plants, in response to instantaneous changes in [CO2]aq, suggested considerable tolerance for fluctuating environmental conditions. However, 60 to 80% of maximum photosynthetic capacity of ambient plants was diverted to photorespiration resulting in limited carbon fixation. The photosynthesis to respiration ratio (P E : R D) of ambient grown plants increased 6-fold when measured under high CO2 because photorespiration was virtually suppressed. Plants acclimated to high CO2 maintained 4-fold higher P E : R D than ambient grown plants as a result of a 60% reduction in photorespiration. The O2 production efficiency per unit chlorophyll was not affected by the CO2 environment in which the plants were grown. Yet, CO2 enrichment decreased the light level to initiate NPQ activity and downregulated the biomass specific pigment content by 50% and area specific pigment content by 30%. Thus, phenotypic acclimation to ocean carbonation in eelgrass, indicating the coupling between the regulation of photosynthetic structure and metabolic carbon demands, involved the downregulation of light harvesting by the photosynthetic apparatus, a reduction in the role of photorespiration and an increase in the role of NPQ in photoprotection. The quasi-mechanistic model developed in this study permits integration of photosynthetic and morphological acclimation to ocean carbonation into seagrass productivity models, by adjusting the limits of the photosynthetic parameters based on substrate availability and physiological capacity.
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Lebrasse MC, Schaeffer BA, Zimmerman RC, Hill VJ, Coffer MM, Whitman PJ, Salls WB, Graybill DD, Osburn CL. Simulated response of St. Joseph Bay, Florida, seagrass meadows and their belowground carbon to anthropogenic and climate impacts. MARINE ENVIRONMENTAL RESEARCH 2022; 179:105694. [PMID: 35850077 PMCID: PMC9924051 DOI: 10.1016/j.marenvres.2022.105694] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 06/22/2022] [Accepted: 06/23/2022] [Indexed: 05/26/2023]
Abstract
Seagrass meadows are degraded globally and continue to decline in areal extent due to human pressures and climate change. This study used the bio-optical model GrassLight to explore the impact of climate change and anthropogenic stressors on seagrass extent, leaf area index (LAI) and belowground organic carbon (BGC) in St. Joseph Bay, Florida, using water quality data and remotely-sensed sea surface temperature (SST) from 2002 to 2020. Model predictions were compared with satellite-derived measurements of seagrass extent and shoot density from the Landsat images for the same period. The GrassLight-derived area of potential seagrass habitat ranged from 36.2 km2 to 39.2 km2, averaging 38.0 ± 0.8 km2 compared to an observed seagrass extent of 23.0 ± 3.0 km2 derived from Landsat (range = 17.9-27.4 km2). GrassLight predicted a mean seagrass LAI of 2.7 m2 leaf m-2 seabed, compared to a mean LAI of 1.9 m2 m-2 estimated from Landsat, indicating that seagrass density in St. Joseph Bay may have been below its light-limited ecological potential. Climate and anthropogenic change simulations using GrassLight predicted the impact of changes in temperature, pH, chlorophyll a, chromophoric dissolved organic matter and turbidity on seagrass meadows. Simulations predicted a 2-8% decline in seagrass extent with rising temperatures that was offset by a 3-11% expansion in seagrass extent in response to ocean acidification when compared to present conditions. Simulations of water quality impacts showed that a doubling of turbidity would reduce seagrass extent by 18% and total leaf area by 21%. Combining climate and water quality scenarios showed that ocean acidification may increase seagrass productivity to offset the negative effects of both thermal stress and declining water quality on the seagrasses growing in St. Joseph Bay. This research highlights the importance of considering multiple limiting factors in understanding the effects of environmental change on seagrass ecosystems.
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Affiliation(s)
- Marie Cindy Lebrasse
- Oak Ridge Institute for Science and Education, U.S. Environmental Protection Agency, Durham, NC, USA; Department of Marine, Earth and Atmospheric Sciences, North Carolina State University, Raleigh, NC, USA.
| | - Blake A Schaeffer
- U.S. Environmental Protection Agency, Office of Research and Development, Durham, NC, USA
| | - Richard C Zimmerman
- Department of Ocean and Earth Sciences, Old Dominion University, Norfolk, VA, USA
| | - Victoria J Hill
- Department of Ocean and Earth Sciences, Old Dominion University, Norfolk, VA, USA
| | - Megan M Coffer
- Oak Ridge Institute for Science and Education, U.S. Environmental Protection Agency, Durham, NC, USA
| | - Peter J Whitman
- Oak Ridge Institute for Science and Education, U.S. Environmental Protection Agency, Durham, NC, USA
| | - Wilson B Salls
- U.S. Environmental Protection Agency, Office of Research and Development, Durham, NC, USA
| | - David D Graybill
- Oak Ridge Institute for Science and Education, U.S. Environmental Protection Agency, Durham, NC, USA
| | - Christopher L Osburn
- Department of Marine, Earth and Atmospheric Sciences, North Carolina State University, Raleigh, NC, USA
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Assessing the Effects of Ocean Warming and Acidification on the Seagrass Thalassia hemprichii. JOURNAL OF MARINE SCIENCE AND ENGINEERING 2022. [DOI: 10.3390/jmse10060714] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Seagrass beds serve as important carbon sinks, and it is thought that increasing the quantity and quality of such sinks could help to slow the rate of global climate change. Therefore, it will be important to (1) gain a better understanding of seagrass bed metabolism and (2) document how these high-productivity ecosystems are impacted by climate change-associated factors, such as ocean acidification (OA) and ocean warming (OW). A mesocosm-based approach was taken herein in which a tropical, Western Pacific seagrass species Thalassia hemprichii was cultured under either control or OA-simulating conditions; the temperature was gradually increased from 25 to 31 °C for both CO2 enrichment treatments, and it was hypothesized that this species would respond positively to OA and elevated temperature. After 12 weeks of exposure, OA (~1200 ppm) led to (1) increases in underground biomass and root C:N ratios and (2) decreases in root nitrogen content. Rising temperatures (25 to 31 °C) increased the maximum quantum yield of photosystem II (Fv:Fm), productivity, leaf growth rate, decomposition rate, and carbon sequestration, but decreased the rate of shoot density increase and the carbon content of the leaves; this indicates that warming alone does not increase the short-term carbon sink capacity of this seagrass species. Under high CO2 and the highest temperature employed (31 °C), this seagrass demonstrated its highest productivity, Fv:Fm, leaf growth rate, and carbon sequestration. Collectively, then, it appears that high CO2 levels offset the negative effects of high temperature on this seagrass species. Whether this pattern is maintained at temperatures that actually induce marked seagrass stress (likely beginning at 33–34 °C in Southern Taiwan) should be the focus of future research.
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Kaldy JE, Brown CA, Pacella SR. Carbon limitation in response to nutrient loading in an eelgrass mesocosm: influence of water residence time. MARINE ECOLOGY PROGRESS SERIES 2022; 689:1-17. [PMID: 35938055 PMCID: PMC9347230 DOI: 10.3354/meps14061] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Altered primary productivity associated with eutrophication impacts not only ecosystem structure but also the biogeochemical cycling of oxygen and carbon. We conducted laboratory experiments to empirically determine how residence time (1, 3, 10 d) influences eutrophication responses in a simplified Pacific Northwest Zostera marina-green macroalgal community. We expected long-residence time (RT) systems to exhibit eutrophication impairments. Instead, we observed an accumulation of nutrients at all RTs and a shift in the dissolved inorganic carbon speciation away from CO2 (aq) with unexpected consequences for eel grass plant condition, including shoot mortality. Most metrics responded more strongly to temperature treatments than to RT treatments. No dramatic shifts in the relative abundance of Z. marina and green macro algae were detected. Z. marina shoot density proliferated in cool temperatures (12°C) with a modest decline at 20°C. Eelgrass loss was associated with high total scale pH (pHT) and CO2 (aq) concentrations of <10 μmol kg-1 CO2 (aq), but not with high nutrients. Z. marina δ13C values support the hypo thesis that carbon availability was greater at short RT. Further, very low leaf sugar concentrations are consistent with extreme photosynthetic CO2 (aq) limitation. We suggest that the effects of extremely low environ mental car bon concentrations (CO2 (aq)) and increased respiration at warm temperatures (20°C) and other physiological processes can lead to internal carbon limitation and shoot mortality. Eutrophication responses to nutrient loading are more nuanced than just light limitation of eelgrass and require additional research on the interaction of the biogeochemical environment and plant physiology to better understand estuarine ecosystem disruption.
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Rodríguez A, Moreno-Borges S, Brito A. Response of Cymodocea nodosa to ocean acidification and warming in the Canary Islands: Direct and indirect effects. MARINE ENVIRONMENTAL RESEARCH 2022; 176:105603. [PMID: 35325757 DOI: 10.1016/j.marenvres.2022.105603] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 03/05/2022] [Accepted: 03/13/2022] [Indexed: 06/14/2023]
Abstract
As detected in warming and ocean acidification, global change can have profound impact on marine life. Its effects on seagrasses are becoming increasingly well-known, since several studies have focused on the responses of these species to global change conditions. However a few studies have assessed the combined effect of temperature and acidification on seagrasses. Overall in this study, the combined effects of increased ocean temperature and pH levels expected at the end of this century (+5 °C and pH 7.5) on Cymodocea nodosa from Canary Islands, were evaluated for one month through manipulative laboratory experiments. Growth, net production, respiration, gross primary production, chlorophyll-a concentration and its vulnerability to herbivory were quantified. Results showed a positive effect of decreased pH on growth and gross primary production, as well as greater vulnerability to consumption by the sea urchin Paracentrotus lividus. In contrast, increased temperature limited net and gross primary production. This study shows than in future scenarios, C. nodosa from the Canary Islands may be a losing species in the global change stakes.
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Affiliation(s)
- Adriana Rodríguez
- Departamento de Biología Animal, Edafología y Geología. Grupo de investigación BIOECOMAC. Facultad de Ciencias, Universidad de La Laguna, Spain; Grupo de investigación BIOCON, IU-ECOAQUA, Universidad de Las Palmas de Gran Canaria, Spain.
| | - Sergio Moreno-Borges
- Departamento de Biología Animal, Edafología y Geología. Grupo de investigación BIOECOMAC. Facultad de Ciencias, Universidad de La Laguna, Spain
| | - Alberto Brito
- Departamento de Biología Animal, Edafología y Geología. Grupo de investigación BIOECOMAC. Facultad de Ciencias, Universidad de La Laguna, Spain
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Beheshti KM, Williams SL, Boyer KE, Endris C, Clemons A, Grimes T, Wasson K, Hughes BB. Rapid enhancement of multiple ecosystem services following the restoration of a coastal foundation species. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2022; 32:e02466. [PMID: 34614246 PMCID: PMC9285811 DOI: 10.1002/eap.2466] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 05/17/2021] [Accepted: 05/27/2021] [Indexed: 06/13/2023]
Abstract
The global decline of marine foundation species (kelp forests, mangroves, salt marshes, and seagrasses) has contributed to the degradation of the coastal zone and threatens the loss of critical ecosystem services and functions. Restoration of marine foundation species has had variable success, especially for seagrasses, where a majority of restoration efforts have failed. While most seagrass restorations track structural attributes over time, rarely do restorations assess the suite of ecological functions that may be affected by restoration. Here we report on the results of two small-scale experimental seagrass restoration efforts in a central California estuary where we transplanted 117 0.25-m2 plots (2,340 shoots) of the seagrass species Zostera marina. We quantified restoration success relative to persistent reference beds, and in comparison to unrestored, unvegetated areas. Within three years, our restored plots expanded ~8,500%, from a total initial area of 29 to 2,513 m2 . The restored beds rapidly began to resemble the reference beds in (1) seagrass structural attributes (canopy height, shoot density, biomass), (2) ecological functions (macrofaunal species richness and abundance, epifaunal species richness, nursery function), and (3) biogeochemical functions (modulation of water quality). We also developed a multifunctionality index to assess cumulative functional performance, which revealed restored plots are intermediate between reference and unvegetated habitats, illustrating how rapidly multiple functions recovered over a short time period. Our comprehensive study is one of few published studies to quantify how seagrass restoration can enhance both biological and biogeochemical functions. Our study serves as a model for quantifying ecosystem services associated with the restoration of a foundation species and demonstrates the potential for rapid functional recovery that can be achieved through targeted restoration of fast-growing foundation species under suitable conditions.
