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Tebbett SB, Schlaefer JA, Bowden CL, Collins WP, Hemingson CR, Ling SD, Morais J, Morais RA, Siqueira AC, Streit RP, Swan S, Bellwood DR. Bio-physical determinants of sediment accumulation on an offshore coral reef: A snapshot study. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 895:165188. [PMID: 37385494 DOI: 10.1016/j.scitotenv.2023.165188] [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: 04/18/2023] [Revised: 06/15/2023] [Accepted: 06/26/2023] [Indexed: 07/01/2023]
Abstract
Sediments are found on all coral reefs around the globe. However, the amount of sediment in different reservoirs, and the rates at which sediments move between reservoirs, can shape the biological functioning of coral reefs. Unfortunately, relatively few studies have examined reef sediment dynamics, and associated bio-physical drivers, simultaneously over matching spatial and temporal scales. This has led to a partial understanding of how sediments and living reef systems are connected, especially on clear-water offshore reefs. To address this problem, four sediment reservoirs/sedimentary processes and three bio-physical drivers were quantified across seven different reef habitats/depths at Lizard Island, an exposed mid-shelf reef on the Great Barrier Reef. Even in this clear-water reef location a substantial load of suspended sediment passed over the reef; a load theoretically capable of replacing the entire standing stock of on-reef turf sediments in just 8 h. However, quantification of actual sediment deposition suggested that just 2 % of this passing sediment settled on the reef. The data also revealed marked spatial incongruence in sediment deposition (sediment trap data) and accumulation (TurfPod data) across the reef profile, with the flat and back reef emerging as key areas of both deposition and accumulation. By contrast, the shallow windward reef crest was an area of deposition but had a limited capacity for sediment accumulation. These cross-reef patterns related to wave energy and reef geomorphology, with low sediment accumulation on the ecologically important reef crest aligning with substantial wave energy. These findings reveal a disconnect between patterns of sediment deposition and accumulation on the benthos, with the 'post-settlement' fate of sediments dependent on local hydrodynamic conditions. From an ecological perspective, the data suggests key contextual constraints (wave energy and reef geomorphology) may predispose some reefs or reef areas to high-load turf sediment regimes.
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Affiliation(s)
- Sterling B Tebbett
- Research Hub for Coral Reef Ecosystem Functions, College of Science and Engineering, James Cook University, Townsville, Queensland 4811, Australia.
| | - Jodie A Schlaefer
- Research Hub for Coral Reef Ecosystem Functions, College of Science and Engineering, James Cook University, Townsville, Queensland 4811, Australia; Commonwealth Scientific and Industrial Research Organisation (CSIRO), Environment, Townsville, Queensland, 4811, Australia
| | - Casey L Bowden
- Research Hub for Coral Reef Ecosystem Functions, College of Science and Engineering, James Cook University, Townsville, Queensland 4811, Australia
| | - William P Collins
- Research Hub for Coral Reef Ecosystem Functions, College of Science and Engineering, James Cook University, Townsville, Queensland 4811, Australia
| | - Christopher R Hemingson
- Research Hub for Coral Reef Ecosystem Functions, College of Science and Engineering, James Cook University, Townsville, Queensland 4811, Australia; Department of Marine Science, The University of Texas at Austin, Marine Science Institute, Port Aransas, TX, USA
| | - Scott D Ling
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart 7001, Australia
| | - Juliano Morais
- Research Hub for Coral Reef Ecosystem Functions, College of Science and Engineering, James Cook University, Townsville, Queensland 4811, Australia
| | - Renato A Morais
- Research Hub for Coral Reef Ecosystem Functions, College of Science and Engineering, James Cook University, Townsville, Queensland 4811, Australia; Paris Sciences et Lettres Université, École Pratique des Hautes Études, EPHE-UPVD-CNRS, USR 3278 CRIOBE, University of Perpignan, Perpignan, France
| | - Alexandre C Siqueira
- Research Hub for Coral Reef Ecosystem Functions, College of Science and Engineering, James Cook University, Townsville, Queensland 4811, Australia
| | - Robert P Streit
- Research Hub for Coral Reef Ecosystem Functions, College of Science and Engineering, James Cook University, Townsville, Queensland 4811, Australia
| | - Sam Swan
- Research Hub for Coral Reef Ecosystem Functions, College of Science and Engineering, James Cook University, Townsville, Queensland 4811, Australia
| | - David R Bellwood
- Research Hub for Coral Reef Ecosystem Functions, College of Science and Engineering, James Cook University, Townsville, Queensland 4811, Australia
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2
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Zhao L, Harvey BP, Higuchi T, Agostini S, Tanaka K, Murakami-Sugihara N, Morgan H, Baker P, Hall-Spencer JM, Shirai K. Ocean acidification stunts molluscan growth at CO 2 seeps. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 873:162293. [PMID: 36813205 DOI: 10.1016/j.scitotenv.2023.162293] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 02/07/2023] [Accepted: 02/13/2023] [Indexed: 06/18/2023]
