2021 Humpback Whale Monitoring Report from Glacier Bay National Park, Alaska
The following report summarizing 2021 humpback whale monitoring results from Glacier Bay National Park, Alaska is now available: Neilson, J.L., C.M. Gabriele, and A.R. Bendlin. 2022. Glacier Bay & Icy Strait Humpback Whale Population Monitoring: 2021 Update. National Park Service Resource Brief, Gustavus, Alaska. https://irma.nps.gov/DataStore/DownloadFile/668731 [2.2 MB, 7 pages] The 2022 field season (our 38th year of monitoring) will be underway soon. Happy spring! KEY FINDINGS FROM 2021: · Effort-corrected counts indicate that the number of whales in Glacier Bay-Icy Strait (GB-IS) declined 5% from 2020 to 2021. In Glacier Bay, abundance declined compared to 2020, while in Icy Strait, abundance increased. · Twenty-seven of 66 adult whales (41%) with a history of strong site fidelity to GB-IS remain missing and most are presumed to have died during or after the 2014-2016 Northeast Pacific marine heatwave (PMH). · Eleven mother/calf pairs (crude birth rate, CBR, 6.6%) is an improvement over 2015-2019 (CBR 0%-3%) but the birth rate remains below average compared to the pre-PMH average (CBR 9.3%). We documented one case of apparent mid-season calf mortality, which is generally uncommon but has been more frequent since the PMH. · A relatively high residency rate and record-low transience rate in 2021 stand in contrast to PMH years. · An increasing proportion of whales (27%) appeared emaciated, including 9 of 11 mothers, compared to recent years. · Overall, these results suggest that the population is still recovering from the PMH. · We opportunistically documented numerous forage fish schools, especially capelin, however annual forage fish monitoring is needed to systematically assess trends. · There was an unusually high number of whale/human interactions, including a severely entangled whale (#2532) in GB who has not been sighted since July 30. -- Janet Neilson Humpback Whale Monitoring Program Glacier Bay National Park & Preserve PO Box 140 Gustavus, AK 99826 907-697-2658 Xunaa Káawu Aaní áwé yéi xat yatee ka ax’ yéi jixané I live and work in Huna Tlingit Homeland.
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Neilson, Janet L