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Affiliation(s)
- Kathryn M. Beheshti
- Department of Ecology and Evolutionary BiologyUniversity of California, Santa CruzSanta CruzCalifornia95060USA
| | - Susan L. Williams
- Department of Ecology and Evolutionary BiologyUniversity of California, DavisDavisCalifornia95616USA
| | - Katharyn E. Boyer
- Estuary & Ocean Science CenterSan Francisco State UniversityTiburonCalifornia94920USA
| | - Charlie Endris
- Moss Landing Marine LaboratoriesMoss LandingCalifornia95039USA
| | - Annakate Clemons
- Department of Ecology and Evolutionary BiologyUniversity of California, Santa CruzSanta CruzCalifornia95060USA
| | - Tracy Grimes
- Department of EcologySan Diego State UniversitySan DiegoCalifornia92182USA
| | - Kerstin Wasson
- Department of Ecology and Evolutionary BiologyUniversity of California, Santa CruzSanta CruzCalifornia95060USA
- Elkhorn Slough National Estuarine Research ReserveRoyal OaksCalifornia95076USA
| | - Brent B. Hughes
- Department of BiologySonoma State UniversityRohnert ParkCalifornia94928USA
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Jueterbock A, Duarte B, Coyer J, Olsen JL, Kopp MEL, Smolina I, Arnaud-Haond S, Hu ZM, Hoarau G. Adaptation of Temperate Seagrass to Arctic Light Relies on Seasonal Acclimatization of Carbon Capture and Metabolism. FRONTIERS IN PLANT SCIENCE 2021; 12:745855. [PMID: 34925400 PMCID: PMC8675887 DOI: 10.3389/fpls.2021.745855] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 10/29/2021] [Indexed: 06/14/2023]
Abstract
Due to rising global surface temperatures, Arctic habitats are becoming thermally suitable for temperate species. Whether a temperate species can immigrate into an ice-free Arctic depends on its ability to tolerate extreme seasonal fluctuations in daylength. Thus, understanding adaptations to polar light conditions can improve the realism of models predicting poleward range expansions in response to climate change. Plant adaptations to polar light have rarely been studied and remain unknown in seagrasses. If these ecosystem engineers can migrate polewards, seagrasses will enrich biodiversity, and carbon capture potential in shallow coastal regions of the Arctic. Eelgrass (Zostera marina) is the most widely distributed seagrass in the northern hemisphere. As the only seagrass species growing as far north as 70°N, it is the most likely candidate to first immigrate into an ice-free Arctic. Here, we describe seasonal (and diurnal) changes in photosynthetic characteristics, and in genome-wide gene expression patterns under strong annual fluctuations of daylength. We compared PAM measurements and RNA-seq data between two populations at the longest and shortest day of the year: (1) a Mediterranean population exposed to moderate annual fluctuations of 10-14 h daylength and (2) an Arctic population exposed to high annual fluctuations of 0-24 h daylength. Most of the gene expression specificities of the Arctic population were found in functions of the organelles (chloroplast and mitochondrion). In winter, Arctic eelgrass conserves energy by repressing respiration and reducing photosynthetic energy fluxes. Although light-reactions, and genes involved in carbon capture and carbon storage were upregulated in summer, enzymes involved in CO2 fixation and chlorophyll-synthesis were upregulated in winter, suggesting that winter metabolism relies not only on stored energy resources but also on active use of dim light conditions. Eelgrass is unable to use excessive amounts of light during summer and demonstrates a significant reduction in photosynthetic performance under long daylengths, possibly to prevent photoinhibition constrains. Our study identified key mechanisms that allow eelgrass to survive under Arctic light conditions and paves the way for experimental research to predict whether and up to which latitude eelgrass can potentially migrate polewards in response to climate change.
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Affiliation(s)
- Alexander Jueterbock
- Algal and Microbial Biotechnology Division, Faculty of Biosciences and Aquaculture, Nord University, Bodø, Norway
| | - Bernardo Duarte
- Marine and Environmental Sciences Centre, Faculty of Sciences of the University of Lisbon, Lisbon, Portugal
- Departamento de Biologia Vegetal da Faculdade de Ciências da Universidade de Lisboa, Lisbon, Portugal
| | - James Coyer
- Shoals Marine Laboratory, University of New Hampshire, Durham, NH, United States
| | - Jeanine L. Olsen
- Ecological Genetics-Genomics Group, Groningen Institute of Evolutionary Life Sciences, University of Groningen, Groningen, Netherlands
| | | | - Irina Smolina
- Marine Molecular Ecology Group, Faculty of Biosciences and Aquaculture, Nord University, Bodø, Norway
| | - Sophie Arnaud-Haond
- UMR MARBEC Marine Biodiversity Exploitation and Conservation, Univ Montpellier, CNRS, IFREMER, IRD, Montpellier, France
| | - Zi-Min Hu
- Ocean School, Yantai University, Yantai, China
| | - Galice Hoarau
- Marine Molecular Ecology Group, Faculty of Biosciences and Aquaculture, Nord University, Bodø, Norway
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12
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Ocean warming and acidification modify top-down and bottom-up control in a tropical seagrass ecosystem. Sci Rep 2021; 11:13605. [PMID: 34193925 PMCID: PMC8245495 DOI: 10.1038/s41598-021-92989-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 06/18/2021] [Indexed: 02/06/2023] Open
Abstract
Seagrass ecosystem is one of the most productive ecosystems in coastal waters providing numerous ecological functions and supporting a large biodiversity. However, various anthropogenic stressors including climate change are impacting these vulnerable habitats. Here, we investigated the independent and combined effects of ocean warming and ocean acidification on plant-herbivore interactions in a tropical seagrass community. Direct and indirect effects of high temperature and high pCO2 on the physiology of the tropical seagrass Thalassia hemprichii and sea urchin Tripneustes gratilla were evaluated. Productivity of seagrass was found to increase under high pCO2, while sea urchin physiology including feeding rate decreased particularly under high temperature. The present study indicated that future climate change will affect the bottom-up and top-down balance, which potentially can modify the ecosystem functions and services of tropical seagrass ecosystems.
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13
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Ani CJ, Robson B. Responses of marine ecosystems to climate change impacts and their treatment in biogeochemical ecosystem models. MARINE POLLUTION BULLETIN 2021; 166:112223. [PMID: 33730556 DOI: 10.1016/j.marpolbul.2021.112223] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 02/18/2021] [Accepted: 02/25/2021] [Indexed: 06/12/2023]
Abstract
To predict the effects of climate change on marine ecosystems and the effectiveness of intervention and mitigation strategies, we need reliable marine ecosystem response models such as biogeochemical models that reproduce climate change effects. We reviewed marine ecosystem parameters and processes that are modified by climate change and examined their representations in biogeochemical ecosystem models. The interactions among important aspects of marine ecosystem modelling are not often considered due to complexity: these include the use of multiple IPCC scenarios, ensemble modelling approach, independent calibration datasets, the consideration of changes in cloud cover, ocean currents, wind speed, sea-level rise, storm frequency, storm intensity, and the incorporation of species adaptation to changing environmental conditions. Including our recommendations in future marine modelling studies could help improve the accuracy and reliability of model predictions of climate change impacts on marine ecosystems.
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Affiliation(s)
- Chinenye J Ani
- College of Science and Engineering, James Cook University, Townsville, QLD 4811, Australia; Australian Institute of Marine Science, Townsville, PMB3, Townsville, QLD 4810, Australia; AIMS@JCU, Australian Institute of Marine Science, College of Science and Engineering, James Cook University, Townsville, QLD, 4811, Australia.
| | - Barbara Robson
- Australian Institute of Marine Science, Townsville, PMB3, Townsville, QLD 4810, Australia
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14
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Mishra AK, Cabaço S, de Los Santos CB, Apostolaki ET, Vizzini S, Santos R. Long-term effects of elevated CO 2 on the population dynamics of the seagrass Cymodocea nodosa: Evidence from volcanic seeps. MARINE POLLUTION BULLETIN 2021; 162:111824. [PMID: 33162054 DOI: 10.1016/j.marpolbul.2020.111824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 09/25/2020] [Accepted: 10/30/2020] [Indexed: 06/11/2023]
Abstract
Population reconstruction techniques was used to assess for the first time the population dynamics of a seagrass, Cymodocea nodosa, exposed to long-term elevated CO2 near three volcanic seeps and compared them with reference sites away from the seeps. Under high CO2, the density of shoots and of individuals (apical shoots), and the vertical and horizontal elongation and production rates, were higher than at the reference sites. Nitrogen limitation effects on rhizome elongation and production rates and on biomass were more evident than CO2 as these were highest at the location where the limitation of nitrogen was highest. At the seep where the availability of CO2 was highest and nitrogen lowest, density of shoots and individuals were highest, probably due to CO2 effects on shoot differentiation and induced reproductive output, respectively. At the three seeps, there was higher short- and long-term shoot recruitment than at the reference sites, and growth rates was around zero, indicating that elevated CO2 increases the turnover of C. nodosa shoots.
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Affiliation(s)
- A K Mishra
- Marine Plant Ecology Research Group (ALGAE), Centre of Marine Sciences (CCMAR), University of Algarve, Faro 8005-139, Portugal; School of Biological and Marine Sciences, Faculty of Science and Engineering, University of Plymouth, Portland Square, Drake Circus, Plymouth PL48LA, UK.
| | - S Cabaço
- Marine Plant Ecology Research Group (ALGAE), Centre of Marine Sciences (CCMAR), University of Algarve, Faro 8005-139, Portugal
| | - C B de Los Santos
- Marine Plant Ecology Research Group (ALGAE), Centre of Marine Sciences (CCMAR), University of Algarve, Faro 8005-139, Portugal
| | - E T Apostolaki
- Institute of Oceanography, Hellenic Center for Marine Research (HCMR), PO Box 2214, 71003 Heraklion-Crete, Greece
| | - S Vizzini
- Department of Earth and Marine Sciences, University of Palermo, via Archirafi 18, 90123 Palermo, Italy; CoNISMa, Piazzale Flaminio 9, 00196 Roma, Italy
| | - R Santos
- Marine Plant Ecology Research Group (ALGAE), Centre of Marine Sciences (CCMAR), University of Algarve, Faro 8005-139, Portugal
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15
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Leaf proteome modulation and cytological features of seagrass Cymodocea nodosa in response to long-term high CO 2 exposure in volcanic vents. Sci Rep 2020; 10:22332. [PMID: 33339849 PMCID: PMC7749125 DOI: 10.1038/s41598-020-78764-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Accepted: 11/24/2020] [Indexed: 11/22/2022] Open
Abstract
Seagrass Cymodocea nodosa was sampled off the Vulcano island, in the vicinity of a submarine volcanic vent. Leaf samples were collected from plants growing in a naturally acidified site, influenced by the long-term exposure to high CO2 emissions, and compared with others collected in a nearby meadow living at normal pCO2 conditions. The differential accumulated proteins in leaves growing in the two contrasting pCO2 environments was investigated. Acidified leaf tissues had less total protein content and the semi-quantitative proteomic comparison revealed a strong general depletion of proteins belonging to the carbon metabolism and protein metabolism. A very large accumulation of proteins related to the cell respiration and to light harvesting process was found in acidified leaves in comparison with those growing in the normal pCO2 site. The metabolic pathways linked to cytoskeleton turnover also seemed affected by the acidified condition, since a strong reduction in the concentration of cytoskeleton structural proteins was found in comparison with the normal pCO2 leaves. Results coming from the comparative proteomics were validated by the histological and cytological measurements, suggesting that the long lasting exposure and acclimation of C. nodosa to the vents involved phenotypic adjustments that can offer physiological and structural tools to survive the suboptimal conditions at the vents vicinity.
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16
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Nakayama K, Komai K, Tada K, Lin H, Yajima H, Yano S, Hipsey M, Tsai J. Modeling dissolved inorganic carbon considering submerged aquatic vegetation. Ecol Modell 2020. [DOI: 10.1016/j.ecolmodel.2020.109188] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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17
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Zayas-Santiago CC, Rivas-Ubach A, Kuo LJ, Ward ND, Zimmerman RC. Metabolic Profiling Reveals Biochemical Pathways Responsible for Eelgrass Response to Elevated CO 2 and Temperature. Sci Rep 2020; 10:4693. [PMID: 32170204 PMCID: PMC7070064 DOI: 10.1038/s41598-020-61684-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 02/25/2020] [Indexed: 11/17/2022] Open
Abstract
As CO2 levels in Earth’s atmosphere and oceans steadily rise, varying organismal responses may produce ecological losers and winners. Increased ocean CO2 can enhance seagrass productivity and thermal tolerance, providing some compensation for climate warming. However, the metabolic shifts driving the positive response to elevated CO2 by these important ecosystem engineers remain unknown. We analyzed whole-plant performance and metabolic profiles of two geographically distinct eelgrass (Zostera marina L.) populations in response to CO2 enrichment. In addition to enhancing overall plant size, growth and survival, CO2 enrichment increased the abundance of Calvin Cycle and nitrogen assimilation metabolites while suppressing the abundance of stress-related metabolites. Overall metabolome differences between populations suggest that some eelgrass phenotypes may be better suited than others to cope with an increasingly hot and sour sea. Our results suggest that seagrass populations will respond variably, but overall positively, to increasing CO2 concentrations, generating negative feedbacks to climate change.
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Affiliation(s)
- Carmen C Zayas-Santiago
- Department of Ocean, Earth & Atmospheric Sciences, Old Dominion University, Norfolk, VA, 23429, USA.
| | - Albert Rivas-Ubach
- Environmental Molecular Sciences Division, Pacific Northwest National Laboratory, 3335 Innovation Boulevard, Richland, WA, 99352, USA
| | - Li-Jung Kuo
- Marine Sciences Laboratory, Pacific Northwest National Laboratory, 1529 W. Sequim Bay Rd., Sequim, WA, 98382, USA
| | - Nicholas D Ward
- Marine Sciences Laboratory, Pacific Northwest National Laboratory, 1529 W. Sequim Bay Rd., Sequim, WA, 98382, USA.,School of Oceanography, University of Washington, Seattle, WA, 98105, USA
| | - Richard C Zimmerman
- Department of Ocean, Earth & Atmospheric Sciences, Old Dominion University, Norfolk, VA, 23429, USA
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18
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Ecological Function of Phenolic Compounds from Mediterranean Fucoid Algae and Seagrasses: An Overview on the Genus Cystoseira sensu lato and Posidonia oceanica (L.) Delile. JOURNAL OF MARINE SCIENCE AND ENGINEERING 2020. [DOI: 10.3390/jmse8010019] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Biodiversity is undergoing rapid and worrying changes, partially driven by anthropogenic activities. Human impacts and climate change (e.g., increasing temperature and ocean acidification), which act at different spatial scales, represent the most serious threats to biodiversity and ecosystem structure and function. In the Mediterranean Sea, complex systems such as fucoid algae and seagrasses, characterized by a high associated biodiversity, are regularly exposed to natural and anthropogenic pressures. These systems, particularly sensitive to a variety of stressors, evolved several physiological and biochemical traits as a response to the different pressures which they are subjected to. For instance, they produce a huge quantity of secondary metabolites such as phenolic compounds, to adapt to different environmental stressors and to defend themselves from biological pressures. These natural products are receiving increasing attention due to their possible applications in a wide range of industrial sectors. In this paper we provide an overview on the ecological role of phenolic compounds from the genus Cystoseira sensu lato and Posidonia oceanica (L.) Delile, also highlighting their potential use as ecological biomarkers.
