Project Information

Title: LTM Program: Long-term Monitoring of Humpback Whale Predation on Pacific Herring in Prince William Sound 20120114-O

Project Year and Number: 2020: 20120114-O

Other Fiscal Years and Numbers for this Project: 2024: 24120114-O, 2023: 23120114-O, 2022: 22120114-O, 2021: 21120114-O, 2019: 19120114-O, 2018: 18120114-O, 2017: 17120114-O, 2016: 16120114-N, 2015: 15120114-N, 2014: 14120114-N, 2013: 13120114-N, 2012: 12120114-N

Principal Investigator (PI): John Moran (NOAA), Jan Straley (University of Alaska Southeast)

Managing Agency: NOAA

Assisting Personnel: None

Project Website: https://gulfwatchalaska.org/monitoring/pelagic-ecosystem/humpback-whales/

Research Location: Prince William Sound

Restoration Category: Monitoring

Injured Resources Addressed: Pacific Herring

Abstract:

The humpback whale monitoring project is part of the Gulf Watch Alaska pelagic component’s integrated predator-prey survey. Humpback whale predation has been identified as a significant source of mortality on over-wintering Pacific herring in Prince William Sound (PWS) and a likely top-down force constraining their recovery. Humpback whales in PWS have a higher percentage of herring in their diet and forage longer on herring during non-summer months than their counterparts in Southeast Alaska. Currently, North Pacific humpback whales in the Gulf of Alaska may be experiencing nutritional stress and increased use of inland waters like PWS could result in increased predation on herring. We will continue to evaluate the impact by humpback whales foraging on Pacific herring populations in PWS following protocols established during 2007/08 and 2008/09 (EVOSTC project PJ090804). Prey selection by humpback whales is determined through acoustic surveys, visual observation, scat analysis, and prey sampling. Chemical analyses of skin and blubber biopsy samples provide a longer-term perspective on shifts in prey type (trophic level from stable isotopes) and quality (energy content). These data are combined in an updated bioenergetic model that allows us to assess the impact of recovering humpback whale populations on the PWS ecosystem. By integrating with the forage fish and fall/winter marine bird components, we contribute to a comprehensive understanding of bottom-up influences and top-down controls on the PWS herring population. We are not proposing changes to this project for FY20.


Proposal: View (302 KB)

Reports:
Annual Report: View (654 KB)
Final Report: See Project 21120114-O

Publications from this Project: None Available