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Schultz J, Berry Gobler DL, Young CS, Perez A, Doall MH, Gobler CJ. Ocean acidification significantly alters the trace element content of the kelp, Saccharina latissima. MARINE POLLUTION BULLETIN 2024; 202:116289. [PMID: 38564822 DOI: 10.1016/j.marpolbul.2024.116289] [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: 11/26/2023] [Revised: 03/05/2024] [Accepted: 03/20/2024] [Indexed: 04/04/2024]
Abstract
Seaweeds are ecosystem engineers that can serve as habitat, sequester carbon, buffer ecosystems against acidification, and, in an aquaculture setting, represent an important food source. One health issue regarding the consumption of seaweeds and specifically, kelp, is the accumulation of some trace elements of concern within tissues. As atmospheric CO2 concentrations rise, and global oceans acidify, the concentrations of elements in seawater and kelp may change. Here, we cultivated the sugar kelp, Saccharina latissima under ambient (~400 μatm) and elevated pCO2 (600-2400 μatm) conditions and examined the accumulation of trace elements using x-ray powder diffraction, sub-micron resolution x-ray imaging, and inductively coupled plasma mass spectrometry. Exposure of S. latissima to higher concentrations of pCO2 and lower pH caused a significant increase (p < 0.05) in the iodine and arsenic content of kelp along with increased subcellular heterogeneity of these two elements as well as bromine. The iodine-to‑calcium and bromine-to‑calcium ratios of kelp also increased significantly under high CO2/low pH (p < 0.05). In contrast, high CO2/low pH significantly reduced levels of copper and cadmium in kelp tissue (p < 0.05) and there were significant inverse correlations between concentrations of pCO2 and concentrations of cadmium and copper in kelp (p < 0.05). Changes in copper and cadmium levels in kelp were counter to expected changes in their free ionic concentrations in seawater, suggesting that the influence of low pH on algal physiology was an important control on the elemental content of kelp. Collectively, these findings reveal the complex effects of ocean acidification on the elemental composition of seaweeds and indicate that the elemental content of seaweeds used as food must be carefully monitored as climate change accelerates this century.
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Affiliation(s)
- Jack Schultz
- Vanderbilt University, Department of Biological Sciences, Nashville, TN 37235, United States of America; Westhampton Beach High School, Westhampton Beach, NY 11978, United States of America
| | - Dianna L Berry Gobler
- Westhampton Beach High School, Westhampton Beach, NY 11978, United States of America; Stony Brook University, School of Marine and Atmospheric Sciences, Southampton, NY 11968, United States of America
| | - Craig S Young
- Stony Brook University, School of Marine and Atmospheric Sciences, Southampton, NY 11968, United States of America
| | - Aleida Perez
- Brookhaven National Laboratory, Department of Educational Programs Upton, NY 11973, United States of America
| | - Michael H Doall
- Stony Brook University, School of Marine and Atmospheric Sciences, Southampton, NY 11968, United States of America
| | - Christopher J Gobler
- Stony Brook University, School of Marine and Atmospheric Sciences, Southampton, NY 11968, United States of America.
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2
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Segaran TC, Azra MN, Mohd Noor MI, Danish-Daniel M, Burlakovs J, Lananan F, Xu J, Kari ZA, Wei LS. Knowledge mapping analysis of the global seaweed research using CiteSpace. Heliyon 2024; 10:e28418. [PMID: 38560172 PMCID: PMC10981124 DOI: 10.1016/j.heliyon.2024.e28418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 03/10/2024] [Accepted: 03/19/2024] [Indexed: 04/04/2024] Open
Abstract
Seaweed research has gained substantial momentum in recent years, attracting the attention of researchers, academic institutions, industries, policymakers, and philanthropists to explore its potential applications and benefits. Despite the growing body of literature, there is a paucity of comprehensive scientometric analyses, highlighting the need for an in-depth investigation. In this study, we utilized CiteSpace to examine the global seaweed research landscape through the Web of Science Core Collection database, assessing publication trends, collaboration patterns, network structures, and co-citation analyses across 48,278 original works published since 1975. Our results demonstrate a diverse and active research community, with a multitude of authors and journals contributing to the advancement of seaweed science. Thematic co-citation cluster analysis identified three primary research areas: "Coral reef," "Solar radiation," and "Mycosporine-like amino acid," emphasizing the multidisciplinary nature of seaweed research. The increasing prominence of "Chemical composition" and "Antioxidant" keywords indicates a burgeoning interest in characterizing the nutritional value and health-promoting properties of seaweed. Timeline co-citation analysis unveils that recent research priorities have emerged around the themes of coral reefs, ocean acidification, and antioxidants, underlining the evolving focus and interdisciplinary approach of the field. Moreover, our analysis highlights the potential of seaweed as a functional food product, poised to contribute significantly to addressing global food security and sustainability challenges. This study underscores the importance of bibliometric analysis in elucidating the global seaweed research landscape and emphasizes the need for sustained knowledge exchange and collaboration to drive the field forward. By revealing key findings and emerging trends, our research offers valuable insights for academics and stakeholders, fostering a more profound understanding of seaweed's potential and informing future research endeavors in this promising domain.
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Affiliation(s)
- Thirukanthan Chandra Segaran
- Institute of Climate Adaptation and Marine Biotechnology (ICAMB), Universiti Malaysia Terengganu (UMT), Kuala Nerus, 21030, Terengganu, Malaysia
| | - Mohamad Nor Azra
- Institute of Climate Adaptation and Marine Biotechnology (ICAMB), Universiti Malaysia Terengganu (UMT), Kuala Nerus, 21030, Terengganu, Malaysia
- Research Center for Marine and Land Bioindustry, Earth Sciences and Maritime Organization, National Research and Innovation Agency (BRIN), Pemenang, 83352, Indonesia
| | - Mohd Iqbal Mohd Noor
- Faculty of Business Management, Universiti Teknologi MARA (UiTM) (Pahang), 27600, Raub, Pahang, Malaysia
- Institute for Biodiversity and Sustainable Development, Universiti Teknologi MARA (UiTM), 40450, Shah Alam, Selangor, Malaysia
| | - Muhd Danish-Daniel
- Institute of Climate Adaptation and Marine Biotechnology (ICAMB), Universiti Malaysia Terengganu (UMT), Kuala Nerus, 21030, Terengganu, Malaysia
| | - Juris Burlakovs
- Mineral and Energy Economy Research Institute of the Polish Academy of Sciences, Poland
| | - Fathurrahman Lananan
- Faculty of Bioresources and Food Industry, Universiti Sultan Zainal Abidin, 22200 Besut, Terengganu, 21300, Malaysia
| | - Juntian Xu
- School of Marine Science and Fisheries, Jiangsu Ocean University, No. 59 Cangwu Road, Haizhou District, Lianyungang City, Jiangsu, China
| | - Zulhisyam Abdul Kari
- Department of Agricultural Science, Faculty of Agro-Based Industry, Universiti Malaysia Kelantan, 17600, Jeli, Kelantan, Malaysia
| | - Lee Seong Wei
- Department of Agricultural Science, Faculty of Agro-Based Industry, Universiti Malaysia Kelantan, 17600, Jeli, Kelantan, Malaysia
- Tropical Rainforest Research Centre (TRaCe), Universiti Malaysia Kelantan, Pulau Banding, 33300, Gerik, Perak, Malaysia
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Ravaglioli C, De Marchi L, Giannessi J, Pretti C, Bulleri F. Seagrass meadows as ocean acidification refugia for sea urchin larvae. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 906:167465. [PMID: 37778543 DOI: 10.1016/j.scitotenv.2023.167465] [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: 07/03/2023] [Revised: 09/15/2023] [Accepted: 09/28/2023] [Indexed: 10/03/2023]
Abstract
Foundation species have been widely documented to provide suitable habitats for other species by ameliorating stressful environmental conditions. Nonetheless, their role in rescuing stress-sensitive species from adverse conditions due to climate change remains often unexplored. Here, we performed a mesocosm experiment to assess whether the seagrass, Posidonia oceanica, through its photosynthetic activity, could mitigate the negative effects of ocean acidification on larval development and growth of the calcifying sea urchin, Paracentrotus lividus. Sea urchin larvae at early and late developmental stages that are generally associated to benthic habitats, were grown in aquaria with or without P. oceanica plants, under ambient or low pH conditions predicted by the end of the century under the worst climate scenario (RCP8.5). The percentage of abnormal larvae and their total body length under different experimental conditions were assessed on early- (i.e., pluteus; 72 h post-fertilization) and final-developmental stages (i.e., echinopluteus; 30 days post-fertilization), respectively. The presence of P. oceanica increased mean daily pH values of ∼0.1 and ∼0.15 units at ambient and low pH conditions, respectively, compared with tanks without plants. When grown at low pH in association with P. oceanica, plutei showed a ∼23 % reduction of malformations and echinoplutei a ∼34 % increase in total body length, respectively, compared with larvae developing in tanks without plants. Our results suggest that P. oceanica, by increasing pH and altering seawater carbonate chemistry through its metabolic activity, could buffer the negative effects of ocean acidification on calcifying organisms and could, thus, represent a tool against climate-driven loss of biodiversity.