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19
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Vizzini S, Apostolaki ET, Ricevuto E, Polymenakou P, Mazzola A. Plant and sediment properties in seagrass meadows from two Mediterranean CO 2 vents: Implications for carbon storage capacity of acidified oceans. MARINE ENVIRONMENTAL RESEARCH 2019; 146:101-108. [PMID: 30929836 DOI: 10.1016/j.marenvres.2019.03.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 03/05/2019] [Accepted: 03/10/2019] [Indexed: 06/09/2023]
Abstract
Assessing the status of important carbon sinks such as seagrass meadows is of primary importance when dealing with potential climate change mitigation strategies. This study examined plant and sediment properties in seagrass meadows (Cymodocea nodosa (Ucria) Asch.) from two high pCO2-low pH Mediterranean vent systems, located at Milos (Greece) and Vulcano (Italy) Islands, providing insights on carbon storage potential in future acidified oceans. Contrary to what has been suggested, carbon content (both inorganic and organic) and its surficial accumulation decreased at high pCO2-low pH in comparison with controls. The decrease in inorganic carbon may result from the higher solubility of carbonates due to the more acidic conditions. At Vulcano, the seagrass properties (e.g., leaf area, biomass) appeared negatively affected by environmental conditions at high pCO2-low pH conditions and this may have had a detrimental effect on the organic carbon content and accumulation. At Milos, organic carbon decreased at high pCO2-low pH conditions, despite the increase in seagrass aboveground biomass, leaf length and area, probably as a consequence of site-specific features, which need further investigation and may include both biotic and abiotic factors (e.g., oligotrophic conditions, decreased sedimentation rate and input of allochthonous material). Results suggest that, in contrast to previous predictions based exclusively on the expected positive response of seagrasses to ocean acidification, carbon storage capacity of the seagrass C. nodosa may not increase at high pCO2-low pH conditions. This study emphasizes the need to investigate further the potential alteration in the climate mitigation service delivered by seagrass meadows in acidified oceans.
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Affiliation(s)
- Salvatrice Vizzini
- Department of Earth and Marine Sciences, University of Palermo, Via Archirafi 18, 90123, Palermo, Italy; National Inter-University Consortium for Marine Sciences, CoNISMa, Piazzale Flaminio 9, 00196, Roma, Italy.
| | - Eugenia T Apostolaki
- Institute of Oceanography, Hellenic Centre for Marine Research, PO Box 2214, GR-71003, Heraklion, Crete, Greece
| | - Elena Ricevuto
- Department of Earth and Marine Sciences, University of Palermo, Via Archirafi 18, 90123, Palermo, Italy
| | - Paraskevi Polymenakou
- Institute of Marine Biology, Biotechnology and Aquaculture, Hellenic Centre for Marine Research, PO Box 2214, GR-71003, Heraklion, Crete, Greece
| | - Antonio Mazzola
- Department of Earth and Marine Sciences, University of Palermo, Via Archirafi 18, 90123, Palermo, Italy; National Inter-University Consortium for Marine Sciences, CoNISMa, Piazzale Flaminio 9, 00196, Roma, Italy
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20
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Bainbridge Z, Lewis S, Bartley R, Fabricius K, Collier C, Waterhouse J, Garzon-Garcia A, Robson B, Burton J, Wenger A, Brodie J. Fine sediment and particulate organic matter: A review and case study on ridge-to-reef transport, transformations, fates, and impacts on marine ecosystems. MARINE POLLUTION BULLETIN 2018; 135:1205-1220. [PMID: 30301020 DOI: 10.1016/j.marpolbul.2018.08.002] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2018] [Revised: 07/27/2018] [Accepted: 08/01/2018] [Indexed: 06/08/2023]
Abstract
Studies documenting the effects of land-derived suspended particulate matter (SPM, i.e., particulate organic matter and mineral sediment) on marine ecosystems are typically disconnected from terrestrial studies that determine their origin, transport and fate. This study reviews sources, transport, transformations, fate and effects of SPM along the 'ridge-to-reef' continuum. We show that some of the SPM can be transported over long distances and transformed into large and easily resuspendible organic-rich sediment flocs. These flocs may lead to prolonged reductions in water clarity, impacting upon coral reef, seagrass and fish communities. Using the Great Barrier Reef (NE Australia) as a case study, we identify the latest research tools to determine thresholds of SPM exposure, allowing for an improved appreciation of marine risk. These tools are used to determine ecologically-relevant end-of-basin load targets and reliable marine water quality guidelines, thereby enabling enhanced prioritisation and management of SPM export from ridge-to-reef.
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Affiliation(s)
- Z Bainbridge
- TropWATER, James Cook University, Townsville 4811, Australia.
| | - S Lewis
- TropWATER, James Cook University, Townsville 4811, Australia
| | - R Bartley
- CSIRO, Brisbane, Queensland 4068, Australia
| | - K Fabricius
- Australian Institute of Marine Science, PMB 3, Townsville MC, QLD 4810, Australia
| | - C Collier
- TropWATER, James Cook University, Townsville 4811, Australia
| | - J Waterhouse
- TropWATER, James Cook University, Townsville 4811, Australia
| | - A Garzon-Garcia
- Department of Environment and Science, GPO Box 5078, Brisbane 4001, Australia
| | - B Robson
- Australian Institute of Marine Science, PMB 3, Townsville MC, QLD 4810, Australia
| | - J Burton
- Department of Environment and Science, GPO Box 5078, Brisbane 4001, Australia
| | - A Wenger
- School of Earth and Environmental Sciences, University of Queensland, St. Lucia, QLD 4072, Australia
| | - J Brodie
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville 4811, Australia
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21
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Koweek DA, Zimmerman RC, Hewett KM, Gaylord B, Giddings SN, Nickols KJ, Ruesink JL, Stachowicz JJ, Takeshita Y, Caldeira K. Expected limits on the ocean acidification buffering potential of a temperate seagrass meadow. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2018; 28:1694-1714. [PMID: 30063809 DOI: 10.1002/eap.1771] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 04/06/2018] [Accepted: 06/11/2018] [Indexed: 05/20/2023]
Abstract
Ocean acidification threatens many marine organisms, especially marine calcifiers. The only global-scale solution to ocean acidification remains rapid reduction in CO2 emissions. Nevertheless, interest in localized mitigation strategies has grown rapidly because of the recognized threat ocean acidification imposes on natural communities, including ones important to humans. Protection of seagrass meadows has been considered as a possible approach for localized mitigation of ocean acidification due to their large standing stocks of organic carbon and high productivity. Yet much work remains to constrain the magnitudes and timescales of potential buffering effects from seagrasses. We developed a biogeochemical box model to better understand the potential for a temperate seagrass meadow to locally mitigate the effects of ocean acidification. Then we parameterized the model using data from Tomales Bay, an inlet on the coast of California, USA which supports a major oyster farming industry. We conducted a series of month-long model simulations to characterize processes that occur during summer and winter. We found that average pH in the seagrass meadows was typically within 0.04 units of the pH of the primary source waters into the meadow, although we did find occasional periods (hours) when seagrass metabolism may modify the pH by up to ±0.2 units. Tidal phasing relative to the diel cycle modulates localized pH buffering within the seagrass meadow such that maximum buffering occurs during periods of the year with midday low tides. Our model results suggest that seagrass metabolism in Tomales Bay would not provide long-term ocean acidification mitigation. However, we emphasize that our model results may not hold in meadows where assumptions about depth-averaged net production and seawater residence time within the seagrass meadow differ from our model assumptions. Our modeling approach provides a framework that is easily adaptable to other seagrass meadows in order to evaluate the extent of their individual buffering capacities. Regardless of their ability to buffer ocean acidification, seagrass meadows maintain many critically important ecosystem goods and services that will be increasingly important as humans increasingly affect coastal ecosystems.
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Affiliation(s)
- David A Koweek
- Department of Global Ecology, Carnegie Insitution for Science, 260 Panama Street, Stanford, California, 94305, USA
| | - Richard C Zimmerman
- Department of Ocean, Earth, and Atmospheric Sciences, Old Dominion University, 4600 Elkhorn Avenue, Norfolk, Virginia, 23529, USA
| | - Kathryn M Hewett
- Bodega Marine Laboratory, University of California Davis, 2099 Westshore Road, Bodega Bay, California, 94923, USA
| | - Brian Gaylord
- Bodega Marine Laboratory, University of California Davis, 2099 Westshore Road, Bodega Bay, California, 94923, USA
| | - Sarah N Giddings
- Scripps Institution of Oceanography, University of California San Diego, 9500 Gilman Drive 0206, La Jolla, California, 92093, USA
| | - Kerry J Nickols
- Department of Biology, California State University Northridge, 18111 Nordhoff Street, Northridge, California, 91330, USA
| | - Jennifer L Ruesink
- Department of Biology, University of Washington, Box 351800, Seattle, Washington, 98195, USA
| | - John J Stachowicz
- Department of Evolution and Ecology, University of California Davis, Davis, California, 95616, USA
| | - Yuichiro Takeshita
- Monterey Bay Aquarium Research Institute, 7700 Sandholdt Road, Moss Landing, California, 95039, USA
| | - Ken Caldeira
- Department of Global Ecology, Carnegie Insitution for Science, 260 Panama Street, Stanford, California, 94305, USA
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22
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Egea LG, Jiménez-Ramos R, Vergara JJ, Hernández I, Brun FG. Interactive effect of temperature, acidification and ammonium enrichment on the seagrass Cymodocea nodosa. MARINE POLLUTION BULLETIN 2018; 134:14-26. [PMID: 29475735 DOI: 10.1016/j.marpolbul.2018.02.029] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Revised: 02/02/2018] [Accepted: 02/15/2018] [Indexed: 05/21/2023]
Abstract
Global (e.g. climate change) and local factors (e.g. nutrient enrichment) act together in nature strongly hammering coastal ecosystems, where seagrasses play a critical ecological role. This experiment explores the combined effects of warming, acidification and ammonium enrichment on the seagrass Cymodocea nodosa under a full factorial mesocosm design. Warming increased plant production but at the expense of reducing carbon reserves. Meanwhile, acidification had not effects on plant production but increased slightly carbon reserves, while a slight stimulation of net production and a slight decrease on carbon reserves under ammonium supply were recorded. When all the factors were combined together improved the production and carbon reserves of Cymodocea nodosa, indicating that acidification improved ammonium assimilation and buffered the enhanced respiration promoted by temperature. Therefore, it could indicate that this temperate species may benefit under the simulated future scenarios, but indirect effects (e.g. herbivory, mechanical stress, etc.) may counteract this balance.
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Affiliation(s)
- L G Egea
- Department of Biology, Faculty of Marine and Environmental Sciences, University of Cadiz, 11510, Puerto Real, Cadiz, Spain.
| | - R Jiménez-Ramos
- Department of Biology, Faculty of Marine and Environmental Sciences, University of Cadiz, 11510, Puerto Real, Cadiz, Spain
| | - J J Vergara
- Department of Biology, Faculty of Marine and Environmental Sciences, University of Cadiz, 11510, Puerto Real, Cadiz, Spain
| | - I Hernández
- Department of Biology, Faculty of Marine and Environmental Sciences, University of Cadiz, 11510, Puerto Real, Cadiz, Spain
| | - F G Brun
- Department of Biology, Faculty of Marine and Environmental Sciences, University of Cadiz, 11510, Puerto Real, Cadiz, Spain
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23
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Oscar MA, Barak S, Winters G. The Tropical Invasive Seagrass, Halophila stipulacea, Has a Superior Ability to Tolerate Dynamic Changes in Salinity Levels Compared to Its Freshwater Relative, Vallisneria americana. FRONTIERS IN PLANT SCIENCE 2018; 9:950. [PMID: 30022993 PMCID: PMC6040085 DOI: 10.3389/fpls.2018.00950] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 06/12/2018] [Indexed: 05/30/2023]
Abstract
The tropical seagrass species, Halophila stipulacea, originated from the Indian Ocean and the Red Sea, subsequently invading the Mediterranean and has recently established itself in the Caribbean Sea. Due to its invasive nature, there is growing interest in understanding this species' capacity to adapt to new conditions. One approach to understanding the natural tolerance of a plant is to compare the tolerant species with a closely related non-tolerant species. We compared the physiological responses of H. stipulacea exposed to different salinities, with that of its nearest freshwater relative, Vallisneria americana. To achieve this goal, H. stipulacea and V. americana plants were grown in dedicated microcosms, and exposed to the following salt regimes: (i) H. stipulacea: control (40 PSU, practical salinity units), hyposalinity (25 PSU) and hypersalinity (60 PSU) for 3 weeks followed by a 4-week recovery phase (back to 40 PSU); (ii) V. americana: control (1 PSU), and hypersalinity (12 PSU) for 3 weeks, followed by a 4-week recovery phase (back to 1 PSU). In H. stipulacea, leaf number and chlorophyll content showed no significant differences between control plants and plants under hypo and hypersalinities, but a significant decrease in leaf area under hypersalinity was observed. In addition, compared with control plants, H. stipulacea plants exposed to hypo and hypersalinity were found to have reduced below-ground biomass and C/N ratios, suggesting changes in the allocation of resources in response to both stresses. There was no significant effect of hypo/hypersalinity on dark-adapted quantum yield of photosystem II (Fv/Fm) suggesting that H. stipulacea photochemistry is resilient to hypo/hypersalinity stress. In contrast to the seagrass, V. americana exposed to hypersalinity displayed significant decreases in above-ground biomass, shoot number, leaf number, blade length and Fv/Fm, followed by significant recoveries of all these parameters upon return of the plants to non-saline control conditions. These data suggest that H. stipulacea shows remarkable tolerance to both hypo and hypersalinity. Resilience to a relatively wide range of salinities may be one of the traits explaining the invasive nature of this species in the Mediterranean and Caribbean Seas.
