Frequent Questions—Live Large Whale Strandings on the West Coast

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Why do whales strand?

Each case is different. Large whales may strand alive for a number of reasons, including:

• Complex topographic and oceanographic conditions
• Contaminants
• Weather conditions
• Natural toxins such as domoic acid or saxitoxin poisoning
• Disease, emaciation or malnourishment
• Human-caused injuries

Are whale populations healthy on the West Coast of the United States?

After 45 years of protection under the Marine Mammal Protection Act, many whale populations are recovering and are reaching healthy population levels. Gray whales are common along the West Coast, and were removed from the endangered species list in 1994. Six species of whales found along the West Coast are currently listed under the Endangered Species Act including:

• Blue whale
• Fin whale
• Humpback whale (some distinct population segments have been recently delisted)
• Northern Pacific right whale
• Sei whale
• Southern Resident Killer whale

How common is it for a large whale to strand alive?

Between 2006–2025, 48 large whales stranded alive in the West Coast region. A majority (35) of these animals died onshore due to underlying health concerns and the negative gravitational effects from being on the beach. Five additional whales were humanely euthanized after they did not self-release after multiple tidal cycles and after health assessments were performed. Only eight whales were returned to the sea, six of which were able to free themselves and swim away. An additional two whales were freed with the assistance of the West Coast Marine Mammal Stranding Network.

Between 2006–2025, 201 large whales stranded alive nationwide. A majority (116) of these animals died onshore due to underlying health concerns and the negative gravitational effects from being on the beach. Sixty one additional whales were humanely euthanized after they did not self-release following multiple tidal cycles or restranded after an intervention. Only 24 whales were returned to the sea, 17 of which were able to unstrand themselves and swim away. Only seven whales were unstranded with human assistance.

Can large whales be saved when they strand?

Every large whale stranding event is unique and poses different challenges. We put human safety in every case when considering how to respond. When a whale strands onshore, a primary concern is that gravitational effects (increased pressure from being out of the water) can lead to respiratory and circulatory collapse. The animal can also experience severe skin blistering, animal scavenging, hyperthermia, distress and serious injury. The West Coast Marine Mammal Stranding Network has used several supportive care methods to address some of these concerns during past live whale strandings. These include using sheets, water buckets, and sprayers to keep whales wet and cool while waiting for the tide to rise or when considering other options, including euthanasia. There may be instances when the whale cannot be safely accessed by the response team, so we must monitor the whales’ condition from a distance.

What are the limitations to responding to a live large whale stranding?

Some of the challenges and limitations include:

• Logistics, particularly for remote locations
• Environmental conditions such as weather and wave conditions
• Animal size and behavior
• Public interest and busy locations
• Resource limitations
• Disposal of the carcass if the animal dies

We need to evaluate many considerations and risks to guide a response such as the welfare of the animal, personnel safety, and the availability of trained and licensed individuals.

Why can’t a whale be pulled off of the beach?

Moving large whales has serious safety risks for the whale and for the Network responders involved. Trying to pull or push a large whale from the beach can also be very resource intensive. It requires specialized equipment, which may or may not be readily available within the critical 24–36 hours after the stranding. Towing live whales by the tail can result in seriously injuring or dislocating the tail, causing paralysis. and is therefore considered inhumane.

There are videos online of “successful” whale re-floating, which generally involve putting a rope or cable around the peduncle/tail of the animal and pulling it off the beach/sandbar with a boat. However, based on input from veterinarians and discussions by the International Whaling Commission, this action is likely to cause pain and physical harm to the animal. It can injure tail muscles, reducing the ability of the whale to swim, feed, and avoid predators. In the worst-case scenario, this process could break the spinal cord which would then paralyze the animal.

Creating a harness to put around the pectoral flippers to pull the animal forward or better position the animal onshore would be a physiologically better alternative, but this method still has multiple complications. Changing the position of the whale onshore is difficult; the harness needs to be safely released so the animal is not entangled. This quick release harness is under development and will need to undergo testing before being used on the beach. Most importantly, this method should only be considered for an animal in good overall condition and when post-release monitoring is available to determine the success of the response efforts.

Can the area around the animal be dredged so it can swim away?

Dredging to remove sediment or sand around a stranded whale has not been tried very often due to resource limitations and potential environmental impacts/approval process. Dredging would require an appropriate vessel and for authorization to be given quickly in an emergency situation, within 24 hours if possible. Dredging to help one animal can also result in significant unintended environmental consequences and may negatively impact other species in the area. Anecdotally, previous attempts to dredge the area around a whale have ended with the whale rolling into the dredged “hole.” Then, unable to right itself to breathe, it drowned.

When does the Network consider euthanasia?

