Entanglement of Marine Life: Risks and Response
Entanglement in fishing gear and marine debris can be dangerous for marine mammals and sea turtles. Learn how NOAA Fisheries and partners work to prevent entanglements and rescue entangled animals.
How do marine animals become entangled?
Many marine animals, like whales, dolphins, seals, sea lions, and sea turtles become entangled in fishing gear and other marine debris as they swim or while on the beach. Many objects can entangle marine life, such as fishing gear that is being used to fish both commercially and recreationally, lost or abandoned gear, and other types of rope/line and trash, including plastic bags that find their way into the marine environment.
How does entanglement harm marine animals?
Entanglement of marine life is a global problem that results in the death of hundreds of thousands of marine mammals and sea turtles worldwide every year. Entangled animals may drown or starve because they are restricted by fishing gear, or they may suffer physical trauma and infections from the gear cutting into their flesh. Entangled animals may also be unable to avoid vessels like they normally would, thus increasing the risk of vessel strikes.
Smaller marine animals, like sea turtles, seals, porpoises, dolphins, and smaller whales, may drown immediately if the gear is large or heavy. Large whales can typically pull gear, or parts of it, off the ocean floor, and are generally not at immediate risk of drowning. But they do face risks from exhaustion and infection. Entanglement is considered a primary cause of human-caused mortality in many whale species, especially right whales, humpback whales, and gray whales.
What is NOAA Fisheries doing to help reduce entanglements?
Our Office of Protected Resources works with entanglement response and stranding network partners around the country to safely free marine mammals and sea turtles from life-threatening entanglements, while also gathering valuable information that can help reduce the frequency and effects of entanglements in the future.
Responders have developed specially designed tools and techniques to disentangle whales and other marine animals, all from the relative safety of small inflatable rescue boats. In addition, we use satellite transmitters and receivers to track an entangled animal over time. This satellite tracking method is especially helpful in relocating entangled whales that cannot be disentangled during the initial response.
Freeing a marine animal in distress can be dangerous, for the animal and the rescuers alike. To safely free large animals, such as whales, rescuers follow whale disentanglement guidelines (PDF) and use a boat-based technique that relies on historic whaling techniques called “kegging.” During these disentanglement efforts, rescuers throw grapples or hooks that attach to the gear entangling the whale, and use large buoys to slow the whale down. Once the whale is approachable, rescuers can safely assess the whale and entanglement situation, and attempt to free the animal of all entangling gear. Large leatherback sea turtles, which can measure more than 6 feet long and weigh a ton, are disentangled using similar techniques.
For smaller animals such as dolphins, seals, sea lions, and smaller sea turtles, entanglement response and stranding network partners can capture animals in the water or on the beach and then remove the entanglement. To do this safely, network members are trained in proper techniques for safe capture, restraint, and removal of gear from various marine species. Depending on the type of animal, severity of injury, and circumstances, the animal may need to be evaluated and treated at a permitted rehabilitation facility.
NOAA Fisheries continues to work with numerous partners to minimize or prevent entanglements. Each successful disentanglement provides information to guide gear modifications and management strategies to further reduce threats.
Who is responsible for disentangling marine animals?
Only responders who have been authorized by NOAA Fisheries and who have the training, experience, equipment, and support needed should attempt to disentangle marine animals. Entanglement response efforts also rely on many state and federal agencies (including law enforcement agencies and the Coast Guard), non-governmental organizations, fishermen, and others working together to respond to, and ultimately prevent, entanglements.
In the mid-1990s, a formalized Large Whale Entanglement Response Network was authorized in the United States to respond to reports of entangled large whales. As our partner networks have expanded, they now also respond to entanglements of other marine animals. The NOAA Fisheries Office of Protected Resources coordinates marine mammal entanglement response efforts around the country through the National Marine Mammal Health and Stranding Response Program and federal permitting. Sea turtle disentanglements are coordinated in a similar fashion by NOAA’s protected species programs.
Regardless of the species, disentangling marine animals is dangerous, and should only be performed by trained professionals.
What should I do if I see an entangled animal?
If you see an animal that appears entangled or in distress, immediately report it. Real-time reporting helps increase the chance of a successful disentanglement. And it allows wildlife managers and responders to better understand what led to the entanglement, which helps guide future responses.
For large whales that appear to be in distress, please contact the entanglement specialists in your region via the national entanglement response and stranding network. If you are on a boat without access to a cell phone, please contact the U.S. Coast Guard on VHF channel 16 (156.8 Mhz). And always remember to keep your distance—100 yards or more is recommended.
If you encounter an entangled dolphin, porpoise, seal, sea lion, or sea turtle contact your local responders via the national entanglement response and stranding network. After you report an entangled animal, the responding team will determine whether a response is possible.
Here are the steps to follow:
- Stay in the boat—never get in the water to help a whale, dolphin, seal, sea lion, or sea turtle.
- Note the GPS coordinates of the location of the entangled animal.
- Call your local responder via the national entanglement response and stranding network.
- Wait for trained, authorized personnel—do not attempt to free an animal on your own.
- Monitor the situation—if a response is possible, authorities may ask that you watch the animal from a safe distance (greater than 100 yards and not directly behind the animal).
- Document the entanglement—if possible take photos and video of the animal from a safe distance.
What can I do to help prevent entanglement of marine animals?
When fishing or boating, do not leave fishing gear or trash behind. Also consider participating in community clean-up efforts. Whether at the beach, river, or local park, trash can often find its way into the ocean and present an entanglement risk.
How can I learn more about marine life entanglement?
Learn more from NOAA's marine debris program:
- Alaska: Marine Mammal Entanglement and Marine Debris in Alaska
- New England/Mid-Atlantic: Marine Mammal and Sea Turtle Disentanglement in the Greater Atlantic.
- Pacific Islands: Stranding and Entanglement Response
- Southeast: Marine Mammal Health and Stranding Response Program
- West Coast: SOS WHALe: the Marine Mammal Disentanglement Network