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Saewong C, Ow YX, Nualla-Ong A, Buapet P. Comparative effects of heat stress on photosynthesis and oxidative stress in Halophila ovalis and Thalassia hemprichii under different light conditions. MARINE ENVIRONMENTAL RESEARCH 2024; 199:106589. [PMID: 38852494 DOI: 10.1016/j.marenvres.2024.106589] [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: 01/29/2024] [Revised: 04/19/2024] [Accepted: 06/03/2024] [Indexed: 06/11/2024]
Abstract
This study investigated the physiological responses of two tropical seagrass species, Halophila ovalis and Thalassia hemprichii, to heat stress under varying light conditions in a controlled 5-day experiment. The experimental design included four treatments: control, saturating light, heat stress under sub-saturating light, and heat stress under saturating light (combined stress). We assessed various parameters, including chlorophyll fluorescence, levels of reactive oxygen species (ROS), antioxidant enzyme activities, and growth rates. In H. ovalis, heat stress resulted in a significant reduction in the maximum quantum yield of photosystem II (Fv/Fm) regardless of the light condition. However, the effects of heat stress on the effective quantum yield of photosystem II (ɸPSII) were more pronounced under saturating light conditions. In T. hemprichii, saturating irradiance exacerbated the heat stress effects on Fv/Fm and ɸPSII, although the overall photoinhibition was less severe than in H. ovalis. Heat stress led to ROS accumulation in H. ovalis and reduced the activity of superoxide dismutase (SOD) and ascorbate peroxidase in the sub-saturating light condition. Conversely, T. hemprichii exhibited elevated SOD activity under saturating light. Heat stress suppressed the growth of both seagrass species, regardless of the light environment. The Biomarker Response Index indicated that H. ovalis displayed severe effects in the heat stress treatment under both light conditions, while T. hemprichii exhibited moderate effects in sub-saturating light and major effects in saturating light conditions. However, the Effect Addition Index revealed an antagonistic interaction between heat stress and high light in both seagrass species. This study underscores the intricate responses of seagrasses, emphasizing the importance of considering both local and global stressors when assessing their vulnerability.
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Affiliation(s)
- Chanida Saewong
- Division of Biological Science, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, 90110, Thailand; Coastal Oceanography and Climate Change Research Center, Prince of Songkla University, Hat Yai, Songkhla, 90110, Thailand
| | - Yan Xiang Ow
- St John's Island National Marine Laboratory, Tropical Marine Science Institute, National University of Singapore, 14 Kent Ridge Road, 119227, Singapore
| | - Aekkaraj Nualla-Ong
- Division of Biological Science, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, 90110, Thailand; Center for Genomics and Bioinformatics Research, Faculty of Science, Prince of Songkla University, Songkhla, 90110, Thailand
| | - Pimchanok Buapet
- Division of Biological Science, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, 90110, Thailand; Coastal Oceanography and Climate Change Research Center, Prince of Songkla University, Hat Yai, Songkhla, 90110, Thailand.
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Skerratt J, Baird ME, Mongin M, Ellis R, Smith RA, Shaw M, Steven ADL. Dispersal of the pesticide diuron in the Great Barrier Reef. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 879:163041. [PMID: 36965738 DOI: 10.1016/j.scitotenv.2023.163041] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 03/16/2023] [Accepted: 03/20/2023] [Indexed: 05/17/2023]
Abstract
Pesticides from urban and agricultural runoff have been detected at concentrations above current water quality guidelines in the Great Barrier Reef (GBR) marine environment. We quantify the load of the pesticide diuron entering GBR waters using the GBR-Dynamic SedNet catchment model. After comparison of simulated distributions with observations at 11 monitoring sites we determined a half-life of diuron in GBR marine waters of 40 days. We followed diuron dispersal in the GBR (2016-2018) using the 1 km resolution eReefs marine model. The highest diuron concentrations in GBR waters occurred in the Mackay-Whitsunday region with a spike in January and March 2017, associated with 126 and 118 kg d-1 diuron loads from Plane Creek and the O'Connell River respectively. We quantify areas of GBR waters exposed to potentially ecotoxic concentrations of diuron. Between 2016 and 2018, 400 km2 and 1400 km2 of the GBR were exposed to concentrations exceeding ecosystem threshold values of 0.43 and 0.075 μg L-1 respectively. Using observed mapped coral and seagrass habitat, 175 km2 of seagrass beds and 50 km2 of coral habitats had peak diuron concentrations above 0.075 μg L-1 during this period. While the highest concentrations are localised to river plumes and inshore environments, non-zero diuron concentrations extend along the Queensland coast. These simulations provide new knowledge for the understanding of pesticide dispersal and management-use in GBR catchments and the design of in-water monitoring systems.
