Uniform TitleFish assemblages and habitat use across a shoreface sand ridge in southern New Jersey
NameVasslides, James (author), Able, Kenneth (chair), Grassle, Judith (internal member), Taghon, Gary (internal member), Grothues, Thomas (outside member), Rutgers University, Graduate School - New Brunswick,
SubjectEcology and Evolution,
DescriptionShoreface sand ridges are prominent components of the inner-continental shelf landscape which may serve as sources for sand material for ongoing beach replenishment projects. In order to determine if these ridges provide unique habitats for fish on the inner continental shelf an analysis of two historic trawl surveys on Beach Haven Ridge (1991-1995 beam trawl and 1997-2006 otter trawl) and a 2006 otter trawl survey from two other sand ridges in the immediate vicinity was conducted to determine if species abundance, richness, and assemblages differed on and away from the ridges. The abundance and food habits of three dominant sciaenid species from Beach Haven Ridge were also examined to ascertain if feeding was influenced by habitat.
Overall species abundance and richness displayed a bimodal distribution across the inlet to offshore transects, with the highest values on either side of the ridges regardless of gear type. Canonical Correspondence Analysis identified three species assemblages; inshore ([less than] 5 meters depth), near-ridge, and offshore ([greater than] 14 meters depth), with variation in the species composition between gear types. The beam trawl assemblages differed primarily in the presence or absence of species while the otter trawl assemblages were differentiated based on the relative abundance of shared species. Environmental factors that corresponded with the assemblage changes included depth, temperature, distance from the top of the ridge, and habitat complexity.
The abundance of the three sciaenid species investigated was highest in the habitats in the immediate vicinity of the sand ridge, with all three species absent from samples from the top of the ridge. The mean relative stomach fullness of each species was similar in each habitat, but the diets of all three species varied among the habitats.
In summary, this study documented higher fish abundances associated with sand ridges (but not on top of the ridge) and the presence of a distinct species assemblage when compared to the surrounding inner continental shelf. Furthermore, sand ridges appear to provide enhanced foraging opportunities for a variety of feeding modes. As such, sand ridges may be an important aspect of the inner continental shelf landscape and deserve special management considerations.
NoteIncludes bibliographical references (p. 85-92).
CollectionGraduate School - New Brunswick Electronic Theses and Dissertations
Organization NameRutgers, The State University of New Jersey
RightsThe author owns the copyright to this work.