Abstract
Ocean acidification can severely affect bivalve molluscs, especially their shell calcification. Assessing the fate of this vulnerable group in a rapidly acidifying ocean is therefore a pressing challenge. Volcanic CO2 seeps are natural analogues of future ocean conditions that offer unique insights into the scope of marine bivalves to cope with acidification. Here, we used a 2-month reciprocal transplantation of the coastal mussel Septifer bilocularis collected from reference and elevated pCO2 habitats to explore how they calcify and grow at CO2 seeps on the Pacific coast of Japan. We found significant decreases in condition index (an indication of tissue energy reserves) and shell growth of mussels living under elevated pCO2 conditions. These negative responses in their physiological performance under acidified conditions were closely associated with changes in their food sources (shown by changes to the soft tissue δ13C and δ15N ratios) and changes in their calcifying fluid carbonate chemistry (based on shell carbonate isotopic and elemental signatures). The reduced shell growth rate during the transplantation experiment was further supported by shell δ13C records along their incremental growth layers, as well as their smaller shell size despite being of comparable ontogenetic ages (5-7 years old, based on shell δ18O records). Taken together, these findings demonstrate how ocean acidification at CO2 seeps affects mussel growth and reveal that lowered shell growth helps them survive stressful conditions.
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Affiliation(s)
- Liqiang Zhao
- College of Fisheries, Guangdong Ocean University, Zhanjiang 524088, China; Atmosphere and Ocean Research Institute, The University of Tokyo, Chiba 277-8564, Japan.
| | - Ben P Harvey
- Shimoda Marine Research Center, University of Tsukuba, Shimoda 415-0025, Japan.
| | - Tomihiko Higuchi
- Atmosphere and Ocean Research Institute, The University of Tokyo, Chiba 277-8564, Japan
| | - Sylvain Agostini
- Shimoda Marine Research Center, University of Tsukuba, Shimoda 415-0025, Japan
| | - Kentaro Tanaka
- Atmosphere and Ocean Research Institute, The University of Tokyo, Chiba 277-8564, Japan
| | | | - Holly Morgan
- School of Biological and Marine Sciences, University of Plymouth, Plymouth PL4 8AA, UK
| | - Phoebe Baker
- School of Biological and Marine Sciences, University of Plymouth, Plymouth PL4 8AA, UK
| | - Jason M Hall-Spencer
- Shimoda Marine Research Center, University of Tsukuba, Shimoda 415-0025, Japan; School of Biological and Marine Sciences, University of Plymouth, Plymouth PL4 8AA, UK
| | - Kotaro Shirai
- Atmosphere and Ocean Research Institute, The University of Tokyo, Chiba 277-8564, Japan
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3
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Hudson CJ, Agostini S, Wada S, Hall-Spencer JM, Connell SD, Harvey BP. Ocean acidification increases the impact of typhoons on algal communities. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 865:161269. [PMID: 36587658 DOI: 10.1016/j.scitotenv.2022.161269] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 12/23/2022] [Accepted: 12/25/2022] [Indexed: 06/17/2023]
Abstract
Long-term environmental change, sudden pulses of extreme perturbation, or a combination of both can trigger regime shifts by changing the processes and feedbacks which determine community assembly, structure, and function, altering the state of ecosystems. Our understanding of the mechanisms that stabilise against regime shifts or lock communities into altered states is limited, yet also critical to anticipating future states, preventing regime shifts, and reversing unwanted state change. Ocean acidification contributes to the restructuring and simplification of algal systems, however the mechanisms through which this occurs and whether additional drivers are involved requires further study. Using monthly surveys over three years at a shallow-water volcanic seep we examined how the composition of algal communities change seasonally and following periods of significant physical disturbance by typhoons at three levels of ocean acidification (equivalent to means of contemporary ∼350 and future ∼500 and 900 μatm pCO2). Sites exposed to acidification were increasingly monopolised by structurally simple, fast-growing turf algae, and were clearly different to structurally complex macrophyte-dominated reference sites. The distinct contemporary and acidified community states were stabilised and maintained at their respective sites by different mechanisms following seasonal typhoon disturbance. Macroalgal-dominated sites were resistant to typhoon damage. In contrast, significant losses of algal biomass represented a near total ecosystem reset by typhoons for the turf-dominated communities at the elevated pCO2 sites (i.e. negligible resistance). A combination of disturbance and subsequent turf recovery maintained the same simplified state between years (elevated CO2 levels promote turf growth following algal removal, inhibiting macroalgal recruitment). Thus, ocean acidification may promote shifts in algal systems towards degraded ecosystem states, and short-term disturbances which reset successional trajectories may 'lock-in' these alternative states of low structural and functional diversity.
