Relación entre frentes de convergencia y localización de la flota pesquera durante la ocurrencia de surgencia costera en Uruguay

Abstract

The Uruguayan coast presents upwelling events during the summer, its implications on the distribution, transport of nutrients and organisms; and their effects on the entire food web, have not been previously analyzed. This work seeks to understand the relationship between the upwelling events and the location of the Uruguayan coastal industrial fleet (B Category). Finite Size Lyapunov Exponents (FSLE) were computed from surface current velocity fields. The temporal averages of these exponents indicate the mixing intensity and presented higher values over the region of more intense upwelling. On the other hand, the maximum FSLE values identify convergence fronts. The fronts identified by this methodology correspond to the turbidity front and close to Montevideo, and temperature fronts directly associated with the upwelling event. During the event, these fronts migrated from the coast, to the southwest and offshore. The location of the frontal regions detected was compared with the satellite position (VMS) of B Category coastal vessels of the Uruguayan fishing fleet. In general, the vessels were positioned on the frontal zones, suggesting a relationship between retention processes and the location of target species; and evidencing the need to deepen the study of these processes.