A bill that would have phased out the use of drift gillnets off the California coast died in committee last month in the state Assembly, but the federal agency charged with protecting marine life says this week that it will shut down the fishery that uses them if a single sperm whale is killed or injured by the nets.
Drift gillnets, previously discussed here at ReWild, are nets that float beneath the surface of the ocean used to catch swordfish and thresher sharks. Up to 6,000 feet in length and extending 200 feet below the surface, the nets have been criticized for years for the damage they cause to other species, including sea turtles and marine mammals.
One of those marine mammals, the sperm whale, is listed as Endangered under the U.S. Endangered Species Act (ESA). In 2010, two sperm whales were found entangled in drift gillnets set by a swordfish fishing boat, a violation of ESA. In order to keep that from happening again, the fisheries office of the National Oceanic and Atmospheric Administration (NOAA Fisheries) announced an emergency rule Wednesday that will close the entire California drift gillnet fishery for the year if a single sperm whale is harmed by the nets.
The largest living species of toothed whale, and thus the world's largest toothed predatory animal, sperm whales (Physeter macrocephalus) occur worldwide. They were hunted aggressively from the 18th to the 20th century for their oil, which was used in applications as wide-raging as cosmetics and industrial lubricants.
By 1970, when the whales were listed as Endangered under ESA, their numbers had dropped to less than a third of their pre-hunting population, estimated at 1.1 million. Though their numbers are thought to be recovering since hunting stopped, that recovery is slow and whales still face a range of threats. Entanglement in fishing nets is one of the most serious of those threats.
NOAA Fisheries' emergency rule, which takes effect today, comes just three weeks after a bill in the California legislature that would have ended the use of drift gillnets in California waters failed to get enough votes to pass out of the Assembly's Water, Parks and Wildlife Committee.
A previous emergency rule protecting the sperm whales expired in January. NOAA Fisheries is soliciting public comment on long-term management of the sperm whale-driftnet conflict.
Drift gillnets used for catching swordfish, which generally have a mesh that allows animals smaller than 14 inches to pass through, are usually deployed between August and January off Southern California, but some fishing for swordfish and thresher sharks does take place from May to August.
During that summer season, drift gillnets must be used at least 75 miles from the shore, and that means deep water. That means that even the more limited summer gillnet season poses a threat to sperm whales, which spend most of their time in deep water. According to NOAA Fisheries, 90 percent of California sightings of sperm whales took place in water deeper than 1,100 fathoms, or about one and a quarter miles deep.
Under NOAA Fisheries's emergency rule, any driftnet vessels operating in waters deeper than 1,100 fathoms must have an independent, agency-certified observer on board. Vessels must notify NOAA Fisheries of each fishing expedition 48 hours in advance of departure, and carry onboard Vessel Monitoring Systems that track their location and report it in realtime to the agency.
If a single sperm whale is injured by gillnets during the deepwater fishing season, NOAA Fisheries will immediately close the season until August 5.
These mile-long driftnets are a deadly trap for endangered sperm whales and other marine mammals," said Catherine Kilduff of the Center for Biological Diversity (CBD). CBD, along with the groups Oceana and Turtle Island Restoration Network, threatened to sue NOAA Fisheries in September unless the agency crafted permanent rules to protect sperm whales from drift gillnets.
"We're glad [the whales] are getting these emergency protections," said Kilduff. But this problem needs a long-term fix. Permanent rules, if not a complete ban on these destructive nets, are long overdue."
"This wasteful driftnet fishery is always in crisis and the emergency never stops for whales, dolphins, and fish that get caught and die by the hundreds," said Turtle Island Restoration Network's Teri Shore. "It's time to ban driftnets instead of constant regulatory triage."