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Affiliation(s)
| | | | | | - Robin Ellis
- Science Division, Department of Environment and Science, Queensland Government, Brisbane, Australia
| | - Rachael A Smith
- Office of the Great Barrier Reef, Department of Environment and Science, Brisbane 4102, QLD, Australia
| | - Melanie Shaw
- Science Division, Department of Environment and Science, Queensland Government, Brisbane, Australia
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3
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van Wyk JW, Adams JB, von der Heyden S. Conservation implications of herbicides on seagrasses: sublethal glyphosate exposure decreases fitness in the endangered Zostera capensis. PeerJ 2022; 10:e14295. [PMID: 36405027 PMCID: PMC9673766 DOI: 10.7717/peerj.14295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 10/03/2022] [Indexed: 11/16/2022] Open
Abstract
Worldwide seagrass populations are in decline, calling for urgent measures in their conservation. Glyphosate is the most widely used herbicide globally, leading to increasing concern about its ecological impact, yet little is known about the prevalence or impact of glyphosate on seagrasses. In this study, we investigated the effect of sublethal glyphosate exposure on the endangered seagrass, Zostera capensis, to identify effects on growth, photosynthetic pigments and leaf morphology as measures of seagrass fitness. Seagrasses were exposed to a single dose of a commercial glyphosate formulation-ranging between 250 to 2,200 µg/L. After three weeks, the median leaf area decreased by up to 27%, with reductions of up to 31% in above ground biomass (p < 0.05). Photosynthetic pigment concentration showed no significant difference between groups. The observed effects on biomass and leaf area were seen at glyphosate levels below the regulatory limits set for surface water by several countries and may negatively affect the long-term resilience of this ecosystem engineer to additional stressors, such as those associated with climate change and anthropogenic pollution. As such, glyphosates and other herbicides that are washed into estuarine and marine ecosystems, pose a significant threat to the persistence of seagrasses and are important factors to consider in seagrass conservation, management and restoration efforts.
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Affiliation(s)
- Johanna W. van Wyk
- Department of Botany and Zoology, Stellenbosch University, Matieland, South Africa
| | - Janine B. Adams
- Institute for Coastal and Marine Research, Department of Botany, Nelson Mandela University, Gqeberha, South Africa
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4
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Zhang P, Wang T, Zhang H, Wang H, Hilt S, Shi P, Cheng H, Feng M, Pan M, Guo Y, Wang K, Xu X, Chen J, Zhao K, He Y, Zhang M, Xu J. Heat waves rather than continuous warming exacerbate impacts of nutrient loading and herbicides on aquatic ecosystems. ENVIRONMENT INTERNATIONAL 2022; 168:107478. [PMID: 35998413 DOI: 10.1016/j.envint.2022.107478] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Revised: 08/13/2022] [Accepted: 08/13/2022] [Indexed: 06/15/2023]
Abstract
Submerged macrophytes are vital components in shallow aquatic ecosystems, but their abundances have declined globally. Shading by periphyton and phytoplankton/turbidity plays a major role in this decline, and the competing aquatic primary producers are subject to the complex influence of multiple stressors such as increasing temperatures, nutrient loading and herbicides. Their joint impact has rarely been tested and is difficult to predict due to potentially opposing effects on the different primary producers, their interactions and their grazers. Here, we used 48 mesocosms (2500 L) to simulate shallow lakes dominated by two typical submerged macrophytes, bottom-dwelling Vallisneria denseserrulata and canopy-forming Hydrilla verticillata, and associated food web components. We applied a combination of nutrient loading, continuous warming, heat waves and glyphosate-based herbicides to test how these stressors interactively impact the growth of submerged macrophytes, phytoplankton and periphyton as competing primary producers. Warming or heat waves alone did not affect phytoplankton and periphyton abundance, but negatively influenced the biomass of V. denseserrulata. Nutrient loading alone increased phytoplankton biomass and water turbidity and thus negatively affected submerged macrophyte biomass, particularly for V. denseserrulata, by shading. Glyphosate alone did not affect biomass of each primary producer under ambient temperatures. However, heat waves facilitated phytoplankton growth under combined nutrient loading and glyphosate treatments more than continuous warming. As a consequence, H. verticillata biomass was lowest under these conditions indicating the potential of multiple stressors for macrophyte decline. Our study demonstrated that multiple stressors interactively alter the biomass of primary producers and their interactions and can eventually lead to a loss of macrophyte communities and shift to phytoplankton dominance. These results show the risks in shallow lakes and ponds in agricultural landscapes and underline the need for multiple stressor studies as a base for their future management.
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Affiliation(s)
- Peiyu Zhang
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Tao Wang
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Huan Zhang
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Huan Wang
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Sabine Hilt
- Department of Community and Ecosystem Ecology, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Berlin, Germany
| | - Penglan Shi
- College of Fisheries, Huazhong Agricultural University, Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Hubei Provincial Engineering Laboratory for Pond Aquaculture, Wuhan, China
| | - Haowu Cheng
- College of Fisheries, Huazhong Agricultural University, Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Hubei Provincial Engineering Laboratory for Pond Aquaculture, Wuhan, China
| | - Mingjun Feng
- College of Fisheries, Huazhong Agricultural University, Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Hubei Provincial Engineering Laboratory for Pond Aquaculture, Wuhan, China
| | - Meng Pan
- College of Fisheries, Huazhong Agricultural University, Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Hubei Provincial Engineering Laboratory for Pond Aquaculture, Wuhan, China
| | - Yulun Guo
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Kang Wang
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Xiaoqi Xu
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Jianlin Chen
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Kangshun Zhao
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Yuhan He
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Min Zhang
- College of Fisheries, Huazhong Agricultural University, Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Hubei Provincial Engineering Laboratory for Pond Aquaculture, Wuhan, China
| | - Jun Xu
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.
