Does a Lagrangian-based dynamic geography match the larval fish assemblage structure of the Gulf of Mexico?s deepwater region?

SHARON ZINAH HERZKA LLONA; SYLVIA PATRICIA ADELHEID JIMENEZ ROSENBERG; LAURA DEL PILAR ECHEVERRI GARCÍA; GONZALO DAUDÉN BENGOA; JESÚS CANO COMPAIRÉ; PAULA PEREZ BRUNIUS; JULIO SHEIMBAUM

Portland

Congreso; Ocean Sciences Meeting; 2018

Association for the Sciences of Limnology and Oceanography

The larval fish communitystructure of the surface waters of the Gulf of Mexico?s (GM) deepwater regionhas been related to the location and hydrodynamic characteristics of mesoscalestructures such as the Loop Current and other mesoscale structures. However,the evaluation of broader biogeographic patterns has been hindered by thelimited number of studies encompassing Mexico?s deepwater region. Recently,Mirón et al. (2017) analyzed an extensive data set of surface drifters releasedwithin the GM, northern Caribbean and southeastern North Atlantic andidentified specific regions that may function as basins of attraction based ontheir Lagrangian characteristics. These regions may reflect the retention oraccumulation of planktonic organisms, including fish larvae, and may thereforeinfluence recruitment, connectivity and diversity. Basins of attraction withinthe gulf include (but are not limited to) the northwestern region(Louisiana-Texas shelf and Perdido Foldbelt), the eastern and western gulf, andthe Bay of Campeche. We test the null hypothesis that larval fish assemblagesfrom stations within attraction basins exhibit a greater degree of similaritycompared with stations outside the basins or in remote locations of the GM. Theabundance and taxonomic composition of the larval fish community collected inthe top 200 m with oblique bongo tows is characterized based on samplescollected during three research cruises spanning the entire deepwater region(> 1000 m) of Mexico?s EEZ. The XIXIMI-1 (Nov 2010), XIXIMI-2 (July 2011)and XIXIMI-4 (August/Sept 2015) cruises covered stations from 25°N southward,including the Bay of Campeche. Multivariate analyses are used to evaluate thecoherence of larval fish assemblages within and between regions of attractionrelative to hydrographic conditions derived from CTD measurements and satellite measurements.