In 2021, a federal survey of the Bering Sea discovered that as many as 10 billion crabs that scientists had expected to find based on prior trends were simply missing.[1] Snow crab stocks fell by a catastrophic ninety percent, drawing significant public attention,[2] but other crab species similarly experienced disastrous collapses.[3] In response, authorities abruptly canceled Alaska’s crabbing season, and crab fisheries in the region have still not recovered.[4]

Researchers traced the cause of the population collapse to a marine heat wave.[5] The increased water temperatures dramatically accelerated the crabs’ metabolisms to the point that the ecosystem could no longer sustain them.[6] An increase of 3°C can double the metabolic rate of snow crabs.[7] Studies of marine food webs show that while heat waves can spur increased productivity in phytoplankton, they wreak havoc across the higher trophic levels.[8] The increased primary productivity is insufficient to offset the increased demands of consumers. Snow crabs, being relatively large secondary consumers primarily consisting of smaller invertebrates, simply could not find enough food to satisfy their elevated metabolism, leading to widespread .[9]

Over the last few decades, the frequency and intensity of marine heat waves have increased drastically due to human-caused climate change.[10] While the 2021 collapse of Bering Sea crab stocks was unprecedented, it is likely to be the first of many unpredictable fishery failures as rising temperatures destabilize the delicate marine ecosystems that support them.[11]

Even without another die-off, these stocks are unlikely to bounce back quickly. Snow crabs produce huge numbers of larvae, but the females take six to eight years to reach maturity,[12] and past harvest records show that even small dips in the number of mature adults can produce steep declines in catch.[13] Larger snow crabs, which contribute disproportionately to reproduction,[14] were probably hit hardest by starvation, so the crash likely removed a substantial share of the population’s breeding capacity. Even if conditions improve, recovery will be slow, and the loss of genetic diversity could leave the species more vulnerable to future heat waves.[15]

The Bering Sea fishery is a crucial source of food and employment for many Alaskan coastal communities and a critical part of the broader American fishing industry.[16] The complete cancellation of the snow crab season in 2022 and 2023 was economically devastating for the people whose livelihoods depend on .[17] A limited season returned in 2024, and in 2025 the fishery reopened with a total allowable catch (TAC) of 9.3 million .[18] While this does show early signs of recovery, it remains well  below pre-collapse levels, when annual TAC routinely exceeded 40 million pounds.[19]

At the international level, the United Nations Convention on the Law of the Sea (UNCLOS) governs control of fisheries.[20] Coastal states have exclusive rights to exploit living marine resources within their 200-nautical-mile exclusive economic zones, but that authority comes with a corresponding duty to conserve those resources.[21] While the United States has never ratified UNCLOS, it generally treats its core provisions as customary international law.[22] Historically, fulfilling the duty to conserve meant setting catch limits, monitoring stocks, and policing illegal fishing.[23] But the Bering Sea collapse shows that this legal framework is no longer adequate. Even perfectly managed fisheries can fail if climate change destabilizes the ecosystems beneath them. Effective conservation now requires coordinated international action to slow climate change, and investment in understanding and mitigating the ecological damage already underway.

Recently, the Agreement under the UNCLOS on the Conservation and Sustainable Use of Marine Biological Diversity of Areas Beyond National Jurisdiction (the BBNJ Agreement) gained the required number of ratifications to enter into force.[24]  This agreement was designed to allow participation by non-UNCLOS states, an accommodation effectively relevant only to the United States. While the U.S participated in the convention and even became a signatory, the U.S. Senate has still not ratified the agreement, and thus not a party to it.[25] When it enters into force this January, the United States will once again be sitting on the sidelines of a major global marine conservation framework.

Traditional tools like catch limits and gear regulations are not enough to protect fisheries in an era of accelerating climate disruption. Preserving marine ecosystems, and the communities and economies that depend on them, will require legal systems capable of responding to rapid, climate-driven ecological change. If we do not modernize our ocean governance frameworks, fishery management will remain reactive, fragmented, and outpaced by the warming oceans of the Anthropocene.

 

 

[1] Cody S. Szuwalski et al., The Collapse of Eastern Bering Sea Snow Crab, 382 Science 306, 307–08 (2023).