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Affiliation(s)
- Callum J Hudson
- Marine Biology and Ecology Research Centre, University of Plymouth, Plymouth PL4 8AA, UK; Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Okinawa 904-0495, Japan
| | - Sylvain Agostini
- Shimoda Marine Research Center, University of Tsukuba, 5-10-1 Shimoda, Shizuoka 415-0025, Japan
| | - Shigeki Wada
- Shimoda Marine Research Center, University of Tsukuba, 5-10-1 Shimoda, Shizuoka 415-0025, Japan
| | - Jason M Hall-Spencer
- Marine Biology and Ecology Research Centre, University of Plymouth, Plymouth PL4 8AA, UK; Shimoda Marine Research Center, University of Tsukuba, 5-10-1 Shimoda, Shizuoka 415-0025, Japan
| | - Sean D Connell
- Southern Seas Ecology Laboratories, School of Biological Sciences, The University of Adelaide, Adelaide, 5005, SA, Australia
| | - Ben P Harvey
- Shimoda Marine Research Center, University of Tsukuba, 5-10-1 Shimoda, Shizuoka 415-0025, Japan.
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4
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Seto M, Harvey BP, Wada S, Agostini S. Potential ecosystem regime shift resulting from elevated CO2 and inhibition of macroalgal recruitment by turf algae. THEOR ECOL-NETH 2023. [DOI: 10.1007/s12080-022-00550-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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5
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Schlaefer JA, Tebbett SB, Bowden CL, Collins WP, Duce S, Hemingson CR, Huertas V, Mihalitsis M, Morais J, Morais RA, Siqueira AC, Streit RP, Swan S, Valenzuela J, Bellwood DR. A snapshot of sediment dynamics on an inshore coral reef. MARINE ENVIRONMENTAL RESEARCH 2022; 181:105763. [PMID: 36206642 DOI: 10.1016/j.marenvres.2022.105763] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 09/25/2022] [Accepted: 09/26/2022] [Indexed: 06/16/2023]
Abstract
Sediments are ubiquitous on coral reefs. However, studies of reef sediments have largely focused on isolated reservoirs, or processes, and rarely consider hydrodynamic drivers. We therefore provide a quantitative snapshot of sediment dynamics on a coral reef. Across a depth profile, we simultaneously examined: suspended sediments, sediment deposition and accumulation, and hydrodynamic and biological movement processes. We reveal the marked potential for the water column to deliver sediments. Currents carried 12.6 t of sediment over the 2,314 m2 study area in 6 days. Sediment traps suggested that a surprisingly high percentage of this sediment was potentially deposited (5.2%). Furthermore, wave-driven resuspension and reworking by parrotfishes separated a highly dynamic sediment regime on the shallow reef flat (3 m), from a more stagnant reef slope (4.5 m-12 m). This study provides a comprehensive model of how hydrodynamic forces and on-reef processes may shape sediment dynamics on a coral reef.
