Temporal Trends in Abundance and Habitat Preferences of Deep Reef Fishes Off The Coast of South Carolina, USA
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Authors
Yeckley, Sean Paul
Issue Date
2017-04
Type
Thesis
Language
en_US
Keywords
Fishery Policy Regulations , Biological Oceanography , Physical Oceanography , Population Density , Bottom Habitat Preferences , Trophic System , Predator/Prey Dynamics , Deep Reef Ecology
Alternative Title
Abstract
ROV and submersible video footage recorded in 1985, 2002, and 2010 from hard bottom habitat known as the Georgetown Hole or Charleston Lumps located NE of Charleston, SC in depths ranging from 175 – 300 m were reviewed to assess temporal trends in demersal fish abundance and bottom habitat preferences for key species. The main purpose of this long-term assessment of deep reef fish abundance and bottom habitat associations was to determine if deep reef fish populations have recovered since the development and implementation of the snapper/grouper fishery management plan (1983) and its various amendments. The major finding of the study was that Snowy Grouper and Blueline Tilefish were found in higher densities above low relief hard bottom areas than over high relief hard bottom. Snowy Grouper were observed to inhabit low relief hard bottom regions in significantly higher densities (18 fish/1000 m3) than over high relief hard bottom regions (3 fish/1000 m3) (P = .0001). Blueline Tilefish were found in the highest densities within low relief areas (5 fish/1000 m3) and mixed hard/soft bottom regions (6 fish/1000m3). The density of Snowy Grouper Hyporthodus niveatus increased from 2 fish per 1000 m3 in 1985 to 7 fish per 1000 m3 in 2010 and Blueline Tilefish Caulolatilus microps density increased from 0 fish in 1985 to 3 fish per 1000 m3 in 2010 so both populations are gradually rising. The density of Yellowfin Bass Anthias nicholsi decreased from 144 fish per 1000 m3 in 1985 to 56 fish per 1000 m3 in 2010. Yellowfin Bass preferred high relief habitat where they were found in the highest densities. Yellowfin Bass density decreased over low relief hard bottom from 199 fish per 1000 m3 in 1985 to only 15 fish per 1000 m3 in 2010. Abundance of Snowy Grouper and Blueline Tilefish have both increased from 1985 to 2010 predominantly within low relief bottom regions where they have significantly lowered prey populations of Yellowfin Bass and restored a balanced deep reef ecosystem.