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Edmunds PJ, Combosch DJ, Torrado H, Sakai K, Sinniger F, Burgess SC. Latitudinal variation in thermal performance of the common coral Pocillopora spp. J Exp Biol 2024; 227:jeb247090. [PMID: 38699869 DOI: 10.1242/jeb.247090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Accepted: 04/26/2024] [Indexed: 05/05/2024]
Abstract
Understanding how tropical corals respond to temperatures is important to evaluating their capacity to persist in a warmer future. We studied the common Pacific coral Pocillopora over 44° of latitude, and used populations at three islands with different thermal regimes to compare their responses to temperature using thermal performance curves (TPCs) for respiration and gross photosynthesis. Corals were sampled in the local autumn from Moorea, Guam and Okinawa, where mean±s.d. annual seawater temperature is 28.0±0.9°C, 28.9±0.7°C and 25.1±3.4°C, respectively. TPCs for respiration were similar among latitudes, the thermal optimum (Topt) was above the local maximum temperature at all three islands, and maximum respiration was lowest at Okinawa. TPCs for gross photosynthesis were wider, implying greater thermal eurytopy, with a higher Topt in Moorea versus Guam and Okinawa. Topt was above the maximum temperature in Moorea, but was similar to daily temperatures over 13% of the year in Okinawa and 53% of the year in Guam. There was greater annual variation in daily temperatures in Okinawa than Guam or Moorea, which translated to large variation in the supply of metabolic energy and photosynthetically fixed carbon at higher latitudes. Despite these trends, the differences in TPCs for Pocillopora spp. were not profoundly different across latitudes, reducing the likelihood that populations of these corals could better match their phenotypes to future more extreme temperatures through migration. Any such response would place a premium on high metabolic plasticity and tolerance of large seasonal variations in energy budgets.
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Affiliation(s)
- P J Edmunds
- Department of Biology, California State University, Northridge, 18111 Nordhoff Street, Northridge, CA 91330-8303, USA
| | - D J Combosch
- Marine Laboratory, University of Guam, 303 University Drive, Mangilao, 96923 Guam, USA
| | - H Torrado
- Marine Laboratory, University of Guam, 303 University Drive, Mangilao, 96923 Guam, USA
| | - K Sakai
- Sesoko Station, Tropical Biosphere Research Center, University of the Ryukyus, 3422 Sesoko, Motobu, 905-0227 Okinawa, Japan
| | - F Sinniger
- Sesoko Station, Tropical Biosphere Research Center, University of the Ryukyus, 3422 Sesoko, Motobu, 905-0227 Okinawa, Japan
| | - S C Burgess
- Department of Biological Science, Florida State University, Tallahassee, FL 32306, USA
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Allen-Waller LR, Jones KG, Martynek MP, Brown KT, Barott KL. Comparative physiology reveals heat stress disrupts acid-base homeostasis independent of symbiotic state in the model cnidarian Exaiptasia diaphana. J Exp Biol 2024; 227:jeb246222. [PMID: 38269486 PMCID: PMC10911193 DOI: 10.1242/jeb.246222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 01/17/2024] [Indexed: 01/26/2024]
Abstract
Climate change threatens the survival of symbiotic cnidarians by causing photosymbiosis breakdown in a process known as bleaching. Direct effects of temperature on cnidarian host physiology remain difficult to describe because heatwaves depress symbiont performance, leading to host stress and starvation. The symbiotic sea anemone Exaiptasia diaphana provides an opportune system to disentangle direct versus indirect heat effects on the host, as it can survive indefinitely without symbionts. We tested the hypothesis that heat directly impairs cnidarian physiology by comparing symbiotic and aposymbiotic individuals of two laboratory subpopulations of a commonly used clonal strain of E. diaphana, CC7. We exposed anemones to a range of temperatures (ambient, +2°C, +4°C and +6°C) for 15-18 days, then measured their symbiont population densities, autotrophic carbon assimilation and translocation, photosynthesis, respiration and host intracellular pH (pHi). Symbiotic anemones from the two subpopulations differed in size and symbiont density and exhibited distinct heat stress responses, highlighting the importance of acclimation to different laboratory conditions. Specifically, the cohort with higher initial symbiont densities experienced dose-dependent symbiont loss with increasing temperature and a corresponding decline in host photosynthate accumulation. In contrast, the cohort with lower initial symbiont densities did not lose symbionts or assimilate less photosynthate when heated, similar to the response of aposymbiotic anemones. However, anemone pHi decreased at higher temperatures regardless of cohort, symbiont presence or photosynthate translocation, indicating that heat consistently disrupts cnidarian acid-base homeostasis independent of symbiotic status or mutualism breakdown. Thus, pH regulation may be a critical vulnerability for cnidarians in a changing climate.
