Reducing the number of large whale entanglements and minimizing the likelihood of large whales becoming entangled in fishing gear promotes the conservation of healthy whale populations along the U.S. West Coast.
NOAA Fisheries is responsible for carrying out the Marine Mammal Protection Act to conserve and manage marine mammal populations and their habitat, and to coordinate responses to strandings and entanglements. The West Coast Region works in partnership with the Pacific Fishery Management Council and state fishery managers from Washington, Oregon, and California to reduce the unintentional entanglement of marine mammals in fishing operations.
By reducing the number of large whale entanglements and minimizing the likelihood of large whales becoming entangled in fishing gear, NOAA Fisheries can continue to promote the recovery and conservation of healthy whale populations along the U.S. West Coast.
Large whales periodically become entangled in active or derelict fishing gear, or other ropes/lines/chains in the marine environment. Some whales that become entangled are able to shed the gear on their own. However, other whales may be unable to shed the gear and can carry it for days, months, or even years. Whales that are entangled can suffer from injuries, infection, and wrapping that can impair their ability to feed or swim. The drag from the gear or debris can cause whales to expend more energy to swim, can make it harder for them to feed, and can result in starvation.
Survival times with an entanglement vary. For example, a recent study found that the average survival time for North Atlantic right whales that could not shed an entanglement was about five months, though it ranged with some living for many years and others dying immediately. Survival will depend on the location of the entanglement on the whale’s body and the severity of the entanglement, among other factors.
The West Coast Region’s Protected Resources Division oversees the Large Whale Entanglement Response Network, which is comprised of whale biologists, researchers, naturalists, veterinarians, veterinary technicians, whale watchers, the U.S. Coast Guard, and state agencies along the West Coast. Due to the dangerous nature of responding to entangled large whales, our responders go through extensive training and many years of apprenticeship to learn the proper techniques and protocols to ensure their safety and that of the animals.
Responders are experts at understanding whale behavior, biology and health, vessel operations, handling ropes under tension, and coordinating entanglement response teams. This work is done under a permit held by NOAA Fisheries’ Marine Mammal Health and Stranding Response Program that provides authorization for responders to approach the whale to attempt the disentanglement.
Over the last few years, NOAA Fisheries has responded to an increasing number of large whale entanglements reported to the West Coast Marine Mammal Stranding Network and Large Whale Entanglement Response Network. In 2018, a total of 46 whales were confirmed entangled off the coasts of California, Oregon, and Washington. We also had 31 confirmed cases in 2017, 48 confirmed cases in 2016, and 50 confirmed cases in 2015. These were the highest annual totals for this region since we started keeping records in 1982.
Between 2000 and 2013, the average was about 10 confirmed whale entanglements reported per year. Entanglement reports may be increasing for a number of reasons, including increasing whale populations, changes in the distribution of fishing effort, changes in the patterns of distribution and movements of whales, and increased public awareness of whale entanglements and reporting procedures. Many of these potential causal factors are, in turn, influenced to some degree by environmental conditions. For example, the late opening of the Dungeness crab fishing season in California in 2016 likely influenced the distribution and concentration of gear in certain areas where whales also congregate.
In 2018, entanglements were reported throughout the coasts of Washington, Oregon, and California, but were concentrated in central and southern California. However, entanglement report locations may not reflect where the entanglement originally occurred.
More information about entanglements per year can be found in our annual reports:
Several species of whales have been reported entangled in recent years, including humpback whales, gray whales, blue whales, fin whales, sei whales, and killer whales. Humpback whales continue to be the predominant species reported as entangled in recent years. The first confirmed blue whale entanglement was reported in 2015, followed by three in 2016, and three in 2017.
The source of entangling gear is unknown for the majority of whale entanglement reports. From 2015 to 2017, 67 out of 129 (52%) confirmed entanglement reports involved gear of unknown origin. Any line, cable, or chain in the ocean can pose an entanglement risk. Detailed fishing gear guides have been developed to help the West Coast Marine Mammal Stranding Network identify the source of gear that is removed from whales and to inform approaches for reducing impacts from those fisheries. Multiple fisheries on the West Coast have been involved with entanglements in recent years, and the number of entanglements related to each fishery type has varied from year to year.
In 2015 and 2016, there was an increase in the number of confirmed whale entanglements associated with the Dungeness crab commercial trap fishery, compared to previous years. Other fisheries identified include gillnet fisheries, sablefish trap fishery, spot prawn trap fishery, and the spiny lobster trap fishery. As the documentation of entanglements has been improved, NOAA Fisheries has increased its ability to identify details associated with entanglement events including gear type, originating location, and the date the gear was set.