[2] NOAA Fisheries, Snow Crab Collapse Due to Ecological Shift in the Bering Sea (Aug. 21, 2024), https://www.fisheries.noaa.gov/feature-story/snow-crab-collapse-due-ecological-shift-bering-sea.

[3] Alaska Dep’t of Fish & Game & Nat’l Marine Fisheries Serv., 2024 Snow Crab Workshop: “Clawing Their Way Back,” 4–6 (Aug. 2025), https://www.adfg.alaska.gov/FedAidPDFs/SP25-11.pdf.

[4] NOAA Fisheries, Alaskan Communities Use Flexibility in Snow Crab Fishery Regulations for Economic Relief (Mar. 31, 2025), https://www.fisheries.noaa.gov/feature-story/alaskan-communities-use-flexibility-snow-crab-fishery-regulations-economic-relief.

[5] Szuwalski et al., supra note 1 at 307–08.

[6] Id. at 308

[7] NOAA Fisheries, Research Confirms Link Between Snow Crab Decline and Marine Heatwave (Oct. 19, 2023), https://www.fisheries.noaa.gov/feature-story/research-confirms-link-between-snow-crab-decline-and-marine-heatwave (noting that “caloric requirements for snow crab in the lab nearly doubled in water temperatures ranging from 0 to 3°C”).

[8] Bif, M.B., Kellogg, C.T.E., Huang, Y. et al., Marine Heatwaves Modulate Food Webs and Carbon Transport Processes, 16 Nat Commun. 8535 (2025), https://doi.org/10.1038/s41467-025-63605-w.

[9] Szuwalski et al., supra note 1, at 308.

[10] Eric C. J. Oliver et al., Longer and More Frequent Marine Heatwaves over the Past Century, 9 Nat. Commun. 1324 (2018).

[11] Christopher M. Free et al., Impacts of Historical Warming on Marine Fisheries Production, 363 Science 979 (2019).

[12] E.G. Dawe & D.R. Mullowney, Large males matter: Low sperm reserves in female snow crab (Chionoecetes opilio) off Newfoundland, Canada, 186 Fisheries Research 539, 543–45 (2017).

[13] Alaska Dep’t of Fish & Game & Nat’l Marine Fisheries Serv., supra note 3 at 7-9.

[14] Dawe & Mullowney, supra note 10, at 543–45; NOAA Fisheries, Alaska Shellfish Reproduction Research, https://www.fisheries.noaa.gov/alaska/science-data/alaska-shellfish-reproduction-research (last visited Nov. 2, 2025).

[15] Cynthia Vasquez et al., Genetic Diversity and Resilience in Benthic Marine Populations, 96 Rev. Chil. Hist. Nat. art. 4 (2023), https://doi.org/10.1186/s40693-023-00117-1.

[16] NOAA Fisheries, supra note 4.

[17] Alaska Dep’t of Fish & Game, 2022/23 Bering Sea Snow Crab Season Closed (Oct. 10, 2022), https://www.adfg.alaska.gov/static/applications/dcfnewsrelease/1441272349.pdf.

[18] Alaska Dep’t of Fish & Game, 2025 Snow Crab Total Allowable Catch Announcement (2025).

[19] NOAA Fisheries, supra note 4 (noting the 2020-21 TAC was 45 million pounds).

[20] United Nations Convention on the Law of the Sea, Dec. 10, 1982, 1833 U.N.T.S. 397 [hereinafter “UNCLOS”].

[21] UNCLOS arts. 56, 61.

[22] See United States Ocean Policy, Statement by President Reagan, 19 Weekly Comp. Pres. Doc. 383 (Mar. 10, 1983) (declaring that the United States will recognize and act in accordance with UNCLOS provisions on traditional uses of the oceans).

[23] UNCLOS art. 61(2)–(5).

[24] Agreement under the United Nations Convention on the Law of the Sea on the Conservation and Sustainable Use of Marine Biological Diversity of Areas beyond National Jurisdiction (BBNJ Agreement), adopted June 19, 2023, https://www.un.org/bbnjagreement/en (last visited Nov. 2, 2025).

[25] Congressional Research Service, Implementing Agreements Under the United Nations Convention on the Law of the Sea (UNCLOS), IF12283, at 3 (2024), https://www.congress.gov/crs-product/IF12283