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Lesser MP, Slattery M. Will coral reef sponges be winners in the Anthropocene? GLOBAL CHANGE BIOLOGY 2020; 26:3202-3211. [PMID: 32052520 DOI: 10.1111/gcb.15039] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 12/10/2019] [Accepted: 02/10/2020] [Indexed: 05/21/2023]
Abstract
Recent observations have shown that increases in climate change-related coral mortality cause changes in shallow coral reef community structure through phase shifts to alternative taxa. As a result, sponges have emerged as a potential candidate taxon to become a "winner," and therefore a numerically and functionally dominant member of many coral reef communities. But, in order for this to occur, there must be sufficient trophic resources to support larger populations of these active filter-feeding organisms. Globally, climate change is causing an increase in sea surface temperatures (SSTs) and a decrease in salinity, which can lead to an intensification in the stratification of shallow nearshore waters (0-200 m), that affects both the mixed layer depth (MLD) and the strength and duration of internal waves. Specifically, climate change-driven increases in SSTs for tropical waters are predicted to cause increased stratification, and more stabilized surface waters. This causes a shallowing of the MLD which prevents nutrients from reaching the euphotic zone, and is predicted to decrease net primary production (NPP) up to 20% by the end of the century. Lower NPP would subsequently affect multiple trophic levels, including shallow benthic filter-feeding communities, as the coupling between water column productivity and the benthos weakens. We argue here that sponge populations may actually be constrained, rather than promoted, by climate change due to decreases in their primary trophic resources, caused by bottom-up forcing, secondary to physical changes in the water column (i.e., stratification and changes in the MLD resulting in lower nutrients and NPP). As a result, we predict sponge-dominated tropical reefs will be rare, or short-lived, if they occur at all into the future in the Anthropocene.
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Affiliation(s)
- Michael P Lesser
- Department of Molecular, Cellular and Biomedical Sciences, School of Marine Science and Ocean Engineering, University of New Hampshire, Durham, NH, USA
| | - Marc Slattery
- Department of BioMolecular Science, University of Mississippi, Oxford, MS, USA
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Lesser MP, Slattery M, Mobley CD. Biodiversity and Functional Ecology of Mesophotic Coral Reefs. ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS 2018. [DOI: 10.1146/annurev-ecolsys-110617-062423] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Mesophotic coral reefs, currently defined as deep reefs between 30 and 150 m, are linked physically and biologically to their shallow water counterparts, have the potential to be refuges for shallow coral reef taxa such as coral and sponges, and might be a source of larvae that could contribute to the resiliency of shallow water reefs. Mesophotic coral reefs are found worldwide, but most are undescribed and understudied. Here, we review our current knowledge of mesophotic coral reefs and their functional ecology as it relates to their geomorphology, changes in the abiotic environment along depth gradients, trophic ecology, their reproduction, and their connectivity to shallow depths. Understanding the ecology of mesophotic coral reefs, and the connectivity between them and their shallow water counterparts, is now a primary focus for many reef studies as the worldwide degradation of shallow coral reefs, and the ecosystem services they provide, continues unabated.
