Title: EXPLORATION AND CHARACTERIZATION OF MESOPHOTIC REEFS OF THE FLOWER GARDEN BANKS NATIONAL MARINE SANCTUARY AND NEIGHBORING BANKS IN THE NORTHWEST GULF OF MEXICO

Abstract: The Flower Garden Banks National Marine Sanctuary (FGBNMS) and adjacent banks in the Northwest Gulf of Mexico (NWGOM) exhibit unique and extensive shelf-edge coral communities. Using remotely operated vehicle (ROV)-based high definition imaging, we conducted 299 stratified random quantitative 100 m phototransects to characterize mesophotic reef habitats and fish communities on East and West Bank within FGBNMS as well as McGrail, Bright, and Geyer Banks lying east of the sanctuary. Benthic community composition differed significantly among habitat types across vertical zones. While Scleractinian corals comprised 66-75% of benthic cover on coral caps of East and West Bank, these shallower habitats account for only ~1% of the total FGBNMS area. Mesophotic communities (46-104 m) in the FGBNMS and adjacent banks were dominated by Scleractinians (14 species), black corals (Antipathidae, Aphanipathidae), and gorgonians Plexauridae, Ellisellidae, Primnoidae). Extensive macroalgal overgrowth was observed at both McGrail and Bright Banks from Sargassum spp. and Codium sp. , respectively. Habitat partitioning among grouper and snapper families was distinct with few species occupying both shallow and mesophotic depths within FGBNMS. The results of this study and others indicate that mesophotic coral habitats in the NWGOM are more extensive and ecologically important than previously known, particularly with respect to supporting biologically diverse faunal assemblages and commercially important fish communities.

Authors: Voss JD, Studivan MS, Williams MA, Clark R, Horn L, Hickerson E, Nutall M, Reed JK, Schmahl GP

Presentation: Oral

Session: 29

Date: 06/22/16

Time: 15:30

Location: 308 A/B

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