Glacier Bay National Park New Humpback Whale Monitoring Report

Colorado River & Trail Expeditions has been operating guided rafting expeditions on the Alsek and Tatshenshini Rivers in Glacier Bay National Park and Preserve since 1978.  From the upstairs window of our warehouse in Haines, Alaska, (on the inland side of the Chilkat Range, “just over the mountains” from Glacier Bay) we have an unimpeded view of the Lynn Canal, the longest and deepest fjord in the United States.

Southeast Alaska, Juneau, Haines, Skagway, and Glacier Bay.

For centuries, the Lynn canal facilitated trade and migration between Native coastal settlements and interior villages in what is now Alaska and northern Canada. In hand-carved sea-worthy canoes, decorated by totemic symbols, aboriginal people paddled up an down the Lynn Canal to hunt, fish, and engage in trade.  They followed the migrations of birds, fish, whales, and other wildlife, and harvested seasonal plants and berries.  Today, the Lynn Canal is still a waterway of major importance both for commerce, tourism and wildlife. It’s fun to look out the window at night and see the festive lights of huge cruise ships heading toward Skagway, which is located at the terminus of the Lynn Canal. During the day, it’s exciting to watch humpback whales breaching, as they migrate up and down the waterway following schools of fish.

We used to see a lot of whales every summer, but not so many any more. There were times when we would see six or seven whales breaching alongside the ferry that brings us from Juneau to Haines. Last summer (2018), the ferry captain spotted one humpback, but we were on the wrong side of the ship and missed it.  It is sad and worrisome to think that the number of whales swimming in the deep waters of the Lynn Canal might be decreasing. Today, we received a report from the National Park Service regarding the declining presence of humpback whales in Glacier Bay and Icy Strait, just a little farther north and west from our location on the Lynn Canal. It’s certainly worth noting and sharing.

SUBJECT: The following report summarizing humpback whale monitoring results from 2018 is now available:
https://irma.nps.gov/DataStore/DownloadFile/620535 [692 K, 6 pages] Neilson, J.L., and C.M. Gabriele. 2019. Glacier Bay & Icy Strait Humpback Whale Population Monitoring: 2018 Update. National Park Service Resource Brief, Gustavus, Alaska.

KEY FINDINGS:

We documented 100 unique humpback whales, our lowest annual count since 2002.

Humpback whale abundance in Glacier Bay and Icy Strait has declined by >50% since peaking in 2013.

This downtrend trend has been most dramatic in Glacier Bay, where we identified only 45 whales in 2018, a 72% decline compared to our record high count of 161 whales in 2013.

We documented only one mother/calf pair in 2018 but by mid-August the mother had lost her calf, marking total reproductive failure for the first time in this 34-year study.

An increasing number of whales that exhibited long-term site fidelity to GB-IS in 2004-2013 (n = 66) have not been documented since 2013. In 2018, over half (56%) of these well-known whales were missing.

For the third year in a row, we observed numerous abnormally thin whales, however it appears this was less common than in 2017.

Although our monitoring results clearly indicate dramatic population level changes over the past five years, we do not know if the declines in whale numbers represent a shift in distribution and/or increased mortality from 2014-2018. Efforts to locate the whales missing from Glacier Bay and Icy Strait in catalogs from other feeding areas (e.g., British Columbia and Prince William Sound) have so far yielded no matches. Through a new collaboration with Happywhale.com, we recently initiated expanding our search area to the broader North Pacific.

Within Alaska, the consistent, long-term, monitoring of humpback whales is limited to Glacier Bay and Icy Strait, although our findings are consistent with negative trends in abundance, reproduction, and body condition for humpbacks in other areas in the central North Pacific.

Growing evidence suggests that recent declines in humpback whales and other marine species may be related to the unprecedented marine heatwave that occurred in the North Pacific from 2014-2016

For more information, contact:
Janet Neilson
Humpback Whale Monitoring Program
Glacier Bay National Park & Preserve
PO Box 140
Gustavus, Alaska 99826
907-697-2658


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