We consider euthanasia if:

• A stranded large whale is in overall poor condition (emaciated, malnourished, severe internal or external injuries, dependent calf with no adult present)
• The whale remains onshore after 1–2 tidal cycles

This will be discussed on a case-by-case basis. The NOAA Regional Stranding Coordinator decides in consultation with the local Network group, attending veterinarian, and Marine Mammal Health and Stranding Response Program staff. This does not mean that euthanasia will be considered in every case. In some areas the location and limited resources may prevent us from intervening safely or considering euthanasia.

The weight of a large whale onshore can result in pressure necrosis on the underlying muscles and their lungs can collapse when a whale is not supported by water. Even if a whale was able to free itself during a subsequent incoming tide, it would not likely survive the stranding following an extended period out of the water. Qualified veterinarians may recommend that euthanasia is the most humane option for the whale based on the condition of the animal, the circumstances, and available resources. If a decision is made to euthanize a large whale, the procedure will be conducted by qualified personnel under the authorization of the Marine Mammal Health and Stranding Response Program permit.

What means of euthanasia are available for large whales?

Many options for humanely euthanizing animals have been considered in order to weigh risks with animal welfare concerns. Currently the preferred method for euthanasia of large whales is through a dose of potassium chloride). This has been used successfully in several cases. There is little toxicity risk to other animals that may scavenge the carcass after euthanasia, allowing for natural carcass disposal. There is also a fairly reasonable cost for resource-limited Networks. This method involves deep sedation so the animal is fully unconscious or “asleep” before administering the potassium chloride. The location and condition of the animal in shallow water or if fully dry stranded may impact the ability of a Network veterinarian to safely approach the whale to administer the solution.

Will the whale be in pain? Will the whale react? How long will it take?

The whale is first given a high dose of a strong sedative and an analgesic (painkiller) before being given the dose of potassium chloride to stop the heart. The initial doses are given with long, skinny needles that do not cause much pain, similar to a vaccine shot. The potassium chloride is then delivered through a large intracardiac needle that reaches the heart. As part of that process, the veterinarian needs to get backflow from the needle to make sure it is in the right place. This process may cause the whale to bleed at the injection site, which can look much worse when a relatively small amount of blood mixes with water.

The whale may react by gaping its mouth or by raising the pectoral flippers or flukes which is known as the “last swim.” This may be difficult to witness but if euthanasia is being administered, qualified veterinarians have determined it is the most humane option for the whale.

The time of death varies for each case; sedation to death can range from 48 minutes to 2 hours and 18 minutes. From the time the potassium chloride is administered to death ranges from 4 minutes to 10 minutes. The potassium chloride works by inhibiting the ability of the heart muscles to contract and effectively stops the heart when administered.

What are the options for responding to a free swimming large whale that has an injury, unusual behavior, or is debilitated?

There are very few options for treating a free-swimming large whale. Many times, treatment with medication such as antibiotics cannot address the underlying reason of why the animal is debilitated or injured. The West Coast Marine Mammal Stranding Network can consider administering antibiotics on a case-by-case basis if the treatment could lead to the improved condition of the whale. Large free-swimming whales cannot be humanely euthanized at sea; the tools to do so safely do not currently exist.

What can be learned from live large whale strandings?

Every year there are thousands of reports of stranded marine mammals (this includes whales, dolphins, porpoises, seals and sea lions) throughout the West Coast region. Each case can hold important information about the species which can contribute to scientific research or public education. The West Coast Marine Mammal Stranding Network conducts necropsies on stranded large whales to better understand the cause of death by collecting a range of samples for analysis. The analysis of these samples may take weeks or even months. As results become available, we can share those results with members of the public or the media if requested. The necropsy is extremely important; it provides valuable insight into the health of these animals and the data collected may help animals in the future.

What is the West Coast Marine Mammal Stranding Network?

The NOAA West Coast Marine Mammal Stranding Network was established in the early 1990s under the Marine Mammal Protection Act. Members of the network respond to marine mammal stranding events along the California, Oregon, and Washington coasts and are part of a nationwide network. The Network responds to all large whale cases to better understand what factors may have contributed to the stranding.

How are the Network responders authorized?

The network is composed of cooperating scientific investigators and institutions, volunteer networks, and individuals. Other organizations also involved are wildlife and fisheries agencies and state and federal law enforcement. NOAA Fisheries authorizes each group to respond to marine mammal strandings within a specific geographic response area through a Stranding Agreement or Stranding Rehabilitation Agreement. The Marine Mammal Protection Act authorizes local or state government officials to respond in the normal course of their duties.

What role does NOAA play?

NOAA’s Marine Mammal Health and Stranding Response Program was formalized by the 1992 amendments to the Marine Mammal Protection Act. NOAA Fisheries was designated as the lead agency to coordinate related activities. Each region (Alaska, Pacific Islands, West Coast, Southeast, and Greater Atlantic) has a Regional Stranding Coordinator that oversees the Network responders.