Hawaiian Monk Seals and Their Prey: Assessing Characteristics of Prey Species Fatty Acid Signatures and Consequences for Estimating Monk Seal Diets Using Quantitative Fatty Acid Signature Analysis

摘要

The Hawaiian monk seal (Monachus schauinslandi) was listed as endangered under the US Endangered Species Act (ESA) in 1976. The species is now estimated to number around 1200 to 1300 seals and declining. Seals live principally at six colonies in the Northwestern Hawaiian Islands (NWHI), but with small and increasing numbers in the main Hawaiian Islands (MHI). In addition to small population size, several natural and anthropogenic factors substantially affect the vitality and likely the persistence of the species, including entanglement in marine debris, predation by sharks, infectious disease, and breeding habitat erosion and disappearance as sea level rises. Moreover, limited availability of food (and perhaps inter- and intra-specific competition for food resources) appears to be an important constraint on growth, survival, recruitment of juveniles, and, consequently, abundance of seals in the NWHI.