| Autor: |
Hoopes LA; Department of Research and Conservation, Georgia Aquarium, Atlanta, GA, 30313, USA. lhoopes@georgiaaquarium.org., Clauss TM; Department of Animal Health, Georgia Aquarium, Atlanta, GA, 30313, USA., Browning NE; Department of Mathematics and Science, Brenau University, Gainesville, GA, 30501, USA., Delaune AJ; Department of Animal Health, Georgia Aquarium, Atlanta, GA, 30313, USA., Wetherbee BM; Department of Biological Sciences, University of Rhode Island, Kingston, Rhode Island, 02881, USA.; The Guy Harvey Research Institute, Halmos College of Natural Sciences and Oceanography, Nova Southeastern University, Dania Beach, Florida, USA., Shivji M; The Guy Harvey Research Institute, Halmos College of Natural Sciences and Oceanography, Nova Southeastern University, Dania Beach, Florida, USA., Harvey JC; Guy Harvey Ocean Foundation, Grand Cayman, KY1-1005, Cayman Islands., Harvey GCM; The Guy Harvey Research Institute, Halmos College of Natural Sciences and Oceanography, Nova Southeastern University, Dania Beach, Florida, USA. |
| Abstrakt: |
Ecotourism opportunities in the marine environment often rely heavily on provisioning to ensure the viewing of cryptic species by the public. However, intentional feeding of wildlife can impact numerous aspects of an animals' behavior and ecology. Southern stingrays (Hypanus americana) provisioned at Stingray City Sandbar (SCS) in Grand Cayman have altered diel activity patterns and decreased measures of health. This study looked at seasonal changes in stable isotope (SI) and fatty acid (FA) profiles of provisioned stingrays at SCS. Plasma δ 15 N was higher in male stingrays (11.86 ± 1.71‰) compared to females (10.70 ± 1.71‰). Lower values for δ 15 N in males and females were measured in October during low tourist season, suggesting stingrays may be forced to rely on native prey items to supplement the decreased amount of provisioned squid available during this time. Plasma FA profiles were significantly different between sexes and across sampling time points, with FAs 22:6n3, 16:0, 20:5n3, 18:1n3C, 18:0 and 18:1n9T contributing to dissimilarity scores between groups. Dietary FAs primarily contributed to differences between males and females lending further evidence to differences in foraging patterns at SCS, likely due to intraspecific competition. Further, canonical analysis of principal coordinates (CAP) analysis of FA profiles suggest similar diets during peak tourist season and differences in diet between males and females during the low season. This study demonstrates alterations in feeding ecology in stingrays at SCS which is of critical importance for effective management of the SCS aggregation. |
