Resource Ecology and Ecosystem Modeling Trophic Interactions Laboratory

 

The Alaska Fisheries Science Center’s Trophic Interactions Laboratory collects and analyzes an array of biological samples in support of ongoing investigations into the Alaskan marine ecosystem. Annually, approximately 15,000 fish stomach samples are collected and analyzed from across multiple trophic levels from a geographic range extending from the southern Gulf of Alaska to the Beaufort Sea, and reaching offshore to the extent of US territorial waters. Most stomach samples are collected and preserved by scientists during research cruises, or by fishery observers aboard commercial fishing vessels.  Samples are returned to the laboratory for prey identification and quantification. During Aleutian Islands and Gulf of Alaska resource surveys, some stomach samples are analyzed at sea by experienced stomach analysts. Each method has unique benefits. To supplement stomach contents data, tissue samples from predators are frozen and prepared for stable isotope analysis and tissue samples from partially digested prey are frozen for genetic analysis. In addition to fish diet samples, our laboratory also analyzes plankton samples, benthic grab samples, and seabird bill load and diet samples. In this poster we describe methods for identifying prey from stomachs and the benefits of the different collection and analysis methods.