Researchers with AOML’s Physical Oceanography Division (PhOD) conduct a collaborative effort with NOAA’s Southeast Fisheries Science Center (SEFSC), which focus on the investigation of the link between the ocean and stock assessment of species with relevant commercial importance. New results on the application of altimeter satellite-derived observations to larvae research in the Gulf of Mexico are being reported in this research activity. Given the strong link between temperature and salinity in habitats, the main mesoscale features are related to larvae distribution of six fish species, bluefin tuna among them. Time series of the northernmost and westernmost locations of the Loop Current and a ring census were obtained from altimetry fields and related with spring larvae distributions from January 1993 to December 2008. Altimetry fields and fishery surveys indicate that when the Loop Current is farther to the south, larvae are more abundant in the eastern Gulf of Mexico than in the central and western portions of the basin. Analysis made from 23 rings shed by the Loop Current during the study period indicate that warm-core rings shed by the Loop Current are generally less likely to contain larvae. Eventually, associations between the inner and outer regions of mesoscale features and larval catches show higher abundances of bluefin tuna, little tunny, Thunnus, Auxis and red snapper in the boundaries and frontal areas of anticyclonic regions. Collaborative work will continue between AOML and SEFSC to analyze the link between ocean features and stock assessment.

Figure 1. Spatial distribution and density of larvae of bluefin tuna, little tunny, Thunnus, Auxis, snappers and dolphin-fishes. Background is SSH field. Field on the left show catches on frontal areas of the LC on April 28, 1993. Field on the right show catches on frontal areas of the LC on May 14, 1997.