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Affiliation(s)
- Jodie A Schlaefer
- Research Hub for Coral Reef Ecosystem Functions, James Cook University, Townsville, QLD, 4811, Australia; ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, 4811, Australia; College of Science and Engineering, James Cook University, Townsville, QLD, 4811, Australia; Commonwealth Scientific and Industrial Research Organisation (CSIRO), Oceans and Atmosphere, Hobart, Tasmania, 7000, Australia
| | - Sterling B Tebbett
- Research Hub for Coral Reef Ecosystem Functions, James Cook University, Townsville, QLD, 4811, Australia; ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, 4811, Australia; College of Science and Engineering, James Cook University, Townsville, QLD, 4811, Australia
| | - Casey L Bowden
- Research Hub for Coral Reef Ecosystem Functions, James Cook University, Townsville, QLD, 4811, Australia; ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, 4811, Australia; College of Science and Engineering, James Cook University, Townsville, QLD, 4811, Australia
| | - William P Collins
- Research Hub for Coral Reef Ecosystem Functions, James Cook University, Townsville, QLD, 4811, Australia; ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, 4811, Australia; College of Science and Engineering, James Cook University, Townsville, QLD, 4811, Australia
| | - Stephanie Duce
- College of Science and Engineering, James Cook University, Townsville, QLD, 4811, Australia
| | - Christopher R Hemingson
- Research Hub for Coral Reef Ecosystem Functions, James Cook University, Townsville, QLD, 4811, Australia; ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, 4811, Australia; College of Science and Engineering, James Cook University, Townsville, QLD, 4811, Australia
| | - Victor Huertas
- Research Hub for Coral Reef Ecosystem Functions, James Cook University, Townsville, QLD, 4811, Australia; ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, 4811, Australia; College of Science and Engineering, James Cook University, Townsville, QLD, 4811, Australia
| | - Michalis Mihalitsis
- Research Hub for Coral Reef Ecosystem Functions, James Cook University, Townsville, QLD, 4811, Australia; ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, 4811, Australia; College of Science and Engineering, James Cook University, Townsville, QLD, 4811, Australia
| | - Juliano Morais
- Research Hub for Coral Reef Ecosystem Functions, James Cook University, Townsville, QLD, 4811, Australia; ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, 4811, Australia; College of Science and Engineering, James Cook University, Townsville, QLD, 4811, Australia
| | - Renato A Morais
- Research Hub for Coral Reef Ecosystem Functions, James Cook University, Townsville, QLD, 4811, Australia; ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, 4811, Australia; College of Science and Engineering, James Cook University, Townsville, QLD, 4811, Australia
| | - Alexandre C Siqueira
- Research Hub for Coral Reef Ecosystem Functions, James Cook University, Townsville, QLD, 4811, Australia; ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, 4811, Australia; College of Science and Engineering, James Cook University, Townsville, QLD, 4811, Australia
| | - Robert P Streit
- Research Hub for Coral Reef Ecosystem Functions, James Cook University, Townsville, QLD, 4811, Australia; ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, 4811, Australia; College of Science and Engineering, James Cook University, Townsville, QLD, 4811, Australia
| | - Sam Swan
- Research Hub for Coral Reef Ecosystem Functions, James Cook University, Townsville, QLD, 4811, Australia; ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, 4811, Australia; College of Science and Engineering, James Cook University, Townsville, QLD, 4811, Australia
| | - Jessica Valenzuela
- Research Hub for Coral Reef Ecosystem Functions, James Cook University, Townsville, QLD, 4811, Australia; ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, 4811, Australia; College of Science and Engineering, James Cook University, Townsville, QLD, 4811, Australia
| | - David R Bellwood
- Research Hub for Coral Reef Ecosystem Functions, James Cook University, Townsville, QLD, 4811, Australia; ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, 4811, Australia; College of Science and Engineering, James Cook University, Townsville, QLD, 4811, Australia.
