Fish Love Worms: Habitat from the Food Perspective
Figure 1. A polychaete sample collected during the 2011 summer Bering Sea bottom trawl survey.
Polychaetes are a large part of the diets of small-mouthed flatfish in the Bering Sea. This diverse and abundant group dominates the infauna of marine soft sediments and is widely used as an indicator of environmental change. It may also be a key factor in habitat suitability to flatfish.
The AFSC's Habitat Research and Resource Ecology and Ecosystem Modeling tasks are jointly studying Bering Sea infauna for linkages with flatfish habitat and trophic dynamics. The research is funded by NOAA's Essential Fish Habitat program. Field data collection has been accomplished through cooperation with the AFSC's annual summer Bering Sea bottom-trawl survey.
Figure 2. Scientists conducting benthic sampling aboard the Alaska Knight.
Research in 2011 focused on diet comparisons between adult and young flatfish in coastal habitats. Alaska plaice, northern rock sole, and yellowfin sole were the target species. Sampling was conducted at the end of the 2011 bottom-trawl survey, along a transect of stations near the Alaska Peninsula.
Benthic samples and underwater video footage of the bottom habitat were collected on the FV Alaska Knight (Figs. 1 and 2). The FV Aldebaran joined in the collection of fish specimens. Fish stomachs and tissue were extracted for prey and stable isotopes analysis, respectively, to trace short- and long-term food sources.
A database of Bering Sea infauna communities and substrate properties is being incrementally assembled to examine spatial correlations with benthivorous flatfish diets and condition, and specifically, to evaluate polychaetes as the food index in habitat suitability.
