2020 Arctic Report Card Highlights Threats to Recovering Bowhead Whales

NOAA recently published the 2020 Arctic Report Card, which highlights the current environmental and ecological conditions of the Arctic Circle. This report has been issued annually for the last fifteen years. This year’s Arctic Report Card highlighted two major issues: (1) unprecedented wildfires in the Arctic Circle; and (2) decreased sea ice and its effects on bowhead whale populations. While devastating wildfires, like the ones in Australia and the Amazon, have attracted attention in recent years, a series of wildfires in Arctic regions of Alaska and Siberia have gotten less coverage. These fires pose a serious threat to the Arctic environment and are a major contributing factor to increasing air temperatures in the Arctic Circle. However, the risk presented to the Arctic environment from these increased air temperatures, and the resulting decrease in sea ice, is perhaps best represented by the threats to the bowhead whale population off the western coast of Alaska, which is known as the Bering-Chuchki-Beaufort (BCB) stock.

The BCB stock is the largest of the five global stocks of bowhead whales, with between 16,000 and 27,000 whales. Currently, the greatest threats to the BCB stock are entanglement, pollution, ocean noise, vessel strikes, and predation. These threats are anticipated to become more prevalent in coming years due to the drastic changes in the Arctic environment. The BCB bowhead whale population has experienced some growth in recent decades, but their population is still fragile and at risk.

Bowhead whales are protected under the Marine Mammal Protection Act (MMPA) (16 U.S.C. § 1371) and the Endangered Species Act (16 U.S.C. § 1533), and they are managed by the National Marine Fisheries Service. Bowhead whales are also protected from most whalers by a moratorium on whaling through the International Convention for the Regulation of Whaling, which the United States supports through domestic regulation. See Whaling Convention Act, 16 U.S.C. § 916c. Hunting bowhead whales is not totally prohibited, however, as the Whaling Convention and MMPA allow for limited subsistence whaling by indigenous populations who rely on whaling for nutritional or cultural purposes.

According to the 2020 Arctic Report Card, the biggest threats to bowheads stem not from whaling, but rather from the severe reduction of sea ice in the Arctic Circle caused by climate change. In September 2020, the average monthly sea ice coverage in the Arctic was the second lowest since records have been kept (42 years). Sea ice coverage has been shrinking since the 1970s. This reduction in Arctic Sea ice presents a challenge for regulators and conservation groups because, as the ice recedes further each year, fishing and crabbing vessels are moving further north into waters that used to be blocked by ice flows. NOAA’s report indicates a likely increase in contamination, vessel strikes, and entanglements for the BCB stock due to this increase in traffic. Additionally, increased traffic may be negatively affecting krill populations, a vital prey species for bowheads. Even in areas that maintain healthy krill populations, many bowheads are not arriving on time to their seasonal feeding grounds, primarily due to ocean noise.

On top of this increased human presence, trends have shown that killer whale populations are a more prevalent threat in northern waters. Bowhead whales would normally use the sea ice as cover and protection from killer whales. While the exact scope of this predatory threat is unclear, rates of killer whale attacks on bowhead whales have increased each decade.

Ultimately, bowheads have proven their resilience through the past century, having returned from the brink of extinction caused by whaling and now numbering in the tens of thousands. While the trends identified in the 2020 Arctic Report Card present new threats to this species, there is good reason to believe that the U.S.’s conservation measures have facilitated these magnificent creatures’ recovery and the whales will be able to adapt to the new challenges they face.