HR: 1330h
AN: OS23A-07    [Abstracts]
TI: Modeling the Transport Success and Retention of Anchovy (Engraulis anchoita) Early Stages in the Southern Brazilian Shelf
AU: * Vaz, A
EM: anacarolina@io.usp.br
AF: Universidade de Sao Paulo Inst. Oceanografico, Praca do Oceanografico, 191 sala 200, Sao Paulo, SP 05508-120 Brazil
AU: Parada, C
EM: Carolina.Parada@noaa.gov
AF: Alaska Fisheries Science Center National Marine Fisheries Service NOAA, 7600 Sand Point Way NE Building 4, Seattle, WA 98115 United States
AU: Palma, E D
EM: uspalma@criba.edu.ar
AF: Universidad Nacional del Sur Dep. de Fisica, Av. Alem 1253, Bahia Blanca, 8000 Argentina
AU: Muelbert, J H
EM: docjhm@furg.br
AF: Fundacao Universidade Federal do Rio Grande, Cx. Postal, 474, Rio Grande, RS 96201900 Brazil
AU: Campos, E D
EM: edmo@io.usp.br
AF: Universidade de Sao Paulo Inst. Oceanografico, Praca do Oceanografico, 191 sala 200, Sao Paulo, SP 05508-120 Brazil
AB: The Southern Brazilian Shelf (SBS) is one of the most productive fishing areas in the Southwestern Atlantic. Eggs and larvae of about 88 fish species distributed among 48 families occur in the plankton community in this area. The processes involving the circulation in this area and its influence on eggs/larvae transport are poorly understood. Recent studies described the spawning activity of anchovy relating it to oceanographic processes. These studies suggest that the predominant onshore Ekman transport, which occurs mainly in the winter and spring periods, keeps the eggs and larvae in coastal areas. It is also known that the continental runoff is a primary factor to the formation of a retention zone for planktonic organisms over the SBS. The formation of a stagnant zone, where the residual currents are weak, favors the patchiness character of plankton communities and nutrients. In our ongoing study we investigate with data and model the dispersion pattern of eggs/larvae of Engraulis anchoita in this region, considering both biological and physical processes. In the modelling approach, surface velocity fields from runs with the Princeton Ocean Model (POM) are used as input data for an Individual Based Model (IBM). This IBM treats every single particle as an individual with its own features, tracking particles (eggs/larvae) trajectories using a Runge-Kutta scheme for spatial interpolation. The analyses of our preliminary results seems to confirm the expected pattern in which the majority of eggs and larvae are transported to their nursery grounds, remaining in these areas.
DE: 4219 Continental shelf processes
DE: 4255 Numerical modeling
DE: 4842 Modeling
SC: Ocean Sciences [OS]
MN: 2005 Joint Assembly