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Affiliation(s)
- C Ravaglioli
- Dipartimento di Biologia, Università di Pisa, CoNISMa, via Derna 1, 56126 Pisa, Italy.
| | - L De Marchi
- Dipartimento di Scienze Veterinarie, Università of Pisa, Via Livornese (lato monte) - 56122 San Piero a Grado, Pisa, Italy.
| | - J Giannessi
- Dipartimento di Scienze Veterinarie, Università of Pisa, Via Livornese (lato monte) - 56122 San Piero a Grado, Pisa, Italy.
| | - C Pretti
- Dipartimento di Scienze Veterinarie, Università of Pisa, Via Livornese (lato monte) - 56122 San Piero a Grado, Pisa, Italy; Interuniversity Consortium of Marine Biology and Applied Ecology "G. Bacci" (CIBM), Viale N.Sauro 4, 57128 Livorno, Italy.
| | - F Bulleri
- Dipartimento di Biologia, Università di Pisa, CoNISMa, via Derna 1, 56126 Pisa, Italy; Centro interdipartimentale di Ricerca per lo Studio degli Effetti del Cambiamento Climatico (CIRSEC), Università di Pisa, Italy.
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Kosek K, Kukliński P. Impact of kelp forest on seawater chemistry - A review. MARINE POLLUTION BULLETIN 2023; 196:115655. [PMID: 37839130 DOI: 10.1016/j.marpolbul.2023.115655] [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: 07/26/2023] [Revised: 09/18/2023] [Accepted: 10/09/2023] [Indexed: 10/17/2023]
Abstract
Kelp forests, globally distributed in cool temperate and polar waters, are renowned for their pivotal role in supporting species diversity and fostering macroalgae productivity. These high-canopy algal ecosystems dynamically influence their surroundings, particularly by altering the physicochemical properties of seawater. This review article aims to underscore the significance of kelp forests in modifying water masses. By serving as effective carbon sinks through the absorption of bicarbonate (HCO3-) and carbon dioxide (CO2) for photosynthesis, kelp forests mitigate nearby acidity levels while enhancing dissolved oxygen concentrations, essential for sustaining diverse marine communities. Additionally, kelp beds have exhibited the need to use inorganic ions (NO3-, NO2-, PO43-) from seawater in order to grow, albeit with associated increases in NH4+ concentrations. Specific examples and findings from relevant studies will be presented to illustrate the profound impact of kelp forests on seawater chemistry, emphasizing their vital role in marine ecosystems.
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Affiliation(s)
- Klaudia Kosek
- Marine Ecology Department, Institute of Oceanology, Polish Academy of Sciences, Powstańców Warszawy 55, 81-712 Sopot, Poland.
| | - Piotr Kukliński
- Marine Ecology Department, Institute of Oceanology, Polish Academy of Sciences, Powstańców Warszawy 55, 81-712 Sopot, Poland
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Chen WH, Armstrong E, Dillingham PW, Moratti SC, Ennis C, McGraw CM. Dual-Lifetime Referencing ( t-DLR) Optical Fiber Fluorescent pH Sensor for Microenvironments. SENSORS (BASEL, SWITZERLAND) 2023; 23:8865. [PMID: 37960564 PMCID: PMC10650387 DOI: 10.3390/s23218865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2023] [Revised: 10/24/2023] [Accepted: 10/27/2023] [Indexed: 11/15/2023]
Abstract
The pH behavior in the μm to cm thick diffusion boundary layer (DBL) surrounding many aquatic species is dependent on light-controlled metabolic activities. This DBL microenvironment exhibits different pH behavior to bulk seawater, which can reduce the exposure of calcifying species to ocean acidification conditions. A low-cost time-domain dual-lifetime referencing (t-DLR) interrogation system and an optical fiber fluorescent pH sensor were developed for pH measurements in the DBL interface. The pH sensor utilized dual-layer sol-gel coatings of pH-sensitive iminocoumarin and pH-insensitive Ru(dpp)3-PAN. The sensor has a dynamic range of 7.41 (±0.20) to 9.42 ± 0.23 pH units (95% CI, T = 20 °C, S = 35), a response time (t90) of 29 to 100 s, and minimal salinity dependency. The pH sensor has a precision of approximately 0.02 pHT units, which meets the Global Ocean Acidification Observing Network (GOA-ON) "weather" measurement quality guideline. The suitability of the t-DLR optical fiber pH sensor was demonstrated through real-time measurements in the DBL of green seaweed Ulva sp. This research highlights the practicability of optical fiber pH sensors by demonstrating real-time pH measurements of metabolic-induced pH changes.
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Affiliation(s)
- Wan-Har Chen
- Department of Chemistry, University of Otago, Dunedin 9054, New Zealand; (W.-H.C.); (S.C.M.); (C.E.)
| | - Evelyn Armstrong
- NIWA/University of Otago Centre for Oceanography, Department of Marine Science, University of Otago, Dunedin 9054, New Zealand;
| | - Peter W. Dillingham
- Department of Mathematics and Statistics, University of Otago, Dunedin 9054, New Zealand;
- Coastal People Southern Skies Centre of Research Excellence, University of Otago, Dunedin 9054, New Zealand
| | - Stephen C. Moratti
- Department of Chemistry, University of Otago, Dunedin 9054, New Zealand; (W.-H.C.); (S.C.M.); (C.E.)
| | - Courtney Ennis
- Department of Chemistry, University of Otago, Dunedin 9054, New Zealand; (W.-H.C.); (S.C.M.); (C.E.)
| | - Christina M. McGraw
- Department of Chemistry, University of Otago, Dunedin 9054, New Zealand; (W.-H.C.); (S.C.M.); (C.E.)
