Populations of annual breeding success of many seabirds fluctuates annually in response to prey availability and quality. Hence, seabirds are frequently used as indicators of food web changes in marine ecosystems. Cassin's auklet is a small diving seabird that feeds primarily on krill, mysids, and some larval fish. There is an existing historical record for this species, including average number of offspring per year from each breeding pair. The large-scale dispersal of this bird species means that range-wide and regional assessment of trend and condition can be made. Pigeon guillemots are found along rocky shores and in inshore waters. They dive and feed on sculpins, sand lance, and smelt. While nesting, pigeon guillemots are sensitive to local disturbance. Prey availability and nest disturbance may be reflected in breeding success for many seabirds (fledging rate).

Focal species: Cassin's auklet, pigeon guillemot, Brandt's cormorant, pelagic cormorant, and common murre