Loggerhead Sea Turtle (Caretta Caretta) Interactions in Pelagic Longline Swordfish Fisheries: A Comparison of the North Pacific and North Atlantic Transitions Zones

Abstract

While many factors have contributed to the decline of worldwide sea turtle populations, longline fishing, in particular, has received a significant amount of attention in the past decade. However, there are still many areas where bycatch composition and rates are largely unknown. Using observer data from the N. Atlantic and N. Pacific longline swordfish fisheries from 1994-2000, this study analyzes the underlying oceanographic conditions that occur when loggerhead sea turtles (Caretta caretta) are caught in longline gear. Using geospatial and statistical analysis, these events are compared to fishing activities that did not result in loggerhead interactions. Within each study area certain predictors emerged, however significant differences were apparent in five of the six variables analyzed. While these differences may be the result of limitations in the data used, it may be attributed to utilization of habitat by loggerheads in the areas studied. In gaining a greater understanding of when bycatch is likely to occur, more effective management can be enacted to help reduce both the frequency of interactions with endangered species and the socioeconomic impacts on fishermen.