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Veenhof RJ, Coleman MA, Champion C, Dworjanyn SA. Urchin grazing of kelp gametophytes in warming oceans. JOURNAL OF PHYCOLOGY 2023; 59:838-855. [PMID: 37432133 DOI: 10.1111/jpy.13364] [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: 05/02/2023] [Revised: 06/08/2023] [Accepted: 06/09/2023] [Indexed: 07/12/2023]
Abstract
Sea urchins can cause extensive damage to kelp forests, and their overgrazing can create extensive barren areas, leading to a loss of biodiversity. Barrens may persist when the recruitment of kelp, which occurs through the microscopic haploid gametophyte stage, is suppressed. However, the ecology of kelp gametophytes is poorly understood, and here we investigate if grazing by juvenile urchins on kelp gametophytes can suppress kelp recruitment and if this is exacerbated by climate change. We compared grazing of Ecklonia radiata gametophytes by two species of juvenile urchins, the tropical Tripneustes gratilla and the temperate Centrostephanus rodgersii, at winter (19°C), summer (23°C), and ocean warming (26°C) temperatures for the low-latitude range edge of E. radiata, which is vulnerable to ocean warming. We examined the rate of recovery of gametophytes following grazing and determined whether they survived and formed sporophytes after ingestion by sea urchins. Both T. gratilla and C. rodgersii grazed E. radiata gametophytes, reducing their abundance compared to no grazing controls. Surprisingly, temperature did not influence grazing rates, but gametophytes did not recover from grazing in the ocean warming (26°C) treatment. Gametophytes survived ingestion by both species of sea urchin and formed sporophytes after ingestion by T. gratilla, but not C. rodgersii. These results suggest complex grazer-gametophyte interactions, in which both negative (reduced abundance and poor recovery with warming) and positive (facilitated recruitment) effects are possible. Small grazers may play a more important role in kelp ecosystem function than previously thought and should be considered in our understanding of alternate stable states.
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Affiliation(s)
- Reina J Veenhof
- National Marine Science Centre, Faculty of Environment, Science and Engineering, Southern Cross University, Coffs Harbour, New South Wales, Australia
| | - Melinda A Coleman
- National Marine Science Centre, Faculty of Environment, Science and Engineering, Southern Cross University, Coffs Harbour, New South Wales, Australia
- NSW Department of Primary Industries, National Marine Science Centre, Coffs Harbour, New South Wales, Australia
| | - Curtis Champion
- National Marine Science Centre, Faculty of Environment, Science and Engineering, Southern Cross University, Coffs Harbour, New South Wales, Australia
- NSW Department of Primary Industries, National Marine Science Centre, Coffs Harbour, New South Wales, Australia
| | - Symon A Dworjanyn
- National Marine Science Centre, Faculty of Environment, Science and Engineering, Southern Cross University, Coffs Harbour, New South Wales, Australia
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Symbiont-induced phenotypic variation in an ecosystem engineer mediates thermal stress for the associated community. J Therm Biol 2023; 112:103428. [PMID: 36796885 DOI: 10.1016/j.jtherbio.2022.103428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 12/08/2022] [Accepted: 12/08/2022] [Indexed: 12/23/2022]
Abstract
Microbial symbionts have strong potential to mediate responses to climate change. Such modulation may be particularly important in the case of hosts that modify the physical habitat structure. By transforming the habitats, ecosystem engineers alter resource availability and modulate environmental conditions which, in turn, indirectly shape the community associated with that habitat. Endolithic cyanobacteria are known to reduce the body temperatures of infested mussels and here, we assessed whether the thermal benefits of endoliths on the intertidal reef-building mussel Mytilus galloprovincialis extends to the invertebrate community utilising mussel beds as habitat. Artificial reefs of biomimetic mussels either colonised or not colonised by microbial endoliths were used to test whether infauna species (the limpet Patella vulgata, the snail Littorina littorea and mussel recruits) in a mussel bed with symbionts experience lower body temperatures than those within a bed composed of mussels without symbionts. We found that infaunal individuals benefitted from being surrounded by mussels with symbionts, an effect that may be particularly critical during intense heat stress. Indirect effects of biotic interactions, complicate our understanding of community and ecosystem responses to climate change, especially in cases involving ecosystem engineers, and accounting for them will improve our predictions.
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Abstract
Coastal marine macrophytes exhibit some of the highest rates of primary productivity in the world. They have been found to host a diverse set of microbes, many of which may impact the biology of their hosts through metabolisms that are unique to microbial taxa. Here, we characterized the metabolic functions of macrophyte-associated microbial communities using metagenomes collected from 2 species of kelp (Laminaria setchellii and Nereocystis luetkeana) and 3 marine angiosperms (Phyllospadix scouleri, P. serrulatus, and Zostera marina), including the rhizomes of two surfgrass species (Phyllospadix spp.), the seagrass Zostera marina, and the sediments surrounding P. scouleri and Z. marina. Using metagenomic sequencing, we describe 63 metagenome-assembled genomes (MAGs) that potentially benefit from being associated with macrophytes and may contribute to macrophyte fitness through their metabolic activity. Host-associated metagenomes contained genes for the use of dissolved organic matter from hosts and vitamin (B1, B2, B7, B12) biosynthesis in addition to a range of nitrogen and sulfur metabolisms that recycle dissolved inorganic nutrients into forms more available to the host. The rhizosphere of surfgrass and seagrass contained genes for anaerobic microbial metabolisms, including nifH genes associated with nitrogen fixation, despite residing in a well-mixed and oxygenated environment. The range of oxygen environments engineered by macrophytes likely explains the diversity of both oxidizing and reducing microbial metabolisms and contributes to the functional capabilities of microbes and their influences on carbon and nitrogen cycling in nearshore ecosystems. IMPORTANCE Kelps, seagrasses, and surfgrasses are ecosystem engineers on rocky shorelines, where they show remarkably high levels of primary production. Through analysis of their associated microbial communities, we found a variety of microbial metabolisms that may benefit the host, including nitrogen metabolisms, sulfur oxidation, and the production of B vitamins. In turn, these microbes have the genetic capabilities to assimilate the dissolved organic compounds released by their macrophyte hosts. We describe a range of oxygen environments associated with surfgrass, including low-oxygen microhabitats in their rhizomes that host genes for nitrogen fixation. The tremendous productivity of coastal seaweeds and seagrasses is likely due in part to the activities of associated microbes, and an increased understanding of these associations is needed.