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Affiliation(s)
- Michael P. Lesser
- Department of Molecular, Cellular and Biomedical Sciences, and School of Marine Science and Ocean Engineering, University of New Hampshire, Durham, New Hampshire 03824, USA
| | - Marc Slattery
- Department of BioMolecular Science, University of Mississippi, Oxford, Mississippi 38677, USA
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Andradi-Brown DA, Grey R, Hendrix A, Hitchner D, Hunt CL, Gress E, Madej K, Parry RL, Régnier-McKellar C, Jones OP, Arteaga M, Izaguirre AP, Rogers AD, Exton DA. Depth-dependent effects of culling-do mesophotic lionfish populations undermine current management? ROYAL SOCIETY OPEN SCIENCE 2017; 4:170027. [PMID: 28573007 PMCID: PMC5451808 DOI: 10.1098/rsos.170027] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 04/27/2017] [Indexed: 05/15/2023]
Abstract
Invasive lionfish (Pterois volitans and P. miles) have spread widely across the western Atlantic and are recognized as a major threat to native marine biodiversity. Although lionfish inhabit both shallow reefs and mesophotic coral ecosystems (MCEs; reefs from 30 to 150 m depth), the primary management response implemented by many countries has been diver-led culling limited to reefs less than 30 m. However, many reef fish undergo ontogenetic migrations, with the largest and therefore most fecund individuals found at greatest depths. Here, we study lionfish density, body size, maturity and dietary patterns across the depth gradient from the surface down to 85 m on heavily culled reefs around Utila, Honduras. We found lionfish at increased densities, body size and weight on MCEs compared with shallow reefs, with MCEs also containing the greatest proportion of actively spawning females, while shallow reefs contained the greatest proportion of immature lionfish. We then compared lionfish behaviour in response to divers on shallow culled and mesophotic unculled Utilan reefs, and on shallow unculled reefs in Tela Bay, on the Honduran mainland. We found that mesophotic lionfish exhibited high alert distances, consistent with individuals previously exposed to culling despite being below the depth limits of removal. In addition, when examining stomach content, we found that fish were the major component of lionfish diets across the depth gradient. Importantly, our results suggest that despite adjacent shallow culling, MCEs retain substantial lionfish populations that may be disproportionately contributing towards continued lionfish recruitment onto the shallow reefs of Utila, potentially undermining current culling-based management.
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Affiliation(s)
- Dominic A. Andradi-Brown
- Department of Zoology, University of Oxford, The Tinbergen Building, South Parks Road, Oxford, OX1 3PS, UK
- Operation Wallacea, Wallace House, Old Bolingbroke, Spilsby, Lincolnshire PE23 4EX, UK
- Author for correspondence: Dominic A. Andradi-Brown e-mail:
| | - Rachel Grey
- Operation Wallacea, Wallace House, Old Bolingbroke, Spilsby, Lincolnshire PE23 4EX, UK
- College of Charleston, 205 Fort Johnson Road, Charleston, SC 29412, USA
| | - Alicia Hendrix
- Operation Wallacea, Wallace House, Old Bolingbroke, Spilsby, Lincolnshire PE23 4EX, UK
| | - Drew Hitchner
- Operation Wallacea, Wallace House, Old Bolingbroke, Spilsby, Lincolnshire PE23 4EX, UK
| | - Christina L. Hunt
- Department of Zoology, University of Oxford, The Tinbergen Building, South Parks Road, Oxford, OX1 3PS, UK
- Operation Wallacea, Wallace House, Old Bolingbroke, Spilsby, Lincolnshire PE23 4EX, UK
| | - Erika Gress
- Operation Wallacea, Wallace House, Old Bolingbroke, Spilsby, Lincolnshire PE23 4EX, UK
| | - Konrad Madej
- Whaleshark and Oceanic Research Center, Main Street, Utila, Bay Islands 34201, Honduras
| | - Rachel L. Parry
- Whaleshark and Oceanic Research Center, Main Street, Utila, Bay Islands 34201, Honduras
| | | | - Owen P. Jones
- Whaleshark and Oceanic Research Center, Main Street, Utila, Bay Islands 34201, Honduras
| | - María Arteaga
- Bay Islands Conservation Association—Utila Chapter, Airport Road, Utila, Bay Islands 34201, Honduras
| | - Andrea P. Izaguirre
- Bay Islands Conservation Association—Utila Chapter, Airport Road, Utila, Bay Islands 34201, Honduras
| | - Alex D. Rogers
- Department of Zoology, University of Oxford, The Tinbergen Building, South Parks Road, Oxford, OX1 3PS, UK
| | - Dan A. Exton
- Operation Wallacea, Wallace House, Old Bolingbroke, Spilsby, Lincolnshire PE23 4EX, UK
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