Isotope Ratio Studies of Marine Mammals in Prince William Sound

This project uses natural stable isotope ratios to assess trophic structure and food webs in Prince William Sound and contributes to the studies by Alaska Department of Fish and Game personnel to determine the reasons for the decline of harbor seal populations. Through a mix of captive animal studies and a comparison of isotope ratios in prey species and archived and current marine mammal tissues, insight into environmental changes causing the decline may be possible. Preliminary data point strongly toward a major decline in the carrying capacity of the northern Pacific Ocean in the past two decades. This decline is evident in the abundance and distribution of marine biota and is reflected in the carbon isotope ratios of marine mammals of the region