Frequent Questions—National Marine Mammal Entanglement Response Networks

Who are members of the National Marine Mammal Entanglement Response Networks?

The U.S. National Entanglement Response Networks are a collaborative and community-based effort composed of:

State and federal agencies
Tribal governments
Non-profit organizations
Universities
Zoos and aquaria
Industry experts
Other experts

All network members have significant experience gained through formal training and entanglement response. The U.S. networks also work closely with networks in Canada and Mexico to cross-train and share information.

NOAA Fisheries’ Marine Mammal Health and Stranding Response Program oversees, manages, and authorizes all marine mammal entanglement response activities in the United States.

What is an entanglement?

Entanglements can be external or internal, or both depending on the entanglement configuration. An external entanglement is where foreign material (e.g., hooks, line, net, debris, etc.) becomes wrapped around, hooked into, or involves the outside of the body of the animal. An internal entanglement is where an animal ingests fishing gear including hooks, line, or other marine debris, which could become embedded in the mouth or throat. Internal entanglements can be hidden and lead to a slow death with no obvious external signs of the gear or debris.

How do entanglements harm marine mammals?

Entanglements are detrimental to the health of marine mammals. Potential health impacts include:

Deep cuts into skin, blubber, muscle, and bone
Risk of infection
Blood loss
Physical and social stressors
Extra energy expenditure
Decreased body condition
Decreased reproductive success

In some species, notably bottlenose dolphins, entanglements may lead to an increased risk of other human interactions such as illegal feeding and harassment. Entanglements are also a welfare concern for the marine mammal. They can harm their physical and mental wellbeing by causing stress, pain, and suffering.

When is an entanglement considered life threatening to a marine mammal?

Not all marine mammal entanglements are considered life threatening and may not warrant an immediate entanglement response effort. Experts assesses many factors before launching an entanglement response, including:

Species of the entangled animal
Gear location
Gear configuration
Entanglement severity
Type of entangling material
Safety of the authorized response team

Trained and authorized responders have documented marine mammals shedding gear on their own as they move or eat. Additionally, by studying entanglement scars on marine mammals, scientists know animals can sometimes shed entanglements on their own. Successful self-release is only possible for a small number of entanglements, and depends on the entangling material and entanglement configuration. Most entanglements are life threatening to the animals, and can lead to:

Starvation
Amputation of flippers, tails, or dorsal fins
Blood loss
Strangulation
Drowning
Hindering vital behaviors such as feeding, swimming, and breathing
Death

Assessing the severity of an entanglement is often difficult. High quality photos and videos help us to make an assessment, in addition to onsite monitoring of an animal’s condition and behavior by trained and authorized experts. We consult with veterinarians, experienced responders, and biologists to determine if an entanglement is life threatening. Given the dangerous nature of removing entangling material from wild marine mammals, trained and authorized responders only attempt to remove an entanglement if it is life threatening to the animal.

What causes marine mammal entanglements?

Entanglements are caused by humans. The sources of entanglement are extensive and diverse, and include:

Active fishing gear (such as commercial, subsistence, and recreational)
Derelict gear (such as lost, discarded or abandoned gear, also known as “ghost gear”)

Marine debris (such as plastic packing bands/straps, large rubber bands, balloon strings, garbage, etc.)

Are some marine mammals more prone to entanglements?

All marine mammal species have the potential to become entangled. However, the National Marine Mammal Entanglement Response Networks receive more reports of certain species. Nationally, the most frequently reported entangled species are:

Large Whales

Entanglements are one of the primary drivers of two large whale Unusual Mortality Events since 2017: North Atlantic right whales and minke whales.

Small Cetaceans

Bottlenose dolphins (with the majority of cases occurring in the U.S. Southeast)
Killer whales

Pinnipeds

These species are more at risk for entanglement due to:

Feeding and diving behavior
Age (e.g., young animals are curious and may play with items found floating in the ocean)
Migration or residency patterns (e.g., seasonal overlap with fisheries, residency in coastal waters with extensive recreational and commercial fisheries)
Morphology
Type of gear/debris in the habitats

The local level of surveillance, reporting, and recovery in proximity to these species may also contribute to the number of entangled marine mammals that are reported.

Why respond to entangled marine mammals?

We and our partners mount response operations to remove entangling gear for conservation and welfare reasons. Removing some or all of the entangling material from an animal by response teams minimizes an individual animal’s suffering and increases its chances of survival.

From a conservation perspective, response activities are especially important for species with small populations—such as those listed as threatened or endangered under the Endangered Species Act. For some species with small populations, the loss of one individual (especially breeding females) could have negative impacts on the population’s recovery. Most rescues involve species that are not considered threatened or endangered. However, the experience and lessons learned by the Entanglement Response Network members from responding to those cases help hone their skills and expertise. This ensures responses to endangered species (such as North Atlantic right whales, blue whales, Steller sea lions, and Hawaiian monk seals) are conducted as skillfully as possible.

Entanglement response to individual animals is not a sustainable solution in the long term. Preventing and minimizing marine mammal entanglement is a critical goal for NOAA and our partners. We document, identify, and recover entangling gear (when possible). Recovered material may be sent to gear experts to identify it, examine its configuration, and where possible, trace it to specific fisheries. We also document which fishing gear and marine debris pose risks to animals.

Why do we need to document entanglements?