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Affiliation(s)
- Michelle A. Oscar
- French Associates Institute for Agriculture and Biotechnology of Drylands, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben-Gurion, Israel
- Dead-Sea & Arava Science Center, Neve Zohar, Israel
| | - Simon Barak
- French Associates Institute for Agriculture and Biotechnology of Drylands, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben-Gurion, Israel
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24
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Groner ML, Burge CA, Cox R, Rivlin ND, Turner M, Van Alstyne KL, Wyllie-Echeverria S, Bucci J, Staudigel P, Friedman CS. Oysters and eelgrass: potential partners in a high pCO 2 ocean. Ecology 2018; 99:1802-1814. [PMID: 29800484 DOI: 10.1002/ecy.2393] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 04/25/2018] [Accepted: 05/03/2018] [Indexed: 12/23/2022]
Abstract
Climate change is affecting the health and physiology of marine organisms and altering species interactions. Ocean acidification (OA) threatens calcifying organisms such as the Pacific oyster, Crassostrea gigas. In contrast, seagrasses, such as the eelgrass Zostera marina, can benefit from the increase in available carbon for photosynthesis found at a lower seawater pH. Seagrasses can remove dissolved inorganic carbon from OA environments, creating local daytime pH refugia. Pacific oysters may improve the health of eelgrass by filtering out pathogens such as Labyrinthula zosterae (LZ), which causes eelgrass wasting disease (EWD). We examined how co-culture of eelgrass ramets and juvenile oysters affected the health and growth of eelgrass and the mass of oysters under different pCO2 exposures. In Phase I, each species was cultured alone or in co-culture at 12°C across ambient, medium, and high pCO2 conditions, (656, 1,158 and 1,606 μatm pCO2 , respectively). Under high pCO2 , eelgrass grew faster and had less severe EWD (contracted in the field prior to the experiment). Co-culture with oysters also reduced the severity of EWD. While the presence of eelgrass decreased daytime pCO2 , this reduction was not substantial enough to ameliorate the negative impact of high pCO2 on oyster mass. In Phase II, eelgrass alone or oysters and eelgrass in co-culture were held at 15°C under ambient and high pCO2 conditions, (488 and 2,013 μatm pCO2 , respectively). Half of the replicates were challenged with cultured LZ. Concentrations of defensive compounds in eelgrass (total phenolics and tannins), were altered by LZ exposure and pCO2 treatments. Greater pathogen loads and increased EWD severity were detected in LZ exposed eelgrass ramets; EWD severity was reduced at high relative to low pCO2 . Oyster presence did not influence pathogen load or EWD severity; high LZ concentrations in experimental treatments may have masked the effect of this treatment. Collectively, these results indicate that, when exposed to natural concentrations of LZ under high pCO2 conditions, eelgrass can benefit from co-culture with oysters. Further experimentation is necessary to quantify how oysters may benefit from co-culture with eelgrass, examine these interactions in the field and quantify context-dependency.
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Affiliation(s)
- Maya L Groner
- Atlantic Veterinary College, University of Prince Edward Island, 550 University Ave., Charlottetown, Prince Edward Island, C1A 4P3, Canada
| | - Colleen A Burge
- Institute of Marine and Environmental Technology, University of Maryland Baltimore County, 701 E Pratt St., Baltimore, Maryland, 21202, USA
| | - Ruth Cox
- Atlantic Veterinary College, University of Prince Edward Island, 550 University Ave., Charlottetown, Prince Edward Island, C1A 4P3, Canada
| | - Natalie D Rivlin
- Institute of Marine and Environmental Technology, University of Maryland Baltimore County, 701 E Pratt St., Baltimore, Maryland, 21202, USA
| | - Mo Turner
- Department of Biology, University of Washington, 24 Kincaid Hall, Seattle, Washington, 98105, USA
| | - Kathryn L Van Alstyne
- Shannon Point Marine Center, Western Washington University, 1900 Shannon Point Rd., Anacortes, Washington, 98221, USA
| | - Sandy Wyllie-Echeverria
- Friday Harbor Laboratories, University of Washington, 620 University Rd., Friday Harbor, Washington, 98250, USA.,Center for Marine and Environmental Studies, University of the Virgin Islands, 2 John Brewers Bay, St. Thomas, Virgin Islands, 00802, USA
| | - John Bucci
- School of Marine Science and Ocean Engineering, University of New Hampshire, 8 College Rd., Durham, New Hampshire, 03824, USA
| | - Philip Staudigel
- Rosenstiel School for Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Causeway, Miami, Florida, 33149, USA
| | - Carolyn S Friedman
- Friday Harbor Laboratories, University of Washington, 620 University Rd., Friday Harbor, Washington, 98250, USA.,School of Aquatic & Fishery Sciences, University of Washington, 1122 NE Boat St., Seattle, Washington, 98105, USA
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25
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Kim M, Brodersen KE, Szabó M, Larkum AWD, Raven JA, Ralph PJ, Pernice M. Low oxygen affects photophysiology and the level of expression of two-carbon metabolism genes in the seagrass Zostera muelleri. PHOTOSYNTHESIS RESEARCH 2018; 136:147-160. [PMID: 0 DOI: 10.1007/s11120-017-0452-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 09/27/2017] [Indexed: 05/03/2023]
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Egea LG, Jiménez-Ramos R, Hernández I, Bouma TJ, Brun FG. Effects of ocean acidification and hydrodynamic conditions on carbon metabolism and dissolved organic carbon (DOC) fluxes in seagrass populations. PLoS One 2018; 13:e0192402. [PMID: 29420625 PMCID: PMC5805273 DOI: 10.1371/journal.pone.0192402] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Accepted: 01/23/2018] [Indexed: 11/18/2022] Open
Abstract
Global change has been acknowledged as one of the main threats to the biosphere and its provision of ecosystem services, especially in marine ecosystems. Seagrasses play a critical ecological role in coastal ecosystems, but their responses to ocean acidification (OA) and climate change are not well understood. There have been previous studies focused on the effects of OA, but the outcome of interactions with co-factors predicted to alter during climate change still needs to be addressed. For example, the impact of higher CO2 and different hydrodynamic regimes on seagrass performance remains unknown. We studied the effects of OA under different current velocities on productivity of the seagrass Zostera noltei, using changes in dissolved oxygen as a proxy for the seagrass carbon metabolism, and release of dissolved organic carbon (DOC) in a four-week experiment using an open-water outdoor mesocosm. Under current pH conditions, increasing current velocity had a positive effect on productivity, but this depended on shoot density. However, this positive effect of current velocity disappeared under OA conditions. OA conditions led to a significant increase in gross production rate and respiration, suggesting that Z. noltei is carbon-limited under the current inorganic carbon concentration of seawater. In addition, an increase in non-structural carbohydrates was found, which may lead to better growing conditions and higher resilience in seagrasses subjected to environmental stress. Regarding DOC flux, a direct and positive relationship was found between current velocity and DOC release, both under current pH and OA conditions. We conclude that OA and high current velocity may lead to favourable growth scenarios for Z. noltei populations, increasing their productivity, non-structural carbohydrate concentrations and DOC release. Our results add new dimensions to predictions on how seagrass ecosystems will respond to climate change, with important implications for the resilience and conservation of these threatened ecosystems.
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Affiliation(s)
- Luis G. Egea
- Department of Biology, Faculty of Marine and Environmental Sciences, University of Cadiz, Puerto Real, Cádiz, Spain
- * E-mail:
| | - Rocío Jiménez-Ramos
- Department of Biology, Faculty of Marine and Environmental Sciences, University of Cadiz, Puerto Real, Cádiz, Spain
| | - Ignacio Hernández
- Department of Biology, Faculty of Marine and Environmental Sciences, University of Cadiz, Puerto Real, Cádiz, Spain
| | - Tjeerd J. Bouma
- Royal Netherlands Institute for Sea Research (NIOZ), Department of Estuarine and Delta Systems, Royal Netherlands Institute for Sea Research (NIOZ), Yerseke, The Netherlands
| | - Fernando G. Brun
- Department of Biology, Faculty of Marine and Environmental Sciences, University of Cadiz, Puerto Real, Cádiz, Spain
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27
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Scartazza A, Moscatello S, Gavrichkova O, Buia MC, Lauteri M, Battistelli A, Lorenti M, Garrard SL, Calfapietra C, Brugnoli E. Carbon and nitrogen allocation strategy in Posidonia oceanica is altered by seawater acidification. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 607-608:954-964. [PMID: 28724227 DOI: 10.1016/j.scitotenv.2017.06.084] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 06/08/2017] [Accepted: 06/10/2017] [Indexed: 05/05/2023]
Abstract
Rising atmospheric CO2 causes ocean acidification that represents one of the major ecological threats for marine biota. We tested the hypothesis that long-term exposure to increased CO2 level and acidification in a natural CO2 vent system alters carbon (C) and nitrogen (N) metabolism in Posidonia oceanica L. (Delile), affecting its resilience, or capability to restore the physiological homeostasis, and the nutritional quality of organic matter available for grazers. Seawater acidification decreased the C to N ratio in P. oceanica tissues and increased grazing rate, shoot density, leaf proteins and asparagine accumulation in rhizomes, while the maximum photochemical efficiency of photosystem II was unaffected. The 13C-dilution in both structural and non-structural C metabolites in the acidified site indicated quali-quantitative changes of C source and/or increased isotopic fractionation during C uptake and carboxylation associated with the higher CO2 level. The decreased C:N ratio in the acidified site suggests an increased N availability, leading to a greater storage of 15N-enriched compounds in rhizomes. The amount of the more dynamic C storage form, sucrose, decreased in rhizomes of the acidified site in response to the enhanced energy demand due to higher shoot recruitment and N compound synthesis, without affecting starch reserves. The ability to modulate the balance between stable and dynamic C reserves could represent a key ecophysiological mechanism for P. oceanica resilience under environmental perturbation. Finally, alteration in C and N dynamics promoted a positive contribution of this seagrass to the local food web.
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Affiliation(s)
- Andrea Scartazza
- Istituto di Biologia Agroambientale e Forestale, Consiglio Nazionale delle Ricerche, Via Salaria km 29,300, 00016 Monterotondo Scalo, RM, Italy; Istituto di Biologia Agroambientale e Forestale, Consiglio Nazionale delle Ricerche, Via G. Marconi 2, 05010 Porano, TR, Italy.
| | - Stefano Moscatello
- Istituto di Biologia Agroambientale e Forestale, Consiglio Nazionale delle Ricerche, Via G. Marconi 2, 05010 Porano, TR, Italy.
| | - Olga Gavrichkova
- Istituto di Biologia Agroambientale e Forestale, Consiglio Nazionale delle Ricerche, Via G. Marconi 2, 05010 Porano, TR, Italy
| | | | - Marco Lauteri
- Istituto di Biologia Agroambientale e Forestale, Consiglio Nazionale delle Ricerche, Via G. Marconi 2, 05010 Porano, TR, Italy
| | - Alberto Battistelli
- Istituto di Biologia Agroambientale e Forestale, Consiglio Nazionale delle Ricerche, Via G. Marconi 2, 05010 Porano, TR, Italy
| | - Maurizio Lorenti
- Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Napoli, Italy
| | | | - Carlo Calfapietra
- Istituto di Biologia Agroambientale e Forestale, Consiglio Nazionale delle Ricerche, Via G. Marconi 2, 05010 Porano, TR, Italy
| | - Enrico Brugnoli
- Istituto di Biologia Agroambientale e Forestale, Consiglio Nazionale delle Ricerche, Via G. Marconi 2, 05010 Porano, TR, Italy
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28
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Campbell JE, Fourqurean JW. Does Nutrient Availability Regulate Seagrass Response to Elevated CO2? Ecosystems 2017. [DOI: 10.1007/s10021-017-0212-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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29
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Ravaglioli C, Lauritano C, Buia MC, Balestri E, Capocchi A, Fontanini D, Pardi G, Tamburello L, Procaccini G, Bulleri F. Nutrient Loading Fosters Seagrass Productivity Under Ocean Acidification. Sci Rep 2017; 7:13732. [PMID: 29062025 PMCID: PMC5653774 DOI: 10.1038/s41598-017-14075-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 09/20/2017] [Indexed: 12/04/2022] Open
Abstract
The effects of climate change are likely to be dependent on local settings. Nonetheless, the compounded effects of global and regional stressors remain poorly understood. Here, we used CO2 vents to assess how the effects of ocean acidification on the seagrass, Posidonia oceanica, and the associated epiphytic community can be modified by enhanced nutrient loading. P. oceanica at ambient and low pH sites was exposed to three nutrient levels for 16 months. The response of P. oceanica to experimental conditions was assessed by combining analyses of gene expression, plant growth, photosynthetic pigments and epiphyte loading. At low pH, nutrient addition fostered plant growth and the synthesis of photosynthetic pigments. Overexpression of nitrogen transporter genes following nutrient additions at low pH suggests enhanced nutrient uptake by the plant. In addition, enhanced nutrient levels reduced the expression of selected antioxidant genes in plants exposed to low pH and increased epiphyte cover at both ambient and low pH. Our results show that the effects of ocean acidification on P. oceanica depend upon local nutrient concentration. More generally, our findings suggest that taking into account local environmental settings will be crucial to advance our understanding of the effects of global stressors on marine systems.