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Polazzo F, Roth SK, Hermann M, Mangold‐Döring A, Rico A, Sobek A, Van den Brink PJ, Jackson M. Combined effects of heatwaves and micropollutants on freshwater ecosystems: Towards an integrated assessment of extreme events in multiple stressors research. GLOBAL CHANGE BIOLOGY 2022; 28:1248-1267. [PMID: 34735747 PMCID: PMC9298819 DOI: 10.1111/gcb.15971] [Citation(s) in RCA: 36] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 10/14/2021] [Accepted: 10/29/2021] [Indexed: 05/11/2023]
Abstract
Freshwater ecosystems are strongly influenced by weather extremes such as heatwaves (HWs), which are predicted to increase in frequency and magnitude in the future. In addition to these climate extremes, the freshwater realm is impacted by the exposure to various classes of chemicals emitted by anthropogenic activities. Currently, there is limited knowledge on how the combined exposure to HWs and chemicals affects the structure and functioning of freshwater ecosystems. Here, we review the available literature describing the single and combined effects of HWs and chemicals on different levels of biological organization, to obtain a holistic view of their potential interactive effects. We only found a few studies (13 out of the 61 studies included in this review) that investigated the biological effects of HWs in combination with chemical pollution. The reported interactive effects of HWs and chemicals varied largely not only within the different trophic levels but also depending on the studied endpoints for populations or individuals. Hence, owing also to the little number of studies available, no consistent interactive effects could be highlighted at any level of biological organization. Moreover, we found an imbalance towards single species and population experiments, with only five studies using a multitrophic approach. This results in a knowledge gap for relevant community and ecosystem level endpoints, which prevents the exploration of important indirect effects that can compromise food web stability. Moreover, this knowledge gap impairs the validity of chemical risk assessments and our ability to protect ecosystems. Finally, we highlight the urgency of integrating extreme events into multiple stressors studies and provide specific recommendations to guide further experimental research in this regard.
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Affiliation(s)
- Francesco Polazzo
- IMDEA Water Institute, Science and Technology Campus of the University of AlcaláAlcalá de HenaresSpain
| | - Sabrina K. Roth
- Department of Environmental ScienceStockholm UniversityStockholmSweden
| | - Markus Hermann
- Aquatic Ecology and Water Quality Management GroupWageningen UniversityWageningenThe Netherlands
| | - Annika Mangold‐Döring
- Aquatic Ecology and Water Quality Management GroupWageningen UniversityWageningenThe Netherlands
| | - Andreu Rico
- IMDEA Water Institute, Science and Technology Campus of the University of AlcaláAlcalá de HenaresSpain
- Cavanilles Institute of Biodiversity and Evolutionary BiologyUniversity of ValenciaValenciaSpain
| | - Anna Sobek
- Department of Environmental ScienceStockholm UniversityStockholmSweden
| | - Paul J. Van den Brink
- Aquatic Ecology and Water Quality Management GroupWageningen UniversityWageningenThe Netherlands
- Wageningen Environmental ResearchWageningenThe Netherlands
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6
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Li J, Zhang W, Lin Z, Huang Y, Bhatt P, Chen S. Emerging Strategies for the Bioremediation of the Phenylurea Herbicide Diuron. Front Microbiol 2021; 12:686509. [PMID: 34475856 PMCID: PMC8406775 DOI: 10.3389/fmicb.2021.686509] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Accepted: 07/16/2021] [Indexed: 02/04/2023] Open
Abstract
Diuron (DUR) is a phenylurea herbicide widely used for the effective control of most annual and perennial weeds in farming areas. The extensive use of DUR has led to its widespread presence in soil, sediment, and aquatic environments, which poses a threat to non-target crops, animals, humans, and ecosystems. Therefore, the removal of DUR from contaminated environments has been a hot topic for researchers in recent decades. Bioremediation seldom leaves harmful intermediate metabolites and is emerging as the most effective and eco-friendly strategy for removing DUR from the environment. Microorganisms, such as bacteria, fungi, and actinomycetes, can use DUR as their sole source of carbon. Some of them have been isolated, including organisms from the bacterial genera Arthrobacter, Bacillus, Vagococcus, Burkholderia, Micrococcus, Stenotrophomonas, and Pseudomonas and fungal genera Aspergillus, Pycnoporus, Pluteus, Trametes, Neurospora, Cunninghamella, and Mortierella. A number of studies have investigated the toxicity and fate of DUR, its degradation pathways and metabolites, and DUR-degrading hydrolases and related genes. However, few reviews have focused on the microbial degradation and biochemical mechanisms of DUR. The common microbial degradation pathway for DUR is via transformation to 3,4-dichloroaniline, which is then metabolized through two different metabolic pathways: dehalogenation and hydroxylation, the products of which are further degraded via cooperative metabolism. Microbial degradation hydrolases, including PuhA, PuhB, LibA, HylA, Phh, Mhh, and LahB, provide new knowledge about the underlying pathways governing DUR metabolism. The present review summarizes the state-of-the-art knowledge regarding (1) the environmental occurrence and toxicity of DUR, (2) newly isolated and identified DUR-degrading microbes and their enzymes/genes, and (3) the bioremediation of DUR in soil and water environments. This review further updates the recent knowledge on bioremediation strategies with a focus on the metabolic pathways and molecular mechanisms involved in the bioremediation of DUR.
