Identifying Essential Habitat (Source vs. Sink Habitat) for Pacific Herring (Clupea pallasi) in Sitka Sound Using Otolith Microchemistry

摘要

The primary objective of this project was to obtain information leading to better identification of essential fish habitat in Prince William Sound. By using trace element signatures of edge portions of juvenile herring otoliths, we identified the otolith chemical signature of individual rearing bays within Sitka Sound. We used trace element signatures of edge portions of adult herring otoliths to identify the otolith chemical signature of spawning areas within Sitka Sound. We also used trace element signatures of edge portions to compare to core portions of juvenile and adult herring to identify source and sink habitat in Sitka Sound. The results of the technique used in this project indicate that herring use different and distinct habitats in Sitka Sound during their life. Once we know which population contributes more to the spawning groups, we can then identify those variables that enhance the life histories of the source population. This will allow managers to protect the most important populations and also identify which variables can be altered to improve habitat for other populations. These techniques used in Sitka Sound can be directly transferred to Prince William Sound, leading to better identification of essential fish habitat in Prince William Sound.