| dcterms.abstract | This thesis examines the diet of loggerhead sea turtles (Caretta caretta) in New York between 1995 – 2014 using stomach contents analysis. Loggerheads are one of four sea turtle species that occur in the temperate waters of New York during summer months. Estuaries of Long Island provide foraging habitat for juvenile loggerheads from June to November. In order to quantify loggerhead diet, I examined individual and inter-annual variation in the stomach contents of 123 individual turtles that stranded along Long Island. Prey items were identified to the lowest possible taxonomic level, and the minimum number of prey items was assessed for each sample. Principal Component Analysis (PCA), Redundancy Analysis (RDA), and Non-Metric Multidimensional Scaling (NMDS) were used to characterize variability in loggerhead diet. Results of these ordination analyses indicated a temporal shift in prey composition before and after 2000, from large prey species such as rock crab (Cancer irroratus) to smaller species such as hermit crabs (Pagurus spp.) and moonsnails (Naticidae). Redundancy analyses suggest that observed diet shifts were likely temperature-driven due to the importance of the Gulf Stream North Wall index. Similar temporal trends were observed in benthic communities in this region, suggesting that loggerhead diet can provide an indicator of the relative abundance of benthic organisms. Additionally, a spatial assessment of loggerhead sea turtle strandings suggested that juvenile loggerheads are predominantly foraging in Long Island Sound, Peconic Bay, and Gardiners Bays, while mature loggerheads appear to exclusively forage in offshore waters, indicating that Long Island estuaries provide important stage-specific foraging habitats for loggerhead sea turtles. | |