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Affiliation(s)
- Jiayi Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
| | - Wenping Zhang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
| | - Ziqiu Lin
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
| | - Yaohua Huang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
| | - Pankaj Bhatt
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
| | - Shaohua Chen
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
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7
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Flores F, Marques JA, Uthicke S, Fisher R, Patel F, Kaserzon S, Negri AP. Combined effects of climate change and the herbicide diuron on the coral Acropora millepora. MARINE POLLUTION BULLETIN 2021; 169:112582. [PMID: 34119962 DOI: 10.1016/j.marpolbul.2021.112582] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 04/12/2021] [Accepted: 05/26/2021] [Indexed: 06/12/2023]
Abstract
The Great Barrier Reef (GBR) is threatened by climate change and local pressures, including contaminants in nearshore habitats. This study investigated the combined effects of a GBR-relevant contaminant, the herbicide diuron, under current and two future climate scenarios on the coral Acropora millepora. All physiological responses tested (effective quantum yield (ΔF/Fm'), photosynthesis, calcification rate) were negatively affected with increasing concentrations of diuron. Interactive effects between diuron and climate were observed for all responses; however, climate had no significant effect on ΔF/Fm' or calcification rates. Photosynthesis was negatively affected as the climate scenarios were adjusted from ambient (28.1 °C, pCO2 = 397 ppm) to RCP8.5 2050 (29.1 °C, pCO2 = 680 ppm) and 2100 (30.2 °C, pCO2 = 858 ppm) with EC50 values declining from 19.4 to 10.6 and 2.6 μg L-1 diuron in turn. These results highlight the likelihood that water quality guideline values may need to be adjusted as the climate changes.
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Affiliation(s)
- Florita Flores
- Australian Institute of Marine Science, Townsville, QLD 4810, Australia.
| | - Joseane A Marques
- Programa de Pós-Graduação em Oceanografia Biológica, Universidade Federal do Rio Grande, RS, Brazil
| | - Sven Uthicke
- Australian Institute of Marine Science, Townsville, QLD 4810, Australia.
| | - Rebecca Fisher
- Australian Institute of Marine Science, Indian Ocean Marine Research Centre, University of Western Australia, Crawley, WA 6009, Australia.
| | - Frances Patel
- Australian Institute of Marine Science, Townsville, QLD 4810, Australia.
| | - Sarit Kaserzon
- Queensland Alliance for Environmental Health Sciences (QAEHS), The University of Queensland, Woolloongabba, QLD 4102, Australia.
| | - Andrew P Negri
- Australian Institute of Marine Science, Townsville, QLD 4810, Australia.
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8
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Nguyen HM, Ralph PJ, Marín-Guirao L, Pernice M, Procaccini G. Seagrasses in an era of ocean warming: a review. Biol Rev Camb Philos Soc 2021; 96:2009-2030. [PMID: 34014018 DOI: 10.1111/brv.12736] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 05/06/2021] [Accepted: 05/07/2021] [Indexed: 12/15/2022]
Abstract
Seagrasses are valuable sources of food and habitat for marine life and are one of Earth's most efficient carbon sinks. However, they are facing a global decline due to ocean warming and eutrophication. In the last decade, with the advent of new technology and molecular advances, there has been a dramatic increase in the number of studies focusing on the effects of ocean warming on seagrasses. Here, we provide a comprehensive review of the future of seagrasses in an era of ocean warming. We have gathered information from published studies to identify potential commonalities in the effects of warming and the responses of seagrasses across four distinct levels: molecular, biochemical/physiological, morphological/population, and ecosystem/planetary. To date, we know that although warming strongly affects seagrasses at all four levels, seagrass responses diverge amongst species, populations, and over depths. Furthermore, warming alters seagrass distribution causing massive die-offs in some seagrass populations, whilst also causing tropicalization and migration of temperate species. In this review, we evaluate the combined effects of ocean warming with other environmental stressors and emphasize the need for multiple-stressor studies to provide a deeper understanding of seagrass resilience. We conclude by discussing the most significant knowledge gaps and future directions for seagrass research.