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Affiliation(s)
- Chiara Ravaglioli
- Dipartimento di Biologia, Università di Pisa, CoNISMa, Via Derna, 1, 56126 Pisa, Italy.
| | - Chiara Lauritano
- Stazione Zoologica Anton Dohrn, Villa Comunale, 80121, Napoli, Italy
| | | | - Elena Balestri
- Dipartimento di Biologia, Università di Pisa, CoNISMa, Via Derna, 1, 56126 Pisa, Italy
| | - Antonella Capocchi
- Dipartimento di Biologia, Università di Pisa, CoNISMa, Via Derna, 1, 56126 Pisa, Italy
| | - Debora Fontanini
- Dipartimento di Biologia, Università di Pisa, CoNISMa, Via Derna, 1, 56126 Pisa, Italy
| | - Giuseppina Pardi
- Dipartimento di Biologia, Università di Pisa, CoNISMa, Via Derna, 1, 56126 Pisa, Italy
| | - Laura Tamburello
- Dipartimento di Biologia, Università di Pisa, CoNISMa, Via Derna, 1, 56126 Pisa, Italy.,CoNISMa, Piazzale Flaminio, 9, 00196, Roma, Italy
| | | | - Fabio Bulleri
- Dipartimento di Biologia, Università di Pisa, CoNISMa, Via Derna, 1, 56126 Pisa, Italy
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30
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Ober GT, Thornber CS. Divergent responses in growth and nutritional quality of coastal macroalgae to the combination of increased pCO 2 and nutrients. MARINE ENVIRONMENTAL RESEARCH 2017; 131:69-79. [PMID: 28943069 DOI: 10.1016/j.marenvres.2017.09.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Revised: 08/29/2017] [Accepted: 09/09/2017] [Indexed: 06/07/2023]
Abstract
Coastal ecosystems are subjected to global and local environmental stressors, including increased atmospheric carbon dioxide (CO2) (and subsequent ocean acidification) and nutrient loading. Here, we tested how two common macroalgal species in the Northwest Atlantic (Ulva spp. and Fucus vesiculosus Linneaus) respond to the combination of increased CO2 and nutrient loading. We utilized two levels of pCO2 with two levels of nutrients in a full factorial design, testing the growth rates and tissue quality of Ulva and Fucus grown for 21 days in monoculture and biculture. We found that the opportunistic, fast-growing Ulva exhibited increased growth rates under high pCO2 and high nutrients, with growth rates increasing three-fold above Ulva grown in ambient pCO2 and ambient nutrients. By contrast, Fucus growth rates were not impacted by either environmental factor. Both species exhibited a decline in carbon to nitrogen ratios (C:N) with elevated nutrients, but pCO2 concentration did not alter tissue quality in either species. Species grown in biculture exhibited similar growth rates to those in monoculture conditions, but Fucus C:N increased significantly when grown with Ulva, indicating an effect of the presence of Ulva on Fucus. Our results suggest that the combination of ocean acidification and nutrients will enhance abundance of opportunistic algal species in coastal systems and will likely drive macroalgal community shifts, based on species-specific responses to future conditions.
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Affiliation(s)
- Gordon T Ober
- WM Keck Sciences, Claremont McKenna College, Claremont, CA 91711, USA.
| | - Carol S Thornber
- Biological and Environmental Sciences, University of Rhode Island, Kingston, RI 02881, USA
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31
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Guilini K, Weber M, de Beer D, Schneider M, Molari M, Lott C, Bodnar W, Mascart T, De Troch M, Vanreusel A. Response of Posidonia oceanica seagrass and its epibiont communities to ocean acidification. PLoS One 2017; 12:e0181531. [PMID: 28792960 PMCID: PMC5549886 DOI: 10.1371/journal.pone.0181531] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 07/03/2017] [Indexed: 11/30/2022] Open
Abstract
The unprecedented rate of CO2 increase in our atmosphere and subsequent ocean acidification (OA) threatens coastal ecosystems. To forecast the functioning of coastal seagrass ecosystems in acidified oceans, more knowledge on the long-term adaptive capacities of seagrass species and their epibionts is needed. Therefore we studied morphological characteristics of Posidonia oceanica and the structure of its epibiont communities at a Mediterranean volcanic CO2 vent off Panarea Island (Italy) and performed a laboratory experiment to test the effect of OA on P. oceanica photosynthesis and its potential buffering capacity. At the study site east of Basiluzzo Islet, venting of CO2 gas was controlled by tides, resulting in an average pH difference of 0.1 between the vent and reference site. P. oceanica shoot and leaf density was unaffected by these levels of OA, although shorter leaves at the vent site suggest increased susceptibility to erosion, potentially by herbivores. The community of sessile epibionts differed in composition and was characterized by a higher species richness at the vent site, though net epiphytic calcium carbonate concentration was similar. These findings suggest a higher ecosystem complexity at the vent site, which may have facilitated the higher diversity of copepods in the otherwise unaffected motile epibiont community. In the laboratory experiment, P. oceanica photosynthesis increased with decreasing pHT (7.6, 6.6, 5.5), which induced an elevated pH at the leaf surfaces of up to 0.5 units compared to the ambient seawater pHT of 6.6. This suggests a temporary pH buffering in the diffusive boundary layer of leaves, which could be favorable for epibiont organisms. The results of this multispecies study contribute to understanding community-level responses and underlying processes in long-term acidified conditions. Increased replication and monitoring of physico-chemical parameters on an annual scale are, however, recommended to assure that the biological responses observed during a short period reflect long-term dynamics of these parameters.
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Affiliation(s)
- Katja Guilini
- Marine Biology Research Group, Department of Biology, Ghent University, Ghent, Belgium
- * E-mail:
| | - Miriam Weber
- HGF-MPG Joint Research Group on Deep Sea Ecology and Technology, Max Planck Institute for Marine Microbiology, Bremen, Germany
- HYDRA Institute for Marine Sciences, Elba Field Station, Italy
| | - Dirk de Beer
- Microsensor Group, Max Planck Institute for Marine Microbiology, Bremen, Germany
| | | | - Massimiliano Molari
- HGF-MPG Joint Research Group on Deep Sea Ecology and Technology, Max Planck Institute for Marine Microbiology, Bremen, Germany
| | - Christian Lott
- HYDRA Institute for Marine Sciences, Elba Field Station, Italy
| | - Wanda Bodnar
- Marine Biology Research Group, Department of Biology, Ghent University, Ghent, Belgium
| | - Thibaud Mascart
- Marine Biology Research Group, Department of Biology, Ghent University, Ghent, Belgium
| | - Marleen De Troch
- Marine Biology Research Group, Department of Biology, Ghent University, Ghent, Belgium
| | - Ann Vanreusel
- Marine Biology Research Group, Department of Biology, Ghent University, Ghent, Belgium
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32
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Ruocco M, Musacchia F, Olivé I, Costa MM, Barrote I, Santos R, Sanges R, Procaccini G, Silva J. Genomewide transcriptional reprogramming in the seagrass Cymodocea nodosa under experimental ocean acidification. Mol Ecol 2017; 26:4241-4259. [PMID: 28614601 DOI: 10.1111/mec.14204] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Revised: 05/18/2017] [Accepted: 05/30/2017] [Indexed: 12/29/2022]
Abstract
Here, we report the first use of massive-scale RNA-sequencing to explore seagrass response to CO2 -driven ocean acidification (OA). Large-scale gene expression changes in the seagrass Cymodocea nodosa occurred at CO2 levels projected by the end of the century. C. nodosa transcriptome was obtained using Illumina RNA-Seq technology and de novo assembly, and differential gene expression was explored in plants exposed to short-term high CO2 /low pH conditions. At high pCO2 , there was a significant increased expression of transcripts associated with photosynthesis, including light reaction functions and CO2 fixation, and also to respiratory pathways, specifically for enzymes involved in glycolysis, in the tricarboxylic acid cycle and in the energy metabolism of the mitochondrial electron transport. The upregulation of respiratory metabolism is probably supported by the increased availability of photosynthates and increased energy demand for biosynthesis and stress-related processes under elevated CO2 and low pH. The upregulation of several chaperones resembling heat stress-induced changes in gene expression highlighted the positive role these proteins play in tolerance to intracellular acid stress in seagrasses. OA further modifies C. nodosa secondary metabolism inducing the transcription of enzymes related to biosynthesis of carbon-based secondary compounds, in particular the synthesis of polyphenols and isoprenoid compounds that have a variety of biological functions including plant defence. By demonstrating which physiological processes are most sensitive to OA, this research provides a major advance in the understanding of seagrass metabolism in the context of altered seawater chemistry from global climate change.
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Affiliation(s)
- Miriam Ruocco
- CCMar-Centre of Marine Sciences, University of Algarve, Faro, Portugal
| | | | - Irene Olivé
- CCMar-Centre of Marine Sciences, University of Algarve, Faro, Portugal
| | - Monya M Costa
- CCMar-Centre of Marine Sciences, University of Algarve, Faro, Portugal
| | - Isabel Barrote
- CCMar-Centre of Marine Sciences, University of Algarve, Faro, Portugal
| | - Rui Santos
- CCMar-Centre of Marine Sciences, University of Algarve, Faro, Portugal
| | - Remo Sanges
- Stazione Zoologica Anton Dohrn, Villa Comunale, Naples, Italy
| | | | - João Silva
- CCMar-Centre of Marine Sciences, University of Algarve, Faro, Portugal
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33
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Orth RJ, Dennison WC, Lefcheck JS, Gurbisz C, Hannam M, Keisman J, Landry JB, Moore KA, Murphy RR, Patrick CJ, Testa J, Weller DE, Wilcox DJ. Submersed Aquatic Vegetation in Chesapeake Bay: Sentinel Species in a Changing World. Bioscience 2017. [DOI: 10.1093/biosci/bix058] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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34
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Olivé I, Silva J, Lauritano C, Costa MM, Ruocco M, Procaccini G, Santos R. Linking gene expression to productivity to unravel long- and short-term responses of seagrasses exposed to CO 2 in volcanic vents. Sci Rep 2017; 7:42278. [PMID: 28205566 PMCID: PMC5304229 DOI: 10.1038/srep42278] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 01/09/2017] [Indexed: 11/09/2022] Open
Abstract
Ocean acidification is a major threat for marine life but seagrasses are expected to benefit from high CO2. In situ (long-term) and transplanted (short-term) plant incubations of the seagrass Cymodocea nodosa were performed near and away the influence of volcanic CO2 vents at Vulcano Island to test the hypothesis of beneficial effects of CO2 on plant productivity. We relate, for the first time, the expression of photosynthetic, antioxidant and metal detoxification-related genes to net plant productivity (NPP). Results revealed a consistent pattern between gene expression and productivity indicating water origin as the main source of variability. However, the hypothesised beneficial effect of high CO2 around vents was not supported. We observed a consistent long- and short-term pattern of gene down-regulation and 2.5-fold NPP decrease in plants incubated in water from the vents and a generalized up-regulation and NPP increase in plants from the vent site incubated with water from the Reference site. Contrastingly, NPP of specimens experimentally exposed to a CO2 range significantly correlated with CO2 availability. The down-regulation of metal-related genes in C. nodosa leaves exposed to water from the venting site suggests that other factors than heavy metals, may be at play at Vulcano confounding the CO2 effects.
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Affiliation(s)
- Irene Olivé
- CCMar-Centre of Marine Sciences, ALGAE - Marine Plant Ecology Research Group. Universidade do Algarve, Campus de Gambelas, 8005-139 Faro, Portugal
| | - João Silva
- CCMar-Centre of Marine Sciences, ALGAE - Marine Plant Ecology Research Group. Universidade do Algarve, Campus de Gambelas, 8005-139 Faro, Portugal
| | - Chiara Lauritano
- Stazione Zoologica Anton Dohrn, Villa Comunale, 80121, Napoli, Italy
| | - Monya M Costa
- CCMar-Centre of Marine Sciences, ALGAE - Marine Plant Ecology Research Group. Universidade do Algarve, Campus de Gambelas, 8005-139 Faro, Portugal
| | - Miriam Ruocco
- Stazione Zoologica Anton Dohrn, Villa Comunale, 80121, Napoli, Italy
| | | | - Rui Santos
- CCMar-Centre of Marine Sciences, ALGAE - Marine Plant Ecology Research Group. Universidade do Algarve, Campus de Gambelas, 8005-139 Faro, Portugal
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35
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Raddatz S, Guy-Haim T, Rilov G, Wahl M. Future warming and acidification effects on anti-fouling and anti-herbivory traits of the brown alga Fucus vesiculosus (Phaeophyceae). JOURNAL OF PHYCOLOGY 2017; 53:44-58. [PMID: 27711971 DOI: 10.1111/jpy.12473] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 07/24/2016] [Indexed: 06/06/2023]
Abstract
Human-induced ocean warming and acidification have received increasing attention over the past decade and are considered to have substantial consequences for a broad range of marine species and their interactions. Understanding how these interactions shift in response to climate change is particularly important with regard to foundation species, such as the brown alga Fucus vesiculosus. This macroalga represents the dominant habitat former on coastal rocky substrata of the Baltic Sea, fulfilling functions essential for the entire benthic community. Its ability to withstand extensive fouling and herbivory regulates the associated community and ecosystem dynamics. This study tested the interactive effects of future warming, acidification, and seasonality on the interactions of a marine macroalga with potential foulers and consumers. F. vesiculosus rockweeds were exposed to different combinations of conditions predicted regionally for the year 2100 (+∆5°C, +∆700 μatm CO2 ) using multifactorial long-term experiments in novel outdoor benthic mesocosms ("Benthocosms") over 9-12-week periods in four seasons. Possible shifts in the macroalgal susceptibility to fouling and consumption were tested using consecutive bioassays. Algal susceptibility to fouling and grazing varied substantially among seasons and between treatments. In all seasons, warming predominantly affected anti-fouling and anti-herbivory interactions while acidification had a subtle nonsignificant influence. Interestingly, anti-microfouling activity was highest during winter under warming, while anti-macrofouling and anti-herbivory activities were highest in the summer under warming. These contrasting findings indicate that seasonal changes in anti-fouling and anti-herbivory traits may interact with ocean warming in altering F. vesiculosus community composition in the future.