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Weigel BL, Miranda KK, Fogarty EC, Watson AR, Pfister CA. Functional Insights into the Kelp Microbiome from Metagenome-Assembled Genomes. mSystems 2022; 7:e0142221. [PMID: 35642511 PMCID: PMC9238374 DOI: 10.1128/msystems.01422-21] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Accepted: 05/13/2022] [Indexed: 11/20/2022] Open
Abstract
Eukaryotic organisms evolved in a microbial world and often have intimate associations with diverse bacterial groups. Kelp, brown macroalgae in the order Laminariales, play a vital role in coastal ecosystems, yet we know little about the functional role of the microbial symbionts that cover their photosynthetic surfaces. Here, we reconstructed 79 bacterial metagenome-assembled genomes (MAGs) from blades of the bull kelp, Nereocystis luetkeana, allowing us to determine their metabolic potential and functional roles. Despite the annual life history of bull kelp, nearly half of the bacterial MAGs were detected across multiple years. Diverse members of the kelp microbiome, spanning 6 bacterial phyla, contained genes for transporting and assimilating dissolved organic matter (DOM), which is secreted by kelp in large quantities and likely fuels the metabolism of these heterotrophic bacteria. Bacterial genomes also contained alginate lyase and biosynthesis genes, involved in polysaccharide degradation and biofilm formation, respectively. Kelp-associated bacterial genomes contained genes for dissimilatory nitrate reduction and urea hydrolysis, likely providing a reduced source of nitrogen to the host kelp. The genome of the most abundant member of the kelp microbiome and common macroalgal symbiont, Granulosicoccus, contained a full suite of genes for synthesizing cobalamin (vitamin B12), suggesting that kelp-associated bacteria have the potential to provide their host kelp with vitamins. Finally, kelp-associated Granulosicoccus contained genes that typify the aerobic anoxygenic phototrophic bacteria, including genes for bacteriochlorophyll synthesis and photosystem II reaction center proteins, making them the first known photoheterotrophic representatives of this genus. IMPORTANCE Kelp (brown algae in the order Laminariales) are foundational species that create essential habitat in temperate and arctic coastal marine ecosystems. These photosynthetic giants host millions of microbial taxa whose functions are relatively unknown, despite their potential importance for host-microbe interactions and nutrient cycling in kelp forest ecosystems. We reconstructed bacterial genomes from metagenomic samples collected from blades of the bull kelp, Nereocystis luetkeana, allowing us to determine the functional gene content of specific members of the kelp microbiome. These bacterial genomes spanned 6 phyla and 19 families and included common alga-associated microbial symbionts such as Granulosicoccus. Key functions encoded in kelp-associated bacterial genomes included dissolved organic matter assimilation, alginate metabolism, vitamin B12 biosynthesis, and nitrogen reduction from nitrate and urea to ammonium, potentially providing the host kelp with vitamins and reduced nitrogen.
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Affiliation(s)
- Brooke L. Weigel
- Committee on Evolutionary Biology, University of Chicago, Chicago, Illinois, USA
| | | | - Emily C. Fogarty
- Committee on Microbiology, University of Chicago, Chicago, Illinois, USA
- Department of Medicine, University of Chicago, Chicago, Illinois, USA
| | - Andrea R. Watson
- Committee on Microbiology, University of Chicago, Chicago, Illinois, USA
- Department of Medicine, University of Chicago, Chicago, Illinois, USA
| | - Catherine A. Pfister
- Department of Ecology & Evolution, University of Chicago, Chicago, Illinois, USA
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In-Situ Estimates of Net Ecosystem Metabolisms in the Rocky Habitats of Dokdo Islets in the East Sea of Korea. JOURNAL OF MARINE SCIENCE AND ENGINEERING 2022. [DOI: 10.3390/jmse10070887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
We measured oxygen (O2) fluxes in two major shallow subtidal benthic habitats (kelp bed (KB) and bare rock (BR) covered with crustose coralline algae) of Dokdo islet in the East Sea by applying noninvasive in-situ aquatic eddy covariance (AEC). The AEC device allows time series measurements (~24 h) of three-dimensional velocity (u, v, and w components) and high-resolution dissolved O2. This allows estimation of O2 exchange flux via benthic habitats. Local flow rates and irradiance levels were found to be major factors controlling O2 exchange flux in the rocky habitats. Gross primary production rates tended to be significantly higher in KB (163 mmol O2 m–2 d–1) than in BR (51 mmol O2 m–2 d–1). The net ecosystem metabolisms were assessed as opposite types, with 8 mmol O2 m–2 d–1 in KB (autotrophy) and –12 mmol O2 m–2 d–1 in BR (heterotrophy). Our results indicate that kelp beds are important for organic carbon cycling in rocky coastal waters and that AEC application to macroalgae habitats is a useful assessment approach.
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Pfister CA, Light SH, Bohannan B, Schmidt T, Martiny A, Hynson NA, Devkota S, David L, Whiteson K. Conceptual Exchanges for Understanding Free-Living and Host-Associated Microbiomes. mSystems 2022; 7:e0137421. [PMID: 35014872 PMCID: PMC8751383 DOI: 10.1128/msystems.01374-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/15/2021] [Indexed: 12/26/2022] Open
Abstract
Whether a microbe is free-living or associated with a host from across the tree of life, its existence depends on a limited number of elements and electron donors and acceptors. Yet divergent approaches have been used by investigators from different fields. The "environment first" research tradition emphasizes thermodynamics and biogeochemical principles, including the quantification of redox environments and elemental stoichiometry to identify transformations and thus an underlying microbe. The increasingly common "microbe first" research approach benefits from culturing and/or DNA sequencing methods to first identify a microbe and encoded metabolic functions. Here, the microbe itself serves as an indicator for environmental conditions and transformations. We illustrate the application of both approaches to the study of microbiomes and emphasize how both can reveal the selection of microbial metabolisms across diverse environments, anticipate alterations to microbiomes in host health, and understand the implications of a changing climate for microbial function.
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Affiliation(s)
- Catherine A. Pfister
- Department of Ecology & Evolution and The Microbiome Center, University of Chicago, Chicago, Illinois, USA
| | - Samuel H. Light
- Department of Microbiology & Duchossois Family Institute, University of Chicago, Chicago, Illinois, USA
| | - Brendan Bohannan
- Environmental Studies and Biology, University of Oregon, Eugene, Oregon, USA
| | - Thomas Schmidt
- Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Adam Martiny
- Earth System Science & Ecology and Evolutionary Biology, University of California Irvine, Irvine, California, USA
| | - Nicole A. Hynson
- Pacific Biosciences Research Center, University of Hawaii at Manoa, Honolulu, Hawaii, USA
| | - Suzanne Devkota
- Microbiome Research, F. Widjaja Foundation Inflammatory Bowel and Immunobiology Research Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Lawrence David
- Molecular Genetics & Microbiology, Duke University, Durham, North Carolina, USA
| | - Katrine Whiteson
- Department of Molecular Biology and Biochemistry, University of California Irvine, Irvine, California, USA
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Hou C, Qu T, Zhao X, Xu J, Zhong Y, Guan C, Zhang H, Lin Z, Tang X, Wang Y. Diel metabolism of Yellow Sea green tide algae alters bacterial community composition under in situ seawater acidification of coastal areas. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 807:150759. [PMID: 34619190 DOI: 10.1016/j.scitotenv.2021.150759] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 09/29/2021] [Accepted: 09/29/2021] [Indexed: 06/13/2023]
Abstract
Ocean acidification in coastal seawaters is a complex process, with coastal pH being affected by numerous factors including watershed and biological processes that also support metabolically diverse bacterial communities. The world's largest macroalgal blooms have occurred consecutively in the Yellow Sea over the last 13 years. In particular, algal mats formed by Yellow Sea green tides (YSGT) significantly influence coastal environments. Herein, we hypothesized that 1) inorganic carbonate chemistry in coastal areas is altered by diel metabolism of these giant algal mats and that 2) bacterial community composition in diffusive boundary layers might be altered along diel cycles due to algal mat metabolism. In situ studies indicated that algal mat metabolism led to changes in diel pH and CO2 in affected seawaters. Such metabolic activities could intensify diel pH fluctuations in algal mat diffusive boundary layers, as noted by pH fluctuations of 0.22 ± 0.01 units, and pCO2 fluctuations of 214.62 ± 29.37 μatm per day. In contrast, pH fluctuations of 0.11 ± 0.02 units and pCO2 fluctuations of 79.02 ± 42.70 μatm were noted in unaffected areas. Furthermore, the bacterial community composition associated with diffusive algal boundary layers, including those of ambient bacteria and epiphytic bacteria, exhibited diel changes, while endophytic bacterial communities were relatively stable. Flavobacteriaceae were particularly highly abundant taxa in the ambient and epiphytic bacterial communities and exhibited increased abundances at night but sharp decreases in abundances during daytime. Flavobacteriaceae are heterotrophic taxa that could contribute to coastal area acidification at night due to the transformation of organic carbon to inorganic carbon. These results provide new insights to understand the variability in coastal ocean acidification via harmful algal blooms while providing a framework for evaluating the effects of YSGT on costal carbon cycling.
