Descriptive density models of scyphozoan jellyfish in the northern Gulf of Mexico

ABSTRACT: Jellyfish play an important role in the food web of many coastal environments but are generally considered a nuisance to scientific fieldwork and industrial and economic trades. A better understanding of how jellyfish densities and distributions are affected by environmental parameters could elucidate population trends and provide assistance in ecological research and undesirable human interactions. In this study, abundance data for scyphozoan medusae, Chrysaora sp. and Aurelia spp., were extracted from Southeast Area Monitoring and Assessment Program trawling surveys for the northern Gulf of Mexico (nGoM) during the summer and fall months. Both in situ and satellite oceanographic measurements were obtained to coincide with the jellyfish data from 2003 to 2013. Data were separated into gulfwide seasonal models and regional (east, west) seasonal models. A generalized additive model was created for 3 methods (remote sensing, in situ, and all parameters) for all models. The regional models were more precise in replicating the observed data, and the all-parameter method produced the best-fit models. The oceanographic variables that were determined to be most descriptive for the nGoM were salinity, surface currents, temperature, chl a concentrations, and distance from shore. Understanding the dynamic relationship between jellyfish densities and oceanographic features in the nGoM is one step closer to better management of these species and the overall ecosystem.