Project Information

Title: LTM Program: Long-term monitoring of humpback whale predation on Pacific herring in Prince William Sound 17120114-O

Project Year and Number: 2017: 17120114-O

Other Fiscal Years and Numbers for this Project: 2024: 24120114-O, 2023: 23120114-O, 2022: 22120114-O, 2021: 21120114-O, 2020: 20120114-O, 2019: 19120114-O, 2018: 18120114-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:

INTEGRATED PREDATOR-PREY SURVEYS 2017-2021: HUMPBACK WHALES, MARINE BIRDS, FORAGE FISH Under the next five year monitoring program, we are proposing to integrate predator-prey survey efforts by combining monitoring work from three of the Prince William Sound (PWS) Pelagic Component projects and collaborating with the Herring Research and Monitoring program. We propose to combine the humpback whale, marine bird and forage fish (including euphausiids) projects into a single, integrated predator-prey survey. The integrated survey would be conducted during the fall, providing insight into predator-prey interactions at a crucial time when forage fish energy is maximized while marine birds and humpback whales are provisioning for the upcoming winter. In addition, the survey would estimate the availability, including species composition, density and depth distribution of prey near seasonally predictable predator aggregations in PWS. The survey would include concurrent habitat and nutrient measurements in conjunction with acoustic measurements of nekton biomass and predator density. A midwater trawl (max depth ~ 100 m) will be used to sample acoustic sign and collect samples of forage fish for further analysis (e.g., diet, energy). Marine bird observations will be conducted concurrent with acoustic transects and humpback whale distribution and abundance will be assessed at the same time and area from a smaller vessel. The simultaneous surveys will reduce vessel cost for the three projects while combining expertise with spatial and temporal consistency, allowing a more comprehensive understanding of the pelagic ecosystem. In addition to a planned research cruise in September/October, the proposed approach may also allow for in-kind contributions from National Oceanic and Atmospheric Administration (NOAA) for vessel charter and an additional survey in March, when humpback whales are returning from their migrations to feed and when we can assess the winter severity on forage fish. The NOAA funds will be applied for and awarded on an annual basis, and a March NOAA cruise, if awarded a second cruise would be an added value to the GWA pelagic monitoring program. HUMPBACK WHALES: LONG-TERM MONITORING OF PREDATION ON PACIFIC HERRING IN PRINCE WILLIAM SOUND: The humpback whale monitoring project is a component of the integrated fall/winter predator-prey survey. We will continue to evaluate the impact by humpback whales foraging on Pacific herring populations in PWS. Following protocols established during the winters of 2007/08 and 2008/09 (EVOSTC project PJ090804). Prey selection by humpback whales will be determined through acoustic surveys, visual observation, scat analysis and prey sampling. Chemical analysis of skin and blubber biopsy samples will provide a longer term perspective on shifts in prey type (trophic level from stable isotopes) and quality (energy content). These data will be combined in a bioenergetic model that will allow us to assess the impact of recovering humpback whale populations on the PWS ecosystem. By integrating with the forage fish and winter seabird components, we will be able to provide a comprehensive understanding of bottom-up influences and top-down controls on herring abundance.


Proposal: View (979 KB)

Reports:
Annual Report FY17: View (779 KB)
Final Report: See Project 21120114-O

Publications from this Project: None Available