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Affiliation(s)
- Chengzong Hou
- College of Marine Life Sciences, Ocean University of China, China.
| | - Tongfei Qu
- College of Marine Life Sciences, Ocean University of China, China.
| | - Xinyu Zhao
- College of Marine Life Sciences, Ocean University of China, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, China
| | - Jinhui Xu
- College of Marine Life Sciences, Ocean University of China, China.
| | - Yi Zhong
- College of Marine Life Sciences, Ocean University of China, China.
| | - Chen Guan
- College of Marine Life Sciences, Ocean University of China, China.
| | - Huanxin Zhang
- College of Geography and Environment, Shandong Normal University, Jinan 250000, China
| | - Zhihao Lin
- College of Marine Life Sciences, Ocean University of China, China.
| | - Xuexi Tang
- College of Marine Life Sciences, Ocean University of China, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, China.
| | - Ying Wang
- College of Marine Life Sciences, Ocean University of China, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, China.
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13
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Paine ER, Schmid M, Boyd PW, Diaz-Pulido G, Hurd CL. Rate and fate of dissolved organic carbon release by seaweeds: A missing link in the coastal ocean carbon cycle. JOURNAL OF PHYCOLOGY 2021; 57:1375-1391. [PMID: 34287891 DOI: 10.1111/jpy.13198] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 06/08/2021] [Accepted: 06/25/2021] [Indexed: 06/13/2023]
Abstract
Dissolved organic carbon (DOC) release by seaweeds (marine macroalgae) is a critical component of the coastal ocean biogeochemical carbon cycle but is an aspect of seaweed carbon physiology that we know relatively little about. Seaweed-derived DOC is found throughout coastal ecosystems and supports multiple food web linkages. Here, we discuss the mechanisms of DOC release by seaweeds and group them into passive (leakage, requires no energy) and active release (exudation, requires energy) with particular focus on the photosynthetic "overflow" hypothesis. The release of DOC from seaweeds was first studied in the 1960s, but subsequent studies use a range of units hindering evaluation: we convert published values to a common unit (μmol C · g DW-1 · h-1 ) allowing comparisons between seaweed phyla, functional groups, biogeographic region, and an assessment of the environmental regulation of DOC production. The range of DOC release rates by seaweeds from each phylum under ambient environmental conditions was 0-266.44 μmol C · g DW-1 · h-1 (Chlorophyta), 0-89.92 μmol C · g DW-1 · h-1 (Ochrophyta), and 0-41.28 μmol C · g DW-1 · h-1 (Rhodophyta). DOC release rates increased under environmental factors such as desiccation, high irradiance, non-optimal temperatures, altered salinity, and elevated dissolved carbon dioxide (CO2 ) concentrations. Importantly, DOC release was highest by seaweeds that were desiccated (<90 times greater DOC release compared to ambient). We discuss the impact of future ocean scenarios (ocean acidification, seawater warming, altered irradiance) on DOC release rates by seaweeds, the role of seaweed-derived DOC in carbon sequestration models, and how they inform future research directions.
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Affiliation(s)
- Ellie R Paine
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, 7001, Australia
| | - Matthias Schmid
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, 7001, Australia
| | - Philip W Boyd
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, 7001, Australia
| | - Guillermo Diaz-Pulido
- Griffith School of Environment, Australian Rivers Institute - Coast and Estuaries, Nathan Campus, Griffith University, Brisbane, Queensland, 4111, Australia
| | - Catriona L Hurd
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, 7001, Australia
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14
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Calcification in free-living coralline algae is strongly influenced by morphology: Implications for susceptibility to ocean acidification. Sci Rep 2021; 11:11232. [PMID: 34045570 PMCID: PMC8160205 DOI: 10.1038/s41598-021-90632-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 05/12/2021] [Indexed: 11/13/2022] Open
Abstract
Rhodolith beds built by free-living coralline algae are important ecosystems for marine biodiversity and carbonate production. Yet, our mechanistic understanding regarding rhodolith physiology and its drivers is still limited. Using three rhodolith species with different branching morphologies, we investigated the role of morphology in species’ physiology and the implications for their susceptibility to ocean acidification (OA). For this, we determined the effects of thallus topography on diffusive boundary layer (DBL) thickness, the associated microscale oxygen and pH dynamics and their relationship with species’ metabolic and light and dark calcification rates, as well as species’ responses to short-term OA exposure. Our results show that rhodolith branching creates low-flow microenvironments that exhibit increasing DBL thickness with increasing branch length. This, together with species’ metabolic rates, determined the light-dependent pH dynamics at the algal surface, which in turn dictated species’ calcification rates. While these differences did not translate in species-specific responses to short-term OA exposure, the differences in the magnitude of diurnal pH fluctuations (~ 0.1–1.2 pH units) between species suggest potential differences in phenotypic plasticity to OA that may result in different susceptibilities to long-term OA exposure, supporting the general view that species’ ecomechanical characteristics must be considered for predicting OA responses.
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15
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Weigel BL, Pfister CA. Oxygen metabolism shapes microbial settlement on photosynthetic kelp blades compared to artificial kelp substrates. ENVIRONMENTAL MICROBIOLOGY REPORTS 2021; 13:176-184. [PMID: 33372322 DOI: 10.1111/1758-2229.12923] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 12/16/2020] [Indexed: 06/12/2023]
Abstract
We examined factors shaping community assembly of the bull kelp (Nereocystis luetkeana) microbiome by comparing microbial biofilm formation on photosynthetic kelp blade tissues and artificial kelp substrates ('agar substrates') deployed into a kelp forest. New kelp blade tissues were colonized by markedly distinct microbial taxa relative to agar substrates during the same time interval, even when agar substrates were infused with N. luetkeana blades, suggesting that microbial settlement onto kelp surfaces is more than just attraction to a polysaccharide-rich surface. Further, common seawater taxa such as Colwellia sp. and Psychromonas sp. became abundant on agar substrates but avoided new kelp blade tissues, indicating that host-specific factors may deter certain surface-associated marine microbial taxa. Over two-thirds of the bacterial taxa in the kelp microbiome were associated with strictly aerobic metabolisms; thus, photosynthetic production of O2 may favour aerobic microbial metabolisms. While living kelp blades primarily recruited aerobic microbes, including the obligate aerobe Granulosicoccus sp., microbes that colonized agar substrates were predominantly facultative anaerobes. We also found that infusion of kelp tissues into agar substrates altered microbial community composition and lowered taxonomic diversity relative to control agar substrates, suggesting that non-living components of the kelp blade also impact microbial community assembly.
