Volume 46, Issue 11 p. 552-563
Feature

Optic–acoustic Analysis of Fish Assemblages at Petroleum Platforms

Derek G. Bolser

Corresponding Author

Derek G. Bolser

Marine Science Institute, The University of Texas at Austin, 750 Channel View Drive, Port Aransas, TX, 78373

Oregon State University, Cooperative Institute for Marine Resources Studies - Hatfield Marine Science Center, Newport, OR

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Jack. P. Egerton

Jack. P. Egerton

Marine Science Institute, The University of Texas at Austin, Port Aransas, TX

Echology Ltd, Menai Bridge, Anglesey, UK

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Arnaud Grüss

Arnaud Grüss

National Institute of Water and Atmospheric Research, Hataitai, Wellington, New Zealand

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Brad E. Erisman

Brad E. Erisman

Marine Science Institute, The University of Texas at Austin, Port Aransas, TX

National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Southwest Fisheries Science Center, La Jolla, CA

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First published: 15 July 2021
Citations: 7

Abstract

Petroleum platforms provide high-relief reef habitat in several ocean basins and are important to fishes and fishers alike. To determine which variables were important for shaping platform-associated fish assemblages on a basin-wide scale in the U.S. Gulf of Mexico, we employed optic and acoustic methods to measure fish distribution (geographic and water-column), abundance, biomass, density, size, diversity, and richness at 54 platforms. We found that variables related to freshwater inflow and meso-scale circulation patterns (e.g., salinity) affected more metrics than platform characteristics (e.g., platform depth). Platform fish assemblages varied gradually along gradients of these variables instead of exhibiting distinct assemblage groupings in non-metric multidimensional scaling space. These effects contributed to the presence of biomass, density, diversity, and richness “hotspots” at platforms offshore of the Atchafalaya River. Our findings underscore the importance of freshwater inflow and circulation patterns in explaining variation in reef fish assemblages in the U.S. Gulf of Mexico.