US Navy

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Marine Species Monitoring

North Pacific Humpback Whale Tagging

Introduction & Objectives

Three (Hawaii, Mexico, and Central America) of 14 Distinct Population Segments (DPSs) of humpback whales (Megaptera novaeangliae) designated by the National Marine Fisheries Service (NMFS) for listing under the Endangered Species Act (ESA) based on their winter breeding grounds can be found along the western coast of North America during the summer feeding season. The mixing of whales from these DPSs in the feeding areas in different proportions complicates assignment of individuals to distinct groups for management purposes without further information. As a result, there is an urgent need for data to help identify and quantify which DPS an individual belongs to as well as how they are using the habitat.  This will help determine their overlap with shipping traffic, fishing grounds, and areas of military operation, in order to prioritize management actions and to mitigate the impacts from these activities.

This project combines tagging, biopsy sampling, and photo-identification efforts along the United States west coast and Hawaii to assign DPS, examine movement patterns and whale use of Navy training and testing areas and NMFS-identified Biologically Important Areas (BIAs), examine migration routes, and analyze dive behavior and ecological relationships between whale locations and oceanographic conditions.

Technical Approach

Humpback whales were studied off the coast of northern Washington, central Oregon, southern California, and Maui, Hawaii.  Whales were tagged with long-duration implant satellite tags.  Satellite locations and depth data from the tags, satellite-sourced ecological data, and models were utilized to examine home range, foraging areas, migration routes and speeds, dive behavior, and ecological relationships. Photos were collected for individual identification and to evaluate effects of tagging.  In addition, photos were uploaded to the HappyWhale database where other researchers as well as citizen scientists also contributed photos, leading to further determinations of migration routes and wound healing.  Biopsy samples were collected for genetic sex determination, and stock identification. Final analyses also took into account humpback whale data from individuals previously tagged by the researchers beginning in 1995.

Progress & Results

This study tagged a total of 118 humpback whales along the U.S. West coast and Hawaii from 2017 to 2019: 19 in summer/fall of 2017 in California, Washington, and Oregon, 25 in spring of 2018 in Hawaii, 25 in summer/fall of 2017 in Washington and Oregon (+1 fin whale), 25 in spring of 2019 in Hawaii, and 24 in fall of 2019 off Washington. 

Satellite tags provided locations and additional data for up to 160 days.  The location data provided information on use of Navy areas and Biologically Important Areas.  Behavior was correlated with ecological variables to examine habitat use.  Results supported humpback whale affinity for continental shelf and shelf-edge habitat on feeding areas and showed direct migration routes between feeding and breeding areas. 

Dive behavior was generally similar for tagged whales in Washington and Oregon feeding areas.  However, some differences in diel pattern and depth of feeding lunges may suggest differences in the targeted prey.  In the Hawaiian breeding area, dive behavior was consistently shallow and likely limited by bottom depth.  Dives during migration were similar in depth and duration with the exception of the first 7-14 days when whales consistently made deep, long-duration dives at night.  The purpose of these dives was unclear. 

DNA profiles showed individuals sampled in Washington showed the highest likelihood of assignment to the Hawaii DPS, followed by the Mexico DPS, Central America DPS, and Western North Pacific DPS, respectively. Individuals sampled in Oregon showed the highest likelihood of assignment to the Hawaii DPS and the Mexico DPS, followed by the Central America DPS.  Individuals sampled in Hawaii all belong to the Hawaii DPS, but were most likely to have genetic profiles similar to whales previously sampled in the feeding areas from Southeastern Alaska and northern Gulf of Alaska.  However, the Hawaii DPS also included individuals that consistently migrate to other feeding areas from Russia to British Columbia. 

Please see reports for additional detailed information. 

Publications:

An at-sea assessment of Argos location accuracy for three species of large whales, and the effect of deep-diving behavior on location error.
Irvine, L.M., Winsor, M.H., Follett, T.M., Mate, B.R., Palacios, D.M. 2020.  Animal Biotelemetry 8, 20. doi: 10.1186/s40317-020-00207-x