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Affiliation(s)
- Brooke L Weigel
- Committee on Evolutionary Biology, University of Chicago, Chicago, IL, USA
| | - Catherine A Pfister
- Committee on Evolutionary Biology, University of Chicago, Chicago, IL, USA
- Department of Ecology and Evolution, University of Chicago, Chicago, IL, USA
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16
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Chen WH, Dillon WDN, Armstrong EA, Moratti SC, McGraw CM. Self-referencing optical fiber pH sensor for marine microenvironments. Talanta 2021; 225:121969. [PMID: 33592803 DOI: 10.1016/j.talanta.2020.121969] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 12/01/2020] [Accepted: 12/02/2020] [Indexed: 10/22/2022]
Abstract
This study presents the development of an optical fiber pH sensor based on evanescent wave absorbance for continuous pH measurements in marine microenvironments. The sensing layer consists of an optimized sol-gel matrix of tetraethoxysilane and dimethyldiethoxysilane, which substantially improves the entrapment efficiency of the pH indicator meta-cresol purple, leading to a long useable lifetime. The optical fiber pH sensor conforms to the Global Ocean Acidification Observing Network "weather" measurement quality guideline with precision of approximately 0.02 pH units, has a dynamic pHT range of 7.4-9.7 in seawater, a response time of 2.5-6.5 min and a useable lifetime of 7 days. The optical fiber pH sensor has additional advantages of being self-referencing, without the need of an external sensor reference, having a simple fabrication method and basic spectrometer instrumentation. The suitability of the optical fiber pH sensor was demonstrated in real-time measurements of the ecologically significant green seaweed Ulva sp. The optical fiber pH sensor monitored pH variations due to metabolic activity over 7 days within the seaweed canopy and 4 days within the diffusion boundary layer interface, demonstrating the suitability for measurements in marine microenvironments.
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Affiliation(s)
- Wan-Har Chen
- Department of Chemistry, University of Otago, Dunedin, New Zealand
| | - Wayne D N Dillon
- Department of Chemistry, University of Otago, Dunedin, New Zealand
| | - Evelyn A Armstrong
- NIWA/University of Otago Centre for Oceanography, Department of Chemistry, University of Otago, Dunedin, New Zealand
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17
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Frontier N, de Bettignies F, Foggo A, Davoult D. Sustained productivity and respiration of degrading kelp detritus in the shallow benthos: Detached or broken, but not dead. MARINE ENVIRONMENTAL RESEARCH 2021; 166:105277. [PMID: 33592375 DOI: 10.1016/j.marenvres.2021.105277] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Revised: 01/28/2021] [Accepted: 02/04/2021] [Indexed: 05/06/2023]
Abstract
Temperate kelp forests contribute significantly to marine primary productivity and fuel many benthic and pelagic food chains. A large proportion of biomass is exported from kelp forests as detritus into recipient marine ecosystems, potentially contributing to Blue Carbon sequestration. The degradation of this organic material is slow and recent research has revealed the preservation of photosynthetic functions over time. However, the physiological correlates of detrital breakdown in Laminaria spp. have not yet been studied. The warming climate threatens to reshuffle the species composition of kelp forests and perturb the dynamics of these highly productive ecosystems. The present study compares the physiological response of degrading detritus from two competing North East Atlantic species; the native Boreal Laminaria hyperborea and the thermally tolerant Boreal-Lusitanian L. ochroleuca. Detrital fragment degradation was measured by a mesocosm experiment across a gradient of spectral attenuation (a proxy for depth) to investigate the changes in physiological performance under different environmental conditions. Degradation of fragments was quantified over 108 days by measuring the biomass, production and respiration (by respirometry) and efficiency of Photosystem II (by PAM fluorometry). Data indicated that whilst degrading, the photosynthetic performance of the species responded differently to simulated depths, but fragments of both species continued to produce oxygen for up to 56 days and sustained positive net primary production. This study reveals the potential for ostensibly detrital kelp to contribute to Blue Carbon fixation through sustained primary production which should be factored into Blue Carbon management. Furthermore, the physiological response of kelp detritus is likely dependent upon the range of habitats to which it is exported. In the context of climate change, shifts in species composition of kelp forests and their detritus are likely to have wide-reaching effects upon the cycling of organic matter in benthic ecosystems.
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Affiliation(s)
- Nadia Frontier
- Sorbonne Université, CNRS, UMR 7144 AD2M, Station Biologique de Roscoff, Place Georges Teissier, F-29680, Roscoff, France; Marine Biology and Ecology Research Centre, School of Biological and Marine Sciences, University of Plymouth, Drake Circus, Plymouth, PL4 8AA, UK.
| | - Florian de Bettignies
- Sorbonne Université, CNRS, UMR 7144 AD2M, Station Biologique de Roscoff, Place Georges Teissier, F-29680, Roscoff, France
| | - Andy Foggo
- Marine Biology and Ecology Research Centre, School of Biological and Marine Sciences, University of Plymouth, Drake Circus, Plymouth, PL4 8AA, UK
| | - Dominique Davoult
- Sorbonne Université, CNRS, UMR 7144 AD2M, Station Biologique de Roscoff, Place Georges Teissier, F-29680, Roscoff, France
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18
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Galloway AWE, von Dassow G, Schram JB, Klinger T, Hill TM, Lowe AT, Chan F, Yoshioka RM, Kroeker KJ. Ghost Factors of Laboratory Carbonate Chemistry Are Haunting Our Experiments. THE BIOLOGICAL BULLETIN 2020; 239:183-188. [PMID: 33347796 DOI: 10.1086/711242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
AbstractFor many historical and contemporary experimental studies in marine biology, seawater carbonate chemistry remains a ghost factor, an uncontrolled, unmeasured, and often dynamic variable affecting experimental organisms or the treatments to which investigators subject them. We highlight how environmental variability, such as seasonal upwelling and biological respiration, drive variation in seawater carbonate chemistry that can influence laboratory experiments in unintended ways and introduce a signal consistent with ocean acidification. As the impacts of carbonate chemistry on biochemical pathways that underlie growth, development, reproduction, and behavior become better understood, the hidden effects of this previously overlooked variable need to be acknowledged. Here we bring this emerging challenge to the attention of the wider community of experimental biologists who rely on access to organisms and water from marine and estuarine laboratories and who may benefit from explicit considerations of a growing literature on the pervasive effects of aquatic carbonate chemistry changes.