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6
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Hall-Spencer JM, Belfiore G, Tomatsuri M, Porzio L, Harvey BP, Agostini S, Kon K. Decreased Diversity and Abundance of Marine Invertebrates at CO2 Seeps in Warm-Temperate Japan. Zoolog Sci 2022; 39:41-51. [DOI: 10.2108/zs210061] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 11/19/2021] [Indexed: 01/06/2023]
Affiliation(s)
- Jason M. Hall-Spencer
- Shimoda Marine Research Center, University of Tsukuba, 5-10-1 Shimoda, Shizuoka 415-0025, Japan
| | - Giuseppe Belfiore
- Shimoda Marine Research Center, University of Tsukuba, 5-10-1 Shimoda, Shizuoka 415-0025, Japan
| | - Morihiko Tomatsuri
- Fujifilm Software Co., Ltd., 2-10-23 Shinyokohama, Kohoku, Yokohama, Kanagawa 222-0033, Japan
| | - Lucia Porzio
- Shimoda Marine Research Center, University of Tsukuba, 5-10-1 Shimoda, Shizuoka 415-0025, Japan
| | - Ben P. Harvey
- Shimoda Marine Research Center, University of Tsukuba, 5-10-1 Shimoda, Shizuoka 415-0025, Japan
| | - Sylvain Agostini
- Shimoda Marine Research Center, University of Tsukuba, 5-10-1 Shimoda, Shizuoka 415-0025, Japan
| | - Koetsu Kon
- Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato, Tokyo 108-8477, Japan
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Wu JY, Hua ZL, Gu L, Li XQ, Gao C, Liu YY. Perfluorinated compounds (PFCs) in regional industrial rivers: Interactions between pollution flux and eukaryotic community phylosymbiosis. ENVIRONMENTAL RESEARCH 2022; 203:111876. [PMID: 34400162 DOI: 10.1016/j.envres.2021.111876] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 07/21/2021] [Accepted: 08/09/2021] [Indexed: 06/13/2023]
Abstract
Perfluorinated compounds (PFCs) pose serious threats to aquatic ecosystems, especially their microbial communities. However, little is known about the phylosymbiosis of aquatic fungal and viridiplantae communities in response to PFC accumulation. We quantified the distribution of 14 PFCs in rivers and found that PFBA was dominant in the transition from water to sediment. High through-put sequencing revealed that phyla Ascomycota, Basidiomycota, Anthophyta, and Chlorophyta were the predominant in eukaryotic community. The effects of PFCs on spatial community coalescence at taxonomic and phylogenetic levels (p < 0.05) were revealed. Fungal community coalescence triggered the spatial assembly of fungal and viridiplantae communities in riverine environments (p < 0.05). Null modeling indicated that PFBA, PFTrDA and PFOS, etc, mediated phylogenetic assembly (p < 0.05) and stochastic processes (86.67-100%) maintain phylogenetic turnover in the fungal community. Meanwhile, variable selection (27.78-54.44%) explained the viridiplantae community assemblage. Finally, we identified fungal genera Hannaella, Naganishia, Purpureocillium and Stachybotrys as indicators for PFC pollution (p < 0.001). These results help explain the effects of PFCs on riverine ecological remediation.
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Affiliation(s)
- Jian-Yi Wu
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake of Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, China; Yangtze Institute for Conservation and Development, Hohai University, Jiangsu, 210098, China
| | - Zu-Lin Hua
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake of Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, China; Yangtze Institute for Conservation and Development, Hohai University, Jiangsu, 210098, China
| | - Li Gu
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake of Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, China; Yangtze Institute for Conservation and Development, Hohai University, Jiangsu, 210098, China.
| | - Xiao-Qing Li
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake of Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, China; Yangtze Institute for Conservation and Development, Hohai University, Jiangsu, 210098, China
| | - Chang Gao
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake of Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, China; Yangtze Institute for Conservation and Development, Hohai University, Jiangsu, 210098, China
| | - Yuan-Yuan Liu
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake of Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, China; Yangtze Institute for Conservation and Development, Hohai University, Jiangsu, 210098, China
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8
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Agostini S, Harvey BP, Milazzo M, Wada S, Kon K, Floc'h N, Komatsu K, Kuroyama M, Hall-Spencer JM. Simplification, not "tropicalization", of temperate marine ecosystems under ocean warming and acidification. GLOBAL CHANGE BIOLOGY 2021; 27:4771-4784. [PMID: 34268836 DOI: 10.1111/gcb.15749] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 05/28/2021] [Accepted: 06/06/2021] [Indexed: 06/13/2023]
Abstract
Ocean warming is altering the biogeographical distribution of marine organisms. In the tropics, rising sea surface temperatures are restructuring coral reef communities with sensitive species being lost. At the biogeographical divide between temperate and tropical communities, warming is causing macroalgal forest loss and the spread of tropical corals, fishes and other species, termed "tropicalization". A lack of field research into the combined effects of warming and ocean acidification means there is a gap in our ability to understand and plan for changes in coastal ecosystems. Here, we focus on the tropicalization trajectory of temperate marine ecosystems becoming coral-dominated systems. We conducted field surveys and in situ transplants at natural analogues for present and future conditions under (i) ocean warming and (ii) both ocean warming and acidification at a transition zone between kelp and coral-dominated ecosystems. We show that increased herbivory by warm-water fishes exacerbates kelp forest loss and that ocean acidification negates any benefits of warming for range extending tropical corals growth and physiology at temperate latitudes. Our data show that, as the combined effects of ocean acidification and warming ratchet up, marine coastal ecosystems lose kelp forests but do not gain scleractinian corals. Ocean acidification plus warming leads to overall habitat loss and a shift to simple turf-dominated ecosystems, rather than the complex coral-dominated tropicalized systems often seen with warming alone. Simplification of marine habitats by increased CO2 levels cascades through the ecosystem and could have severe consequences for the provision of goods and services.
