Dolphinfish (Coryphaena hippurus) distribution in relation to biophysical ocean conditions in the northwest Atlantic

We analyzed temporal and spatial catch per unit effort (CPUE) of dolphinfish (Coryphaena hippurus) along the U.S. east coast using pelagic longline logbook data (1999-2007). A zero-inflated negative binomial model was fit using a variety of oceanographic variables to better understand distribution and abundance. The two most important dynamic oceanographic variables were sea surface temperature and chlorophyll-a concentration. We also used catch and release locations of dolphinfish caught by recreational fishermen (2002-2007) to compare conditions between datasets and for model evaluation. Dolphinfish CPUE was highest at 22-25 °C with a peak at 24 °C for the longline dataset, while recreational dolphinfish were caught in waters >19 °C with peak catches occurring at 27 °C. Dolphinfish CPUE was highest when chlorophyll-a concentration was <0.2 mg m−3, and the majority of recreational dolphinfish were captured in waters <0.1 mg m−3 with a peak at 0.02 mg m−3. We also found that a majority (73.26%) of recreational dolphinfish were caught in association with Sargassum spp., and larger dolphinfish (>82.3 cm FL) are caught more frequently outside of the floating mats.