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19
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Fujise L, Suggett DJ, Stat M, Kahlke T, Bunce M, Gardner SG, Goyen S, Woodcock S, Ralph PJ, Seymour JR, Siboni N, Nitschke MR. Unlocking the phylogenetic diversity, primary habitats, and abundances of free-living Symbiodiniaceae on a coral reef. Mol Ecol 2020; 30:343-360. [PMID: 33141992 DOI: 10.1111/mec.15719] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2019] [Revised: 10/21/2020] [Accepted: 10/27/2020] [Indexed: 01/04/2023]
Abstract
Dinoflagellates of the family Symbiodiniaceae form mutualistic symbioses with marine invertebrates such as reef-building corals, but also inhabit reef environments as free-living cells. Most coral species acquire Symbiodiniaceae horizontally from the surrounding environment during the larval and/or recruitment phase, however the phylogenetic diversity and ecology of free-living Symbiodiniaceae on coral reefs is largely unknown. We coupled environmental DNA sequencing and genus-specific qPCR to resolve the community structure and cell abundances of free-living Symbiodiniaceae in the water column, sediment, and macroalgae and compared these to coral symbionts. Sampling was conducted at two time points, one of which coincided with the annual coral spawning event when recombination between hosts and free-living Symbiodiniaceae is assumed to be critical. Amplicons of the internal transcribed spacer (ITS2) region were assigned to 12 of the 15 Symbiodiniaceae genera or genera-equivalent lineages. Community compositions were separated by habitat, with water samples containing a high proportion of sequences corresponding to coral symbionts of the genus Cladocopium, potentially as a result of cell expulsion from in hospite populations. Sediment-associated Symbiodiniaceae communities were distinct, potentially due to the presence of exclusively free-living species. Intriguingly, macroalgal surfaces displayed the highest cell abundances of Symbiodiniaceae, suggesting a key role for macroalgae in ensuring the ecological success of corals through maintenance of a continuum between environmental and symbiotic populations of Symbiodiniaceae.
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Affiliation(s)
- Lisa Fujise
- Faculty of Science, Climate Change Cluster, University of Technology Sydney, Sydney, NSW, Australia
| | - David J Suggett
- Faculty of Science, Climate Change Cluster, University of Technology Sydney, Sydney, NSW, Australia
| | - Michael Stat
- Trace and Environmental DNA (TrEnD) Laboratory, Curtin University, Bentley, Perth, WA, Australia.,School of Environmental and Life Sciences, The University of Newcastle, Callaghan, NSW, Australia
| | - Tim Kahlke
- Faculty of Science, Climate Change Cluster, University of Technology Sydney, Sydney, NSW, Australia
| | - Michael Bunce
- Trace and Environmental DNA (TrEnD) Laboratory, Curtin University, Bentley, Perth, WA, Australia
| | - Stephanie G Gardner
- Faculty of Science, Climate Change Cluster, University of Technology Sydney, Sydney, NSW, Australia.,Centre for Marine Science and Innovation, University of New South Wales Australia, Kensington, NSW, Australia
| | - Samantha Goyen
- Faculty of Science, Climate Change Cluster, University of Technology Sydney, Sydney, NSW, Australia
| | - Stephen Woodcock
- Faculty of Science, Climate Change Cluster, University of Technology Sydney, Sydney, NSW, Australia
| | - Peter J Ralph
- Faculty of Science, Climate Change Cluster, University of Technology Sydney, Sydney, NSW, Australia
| | - Justin R Seymour
- Faculty of Science, Climate Change Cluster, University of Technology Sydney, Sydney, NSW, Australia
| | - Nachshon Siboni
- Faculty of Science, Climate Change Cluster, University of Technology Sydney, Sydney, NSW, Australia
| | - Matthew R Nitschke
- Faculty of Science, Climate Change Cluster, University of Technology Sydney, Sydney, NSW, Australia.,School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
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20
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Guy-Haim T, Silverman J, Wahl M, Aguirre J, Noisette F, Rilov G. Epiphytes provide micro-scale refuge from ocean acidification. MARINE ENVIRONMENTAL RESEARCH 2020; 161:105093. [PMID: 32798779 DOI: 10.1016/j.marenvres.2020.105093] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Revised: 07/23/2020] [Accepted: 07/25/2020] [Indexed: 06/11/2023]
Abstract
Coralline algae, a major calcifying component of coastal shallow water communities, have been shown to be one of the more vulnerable taxonomic groups to ocean acidification (OA). Under OA, the interaction between corallines and epiphytes was previously described as both positive and negative. We hypothesized that the photosynthetic activity and the complex structure of non-calcifying epiphytic algae that grow on corallines ameliorate the chemical microenvironmental conditions around them, providing protection from OA. Using mesocosm and microsensor experiments, we showed that the widespread coralline Ellisolandia elongata is less susceptible to the detrimental effects of OA when covered with non-calcifying epiphytic algae, and its diffusive boundary layer is thicker than when not covered by epiphytes. By modifying the microenvironmental carbonate chemistry, epiphytes, facilitated by OA, create micro-scale shield (and refuge) with more basic conditions that may allow the persistence of corallines associated with them during acidified conditions. Such ecological refugia could also assist corallines under near-future anthropogenic OA conditions.
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Affiliation(s)
- Tamar Guy-Haim
- Israel Oceanographic and Limnological Research, National Institute of Oceanography, P.O. Box 8030, Haifa, 31080, Israel; The Leon H. Charney School of Marine Sciences, Marine Biology Department, University of Haifa, Mt. Carmel, Haifa, 31905, Israel; GEOMAR, Helmholtz Centre for Ocean Research, Experimental Ecology, Düsternbrooker Weg 20, Kiel, 24105, Germany.
| | - Jacob Silverman
- Israel Oceanographic and Limnological Research, National Institute of Oceanography, P.O. Box 8030, Haifa, 31080, Israel
| | - Martin Wahl
- GEOMAR, Helmholtz Centre for Ocean Research, Experimental Ecology, Düsternbrooker Weg 20, Kiel, 24105, Germany
| | - Julio Aguirre
- Department of Stratigraphy and Paleontology, University of Granada, Fuentenueva S/n, 18002, Granada, Spain
| | - Fanny Noisette
- Institut des Sciences de la Mer de Rimouski, Université du Québec à Rimouski, Quebec, Canada
| | - Gil Rilov
- Israel Oceanographic and Limnological Research, National Institute of Oceanography, P.O. Box 8030, Haifa, 31080, Israel; The Leon H. Charney School of Marine Sciences, Marine Biology Department, University of Haifa, Mt. Carmel, Haifa, 31905, Israel
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21
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Ainsworth TD, Hurd CL, Gates RD, Boyd PW. How do we overcome abrupt degradation of marine ecosystems and meet the challenge of heat waves and climate extremes? GLOBAL CHANGE BIOLOGY 2020; 26:343-354. [PMID: 31873988 DOI: 10.1111/gcb.14901] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 10/15/2019] [Accepted: 10/17/2019] [Indexed: 05/06/2023]
Abstract
Extreme heat wave events are now causing ecosystem degradation across marine ecosystems. The consequences of this heat-induced damage range from the rapid loss of habitat-forming organisms, through to a reduction in the services that ecosystems support, and ultimately to impacts on human health and society. How we tackle the sudden emergence of ecosystem-wide degradation has not yet been addressed in the context of marine heat waves. An examination of recent marine heat waves from around Australia points to the potential important role that respite or refuge from environmental extremes can play in enabling organismal survival. However, most ecological interventions are being devised with a target of mid to late-century implementation, at which time many of the ecosystems, that the interventions are targeted towards, will have already undergone repeated and widespread heat wave induced degradation. Here, our assessment of the merits of proposed ecological interventions, across a spectrum of approaches, to counter marine environmental extremes, reveals a lack preparedness to counter the effects of extreme conditions on marine ecosystems. The ecological influence of these extremes are projected to continue to impact marine ecosystems in the coming years, long before these interventions can be developed. Our assessment reveals that approaches which are technologically ready and likely to be socially acceptable are locally deployable only, whereas those which are scalable-for example to features as large as major reef systems-are not close to being testable, and are unlikely to obtain social licence for deployment. Knowledge of the environmental timescales for survival of extremes, via respite or refuge, inferred from field observations will help test such intervention tools. The growing frequency of extreme events such as marine heat waves increases the urgency to consider mitigation and intervention tools that support organismal and ecosystem survival in the immediate future, while global climate mitigation and/or intervention are formulated.