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Affiliation(s)
- Hung Manh Nguyen
- Stazione Zoologica Anton Dohrn, Villa Comunale, Napoli, 80121, Italy
| | - Peter J Ralph
- Faculty of Science, Climate Change Cluster (C3), University of Technology Sydney, Sydney, NSW, 2007, Australia
| | - Lázaro Marín-Guirao
- Stazione Zoologica Anton Dohrn, Villa Comunale, Napoli, 80121, Italy.,Seagrass Ecology Group, Oceanographic Centre of Murcia, Spanish Institute of Oceanography, C/Varadero, San Pedro del Pinatar, Murcia, 30740, Spain
| | - Mathieu Pernice
- Faculty of Science, Climate Change Cluster (C3), University of Technology Sydney, Sydney, NSW, 2007, Australia
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9
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Marques JA, Flores F, Patel F, Bianchini A, Uthicke S, Negri AP. Acclimation history modulates effect size of calcareous algae (Halimeda opuntia) to herbicide exposure under future climate scenarios. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 739:140308. [PMID: 32846507 DOI: 10.1016/j.scitotenv.2020.140308] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 06/11/2020] [Accepted: 06/15/2020] [Indexed: 06/11/2023]
Abstract
Tropical marine habitat-builders such as calcifying green algae can be susceptible to climate change (warming and acidification). This study evaluated the cumulative effects of ocean warming (OW), ocean acidification (OA) and the herbicide diuron on the calcifying green algae Halimeda opuntia. We also assessed the influence of acclimation history to experimental climate change conditions on physiological responses. H. opuntia were exposed for 15 days to orthogonal combinations of three climate scenarios [ambient (28 °C, pCO2 = 378 ppm), 2050 (29 °C, pCO2 = 567 ppm) and 2100 (30 °C, pCO2 = 721 ppm)] and to six diuron concentrations (up to 29 μg L-1). Half of the H. opuntia had been acclimated for eight months to the climate scenarios in a mesocosm approach, while the remaining half were not pre-acclimated, as is current practice in most experiments. Climate effects on quantum yield (ΔF/Fm'), photosynthesis and calcification in future climate scenarios were significantly stronger (by -24, -46 and +26%, respectively) in non-acclimated algae, suggesting experimental bias may exaggerate effects in organisms not appropriately acclimated to future-climate conditions. Thus, full analysis was done on acclimated plants only. Interactive effects of future climate scenarios and diuron were observed for ΔF/Fm', while the detrimental effects of climate and diuron on net photosynthesis and total antioxidant capacity (TAC) were additive. Calcification-related enzymes were negatively affected only by diuron, with inhibition of Ca-ATPase and upregulation of carbonic anhydrase. The combined and consistent physiological and biochemical evidence of negative impacts (across six indicators) of both herbicide and future-climate conditions on the health of H. opuntia highlights the need to address both climate change and water quality. Guideline values for contaminants may also need to be lowered considering 'climate adjusted thresholds'. Importantly, this study highlights the value of applying substantial future climate acclimation periods in experimental studies to avoid exaggerated organism responses to OW and OA.
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Affiliation(s)
- Joseane A Marques
- Programa de Pós-Graduação em Oceanografia Biológica, Universidade Federal do Rio Grande, RS, Brazil.
| | - Florita Flores
- Australian Institute of Marine Science, Townsville, QLD 4810, Australia.
| | - Frances Patel
- Australian Institute of Marine Science, Townsville, QLD 4810, Australia.
| | - Adalto Bianchini
- Instituto de Ciências Biológicas, Universidade Federal do Rio Grande, RS, Brazil.
| | - Sven Uthicke
- Australian Institute of Marine Science, Townsville, QLD 4810, Australia.
| | - Andrew P Negri
- Australian Institute of Marine Science, Townsville, QLD 4810, Australia.
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10
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Negri AP, Smith RA, King O, Frangos J, Warne MSJ, Uthicke S. Adjusting Tropical Marine Water Quality Guideline Values for Elevated Ocean Temperatures. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:1102-1110. [PMID: 31845576 DOI: 10.1021/acs.est.9b05961] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Increased frequency of summer heatwaves and poor water quality are two of the most prevalent and severe pressures faced by coral reefs. While these pressures often co-occur, their potential risks to tropical marine species are usually considered independently. Here, we extended the application of multisubstance-Potentially Affected Fraction (ms-PAF) to a nonchemical stressor, elevated sea surface temperature. We then applied this method to calculate climate-adjusted water quality guideline values (GVs) for two reference toxicants, copper and the herbicide diuron, for tropical marine species. First, we developed a species sensitivity distribution (SSD) for thermal stress based on published experimental data for 41 tropical benthic marine species using methods adapted from water quality GV derivation. This enabled quantitative predictions of community effects as temperatures exceeded acclimation values. The resulting protective temperature values (PTx) were similar to temperatures known to initiate coral bleaching and are therefore relevant for application in multistressor risk assessments. The extended ms-PAF method enabled the adjustment of current water quality GVs to account for thermal stress events. This approach could be applied to other ecosystems and other non-contaminant stressors (e.g., sediment, low salinity, anoxia, and ocean acidification), offering an alternative approach for deriving environmental GVs, reporting and assessing the risk posed by multiple stressors.
