Meeting Abstracts
Lagrangian observations of billfish larvae in the Florida Current.
Robert K. Cowen, David E. Richardson, Joel K. Lopiz, Cedric Guigand, and Gary L. Hitchcock
University of Miami
(Abstract received 05/21/2012 for session B)
ABSTRACT
Large pelagic fishes, such as billfish, can selectively spawn in oceanographic features such as fronts and eddies. A spawned ‘patch’ of sailfish (Istiophorus platyperus) was identified in a Florida Current frontal eddy in June 2004 adjacent to the Florida Keys. Through use of Lagrangian sampling techniques (i.e. sampling tracked surface drifters), the temporal history of the patch, along with the prey of the larval sailfish, was followed over 65 hours as the eddy was advected north and east. The larval and prey distributions indicate that the eddy provided a favorable environment for survival of young sailfish. A subsequent series of drifter deployments in summer 2005 in the eastern Florida Current did not reveal a similarly rich eddy environment. This variability in the retentive structures in the Florida Current may contribute to the cross-Current distribution observed in sailfish larvae, as well as to spatial and temporal variability in reproductive success. Static or survey-oriented sampling protocols would not have been able to highlight the tight eddy/larval and prey linkages that were observed.