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Affiliation(s)
| | - Katelyn G. Jones
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | | | - Kristen T. Brown
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Katie L. Barott
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA
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Fähse M, Orejas C, Titschack J, Försterra G, Richter C, Laudien J. Ecophysiological and behavioural response of juveniles of the Chilean cold-water coral Caryophyllia (Caryophyllia) huinayensis to increasing sediment loads. Sci Rep 2023; 13:21538. [PMID: 38057359 PMCID: PMC10700329 DOI: 10.1038/s41598-023-47116-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Accepted: 11/09/2023] [Indexed: 12/08/2023] Open
Abstract
Chilean Patagonia is a hotspot of biodiversity, harbouring cold-water corals (CWCs) that populate steep walls and overhangs of fjords and channels. Through anthropogenic activities such as deforestation, roadworks, aquafarming and increased landslide frequency, sediment input increases in the fjord region. While the absence of CWCs on moderately steep slopes has been suggested to reflect high vulnerability to sedimentation, experimental evidence has been lacking. Here, we investigated the sensitivity of CWCs to sediment stress, using juvenile Caryophyllia (Caryophyllia) huinayensis as a model. A 12-week aquarium experiment was conducted with three sediment loads: the average natural sediment concentration in Comau Fjord, 100- and 1000-fold higher sediment levels, expected from gravel road use and coastal erosion. Changes in coral mass and calyx dimensions, polyp expansion, tissue retraction and respiration were measured. For CWCs exposed to two and three order of magnitude higher sediment concentrations, 32% and 80% of the animals experienced a decrease in tissue cover, respectively, along with a decrease in respiration rate of 34% and 66%. Under the highest concentration corals showed reduced polyp expansion and a significantly reduced growth of ~ 95% compared to corals at natural concentration. The results show that C. huinayensis is affected by high sediment loads. As human activities that increase sedimentation steadily intensify, coastal planners need to consider detrimental effects on CWCs.
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Affiliation(s)
- Melanie Fähse
- Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, 27515, Bremerhaven, Germany
| | - Covadonga Orejas
- Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, 27515, Bremerhaven, Germany
- Instituto Español de Oceanografía, Centro Oceanográfico de Gijón (IEO, CSIC), Avenida Príncipe de Asturias 70 Bis, 33212, Gijón, Spain
- Hanse-Wissenschaftskolleg - Institute for Advanced Study (HWK), Lehmkuhlenbusch 4, 27753, Delmenhorst, Germany
| | - Jürgen Titschack
- MARUM-Center for Marine Environmental Sciences, University of Bremen, Leobener Str. 8, 28359, Bremen, Germany
- Senckenberg Am Meer, Marine Research Department, Südstrand 40, 26382, Wilhelmshaven, Germany
| | - Günter Försterra
- Huinay Scientific Field Station, Casilla 462, Puerto Montt, Chile
- Facultad de Recursos Naturales, Pontificia Universidad Católica de Valparaíso, Escuela de Ciencias del Mar, Valparaíso, Chile
| | - Claudio Richter
- Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, 27515, Bremerhaven, Germany
- Universität Bremen, Bibliothekstraße 1, 28359, Bremen, Germany
| | - Jürgen Laudien
- Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, 27515, Bremerhaven, Germany.