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Affiliation(s)
- Andrew P Negri
- Australian Institute of Marine Science , Townsville , Queensland 4810 , Australia
| | - Rachael A Smith
- Office of the Great Barrier Reef, Queensland Department of Environment and Science , Brisbane , Queensland 4001 , Australia
| | - Olivia King
- Australian Rivers Institute-Coast and Estuaries, School of Environment and Science , Griffith University , Gold Coast , Queensland 4215 , Australia
| | - Julius Frangos
- Office of the Great Barrier Reef, Queensland Department of Environment and Science , Brisbane , Queensland 4001 , Australia
| | - Michael St J Warne
- School of Earth and Environmental Sciences, Faculty of Science , University of Queensland , St. Lucia , Queensland 4072 , Australia
- Department of Environment and Science , Brisbane , Queensland 4001 , Australia
- Centre for Agroecology, Water and Resilience , Coventry University , Coventry , West Midlands CV1 5FB , U.K
| | - Sven Uthicke
- Australian Institute of Marine Science , Townsville , Queensland 4810 , Australia
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Ontoria Y, Cuesta-Gracia A, Ruiz JM, Romero J, Pérez M. The negative effects of short-term extreme thermal events on the seagrass Posidonia oceanica are exacerbated by ammonium additions. PLoS One 2019; 14:e0222798. [PMID: 31536606 PMCID: PMC6752784 DOI: 10.1371/journal.pone.0222798] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Accepted: 09/06/2019] [Indexed: 01/02/2023] Open
Abstract
Global warming is increasingly affecting our biosphere. However, in addition to global warming, a panoply of local stressors caused by human activities is having a profound impact on our environment. The risk that these local stressors could modify the response of organisms to global warming has attracted interest and fostered research on their combined effect, especially with a view to identifying potential synergies. In coastal areas, where human activities are heavily concentrated, this scenario is particularly worrying, especially for foundation species such as seagrasses. In this study we explore these potential interactions in the seagrass Posidonia oceanica. This species is endemic to the Mediterranean Sea. It is well known that the Mediterranean is already experiencing the effects of global warming, especially in the form of heat waves, whose frequency and intensity are expected to increase in the coming decades. Moreover, this species is especially sensitive to stress and plays a key role as a foundation species. The aim of this work is thus to evaluate plant responses (in terms of photosynthetic efficiency and growth) to the combined effects of short-term temperature increases and ammonium additions.To achieve this, we conducted a mesocosm experiment in which plants were exposed to three thermal treatments (20°C, 30°C and 35°C) and three ammonium concentrations (ambient, 30 μM and 120 μM) in a full factorial experiment. We assessed plant performance by measuring chlorophyll fluorescence variables (maximum quantum yield (Fv/Fm), effective quantum yield of photosystem II (ΔF/Fm'), maximum electron transport rate (ETRmax) and non-photochemical quenching (NPQ)), shoot growth rate and leaf necrosis incidence. At ambient ammonium concentrations, P. oceanica tolerates short-term temperature increases up to 30°C. However, at 35°C, the plant loses functionality as indicated by a decrease in photosynthetic performance, an inhibition of plant growth and an increase of the necrosis incidence in leaves. On the other hand, ammonium additions at control temperatures showed only a minor effect on seagrass performance. However, the combined effects of warming and ammonium were much worse than those of each stressor in isolation, given that photosynthetic parameters and, above all, leaf growth were affected. This serves as a warning that the impact of global warming could be even worse than expected (based on temperature-only approaches) in environments that are already subject to eutrophication, especially in persistent seagrass species living in oligotrophic environments.
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Affiliation(s)
- Yaiza Ontoria
- Department of Evolutionary Biology, Ecology and Environmental Sciences, University of Barcelona, Barcelona, Spain
| | - Ainhoa Cuesta-Gracia
- Department of Evolutionary Biology, Ecology and Environmental Sciences, University of Barcelona, Barcelona, Spain
| | - Juan M. Ruiz
- Seagrass Ecology Group, Oceanographic Centre of Murcia, Spanish Institute of Oceanography, San Pedro del Pinatar, Murcia, Spain
| | - Javier Romero
- Department of Evolutionary Biology, Ecology and Environmental Sciences, University of Barcelona, Barcelona, Spain
| | - Marta Pérez
- Department of Evolutionary Biology, Ecology and Environmental Sciences, University of Barcelona, Barcelona, Spain
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Chakravarti LJ, Negri AP, van Oppen MJH. Thermal and Herbicide Tolerances of Chromerid Algae and Their Ability to Form a Symbiosis With Corals. Front Microbiol 2019; 10:173. [PMID: 30809207 PMCID: PMC6379472 DOI: 10.3389/fmicb.2019.00173] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 01/22/2019] [Indexed: 11/13/2022] Open
Abstract
Reef-building corals form an obligate symbiosis with photosynthetic microalgae in the family Symbiodiniaceae that meet most of their energy requirements. This symbiosis is under threat from the unprecedented rate of ocean warming as well as the simultaneous pressure of local stressors such as poor water quality. Only 1°C above mean summer sea surface temperatures (SSTs) on the Great Barrier Reef (GBR) can trigger the loss of Symbiodiniaceae from the host, and very low concentrations of the most common herbicide, diuron, can disrupt the photosynthetic activity of microalgae. In an era of rapid environmental change, investigation into the assisted evolution of the coral holobiont is underway in an effort to enhance the resilience of corals. Apicomplexan-like microalgae were discovered in 2008 and the Phylum Chromerida (chromerids) was created. Chromerids have been isolated from corals and contain a functional photosynthetic plastid. Their discovery therefore opens a new avenue of research into the use of alternative/additional photosymbionts of corals. However, only two studies to-date have investigated the symbiotic nature of Chromera velia with corals and thus little is known about the coral-chromerid relationship. Furthermore, the response of chromerids to environmental stressors has not been examined. Here we tested the performance of four chromerid strains and the common dinoflagellate symbiont Cladocopium goreaui (formerly Symbiodinium goreaui, ITS2 type C1) in response to elevated temperature, diuron and their combined exposure. Three of the four chromerid strains exhibited high thermal tolerances and two strains showed exceptional herbicide tolerances, greater than observed for any photosynthetic microalgae, including C. goreaui. We also investigated the onset of symbiosis between the chromerids and larvae of two common GBR coral species under ambient and stress conditions. Levels of colonization of coral larvae with the chromerid strains were low compared to colonization with C. goreaui. We did not observe any overall negative or positive larval fitness effects of the inoculation with chromerid algae vs. C. goreaui. However, we cannot exclude the possibility that chromerid algae may have more important roles in later coral life stages and recommend this be the focus of future studies.