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Affiliation(s)
- Tracy D Ainsworth
- Biological, Earth and Environmental Sciences, The University of New South Wales, Sydney, NSW, Australia
| | - Catriona L Hurd
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tas., Australia
| | - Ruth D Gates
- Hawaii Institute for Marine Biology, University of Hawai'i, Manoa, HI, USA
| | - Philip W Boyd
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tas., Australia
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22
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Kroeker KJ, Bell LE, Donham EM, Hoshijima U, Lummis S, Toy JA, Willis-Norton E. Ecological change in dynamic environments: Accounting for temporal environmental variability in studies of ocean change biology. GLOBAL CHANGE BIOLOGY 2020; 26:54-67. [PMID: 31743515 DOI: 10.1111/gcb.14868] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 09/03/2019] [Indexed: 06/10/2023]
Abstract
The environmental conditions in the ocean have long been considered relatively more stable through time compared to the conditions on land. Advances in sensing technologies, however, are increasingly revealing substantial fluctuations in abiotic factors over ecologically and evolutionarily relevant timescales in the ocean, leading to a growing recognition of the dynamism of the marine environment as well as new questions about how this dynamism may influence species' vulnerability to global environmental change. In some instances, the diurnal or seasonal variability in major environmental change drivers, such as temperature, pH and seawater carbonate chemistry, and dissolved oxygen, can exceed the changes expected with continued anthropogenic global change. While ocean global change biologists have begun to experimentally test how variability in environmental conditions mediates species' responses to changes in the mean, the extensive literature on species' adaptations to temporal variability in their environment and the implications of this variability for their evolutionary responses has not been well integrated into the field. Here, we review the physiological mechanisms underlying species' responses to changes in temperature, pCO2 /pH (and other carbonate parameters), and dissolved oxygen, and discuss what is known about behavioral, plastic, and evolutionary strategies for dealing with variable environments. In addition, we discuss how exposure to variability may influence species' responses to changes in the mean conditions and highlight key research needs for ocean global change biology.
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Affiliation(s)
- Kristy J Kroeker
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Lauren E Bell
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Emily M Donham
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Umihiko Hoshijima
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Sarah Lummis
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Jason A Toy
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Ellen Willis-Norton
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
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23
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Kapsenberg L, Cyronak T. Ocean acidification refugia in variable environments. GLOBAL CHANGE BIOLOGY 2019; 25:3201-3214. [PMID: 31199553 PMCID: PMC6851593 DOI: 10.1111/gcb.14730] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Accepted: 06/05/2019] [Indexed: 05/04/2023]
Abstract
Climate change refugia in the terrestrial biosphere are areas where species are protected from global environmental change and arise from natural heterogeneity in landscapes and climate. Within the marine realm, ocean acidification, or the global decline in seawater pH, remains a pervasive threat to organisms and ecosystems. Natural variability in seawater carbon dioxide (CO2 ) chemistry, however, presents an opportunity to identify ocean acidification refugia (OAR) for marine species. Here, we review the literature to examine the impacts of variable CO2 chemistry on biological responses to ocean acidification and develop a framework of definitions and criteria that connects current OAR research to management goals. Under the concept of managing vulnerability, the most likely mechanisms by which OAR can mitigate ocean acidification impacts are by reducing exposure to harmful conditions or enhancing adaptive capacity. While local management options, such as OAR, show some promise, they present unique challenges, and reducing global anthropogenic CO2 emissions must remain a priority.
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Affiliation(s)
- Lydia Kapsenberg
- Department of Marine Biology and OceanographyCSIC Institute of Marine SciencesBarcelonaSpain
| | - Tyler Cyronak
- Department of Marine and Environmental SciencesHalmos College of Natural Sciences and OceanographyNova Southeastern UniversityDania BeachFlorida
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Gao G, Fu Q, Beardall J, Wu M, Xu J. Combination of ocean acidification and warming enhances the competitive advantage of Skeletonema costatum over a green tide alga, Ulva linza. HARMFUL ALGAE 2019; 85:101698. [PMID: 31810528 DOI: 10.1016/j.hal.2019.101698] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2019] [Revised: 10/22/2019] [Accepted: 10/23/2019] [Indexed: 06/10/2023]
Abstract
Red tide and green tide are two common algal blooms that frequently occur in many areas in the global oceans. The algae causing red tide and green tide often interact with each other in costal ecosystems. However, little is known on how future CO2-induced ocean acidification combined with temperature variation would affect the interaction of red and green tides. In this study, we cultured the red tide alga Skeletonema costatum and the green tide alga Ulva linza under ambient (400 ppm) and future CO2 (1000 ppm) levels and three temperatures (12, 18, 24 °C) in both monoculture and coculture systems. Coculture did not affect the growth rate of U. linza but significantly decreased it for S. costatum. Elevated CO2 relieved the inhibitory effect of U. linza on the growth of S. costatum, particularly for higher temperatures. At elevated CO2, higher temperature increased the growth rate of S. costatum but reduced it for U. linza. Coculture with U. linza reduced the net photosynthetic rate of S. costatum, which was relieved by elevated CO2. This pattern was also found in Chl a content, indicating that U. linza may inhibit growth of S. costatum via harming pigment synthesis and thus photosynthesis. In monoculture, higher temperature did not affect respiration rate of S. costatum but increased it in U. linza. Coculture did not affect respiration of U. linza but stimulated it for S. costatum, which was a signal of responding to biotic and/abiotic stress. The increased growth of S. costatum at higher temperature and decreased inhibition of U. linza on S. costatum at elevated CO2 suggest that red tides may have more advantages over green tides in future warmer and CO2-enriched oceans.
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Affiliation(s)
- Guang Gao
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Jiangsu Ocean University, Lianyungang, 222005, China; State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, 361005, China
| | - Qianqian Fu
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Jiangsu Ocean University, Lianyungang, 222005, China
| | - John Beardall
- School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia
| | - Min Wu
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Jiangsu Ocean University, Lianyungang, 222005, China
| | - Juntian Xu
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Jiangsu Ocean University, Lianyungang, 222005, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Lianyungang 222005, China; Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang 222005, China.
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