Importance of a northern Gulf of Mexico spring transition as inferred from marine fish biochronologies
Linkages between climate variability and productivity and functioning of marine ecosystems have thus far remained poorly described in the Gulf of Mexico, in large part due to a lack of time series that are of sufficient length to generate robust relationships. Multidecadal biochronologies were generated from otolith growth-increment widths of red snapper (Lutjanus campechanus), gray snapper (L. griseus), black drum (Pogonia cromis), and king mackerel (Scomberomorus cavalla) all collected from the Gulf of Mexico. Synchronous growth patterns were evident between red snapper, gray snapper, and black drum, which were all significantly (p < 0.05) correlated to each other, but not with king mackerel. The growth pattern shared by the snapper and drum species was associated with anomalously warm sea surface temperature, southeast wind stress and high sea level pressure in the western Atlantic, all during the early spring months. These data suggest that an early transition from a winter climate pattern to a summer climate pattern is favorable to fish growth in the northern Gulf of Mexico. In contrast, king mackerel significantly (p < 0.01) and negatively correlated to the Atlantic Multidecadal Oscillation (AMO), consistent with a growing body of evidence as to AMOs ecological relevance in this region. Overall, the results of this study point to the importance of a spring transition for the resident coastal species in the northern Gulf of Mexico as well as the importance of life history and geography to climate-biology relationships, as underscored by the coupling of mackerel with the AMO.