Environmental factors that define the spawning and nursery areas for Percophis brasiliensis (Teleostei: Percophididae) in a multispecific reproductive coastal zone, El Rincn (39A degrees-41A degrees S), Argentina

摘要

The spatial distribution of Percophis brasiliensis at different maturity stages and its relationship to environmental factors was evaluated in the El Rincon area (39A degrees-41A degrees S) between 1994 and 2008 during eight cruises carried out in spring. For this, a canonical correspondence analysis was used. Results indicate that bottom temperature and bottom salinity horizontal gradient (BSHG) were the most important variables affecting the spatial distribution of P. brasiliensis maturity stages. Juveniles were mainly located in shallow waters with low salinity, high temperatures and vertical stratification. Conversely, gravid and running individuals were found in high BSHG and low temperatures. This link suggests that adults spawn in a well-defined area of hydrographic conditions that would tend to retain pelagic eggs and larvae, thus minimizing dispersal, and ensuring their transport from the spawning to nursery areas. On the coastal shelf of El Rincon, the water mass circulation shows an anti-cyclonic gyre whose recirculation cell during spring and summer is more constrained to inshore areas than during winter. Maximum reproductive activity of P. brasiliensis coincides with the highest retention period; therefore, dispersal of early-life stages (eggs) depends on the circulation pattern and transport pathway which would contribute importantly to its recruitment variability.