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Mahmood M, Wang Y, Ahmed W, Mehmood S, Ayyoub A, Elnahal ASM, Li W, Zhan X. Exploring biochar and fishpond sediments potential to change soil phosphorus fractions and availability. FRONTIERS IN PLANT SCIENCE 2023; 14:1224583. [PMID: 37636081 PMCID: PMC10450619 DOI: 10.3389/fpls.2023.1224583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 07/21/2023] [Indexed: 08/29/2023]
Abstract
Phosphorus (P) availability in soil is paradoxical, with a significant portion of applied P accumulating in the soil, potentially affecting plant production. The impact of biochar (BR) and fishpond sediments (FPS) as fertilizers on P fixation remains unclear. This study aimed to determine the optimal ratio of BR, modified biochar (MBR), and FPS as fertilizer replacements. A pot experiment with maize evaluated the transformation of P into inorganic (Pi) and organic (Po) fractions and their contribution to P uptake. Different percentages of FPS, BR, and MBR were applied as treatments (T1-T7), T1 [(0.0)], T2 [FPS (25.0%)], T3 [FPS (25.0%) + BR (1%)], T [FPS (25%) +MBR (3%)], T5 [FPS (35%)], T6 [FPS (35%) +BR (1%)], and T7 [FPS (35%) + MBR (1%)]. Using the modified Hedley method and the Tiessen and Moir fractionation scheme, P fractions were determined. Results showed that various rates of MBR, BR, and FPS significantly increased labile and moderately labile P fractions (NaHCO3-Pi, NaHCO3-Po, HClD-Pi, and HClC-Pi) and residual P fractions compared with the control (T1). Positive correlations were observed between P uptake, phosphatase enzyme activity, and NaHCO3-Pi. Maximum P uptake and phosphatase activity were observed in T6 and T7 treatments. The addition of BR, MBR, and FPS increased Po fractions. Unlike the decline in NaOH-Po fraction, NaHCO3-Po and HClc-Po fractions increased. All Pi fractions, particularly apatite (HClD-Pi), increased across the T1-T7 treatments. HClD-Pi was the largest contributor to total P (40.7%) and can convert into accessible P over time. The T5 treatment showed a 0.88% rise in residual P. HClD-Pi and residual P fractions positively correlated with P uptake, phosphatase activity, NaOH-Pi, and NaOH-Po moderately available fractions. Regression analysis revealed that higher concentrations of metals such as Ca, Zn, and Cr significantly decreased labile organic and inorganic P fractions (NaHCO3-Pi, R 2 = 0.13, 0.36, 0.09) and their availability (NaHCO3-Po, R 2 = 0.01, 0.03, 0.25). Excessive solo BR amendments did not consistently increase P availability, but optimal simple and MBR increased residual P contents in moderately labile and labile forms (including NaOH-Pi, NaHCO3-Pi, and HClD-Pi). Overall, our findings suggest that the co-addition of BR and FPS can enhance soil P availability via increasing the activity of phosphatase enzyme, thereby enhancing plant P uptake and use efficiency, which eventually maintains the provision of ecosystem functions and services.
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Affiliation(s)
- Mohsin Mahmood
- Key Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation of Hainan Province, Hainan University, Haikou, China
- Center for Eco-Environment Restoration Engineering of Hainan Province, Hainan University, Haikou, China
| | - Yunting Wang
- Key Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation of Hainan Province, Hainan University, Haikou, China
- Center for Eco-Environment Restoration Engineering of Hainan Province, Hainan University, Haikou, China
| | - Waqas Ahmed
- Key Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation of Hainan Province, Hainan University, Haikou, China
- Center for Eco-Environment Restoration Engineering of Hainan Province, Hainan University, Haikou, China
| | - Sajid Mehmood
- Key Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation of Hainan Province, Hainan University, Haikou, China
- Center for Eco-Environment Restoration Engineering of Hainan Province, Hainan University, Haikou, China
| | - Anam Ayyoub
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China
| | - Ahmed S. M. Elnahal
- Pathology Department, Faculty of Agriculture, Zagazig University, Zagazig, Egypt
| | - Weidong Li
- Key Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation of Hainan Province, Hainan University, Haikou, China
- Center for Eco-Environment Restoration Engineering of Hainan Province, Hainan University, Haikou, China
| | - Xin Zhan
- Key Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation of Hainan Province, Hainan University, Haikou, China
- State Key Laboratory of Marine Resource Utilization in South China Sea, College of Marine Science, Hainan University, Haikou, China
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