Documentation is crucial to learn about how, where, when, and which marine mammals get entangled as well as what is entangling them. This information is critical in:

Understanding the magnitude of this pervasive problem
Reducing the risk of future entanglements
Informing management efforts such as take reduction plans and teams

Monitoring individual animals after a disentanglement can document their survival and fitness, and provide further insight into how wounds heal over time. Monitoring can also help quantify how many animals die from their injuries despite the full or partial removal of gear.

Why should only trained and authorized responders cut the animals free?

Only trained and authorized responders should attempt to disentangle or closely approach an entangled marine mammal. Marine mammals are powerful, wild animals that can behave unpredictably. Entangled animals that are stressed and injured can pose significant risks to humans. They have been known to bite, injure, and kill well-intentioned rescuers, even people with training and experience. If you see an entangled marine mammal, the best way to help is to immediately report it and remain at the recommended distance away from the animal.

All marine mammals in the United States are protected by the Marine Mammal Protection Act. Some species or populations are listed as threatened or endangered under the Endangered Species Act. These laws prohibit the harassment of marine mammals, but allow trained professional responders to get the necessary authorizations to closely approach and disentangle animals.

There have been cases in which members of the public have tried to disentangle an animal. Their well-intentioned attempts made the situation worse and needlessly put them in danger. These attempts made it more difficult for trained and authorized responders to fully disentangle the animal and more likely that the animal would die from the entanglement. Responders also lost critical information about the type and source of gear and the severity of entanglement. Every piece of information we retain can help tell the story of each case and help guide future management decisions. These setbacks underscore the need for entanglement response operations to be conducted by trained professionals with the proper tools and equipment to safely remove and retain gear.

Why don’t responders enter the water to cut the animals free?

Getting in the water with an entangled marine mammal is extremely dangerous. Marine mammals are large and powerful wild animals that display unpredictable behaviors when entangled. Even when entangled, they can swim much faster than humans. Trying to disentangle marine mammals in the water would make it very difficult for trained and authorized responders to effectively document the entanglement and remove it. The Marine Mammal Entanglement Response Networks have developed specialized tools and techniques to respond to free-swimming and anchored entangled marine mammals from the safety of a vessel. These allow for a higher success rate than when untrained and unauthorized people respond.

How do entanglement response teams ensure their own safety?

While working closely with entangled marine mammals, rescue teams make every effort to keep themselves safe. These safety measures include:

Extensive training and preparation to identify and anticipate potential health and safety risks
Protective gear such as helmets, gloves, and personal floatation devices (when working on the water)
Specialized tools, such as knives mounted on long poles
Specialized techniques, such as darting with sedatives to reduce proximity and time responders spend near an animal)
Significant planning for each entanglement response effort
Collective lessons learned from each response are shared broadly with teams in other regions and around the world

Experts continue to develop specialized tools and techniques to increase safety. However, accidents still happen and trained responders have been seriously injured or killed during rescue operations. All entanglement responses prioritize human safety to ensure entanglement response teams, and the public, avoid injuries. While every effort is made to respond to entangled marine mammals, it is not always possible. Human safety is always paramount.

What is NOAA Fisheries doing to prevent future marine mammal entanglements?

NOAA Fisheries continues to work with partners, including fishermen, to reduce marine debris and to minimize and prevent entanglements. Each response to an entangled animal, and the wealth of data collected throughout the process, provides information to guide gear modifications and management strategies to further reduce threats.

We work closely with the fishing industry and fishery managers to promote improved marking of fishing gear. This makes it easier to identify sources of fishing-related entanglements, monitor fishery impacts on populations, and help develop measures to reduce entanglements in the future.

We are also working with fishermen, biologists, and engineers to develop new fishing gear technologies that reduce or eliminate rope and line in the water column. There have been promising advancements in the field of “on-demand gear” in recent years. We invest in bycatch reduction technologies in several ways, including the Bycatch Reduction Engineering Program.

How can I help prevent the entanglement of marine mammals and other marine life?

Together, we can prevent the entanglement of marine mammals and other marine life.

Dispose of all trash properly: If trash is left loose it can wash overboard or into sewer and storm drains, local waterways, and into the ocean
Dispose of or recycle recreational fishing gear properly after use to ensure it doesn’t end up in the ocean
Participate in community clean-up efforts: Whether at the beach, river, or local park, trash and discarded line can often find its way into the ocean and present an entanglement risk
Remove entangling materials from the marine environment (e.g., mooring, fishing gear, anchoring systems) when not in use
Remember to “lose the loop”—cut any loop before properly discarding it in the trash so that it does not become an entanglement hazard
Support fishermen who are pioneering the use of new fishing technologies that reduce the amount of rope/line in the water
Use fishing gear that is less harmful to marine mammals, such as barbless hooks
Move to a new fishing area if marine mammals are present

If you accidentally hook or entangle a marine mammal, immediately report it so trained and authorized responders can safely respond.

Outreach and education with the public are critical parts of conservation. Increasing public awareness and promoting stewardship will ultimately reduce the entanglement threat, support conservation efforts, and aid in recovering protected species.

What should I do if I see an entangled marine mammal?

The best way you can help entangled marine mammals is to immediately report sightings. Only experienced responders authorized by NOAA Fisheries and have the appropriate training, experience, equipment, and support should attempt to disentangle or closely approach an entangled marine mammal.

Learn more about what to do if you see an entangled marine mammal

Last updated by Office of Protected Resources on 06/26/2024