Fatty Acid Profile and Lipid Class Analysis for Estimating Diet Composition and Quality at Different Trophic Levels

摘要

We examined spatial and temporal variation in the lipid content of young-of-the-year (YOY) Pacific sand lance (Ammodytes hexapterus) and spatial variation in YOY Pacific herring (Clupea pallasi). Spatial variation of YOY herring and sand lance was evaluated by collecting fish from six locations in Prince William Sound, Alaska between July 15 and August 2, 1997. This allowed us to remove the effects of season and age as alternative sources of variation. Lipid content of herring and sand lance varied between sites, and fish from sites in southwestern PWS generally had the highest lipid contents. After accounting for size differences between sites, herring ranged between 8% and 10% lipid (dry weight) and sand lance between 9% and 16%. To examine temporal variation, we sampled age-0 and age-1 sand lance from a single location in Cook Inlet, Alaska between May 22 and August 28, 1998. Temporal variation in lipid content of age-0 and age-1 sand lance followed different patterns. Lipid content of age-0 sand lance declined by 50% between June 1 and July 9. In contrast, age-1 had increased their lipid content during the same period. These differences in pattern are believed to result from differing energy allocation strategies that relate to the differences in their life histories.