Belcher, C. N. and C. A. Jennings. 2010. Utility of Mesohabitat Features for Determining Habitat Associations of Sub-adult Sharks in Georgia’s Estuaries. Environmental Biology of Fishes 88:349-359.
We examined the effects of selected water quality variables on the presence of sub-adult sharks in six of nine Georgia estuaries. During 231 longline sets, we captured 415 individuals representing nine species. Atlantic sharpnose shark (Rhizoprionodon terranovae), bonnethead shark (Sphyrna tiburo), blacktip shark (Carcharhinus limbatus) and sandbar shark (C. plumbeus) comprised 96.1% of the catch. Canonical Correlation Analysis (CCA) was used to assess environmental influences on the assemblage of the four common species, and indicated bonnethead sharks and sandbar sharks were correlated with each other and with a subset of environmental variables. Discriminant Analyses (DA) were used to assess environmental influences on individual species, and also indicated correlations between selected species and a subset of environmental variables. Although significant relationships existed at each level of analysis, dissolved oxygen, salinity, turbidity, and depth accounted < 16% of the total variation in each. Macrohabitat, prey availability, and susceptibility to predation may have stronger influences on the presence and distribution of sub-adult shark species among sites.