Humpback whale monitoring in Glacier Bay and adjacent waters 2016: Annual progress report

Neilson JL, Gabriele CM, Taylor-Thomas LF. 2017. Humpback whale monitoring in Glacier Bay and adjacent waters 2016: Annual progress report. Natural Resource Report. NPS/GLBA/NRR—2017/1503. National Park Service. Fort Collins, Colorado

Migratory humpback whales (Megaptera novaeangliae) use southeastern Alaska as summer feeding habitat, including the waters in and around Glacier Bay National Park and Preserve (GBNPP). This report summarizes GBNPP’s humpback whale monitoring program in Glacier Bay and Icy Strait (GB-IS) in 2016, the 32nd consecutive year of consistent data collection. In June-August, we documented 164 unique whales in GB-IS, our lowest count since 2008. Counts corrected for effort reveal an increasing trend following a dramatic decline in whale abundance in 2014. We found decreases in within-year and between-year site fidelity, with over one-third (35.6%) of our ‘regularly sighted’ whales missing in 2016. We identified only one mother/calf pair, resulting in the lowest crude birth rate (0.6%) since monitoring began in 1985, and there was also a notable absence of one and two-year-old whales. Many of the whales that we observed (13%) appeared to be abnormally thin. The ‘core group’ at Point Adolphus was not sighted and many of the whales typically associated with the group were not documented. In June, whale #441 was found dead marking the end of his 45-year sighting history (1972-2016), the world’s longest for a humpback whale. There is mounting evidence that site fidelity, calving, and juvenile return rates in Glacier Bay-Icy Strait have declined substantially in recent years. Within Alaska, the long-term, consistent monitoring of humpback whales is limited to GB-IS, making it difficult to determine over what geographic scale these changes are occurring.

Type
Published Report
Authors
Neilson, Janet; Gabriele, Christine; Taylor-Thomas, Louise
Date of Issue
2017-08
Publisher
National Park Service
Units
GLBA , NRSS
Keywords
Alaska, Glacier Bay National Park, GLBA, humpback whale, Preserve, whale monitoring
Subjects
Ecological Framework: Biological Integrity | Focal Species or Communities | Marine Communities , Ecological Framework: Biological Integrity | Focal Species or Communities | Mammals

Full text (PDF)

Series

See also

Browse the catalog