February 14, 2020 — The Dungeness crab fishery in California recently shut down months early after a 2017 lawsuit filed by the Center for Biological Diversity (CBD) that required crab fishers to pull their gear out of the water with only 3 weeks notice. A settlement agreement was reached in March 2019, which included an early closure for the 2018-2019 Dungeness crab fishing season. Fishing gear is a serious threat to whales that live in, and migrate through, California waters. The California Dungeness Crab Fishing Gear Working Group, convened by the California Department of Fish and Wildlife (CDFW), informs regulators on ways in which to minimize entanglement risks and protect whales.
Why have there more whale entanglements recently?
According to a new paper published in the journal Nature Communications climate change could be responsible. According to lead researcher Jarrod Santora, warming events in recent years, combined with recovering whale populations cause whales to come in contact with crab fishing gear more regularly.
Crab season in California occurs between November and mid-July. Warming events in 2014-2016 caused an increase in the marine algae Pseudo-nitzschia which produce the neurotoxin domoic acid (the toxin causes shellfish poisoning in humans). In 2016, high levels of toxins delayed the crab season until March. In addition, the warmer waters changed feeding habits of humpback whales, steering them closer to shore where food was more prevalent. This perfect storm of events led to a sharp spike in observed whale entanglements in 2017. 70% of the whale entanglements reported in 2017 in the United States involved fishing gear.