Medium resolution remote sensing in the coastal zone: A frame for small-scale fisheries assessment in Patagonia (Argentina)

AMOROSO, R.; GAGLIARDINI, A.; PARMA, A.M.; ORENSANZ, J.M.

Kochi

Simposio; Remote Sensing and Fisheries International Symposium; 2010

Management of small-scale fisheries targeting sedentary stocks requires integration of information about processes operating, and observable, at different spatial scales. Biological data on commercial stocks are often gathered systematically, but they are myopic: informative only about local phenomena. Information about oceanographic processes that shape meso-scale components of the population dynamics is usually unavailable or fragmentary in coastal environments. Remote sensing can provide the missing macroscopic frame. We developed an integrative strategy, with a scallop fishery from a small semi-enclosed basin in Patagonia as a demonstrational case. A multi-sensor approach was used to identify circulation patterns, which, combined with information from shery surveys and recruitment experiments, allowed us to link oceanography and population dynamics. We identified a frontal system that splits the gulf into two oceanographic domains (east and west) with distinct hydrographic regimes. At the west domain, where circulation is highly advective and governed by turbulent fluxes, post-larval settlement on artificial collectors was insignificant and no important scallops grounds were found. At the east domain, where the main fishing grounds occur, post-larval settlement was variable between sites and years, but always important. Within this domain, growth rates showed a strong decline, decreasing clockwise from the gulfs mouth, reflecting inferred circulation and nutrient-extinction. These patterns would be uninterpretable in the absence of our integrative approach.