Feeding Ecology of Maturing Sockeye Salmon (Oncorhychus merka) in Nearshore Waters of the Kodiak Archipelago.

摘要

The diet and feeding behavior of maturing sockeye salmon (Oncorhynchus nerka) were investigated during the final marine phase of the spawning migration, immendiately prior to re-entry into natal streams. The stomach contents of commercially caught sockeye salmon, migrating through the nearshore waters of the Kodiak Island Archipelago during 1998 and 1999, were examined to determine level of feeding activity and taxa of dominant prey items. Representative samples were collected throughout the majority of the migration (early June to late August) from areas known to be principally migration corridors, and from areas proximate to several natal streams. Dominant prey of sockeye salmon were decapod larvae, Pacific sandlance (Ammodytes hexapterus), and the pteropod Limacina Helicina. Feeding levels and dominant prey varied between areas and within areas over time. Feeding levels for the population appear to gradually diminish, rather than ceasing abruptly, prior to entering freshwater.