Seventy-six whales became entangled in fishing gear and other ropes and cables off the U.S. coast in 2017 — and nearly a third of the cases were in California waters, according to an annual report by the National Oceanic and Atmospheric Administration.
Seven humpback whales were tangled in nets or lines in Monterey Bay and eight gray whales were found in the lower half of the Southern California Bight, the report said.
Other cases were scattered up and down along the state, including two blue whales off the San Francisco Bay and a gray whale off the Central Coast.
In several of those cases, the sources of the nets and lines entangling the large animals were commercial and recreational crap trap fisheries, according to a West Coast Entanglement Summary.
Other locations of frequent entanglements include off the coast of the main Hawaiian islands and off Cape Cod and Stellwagen Bank in Massachusetts, the NOAA report said.
Nationwide, six entangled whales were confirmed dead in 2017, 25 were rescued by highly-trained responders or freed themselves, according to the report. The fate of 45 of the whales is unknown.
NOAA Fisheries tracks the number of confirmed cases because entanglements can kill or seriously injure large whales, many of which are endangered or protected species. That can have significant affects on the species’ population and tracking cases allows biologists to consider whether management approaches should change, according to Sarah Wilkin, who coordinates NOAA’s National Stranding and Emergency Response Program.
Video of rescues show highly trained responders approaching entangled whales on small rubber rafts, using a combination of ropes and long, sharp blades to lasso and then cut the large animals free from the lines and nets.
In one clip, a blue rope is wrapped tightly across the base of a whale’s tale and has rubbed through its flesh. A curved knife then slices the rope loose.
NOAA reported that the Large Whale Entanglement Response Network was able to respond to 50 cases of entangled whales and fully or partially disentangle 25 animals. Rescuers were unable to locate 24 other whales; scientists don’t know if they are still entangled, have died or shed their gear.
One blue whale was disentangled by members of the public, which is generally advised against because it can be extremely dangerous for the whale and the people involved, Wilkin said.
Rescuers ask anyone who encounters an entangled whale to contact a local hotline or the U.S. Coast Guard on VHF CH-16.
In California, Oregon and Washington, call 877-SOS-WHALE (877-767-9425).