You may know that the endangered Southern Resident killer whales rely on Chinook salmon for food, especially from the Fraser River. Did you know, however, a recent study has found there is significant variation amongst Fraser River Chinook in how fat (high quality) these fish are? This, in turn, affects the energetic value of these fish to SRKWs. Jacob Lerner, a PhD Candidate from the University of British Columbia, discusses these findings and how they might be impacting SRKW foraging patterns and even the ability of SRKWs to recover as a population.