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Affiliation(s)
- Stefanie Raddatz
- Department of Benthic Ecology, GEOMAR, Helmholtz Centre for Ocean Research Kiel, Düsternbrooker Weg 20, 24105, Kiel, Germany
| | - Tamar Guy-Haim
- Department of Marine Biology, Israel Oceanographic and Limnological Research, National Institute of Oceanography, P.O. Box 8030, Haifa, 31080, Israel
- Marine Biology Department, The Leon H. Charney School of Marine Sciences, University of Haifa, Mt. Carmel, Haifa, 31905, Israel
| | - Gil Rilov
- Department of Marine Biology, Israel Oceanographic and Limnological Research, National Institute of Oceanography, P.O. Box 8030, Haifa, 31080, Israel
| | - Martin Wahl
- Department of Benthic Ecology, GEOMAR, Helmholtz Centre for Ocean Research Kiel, Düsternbrooker Weg 20, 24105, Kiel, Germany
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Repolho T, Duarte B, Dionísio G, Paula JR, Lopes AR, Rosa IC, Grilo TF, Caçador I, Calado R, Rosa R. Seagrass ecophysiological performance under ocean warming and acidification. Sci Rep 2017; 7:41443. [PMID: 28145531 PMCID: PMC5286439 DOI: 10.1038/srep41443] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 12/19/2016] [Indexed: 11/09/2022] Open
Abstract
Seagrasses play an essential ecological role within coastal habitats and their worldwide population decline has been linked to different types of anthropogenic forces. We investigated, for the first time, the combined effects of future ocean warming and acidification on fundamental biological processes of Zostera noltii, including shoot density, leaf coloration, photophysiology (electron transport rate, ETR; maximum PSII quantum yield, Fv/Fm) and photosynthetic pigments. Shoot density was severely affected under warming conditions, with a concomitant increase in the frequency of brownish colored leaves (seagrass die-off). Warming was responsible for a significant decrease in ETR and Fv/Fm (particularly under control pH conditions), while promoting the highest ETR variability (among experimental treatments). Warming also elicited a significant increase in pheophytin and carotenoid levels, alongside an increase in carotenoid/chlorophyll ratio and De-Epoxidation State (DES). Acidification significantly affected photosynthetic pigments content (antheraxanthin, β-carotene, violaxanthin and zeaxanthin), with a significant decrease being recorded under the warming scenario. No significant interaction between ocean acidification and warming was observed. Our findings suggest that future ocean warming will be a foremost determinant stressor influencing Z. noltii survival and physiological performance. Additionally, acidification conditions to occur in the future will be unable to counteract deleterious effects posed by ocean warming.
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Affiliation(s)
- Tiago Repolho
- MARE - Marine and Environmental Sciences Centre, Laboratório Marítimo da Guia, Faculdade de Ciências da Universidade de Lisboa, Avenida Nossa Senhora do Cabo 939, 2750-374 Cascais, Portugal
| | - Bernardo Duarte
- MARE - Marine and Environmental Sciences Centre, Faculdade de Ciências da Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal
| | - Gisela Dionísio
- MARE - Marine and Environmental Sciences Centre, Laboratório Marítimo da Guia, Faculdade de Ciências da Universidade de Lisboa, Avenida Nossa Senhora do Cabo 939, 2750-374 Cascais, Portugal
- Departamento de Biologia & CESAM, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal
| | - José Ricardo Paula
- MARE - Marine and Environmental Sciences Centre, Laboratório Marítimo da Guia, Faculdade de Ciências da Universidade de Lisboa, Avenida Nossa Senhora do Cabo 939, 2750-374 Cascais, Portugal
| | - Ana R. Lopes
- MARE - Marine and Environmental Sciences Centre, Laboratório Marítimo da Guia, Faculdade de Ciências da Universidade de Lisboa, Avenida Nossa Senhora do Cabo 939, 2750-374 Cascais, Portugal
| | - Inês C. Rosa
- MARE - Marine and Environmental Sciences Centre, Laboratório Marítimo da Guia, Faculdade de Ciências da Universidade de Lisboa, Avenida Nossa Senhora do Cabo 939, 2750-374 Cascais, Portugal
| | - Tiago F. Grilo
- MARE - Marine and Environmental Sciences Centre, Laboratório Marítimo da Guia, Faculdade de Ciências da Universidade de Lisboa, Avenida Nossa Senhora do Cabo 939, 2750-374 Cascais, Portugal
| | - Isabel Caçador
- MARE - Marine and Environmental Sciences Centre, Faculdade de Ciências da Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal
| | - Ricardo Calado
- Departamento de Biologia & CESAM, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal
| | - Rui Rosa
- MARE - Marine and Environmental Sciences Centre, Laboratório Marítimo da Guia, Faculdade de Ciências da Universidade de Lisboa, Avenida Nossa Senhora do Cabo 939, 2750-374 Cascais, Portugal
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Hernán G, Ramajo L, Basso L, Delgado A, Terrados J, Duarte CM, Tomas F. Seagrass (Posidonia oceanica) seedlings in a high-CO 2 world: from physiology to herbivory. Sci Rep 2016; 6:38017. [PMID: 27905514 PMCID: PMC5131316 DOI: 10.1038/srep38017] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 11/02/2016] [Indexed: 11/16/2022] Open
Abstract
Under future increased CO2 concentrations, seagrasses are predicted to perform better as a result of increased photosynthesis, but the effects in carbon balance and growth are unclear and remain unexplored for early life stages such as seedlings, which allow plant dispersal and provide the potential for adaptation under changing environmental conditions. Furthermore, the outcome of the concomitant biochemical changes in plant-herbivore interactions has been poorly studied, yet may have important implications in plant communities. In this study we determined the effects of experimental exposure to current and future predicted CO2 concentrations on the physiology, size and defense strategies against herbivory in the earliest life stage of the Mediterranean seagrass Posidonia oceanica. The photosynthetic performance of seedlings, assessed by fluorescence, improved under increased pCO2 conditions after 60 days, although these differences disappeared after 90 days. Furthermore, these plants exhibited bigger seeds and higher carbon storage in belowground tissues, having thus more resources to tolerate and recover from stressors. Of the several herbivory resistance traits measured, plants under high pCO2 conditions had a lower leaf N content but higher sucrose. These seedlings were preferred by herbivorous sea urchins in feeding trials, which could potentially counteract some of the positive effects observed.
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Affiliation(s)
- Gema Hernán
- Departament of Ecology and Marine Resources, Mediterranean institute for advanced studies (CSIC-UIB), 07190, Esporles, Balearic Islands, Spain
| | - Laura Ramajo
- Departament of Global Change Research, Mediterranean institute for advanced studies (CSIC-UIB), 07190, Esporles, Balearic Islands, Spain
- Department of Science, Liberal Arts School. Universidad Adolfo Ibáñez, 2640, Santiago, Chile
- Center of Research and Innovation for Climate Change (CiiCC). Universidad Santo Tomás, Santiago, Chile
| | - Lorena Basso
- Departament of Global Change Research, Mediterranean institute for advanced studies (CSIC-UIB), 07190, Esporles, Balearic Islands, Spain
- Department of Biological and Environmental Sciences and Technologies (DiSTeBA), University of Salento, 73100 Lecce, Italy
| | - Antonio Delgado
- Stable Isotope Biogeochemistry Laboratory, Andalusian Institute of Earth Science (CSIC-UGR), 18100 Armilla, Granada, Spain
| | - Jorge Terrados
- Departament of Ecology and Marine Resources, Mediterranean institute for advanced studies (CSIC-UIB), 07190, Esporles, Balearic Islands, Spain
| | - Carlos M. Duarte
- Departament of Global Change Research, Mediterranean institute for advanced studies (CSIC-UIB), 07190, Esporles, Balearic Islands, Spain
- King Abdullah University of Science and Technology (KAUST), Red Sea Research Center (RSRC), Thuwal, 23955-6900, Saudi Arabia
| | - Fiona Tomas
- Departament of Ecology and Marine Resources, Mediterranean institute for advanced studies (CSIC-UIB), 07190, Esporles, Balearic Islands, Spain
- Department of Fisheries and Wildlife, Oregon State University, Corvallis, OR, USA
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Pajusalu L, Martin G, Paalme T, Põllumäe A. The effect of CO 2 enrichment on net photosynthesis of the red alga Furcellaria lumbricalis in a brackish water environment. PeerJ 2016; 4:e2505. [PMID: 27761318 PMCID: PMC5068446 DOI: 10.7717/peerj.2505] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Accepted: 08/30/2016] [Indexed: 11/24/2022] Open
Abstract
Anthropogenic carbon dioxide (CO2) emissions to the atmosphere are causing reduction in the global ocean pH, also known as ocean acidification. This change alters the equilibrium of different forms of dissolved inorganic carbon in seawater that macroalgae use for their photosynthesis. In the Baltic Sea, benthic macroalgae live in a highly variable environment caused by seasonality and rapid changes in meteorological conditions. The effect of increasing water CO2 concentration on the net photosynthesis of the red macroalgae Furcellaria lumbricalis (Hudson) Lamouroux was tested in short-term mesocosm experiments conducted in Kõiguste Bay (N Gulf of Riga) in June–July 2012 and 2013. Separate mesocosms were maintained at different pCO2 levels: ca. 2,000, ca. 1,000 and ca. 200 µatm. In parallel, different environmental factors were measured such as nutrients, light and water temperature. Thus, the current study also investigated whether elevated pCO2 and different environmental factors exerted interactive effects on the photosynthetic rate of F. lumbricalis. In addition, laboratory experiments were carried out to determine the optimal temperature for photosynthesis of F. lumbricalis. The results of our field experiments demonstrated that elevated pCO2 levels may remarkably enhance the photosynthetic rate of F. lumbricalis. However, the magnitude of this effect is altered by different environmental factors, mainly by changes in water temperature.
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Affiliation(s)
- Liina Pajusalu
- Department of Marine Biology, Estonian Marine Institute, University of Tartu , Tallinn , Estonia
| | - Georg Martin
- Department of Marine Biology, Estonian Marine Institute, University of Tartu , Tallinn , Estonia
| | - Tiina Paalme
- Department of Marine Biology, Estonian Marine Institute, University of Tartu , Tallinn , Estonia
| | - Arno Põllumäe
- Department of Marine Biology, Estonian Marine Institute, University of Tartu , Tallinn , Estonia
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Reyes-Fox M, Steltzer H, LeCain DR, McMaster GS. Five years of phenology observations from a mixed-grass prairie exposed to warming and elevated CO 2. Sci Data 2016; 3:160088. [PMID: 27727235 PMCID: PMC5113067 DOI: 10.1038/sdata.2016.88] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 08/31/2016] [Indexed: 11/21/2022] Open
Abstract
Atmospheric CO2 concentrations have been steadily increasing since the Industrial Era and contribute to concurrent increases in global temperatures. Many observational studies suggest climate warming alone contributes to a longer growing season. To determine the relative effect of warming on plant phenology, we investigated the individual and joint effects of warming and CO2 enrichment on a mixed-grass prairie plant community by following the development of six common grassland species and recording four major life history events. Our data support that, in a semi-arid system, while warming advances leaf emergence and flower production, it also expedites seed maturation and senescence at the species level. However, the additive effect can be an overall lengthening of the growing and reproductive seasons since CO2 enrichment, particularly when combined with warming, contributed to a longer growing season by delaying plant maturation and senescence. Fostering synthesis across multiple phenology datasets and identifying key factors affecting plant phenology will be vital for understanding regional plant community responses to climate change.
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Affiliation(s)
- Melissa Reyes-Fox
- USDA-ARS, Soil Plant Nutrient Research Unit and Northern Plains Area, Fort Collins, Colorado 80526, USA
| | - Heidi Steltzer
- Department of Biology, Fort Lewis College, Durango, Colorado 81301, USA
| | - Daniel R LeCain
- USDA-ARS, Rangeland Resources Research Unit, Fort Collins, Colorado 80526, USA
| | - Gregory S McMaster
- USDA-ARS, Agricultural Systems Research Unit and Northern Plains Area, Fort Collins, Colorado 80526, USA
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Ow YX, Vogel N, Collier CJ, Holtum JAM, Flores F, Uthicke S. Nitrate fertilisation does not enhance CO2 responses in two tropical seagrass species. Sci Rep 2016; 6:23093. [PMID: 26976685 PMCID: PMC4792133 DOI: 10.1038/srep23093] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Accepted: 02/26/2016] [Indexed: 12/05/2022] Open
Abstract
Seagrasses are often considered "winners" of ocean acidification (OA); however, seagrass productivity responses to OA could be limited by nitrogen availability, since nitrogen-derived metabolites are required for carbon assimilation. We tested nitrogen uptake and assimilation, photosynthesis, growth, and carbon allocation responses of the tropical seagrasses Halodule uninervis and Thalassia hemprichii to OA scenarios (428, 734 and 1213 μatm pCO2) under two nutrients levels (0.3 and 1.9 μM NO3(-)). Net primary production (measured as oxygen production) and growth in H. uninervis increased with pCO2 enrichment, but were not affected by nitrate enrichment. However, nitrate enrichment reduced whole plant respiration in H. uninervis. Net primary production and growth did not show significant changes with pCO2 or nitrate by the end of the experiment (24 d) in T. hemprichii. However, nitrate incorporation in T. hemprichii was higher with nitrate enrichment. There was no evidence that nitrogen demand increased with pCO2 enrichment in either species. Contrary to our initial hypothesis, nutrient increases to levels approximating present day flood plumes only had small effects on metabolism. This study highlights that the paradigm of increased productivity of seagrasses under ocean acidification may not be valid for all species under all environmental conditions.