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Affiliation(s)
- Leela J. Chakravarti
- Australian Institute of Marine Science, Townsville MC, QLD, Australia
- AIMS@JCU, Australian Institute of Marine Science, College of Marine and Environmental Sciences, James Cook University, Townsville, QLD, Australia
- College of Marine and Environmental Sciences, James Cook University, Townsville, QLD, Australia
| | - Andrew P. Negri
- Australian Institute of Marine Science, Townsville MC, QLD, Australia
| | - Madeleine J. H. van Oppen
- Australian Institute of Marine Science, Townsville MC, QLD, Australia
- School of BioSciences University of Melbourne, Parkville, VIC, Australia
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De Valck J, Rolfe J. Linking water quality impacts and benefits of ecosystem services in the Great Barrier Reef. MARINE POLLUTION BULLETIN 2018; 130:55-66. [PMID: 29866569 DOI: 10.1016/j.marpolbul.2018.03.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 03/09/2018] [Accepted: 03/10/2018] [Indexed: 06/08/2023]
Abstract
Water quality degradation in the Great Barrier Reef, associated with increased loads of nutrients, sediments and pesticides from agriculture, has become a major concern. Improved management practices and water quality targets were set in the Reef Plan 2013, but with limited success. The causality between water quality degradation, ecosystem health and benefits to society remains poorly understood, questioning the relevance of current water quality targets. We argue that ecosystem service valuation may help identify the benefits generated by ecosystems and help prioritise further investments in water quality improvement. We estimate the loss of benefits to society resulting from water quality reduction, concentrating on the influence of pollutants on mangroves, seagrass and coral reefs. Our results suggest that failing to meet Government's water quality targets by 1% would result in losses between AU$22 k/year and AU$6.9 M/year depending on the industry. We then discuss the implications stemming from these results for local policy-making.
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Affiliation(s)
- Jeremy De Valck
- Central Queensland University, School of Business and Law, Rockhampton, Queensland, Australia.
| | - John Rolfe
- Central Queensland University, School of Business and Law, Rockhampton, Queensland, Australia
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Campbell ML, Heppenstall LD, Hendry R, Martin R, Sørensen S, Rubenstein AN, Hewitt CL. Niche partitioning of intertidal seagrasses: evidence of the influence of substrate temperature. THE NEW PHYTOLOGIST 2018; 217:1449-1462. [PMID: 29238982 DOI: 10.1111/nph.14944] [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: 08/15/2017] [Accepted: 11/09/2017] [Indexed: 06/07/2023]
Abstract
The influence of soil temperature on rhizome depths of four intertidal seagrass species was investigated in central Queensland, Australia. We postulated that certain intertidal seagrass species are soil temperature-sensitive and vertically stratify rhizome depths. Below-ground vertical stratification of intertidal seagrass rhizome depths was analysed based upon microclimate (soil temperature) and microhabitat (soil type). Soil temperature profiles exhibited heat transfer from surface layers to depth that varied by microhabitat, with vertical stratification of rhizome depths between species. Halodule uninervis rhizomes maintain a narrow median soil temperature envelope; compensating for high surface temperatures by occupying deeper, cooler soil substrates. Halophila decipiens, Halophila ovalis and Zostera muelleri rhizomes are shallow-rooted and exposed to fluctuating temperatures, with broader median temperature envelopes. Halodule uninervis appears to be a niche specialist, with the two Halophila species considered as generalist niche usage species. The implications of niche use based upon soil temperature profiles and rhizome rooting depths are discussed in the context of species' thermal tolerances and below-ground biomass O2 demand associated with respiration and maintenance of oxic microshields. This preliminary evidence suggests that soil temperature interaction with rhizome rooting depths may be a factor that influences the distribution of intertidal seagrasses.
