Fisheries Oceanography of the Southeast Bering Sea: Simulated Dispersal ofHerring and Sand Lance Larvae in Port Moller, Alaska, Using a Three-Dimensional Hydrodynamic Model

摘要

Studies of Pacific herring and sand lance larvae in the Port Moller estuary ofthe southeast Bering Sea have shown that larvae are retained within the estuary, suggesting that retention may be important for successful year-class formation. To determine the mechanisms of retention, a three-dimensional numerical hydrodynamic model of the estuary was used to stimulate dispersal of fish larvae. Directed motion against the current reproduced the observed densities of herring larvae far better than passive drift, but passive drift of sand lance larvae produced roughly the same fit as directed motion. The authors conclude that herring and sand lance have different strategies for larval retention. Most herring larvae were found in the turbulent waters of upper Moller Bay, so directed motion may be a necessary strategy to stay there. Most sand lance larvae are retained in the quieter waters of Herendeen Bay and they can move there by passive drift on tidal currents. For both species, the location of the eggs in relation to oceanographic features appears to be crucial for larval retention.