NOAA Fisheries is working closely with the fishing industry and fishery managers, including the Dungeness crab fishery participants and managers, to promote improved marking of gear to make it easier to identify specific sources of entanglements and develop measures to reduce entanglements.
Fishing Gear Guides (PDF, 48 pages)
The International Whaling Commission identifies entanglements as the main human-caused threat to large whales, estimating that worldwide 300,000 whales, dolphins, and porpoises die from entanglements each year. The documentation collected during an entanglement response can inform researchers and fishery managers how the whale became entangled and may hold insights that can inform new strategies to prevent future entanglements.
Disentangling a whale can be dangerous, even for highly trained responders, and can be stressful for the whale involved. Having a Large Whale Entanglement Response Program with skilled responders reduces the temptation for untrained members of the public to attempt disentanglement themselves. Attempts to disentangle whales by untrained persons not only harm the whale but can lead to the injury or death of the untrained individual.
In recent unauthorized disentanglement cases, human injuries thankfully did not occur. However, the limited photo and video documentation provided revealed some very dangerous actions taken by unauthorized responders. Attempts to disentangle whales have resulted in the death of would-be-rescuers in the past. In addition, the wealth of important data that is normally collected on each disentanglement event was not collected during these unauthorized cases, leaving substantial information gaps for each case.
Most entanglement reports are not immediately life-threatening to the whale, and there is usually time for a NOAA Fisheries response team to mount a safe and effective response to the entanglement. If responders can confirm that the entanglement is not a threat to the whale’s survival, and/or the whale is likely to shed the gear on its own, responders may monitor the situation, particularly in dangerous conditions, rather than attempt disentanglement. Responders may collect photos and video to identify the whale in the future, document any injuries from the entanglement, and/or take a small biopsy of skin and fat to genetically identify the population the whale belongs to, as well as to identify the individual in case it is ever found dead.
Whales are wild animals that have unpredictable behaviors. The size and power of large whales create risks to the disentanglement team when they closely approach whales in small vessels to document and remove entangling gear. In addition, the tools used for disentanglements, such as specialized knives, lines, and large buoys, can also present dangers for responders, including being pulled overboard.
The techniques that have been developed over the last 40 years rely on working from a small inflatable boat with hooked knives on long poles that keep responders at a safe distance from the whale and reduce risks. Even so, accidents do still occur and even trained responders have been injured or killed.
NOAA Fisheries has done significant outreach on the West Coast to the fishing industry, state and federal fishery managers, and the public to make them aware of the issue, promote the development of ideas to reduce entanglements, and improve the reporting of entanglements. California, Oregon, and Washington have all convened working groups to address the recent increase in entanglement reports and discuss potential solutions to the problem. The California Dungeness Crab Fishing Gear Working Group, for example, produced an updated Best Practices Guide to reduce entanglements caused by Dungeness Crab fishing gear in 2016.
In 2017, funding to promote research to help reduce future whale entanglement risk along the West Coast was provided to multiple groups through NOAA Fisheries’ Bycatch Reduction Engineering Program (BREP). This funding will support research to improve understanding of current gear and fishing practices, as well as potential gear modifications. BREP funding also supported a workshop in 2017 to bring together a diverse group to identify the most promising ideas for innovation to address the entanglement issue along the West Coast.
Use this Large Whale Entanglement Photo Documentation Checklist
Please also understand that while every effort is made to respond to each entangled whale, sometimes it is not possible, but every report of an entanglement is crucial to our understanding of this problem and our attempts to mitigate it.
The two most common baleen whales entangled in the Northwest are the Humpback Whale and the Gray Whale. For help identifying cetacean species, visit the Whales species page or the Dolphins and Porpoises species page.
To report entangled marine mammals:
Forming a response to an entangled whale is very complex and requires a lot of time and coordination. Real-time updates are rarely available as the response team must focus on helping the animal in need. NOAA Fisheries’ Regional Stranding Coordinators keep the NOAA Fisheries WCR Communications Team up-to-date on responses in the field.
Media inquiries should be directed to:
An oceanic whitetip shark swims near the surface of the water. Photo courtesy of John Carlson.
A U.S. Fish and Wildlife employee reintroduces salmon into a Central Valley river.
Aerial view of restored floodplain habitat and agricultural property near Sacramento, California.