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Affiliation(s)
- Y. X. Ow
- College of Marine and Environmental Science, James Cook University, Townsville Queensland 4811, Australia
- Australian Institute of Marine Science, Townville MC Queensland 4810, Australia
- Experimental Marine Ecology Laboratory, Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Blk S3, #02-05, 117543, Singapore
| | - N. Vogel
- Australian Institute of Marine Science, Townville MC Queensland 4810, Australia
| | - C. J. Collier
- College of Marine and Environmental Science, James Cook University, Townsville Queensland 4811, Australia
- Centre for Tropical Water & Aquatic Ecosystem Research (TropWATER), James Cook University, Cairns, Queensland 4870, Australia
| | - J. A. M. Holtum
- College of Marine and Environmental Science, James Cook University, Townsville Queensland 4811, Australia
| | - F. Flores
- Australian Institute of Marine Science, Townville MC Queensland 4810, Australia
| | - S. Uthicke
- Australian Institute of Marine Science, Townville MC Queensland 4810, Australia
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41
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Ow YX, Uthicke S, Collier CJ. Light Levels Affect Carbon Utilisation in Tropical Seagrass under Ocean Acidification. PLoS One 2016; 11:e0150352. [PMID: 26938454 PMCID: PMC4777487 DOI: 10.1371/journal.pone.0150352] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Accepted: 02/12/2016] [Indexed: 11/18/2022] Open
Abstract
Under future ocean acidification (OA), increased availability of dissolved inorganic carbon (DIC) in seawater may enhance seagrass productivity. However, the ability to utilise additional DIC could be regulated by light availability, often reduced through land runoff. To test this, two tropical seagrass species, Cymodocea serrulata and Halodule uninervis were exposed to two DIC concentrations (447 μatm and 1077 μatm pCO2), and three light treatments (35, 100, 380 μmol m(-2) s(-1)) for two weeks. DIC uptake mechanisms were separately examined by measuring net photosynthetic rates while subjecting C. serrulata and H. uninervis to changes in light and addition of bicarbonate (HCO3-) use inhibitors (carbonic anhydrase inhibitor, acetazolamide) and TRIS buffer (pH 8.0). We observed a strong dependence on energy driven H+-HCO3- co-transport (TRIS, which disrupts H+ extrusion) in C. serrulata under all light levels, indicating greater CO2 dependence in low light. This was confirmed when, after two weeks exposure, DIC enrichment stimulated maximum photosynthetic rates (Pmax) and efficiency (α) more in C. serrulata grown under lower light levels (36-60% increase) than for those in high light (4% increase). However, C. serrulata growth increased with both DIC enrichment and light levels. Growth, NPP and photosynthetic responses in H. uninervis increased with higher light treatments and were independent of DIC availability. Furthermore, H. uninervis was found to be more flexible in HCO3- uptake pathways. Here, light availability influenced productivity responses to DIC enrichment, via both carbon fixation and acquisition processes, highlighting the role of water quality in future responses to OA.
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Affiliation(s)
- Yan X. Ow
- College of Marine and Environmental Science, James Cook University, Townsville, Queensland, Australia
- Australian Institute of Marine Science, Townville, Queensland, Australia
- Experimental Marine Ecology Laboratory, Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - Sven Uthicke
- Australian Institute of Marine Science, Townville, Queensland, Australia
| | - Catherine J. Collier
- College of Marine and Environmental Science, James Cook University, Townsville, Queensland, Australia
- Centre for Tropical Water & Aquatic Ecosystem Research (TropWATER), James Cook University, Cairns, Queensland, Australia
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Abrams JF, Hohn S, Rixen T, Baum A, Merico A. The impact of Indonesian peatland degradation on downstream marine ecosystems and the global carbon cycle. GLOBAL CHANGE BIOLOGY 2016; 22:325-337. [PMID: 26416553 DOI: 10.1111/gcb.13108] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 09/10/2015] [Indexed: 06/05/2023]
Abstract
Tropical peatlands are among the most space-efficient stores of carbon on Earth containing approximately 89 Gt C. Of this, 57 Gt (65%) are stored in Indonesian peatlands. Large-scale exploitation of land, including deforestation and drainage for the establishment of oil palm plantations, is changing the carbon balance of Indonesian peatlands, turning them from a natural sink to a source via outgassing of CO2 to the atmosphere and leakage of dissolved organic carbon (DOC) into the coastal ocean. The impacts of this perturbation to the coastal environment and at the global scale are largely unknown. Here, we evaluate the downstream effects of released Indonesian peat carbon on coastal ecosystems and on the global carbon cycle. We use a biogeochemical box model in combination with novel and literature observations to investigate the impact of different carbon emission scenarios on the combined ocean-atmosphere system. The release of all carbon stored in the Indonesian peat pool, considered as a worst-case scenario, will increase atmospheric pCO2 by 8 ppm to 15 ppm within the next 200 years. The expected impact on the Java Sea ecosystems is most significant on the short term (over a few hundred years) and is characterized by an increase of 3.3% in phytoplankton, 32% in seagrass biomass, and 5% decrease in coral biomass. On the long term, however, the coastal ecosystems will recover to reach near pre-excursion conditions. Our results suggest that the ultimate fate of the peat carbon is in the deep ocean with 69% of it landing in the deep DIC pool after 1000 years, but the effects on the global ocean carbonate chemistry will be marginal.
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Affiliation(s)
- Jesse F Abrams
- Systems Ecology, Leibniz Center for Tropical Marine Ecology, Fahrenheitstrasse 6, 28359, Bremen, Germany
- Faculty of Physics & Earth Sciences, Jacobs University Bremen, Campus Ring 1, 28759, Bremen, Germany
| | - Sönke Hohn
- Systems Ecology, Leibniz Center for Tropical Marine Ecology, Fahrenheitstrasse 6, 28359, Bremen, Germany
| | - Tim Rixen
- Carbon and Nutrient Cycling, Leibniz Center for Tropical Marine Ecology, Fahrenheitstrasse 6, 28359, Bremen, Germany
| | - Antje Baum
- Carbon and Nutrient Cycling, Leibniz Center for Tropical Marine Ecology, Fahrenheitstrasse 6, 28359, Bremen, Germany
| | - Agostino Merico
- Systems Ecology, Leibniz Center for Tropical Marine Ecology, Fahrenheitstrasse 6, 28359, Bremen, Germany
- Faculty of Physics & Earth Sciences, Jacobs University Bremen, Campus Ring 1, 28759, Bremen, Germany
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Unsworth RKF, Collier CJ, Waycott M, Mckenzie LJ, Cullen-Unsworth LC. A framework for the resilience of seagrass ecosystems. MARINE POLLUTION BULLETIN 2015; 100:34-46. [PMID: 26342389 DOI: 10.1016/j.marpolbul.2015.08.016] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Revised: 08/13/2015] [Accepted: 08/16/2015] [Indexed: 05/08/2023]
Abstract
Seagrass ecosystems represent a global marine resource that is declining across its range. To halt degradation and promote recovery over large scales, management requires a radical change in emphasis and application that seeks to enhance seagrass ecosystem resilience. In this review we examine how the resilience of seagrass ecosystems is becoming compromised by a range of local to global stressors, resulting in ecological regime shifts that undermine the long-term viability of these productive ecosystems. To examine regime shifts and the management actions that can influence this phenomenon we present a conceptual model of resilience in seagrass ecosystems. The model is founded on a series of features and modifiers that act as interacting influences upon seagrass ecosystem resilience. Improved understanding and appreciation of the factors and modifiers that govern resilience in seagrass ecosystems can be utilised to support much needed evidence based management of a vital natural resource.
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Affiliation(s)
- Richard K F Unsworth
- Seagrass Ecosystem Research Group, College of Science, Swansea University SA2 8PP, UK.
| | - Catherine J Collier
- Centre for Tropical Water & Aquatic Ecosystem Research (TropWATER), James Cook University, Cairns, QLD 4870, Australia; College of Marine and Environmental Sciences, James Cook University, Cairns, QLD 4870, Australia
| | - Michelle Waycott
- School of Biological Sciences, Environment Institute, Australian Centre for Evolutionary Biology and Biodiversity, The University of Adelaide, SA 5001, Australia
| | - Len J Mckenzie
- Centre for Tropical Water & Aquatic Ecosystem Research (TropWATER), James Cook University, Cairns, QLD 4870, Australia
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Linares C, Vidal M, Canals M, Kersting DK, Amblas D, Aspillaga E, Cebrián E, Delgado-Huertas A, Díaz D, Garrabou J, Hereu B, Navarro L, Teixidó N, Ballesteros E. Persistent natural acidification drives major distribution shifts in marine benthic ecosystems. Proc Biol Sci 2015; 282:20150587. [PMID: 26511045 PMCID: PMC4650147 DOI: 10.1098/rspb.2015.0587] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Accepted: 09/29/2015] [Indexed: 11/12/2022] Open
Abstract
Ocean acidification is receiving increasing attention because of its potential to affect marine ecosystems. Rare CO2 vents offer a unique opportunity to investigate the response of benthic ecosystems to acidification. However, the benthic habitats investigated so far are mainly found at very shallow water (less than or equal to 5 m depth) and therefore are not representative of the broad range of continental shelf habitats. Here, we show that a decrease from pH 8.1 to 7.9 observed in a CO2 vent system at 40 m depth leads to a dramatic shift in highly diverse and structurally complex habitats. Forests of the kelp Laminaria rodriguezii usually found at larger depths (greater than 65 m) replace the otherwise dominant habitats (i.e. coralligenous outcrops and rhodolith beds), which are mainly characterized by calcifying organisms. Only the aragonite-calcifying algae are able to survive in acidified waters, while high-magnesium-calcite organisms are almost completely absent. Although a long-term survey of the venting area would be necessary to fully understand the effects of the variability of pH and other carbonate parameters over the structure and functioning of the investigated mesophotic habitats, our results suggest that in addition of significant changes at species level, moderate ocean acidification may entail major shifts in the distribution and dominance of key benthic ecosystems at regional scale, which could have broad ecological and socio-economic implications.
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Affiliation(s)
- C Linares
- Departament d'Ecologia, Facultat de Biologia, Universitat de Barcelona, Avda. Diagonal 643, Barcelona 08028, Spain
| | - M Vidal
- Departament d'Ecologia, Facultat de Biologia, Universitat de Barcelona, Avda. Diagonal 643, Barcelona 08028, Spain
| | - M Canals
- GRC Geociències Marines, Departament d'Estratigrafia, Paleontologia i Geociències Marines, Facultat de Geologia, Universitat de Barcelona, Martí i Franquès s/n, Barcelona 08028, Spain
| | - D K Kersting
- Departament d'Ecologia, Facultat de Biologia, Universitat de Barcelona, Avda. Diagonal 643, Barcelona 08028, Spain
| | - D Amblas
- GRC Geociències Marines, Departament d'Estratigrafia, Paleontologia i Geociències Marines, Facultat de Geologia, Universitat de Barcelona, Martí i Franquès s/n, Barcelona 08028, Spain
| | - E Aspillaga
- Departament d'Ecologia, Facultat de Biologia, Universitat de Barcelona, Avda. Diagonal 643, Barcelona 08028, Spain
| | - E Cebrián
- Centre d'Estudis Avançats de Blanes, CSIC, Accés Cala St Francesc 14, Blanes, Girona 17300, Spain Departament de Ciències Ambientals, Universitat de Girona, Campus Montilivi, Girona 17071, Spain
| | - A Delgado-Huertas
- Instituto Andaluz de Ciencias de la Tierra, CSIC-UGR, Avenida de las Palmeras 4, Armilla 18100, Spain
| | - D Díaz
- Instituto Español de Oceanografía, C/ Moll de Ponent s/n, Palma de Mallorca 07015, Spain Institut de Ciències del Mar, CSIC, Passeig Marítim de la Barceloneta 37-49, Barcelona 08003, Spain
| | - J Garrabou
- Institut de Ciències del Mar, CSIC, Passeig Marítim de la Barceloneta 37-49, Barcelona 08003, Spain
| | - B Hereu
- Departament d'Ecologia, Facultat de Biologia, Universitat de Barcelona, Avda. Diagonal 643, Barcelona 08028, Spain
| | - L Navarro
- Departament d'Ecologia, Facultat de Biologia, Universitat de Barcelona, Avda. Diagonal 643, Barcelona 08028, Spain
| | - N Teixidó
- Stazione Zoologica Anton Dohrn, Villa Dohrn-Benthic Ecology Center, Punta San Pietro, Ischia, Naples 80077, Italy
| | - E Ballesteros
- Centre d'Estudis Avançats de Blanes, CSIC, Accés Cala St Francesc 14, Blanes, Girona 17300, Spain
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Tomas F, Martínez-Crego B, Hernán G, Santos R. Responses of seagrass to anthropogenic and natural disturbances do not equally translate to its consumers. GLOBAL CHANGE BIOLOGY 2015; 21:4021-4030. [PMID: 26152761 DOI: 10.1111/gcb.13024] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Revised: 06/10/2015] [Accepted: 06/16/2015] [Indexed: 06/04/2023]
Abstract
Coastal communities are under threat from many and often co-occurring local (e.g., pollution, eutrophication) and global stressors (e.g., climate change), yet understanding the interactive and cumulative impacts of multiple stressors in ecosystem function is far from being accomplished. Ecological redundancy may be key for ecosystem resilience, but there are still many gaps in our understanding of interspecific differences within a functional group, particularly regarding response diversity, that is, whether members of a functional group respond equally or differently to anthropogenic stressors. Herbivores are critical in determining plant community structure and the transfer of energy up the food web. Human disturbances may alter the ecological role of herbivory by modifying the defense strategies of plants and thus the feeding patterns and performance of herbivores. We conducted a suite of experiments to examine the independent and interactive effects of anthropogenic (nutrient and CO2 additions) and natural (simulated herbivory) disturbances on a seagrass and its interaction with two common generalist consumers to understand how multiple disturbances can impact both a foundation species and a key ecological function (herbivory) and to assess the potential existence of response diversity to anthropogenic and natural changes in these systems. While all three disturbances modified seagrass defense traits, there were contrasting responses of herbivores to such plant changes. Both CO2 and nutrient additions influenced herbivore feeding behavior, yet while sea urchins preferred nutrient-enriched seagrass tissue (regardless of other experimental treatments), isopods were deterred by these same plant tissues. In contrast, carbon enrichment deterred sea urchins and attracted isopods, while simulated herbivory only influenced isopod feeding choice. These contrasting responses of herbivores to disturbance-induced changes in seagrass help to better understand the ecological functioning of seagrass ecosystems in the face of human disturbances and may have important implications regarding the resilience and conservation of these threatened ecosystems.