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Affiliation(s)
- Marnie L Campbell
- The Environmental Research Institute, University of Waikato, Private Bag 3105, Hamilton, 3240, New Zealand
- School of Medical and Applied Science, Central Queensland University, Bryan Jordan Drive, Gladstone, Qld, 4680, Australia
| | - Lara D Heppenstall
- The Environmental Research Institute, University of Waikato, Private Bag 3105, Hamilton, 3240, New Zealand
| | - Rebecca Hendry
- School of Medical and Applied Science, Central Queensland University, Bryan Jordan Drive, Gladstone, Qld, 4680, Australia
| | - Ross Martin
- The Environmental Research Institute, University of Waikato, Private Bag 3105, Hamilton, 3240, New Zealand
- School of Science, University of Waikato, Private Bag 3105, Hamilton, 3240, New Zealand
| | - Stine Sørensen
- The Environmental Research Institute, University of Waikato, Private Bag 3105, Hamilton, 3240, New Zealand
- School of Science, University of Waikato, Private Bag 3105, Hamilton, 3240, New Zealand
| | - Ashley N Rubenstein
- The Environmental Research Institute, University of Waikato, Private Bag 3105, Hamilton, 3240, New Zealand
- School of Science, University of Waikato, Private Bag 3105, Hamilton, 3240, New Zealand
| | - Chad L Hewitt
- The Environmental Research Institute, University of Waikato, Private Bag 3105, Hamilton, 3240, New Zealand
- School of Science, University of Waikato, Private Bag 3105, Hamilton, 3240, New Zealand
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15
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Collier CJ, Ow YX, Langlois L, Uthicke S, Johansson CL, O'Brien KR, Hrebien V, Adams MP. Optimum Temperatures for Net Primary Productivity of Three Tropical Seagrass Species. FRONTIERS IN PLANT SCIENCE 2017; 8:1446. [PMID: 28878790 PMCID: PMC5572403 DOI: 10.3389/fpls.2017.01446] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Accepted: 08/03/2017] [Indexed: 05/21/2023]
Abstract
Rising sea water temperature will play a significant role in responses of the world's seagrass meadows to climate change. In this study, we investigated seasonal and latitudinal variation (spanning more than 1,500 km) in seagrass productivity, and the optimum temperatures at which maximum photosynthesis and net productivity (for the leaf and the whole plant) occurs, for three seagrass species (Cymodocea serrulata, Halodule uninervis, and Zostera muelleri). To obtain whole plant net production, photosynthesis, and respiration rates of leaves and the root/rhizome complex were measured using oxygen-sensitive optodes in closed incubation chambers at temperatures ranging from 15 to 43°C. The temperature-dependence of photosynthesis and respiration was fitted to empirical models to obtain maximum metabolic rates and thermal optima. The thermal optimum (Topt) for gross photosynthesis of Z. muelleri, which is more commonly distributed in sub-tropical to temperate regions, was 31°C. The Topt for photosynthesis of the tropical species, H. uninervis and C. serrulata, was considerably higher (35°C on average). This suggests that seagrass species are adapted to water temperature within their distributional range; however, when comparing among latitudes and seasons, thermal optima within a species showed limited acclimation to ambient water temperature (Topt varied by 1°C in C. serrulata and 2°C in H. uninervis, and the variation did not follow changes in ambient water temperature). The Topt for gross photosynthesis were higher than Topt calculated from plant net productivity, which includes above- and below-ground respiration for Z. muelleri (24°C) and H. uninervis (33°C), but remained unchanged at 35°C in C. serrulata. Both estimated plant net productivity and Topt are sensitive to the proportion of below-ground biomass, highlighting the need for consideration of below- to above-ground biomass ratios when applying thermal optima to other meadows. The thermal optimum for plant net productivity was lower than ambient summer water temperature in Z. muelleri, indicating likely contemporary heat stress. In contrast, thermal optima of H. uninervis and C. serrulata exceeded ambient water temperature. This study found limited capacity to acclimate: thus the thermal optima can forewarn of both the present and future vulnerability to ocean warming during periods of elevated water temperature.
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Affiliation(s)
- Catherine J. Collier
- Centre for Tropical Water and Aquatic Ecosystem Research, James Cook University CairnsCairns, QLD, Australia
- *Correspondence: Catherine J. Collier
| | - Yan X. Ow
- Centre for Tropical Water and Aquatic Ecosystem Research, James Cook University CairnsCairns, QLD, Australia
- College of Marine and Environmental Sciences, James Cook University TownsvilleTownsville, QLD, Australia
- Australian Institute of Marine ScienceTownsville, QLD, Australia
| | - Lucas Langlois
- Centre for Tropical Water and Aquatic Ecosystem Research, James Cook University CairnsCairns, QLD, Australia
| | - Sven Uthicke
- Australian Institute of Marine ScienceTownsville, QLD, Australia
| | | | - Katherine R. O'Brien
- School of Chemical Engineering, The University of QueenslandBrisbane, QLD, Australia
| | - Victoria Hrebien
- College of Marine and Environmental Sciences, James Cook University TownsvilleTownsville, QLD, Australia
| | - Matthew P. Adams
- School of Chemical Engineering, The University of QueenslandBrisbane, QLD, Australia
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