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Affiliation(s)
- Sylvain Agostini
- Shimoda Marine Research Center, University of Tsukuba, Shimoda, Shizuoka, Japan
| | - Ben P Harvey
- Shimoda Marine Research Center, University of Tsukuba, Shimoda, Shizuoka, Japan
| | - Marco Milazzo
- Dipartimento di Scienze della Terra e del Mare, University of Palermo, Palermo, Italy
- Consorzio Nazionale Interuniversitario per le Scienze del Mare (CoNISMa, Rome, Italy
| | - Shigeki Wada
- Shimoda Marine Research Center, University of Tsukuba, Shimoda, Shizuoka, Japan
| | - Koetsu Kon
- Shimoda Marine Research Center, University of Tsukuba, Shimoda, Shizuoka, Japan
| | - Nicolas Floc'h
- Ecole Européenne Supérieure d'Art de Bretagne, Rennes, France
| | - Kosei Komatsu
- Atmosphere and Ocean Research Institute, University of Tokyo, Kashiwa, Japan
| | - Mayumi Kuroyama
- Atmosphere and Ocean Research Institute, University of Tokyo, Kashiwa, Japan
| | - Jason M Hall-Spencer
- Shimoda Marine Research Center, University of Tsukuba, Shimoda, Shizuoka, Japan
- Marine Biology and Ecology Research Centre, University of Plymouth, Plymouth, UK
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9
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Harvey BP, Allen R, Agostini S, Hoffmann LJ, Kon K, Summerfield TC, Wada S, Hall-Spencer JM. Feedback mechanisms stabilise degraded turf algal systems at a CO 2 seep site. Commun Biol 2021; 4:219. [PMID: 33594188 PMCID: PMC7901039 DOI: 10.1038/s42003-021-01712-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 01/08/2021] [Indexed: 01/04/2023] Open
Abstract
Human activities are rapidly changing the structure and function of coastal marine ecosystems. Large-scale replacement of kelp forests and coral reefs with turf algal mats is resulting in homogenous habitats that have less ecological and human value. Ocean acidification has strong potential to substantially favour turf algae growth, which led us to examine the mechanisms that stabilise turf algal states. Here we show that ocean acidification promotes turf algae over corals and macroalgae, mediating new habitat conditions that create stabilising feedback loops (altered physicochemical environment and microbial community, and an inhibition of recruitment) capable of locking turf systems in place. Such feedbacks help explain why degraded coastal habitats persist after being initially pushed past the tipping point by global and local anthropogenic stressors. An understanding of the mechanisms that stabilise degraded coastal habitats can be incorporated into adaptive management to better protect the contribution of coastal systems to human wellbeing. Ben Harvey et al. use the gradient provided by a natural CO2 seep off Shikine Island, Japan and lab microcosm experiments to determine how ocean acidification promotes turf algal habitat conditions that create stabilizing feedback loops and hysteresis capable of locking turf systems in place. These results further our understanding of feedback loops initiated by ocean acidification, and can assist in the management of coastal habitats.
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Affiliation(s)
- Ben P Harvey
- Shimoda Marine Research Center, University of Tsukuba, 5-10-1 Shimoda, Shizuoka, 415-0025, Japan.
| | - Ro Allen
- Department of Botany, University of Otago, Dunedin, New Zealand.,The Marine Biological Association, Plymouth, Devon, PL1 2PB, UK
| | - Sylvain Agostini
- Shimoda Marine Research Center, University of Tsukuba, 5-10-1 Shimoda, Shizuoka, 415-0025, Japan
| | - Linn J Hoffmann
- Department of Botany, University of Otago, Dunedin, New Zealand
| | - Koetsu Kon
- Shimoda Marine Research Center, University of Tsukuba, 5-10-1 Shimoda, Shizuoka, 415-0025, Japan
| | | | - Shigeki Wada
- Shimoda Marine Research Center, University of Tsukuba, 5-10-1 Shimoda, Shizuoka, 415-0025, Japan
| | - Jason M Hall-Spencer
- Shimoda Marine Research Center, University of Tsukuba, 5-10-1 Shimoda, Shizuoka, 415-0025, Japan.,School of Biological and Marine Sciences, University of Plymouth, Plymouth, PL4 8AA, UK
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