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Affiliation(s)
- Fiona Tomas
- Instituto Mediterráneo de Estudios Avanzados (UIB-CSIC), C/ Miquel Marquès, 21 07190, Esporles Illes Balears, Spain
- Centre d'Estudis Avançats de Blanes Carrer Accés Cala Sant Francesc, 14, 17300, Blanes, Girona, Spain
- Department of Fisheries and Wildlife, Oregon State University, 104 Nash Hall, 2820 SW Campus Way, Corvallis, OR, 97331, USA
| | - Begoña Martínez-Crego
- Centre of Marine Sciences (CCMAR), Universidade do Algarve Campus de Gambelas, 8005-139, Faro, Portugal
| | - Gema Hernán
- Instituto Mediterráneo de Estudios Avanzados (UIB-CSIC), C/ Miquel Marquès, 21 07190, Esporles Illes Balears, Spain
- Centre d'Estudis Avançats de Blanes Carrer Accés Cala Sant Francesc, 14, 17300, Blanes, Girona, Spain
| | - Rui Santos
- Centre of Marine Sciences (CCMAR), Universidade do Algarve Campus de Gambelas, 8005-139, Faro, Portugal
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Haigh R, Ianson D, Holt CA, Neate HE, Edwards AM. Effects of Ocean Acidification on Temperate Coastal Marine Ecosystems and Fisheries in the Northeast Pacific. PLoS One 2015; 10:e0117533. [PMID: 25671596 PMCID: PMC4324998 DOI: 10.1371/journal.pone.0117533] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 12/23/2014] [Indexed: 11/29/2022] Open
Abstract
As the oceans absorb anthropogenic CO2 they become more acidic, a problem termed ocean acidification (OA). Since this increase in CO2 is occurring rapidly, OA may have profound implications for marine ecosystems. In the temperate northeast Pacific, fisheries play key economic and cultural roles and provide significant employment, especially in rural areas. In British Columbia (BC), sport (recreational) fishing generates more income than commercial fishing (including the expanding aquaculture industry). Salmon (fished recreationally and farmed) and Pacific Halibut are responsible for the majority of fishery-related income. This region naturally has relatively acidic (low pH) waters due to ocean circulation, and so may be particularly vulnerable to OA. We have analyzed available data to provide a current description of the marine ecosystem, focusing on vertical distributions of commercially harvested groups in BC in the context of local carbon and pH conditions. We then evaluated the potential impact of OA on this temperate marine system using currently available studies. Our results highlight significant knowledge gaps. Above trophic levels 2–3 (where most local fishery-income is generated), little is known about the direct impact of OA, and more importantly about the combined impact of multi-stressors, like temperature, that are also changing as our climate changes. There is evidence that OA may have indirect negative impacts on finfish through changes at lower trophic levels and in habitats. In particular, OA may lead to increased fish-killing algal blooms that can affect the lucrative salmon aquaculture industry. On the other hand, some species of locally farmed shellfish have been well-studied and exhibit significant negative direct impacts associated with OA, especially at the larval stage. We summarize the direct and indirect impacts of OA on all groups of marine organisms in this region and provide conclusions, ordered by immediacy and certainty.
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Affiliation(s)
- Rowan Haigh
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Pacific Biological Station, Fisheries and Oceans Canada, 3190 Hammond Bay Road, Nanaimo, British Columbia, V9T 6N7, Canada
| | - Debby Ianson
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Institute of Ocean Sciences, Fisheries and Oceans Canada, 9860 West Saanich Road, Sidney, British Columbia, V8L 4B2, Canada
- * E-mail:
| | - Carrie A. Holt
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Pacific Biological Station, Fisheries and Oceans Canada, 3190 Hammond Bay Road, Nanaimo, British Columbia, V9T 6N7, Canada
| | - Holly E. Neate
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Pacific Biological Station, Fisheries and Oceans Canada, 3190 Hammond Bay Road, Nanaimo, British Columbia, V9T 6N7, Canada
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Department of Biology, University of Victoria, P.O. Box 1700, Station CSC, Victoria, British Columbia, V8W 2Y2, Canada
| | - Andrew M. Edwards
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Pacific Biological Station, Fisheries and Oceans Canada, 3190 Hammond Bay Road, Nanaimo, British Columbia, V9T 6N7, Canada
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Department of Biology, University of Victoria, P.O. Box 1700, Station CSC, Victoria, British Columbia, V8W 2Y2, Canada
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Burnell OW, Connell SD, Irving AD, Watling JR, Russell BD. Contemporary reliance on bicarbonate acquisition predicts increased growth of seagrass Amphibolis antarctica in a high-CO2 world. CONSERVATION PHYSIOLOGY 2014; 2:cou052. [PMID: 27293673 PMCID: PMC4732469 DOI: 10.1093/conphys/cou052] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Revised: 07/30/2014] [Accepted: 10/16/2014] [Indexed: 05/30/2023]
Abstract
Rising atmospheric CO2 is increasing the availability of dissolved CO2 in the ocean relative to HCO3 (-). Currently, many marine primary producers use HCO3 (-) for photosynthesis, but this is energetically costly. Increasing passive CO2 uptake relative to HCO3 (-) pathways could provide energy savings, leading to increased productivity and growth of marine plants. Inorganic carbon-uptake mechanisms in the seagrass Amphibolis antarctica were determined using the carbonic anhydrase inhibitor acetazolamide (AZ) and the buffer tris(hydroxymethyl)aminomethane (TRIS). Amphibolis antarctica seedlings were also maintained in current and forecasted CO2 concentrations to measure their physiology and growth. Photosynthesis of A. antarctica was significantly reduced by AZ and TRIS, indicating utilization of HCO3 (-)-uptake mechanisms. When acclimated plants were switched between CO2 treatments, the photosynthetic rate was dependent on measurement conditions but not growth conditions, indicating a dynamic response to changes in dissolved CO2 concentration, rather than lasting effects of acclimation. At forecast CO2 concentrations, seedlings had a greater maximum electron transport rate (1.4-fold), photosynthesis (2.1-fold), below-ground biomass (1.7-fold) and increase in leaf number (2-fold) relative to plants in the current CO2 concentration. The greater increase in photosynthesis (measured as O2 production) compared with the electron transport rate at forecasted CO2 concentration suggests that photosynthetic efficiency increased, possibly due to a decrease in photorespiration. Thus, it appears that the photosynthesis and growth of seagrasses reliant on energetically costly HCO3 (-) acquisition, such as A. antarctica, might increase at forecasted CO2 concentrations. Greater growth might enhance the future prosperity and rehabilitation of these important habitat-forming plants, which have experienced declines of global significance.
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Affiliation(s)
- Owen W. Burnell
- School of Earth & Environmental Sciences, University of Adelaide, Adelaide, SA 5005, Australia
| | - Sean D. Connell
- School of Earth & Environmental Sciences, University of Adelaide, Adelaide, SA 5005, Australia
| | - Andrew D. Irving
- School of Medical and Applied Sciences, Central Queensland University, Bruce Highway, Rockhampton, QLD 4702, Australia
| | - Jennifer R. Watling
- School of Earth & Environmental Sciences, University of Adelaide, Adelaide, SA 5005, Australia
| | - Bayden D. Russell
- School of Earth & Environmental Sciences, University of Adelaide, Adelaide, SA 5005, Australia
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Garrard SL, Beaumont NJ. The effect of ocean acidification on carbon storage and sequestration in seagrass beds; a global and UK context. MARINE POLLUTION BULLETIN 2014; 86:138-146. [PMID: 25103900 DOI: 10.1016/j.marpolbul.2014.07.032] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Revised: 07/14/2014] [Accepted: 07/19/2014] [Indexed: 05/03/2023]
Abstract
Ocean acidification will have many negative consequences for marine organisms and ecosystems, leading to a decline in many ecosystem services provided by the marine environment. This study reviews the effect of ocean acidification (OA) on seagrasses, assessing how this may affect their capacity to sequester carbon in the future and providing an economic valuation of these changes. If ocean acidification leads to a significant increase in above- and below-ground biomass, the capacity of seagrass to sequester carbon will be significantly increased. The associated value of this increase in sequestration capacity is approximately £500 and 600 billion globally between 2010 and 2100. A proportionally similar increase in carbon sequestration value was found for the UK. This study highlights one of the few positive stories for ocean acidification and underlines that sustainable management of seagrasses is critical to avoid their continued degradation and loss of carbon sequestration capacity.
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Affiliation(s)
- Samantha L Garrard
- Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth PL1 3DH, UK; Marine and Fisheries Unit, Ascension Island Government Conservation Department, Georgetown, Ascension Island, South Atlantic ASCN 1ZZ, UK.
| | - Nicola J Beaumont
- Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth PL1 3DH, UK
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49
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Apostolaki ET, Vizzini S, Hendriks IE, Olsen YS. Seagrass ecosystem response to long-term high CO2 in a Mediterranean volcanic vent. MARINE ENVIRONMENTAL RESEARCH 2014; 99:9-15. [PMID: 25081848 DOI: 10.1016/j.marenvres.2014.05.008] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Revised: 05/02/2014] [Accepted: 05/08/2014] [Indexed: 05/21/2023]
Abstract
We examined the long-term effect of naturally acidified water on a Cymodocea nodosa meadow growing at a shallow volcanic CO2 vent in Vulcano Island (Italy). Seagrass and adjacent unvegetated habitats growing at a low pH station (pH = 7.65 ± 0.02) were compared with corresponding habitats at a control station (pH = 8.01 ± 0.01). Density and biomass showed a clear decreasing trend at the low pH station and the below- to above-ground biomass ratio was more than 10 times lower compared to the control. C content and δ(13)C of leaves and epiphytes were significantly lower at the low pH station. Photosynthetic activity of C. nodosa was stimulated by low pH as seen by the significant increase in Chla content of leaves, maximum electron transport rate and compensation irradiance. Seagrass community metabolism was intense at the low pH station, with significantly higher net community production, respiration and gross primary production than the control community, whereas metabolism of the unvegetated community did not differ between stations. Productivity was promoted by the low pH, but this was not translated into biomass, probably due to nutrient limitation, grazing or poor environmental conditions. The results indicate that seagrass response in naturally acidified conditions is dependable upon species and geochemical characteristics of the site and highlight the need for a better understanding of complex interactions in these environments.
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Affiliation(s)
- Eugenia T Apostolaki
- Institute of Oceanography, Hellenic Centre for Marine Research, PO Box 2214, 71003 Heraklion, Crete, Greece.
| | - Salvatrice Vizzini
- Department of Earth and Marine Sciences, University of Palermo, Via Archirafi 18, 90123 Palermo, Italy
| | - Iris E Hendriks
- Global Change Department, Mediterranean Institute for Advanced Studies (CSIC-UIB), c/ Miquel Marquès 21, 07190 Esporles, Balearic Islands, Spain
| | - Ylva S Olsen
- Global Change Department, Mediterranean Institute for Advanced Studies (CSIC-UIB), c/ Miquel Marquès 21, 07190 Esporles, Balearic Islands, Spain; The UWA Oceans Institute and School of Plant Biology, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
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50
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Macreadie PI, Baird ME, Trevathan-Tackett SM, Larkum AWD, Ralph PJ. Quantifying and modelling the carbon sequestration capacity of seagrass meadows--a critical assessment. MARINE POLLUTION BULLETIN 2014; 83:430-9. [PMID: 23948090 DOI: 10.1016/j.marpolbul.2013.07.038] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Revised: 06/11/2013] [Accepted: 07/20/2013] [Indexed: 05/05/2023]
Abstract
Seagrasses are among the planet's most effective natural ecosystems for sequestering (capturing and storing) carbon (C); but if degraded, they could leak stored C into the atmosphere and accelerate global warming. Quantifying and modelling the C sequestration capacity is therefore critical for successfully managing seagrass ecosystems to maintain their substantial abatement potential. At present, there is no mechanism to support carbon financing linked to seagrass. For seagrasses to be recognised by the IPCC and the voluntary C market, standard stock assessment methodologies and inventories of seagrass C stocks are required. Developing accurate C budgets for seagrass meadows is indeed complex; we discuss these complexities, and, in addition, we review techniques and methodologies that will aid development of C budgets. We also consider a simple process-based data assimilation model for predicting how seagrasses will respond to future change, accompanied by a practical list of research priorities.
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Affiliation(s)
- P I Macreadie
- Plant Functional Biology and Climate Change Cluster, University of Technology, Sydney, PO Box 123, 2007, Broadway, Australia; Centre for Environmental Sustainability, School of the Environment, University of Technology, Sydney, PO Box 123, 2007, Broadway, Australia.
| | - M E Baird
- Plant Functional Biology and Climate Change Cluster, University of Technology, Sydney, PO Box 123, 2007, Broadway, Australia
| | - S M Trevathan-Tackett
- Plant Functional Biology and Climate Change Cluster, University of Technology, Sydney, PO Box 123, 2007, Broadway, Australia
| | - A W D Larkum
- Plant Functional Biology and Climate Change Cluster, University of Technology, Sydney, PO Box 123, 2007, Broadway, Australia
| | - P J Ralph
- Plant Functional Biology and Climate Change Cluster, University of Technology, Sydney, PO Box 123, 2007, Broadway, Australia
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