Title: FISH ASSEMBLAGES ASSOCIATED WITH RED GROUPER PITS AT PULLEY RIDGE, THE DEEPEST PHOTOSYNTHETIC CORAL REEF IN THE CONTINENTAL U.S.

Abstract: Pulley Ridge is a series of drowned barrier islands on the southwest Florida Shelf and is known to be the deepest photosynthetic coral reef in the continental U.S. The fishes at Pulley Ridge are unique in that they comprise a mixture of shallow water and deep species. With the majority of the ridge being low rugosity habitat comprised of algae and plate corals, fish densities are low compared to other mesophotic reefs. The exceptions to this are the pits which red grouper excavate throughout the area. These pits form high rugosity rock habitat which act as small biodiversity hotspots. ROV dives were conducted annually at Pulley Ridge from 2012 to 2015 to characterize grouper pits, examine their importance to the ecosystem, and determine the impact of lionfish invasion on their species composition. Approximately 66% of red grouper and 71% of lionfish observed were associated with a pit. Juveniles and small fish species were also associated with the excavations, particularly those that contained red grouper and/or lionfish compared to pits with neither species present. Lionfish and red grouper abundances both increased between 2012 and 2014 and then decreased in 2015 while abundance of juveniles and small fish displayed the exact opposite trend. PRIMER analyses also indicate that fish species assemblages were distinct among pits depending on red grouper and/or lionfish presence. Future analyses will compare fish assemblages from the current data with those conducted in 2008 & 2009, before the lionfish invasion, to examine the impact this species has on the ecosystem.

Authors: Harter SL, Moe HL, David AW

Presentation: Poster (#188)

Session: 15

Date: 06/21/16

Time: 18:15 - 19:45

Location: Poster/Exhibit Hall

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