Displaced Dolphins: Post-hurricane Response

Following major storms, the National Marine Mammal Stranding Network sometimes receives reports of displaced marine mammals in unusual inshore locations. These animals are often trapped and may need professional assistance to return them to their natural habitat. NOAA Fisheries consults with marine mammal behavior specialists, veterinarians, scientists, and other experts to determine the best course of action, which may include intervention such as capture and release.

Severe Weather Threats

Every year, residents in coastal communities are on high alert for severe tropical weather during the Atlantic hurricane season (June through November). Hurricanes and tropical storms can lead to storm surges and coastal flooding. They can cause marine mammals—usually coastal dolphin species and, rarely, offshore species—to strand on land or become displaced when they are pushed inland. Low-lying areas in the southeastern United States are particularly vulnerable to coastal flooding from storms. At the peak of the storm surge, the water is deep enough between the ocean and inland waters for nearshore dolphins to enter freshwater areas. As storm waters recede, dolphins are sometimes reported in areas where they are not typically observed (“out-of-habitat”). In the past, dolphins have been found in unusual places after hurricanes including:

• Ponds and lakes
• Land-locked canals
• Levees
• Drainage ditches
• Flooded fields

These animals may remain in these areas for weeks to months following severe weather events. They might require rescue by trained and authorized responders to return to their natural habitat.

Health Impacts

In many cases, displaced animals are trapped in areas with low salinity water, poor water quality (e.g., high levels of contaminants or storm debris), little to no food, and/or quickly receding waters. Dolphins experiencing prolonged exposure (days or weeks) to low salinity can develop illnesses, including skin lesions, blood chemistry abnormalities, secondary infections, and swelling. These health effects can be exacerbated in dolphins with pre-existing conditions, such as injuries, infection, or poor nutrition. Continued exposure can lead to death. Animals trapped in locations with  enough water depth, sufficient salinity levels, and some prey options may still be impacted by poor water quality. A rescue is generally warranted if animals are assessed as ill or injured and when conditions are relatively safe for responders to access the area.

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Is Intervention Necessary?

When evaluating whether to intervene, NOAA Fisheries considers:

• The likelihood of the animal leaving on its own
• The animal’s chances of survival if no intervention occurs
• If the environment is safe for the response team and the animal(s)
• The potential strain of a rescue attempt on local infrastructure and communities in need

NOAA Fisheries consults with marine mammal behavior specialists, veterinarians, scientists, and other experts to determine the best course of action. We always prioritize human and animal safety. Following catastrophic weather events, access to a “disaster zone” may be restricted. Severe damage to property and equipment, loss of power, limited resources, road blockages, and inland flooding can prevent the team from accessing the area. These constraints are potential health and safety hazards and may delay the response for several weeks.

A Coordinated Response

Only trained and authorized responders should rescue a trapped or out-of-habitat dolphin. In-water captures are dangerous for both people and the dolphin, logistically complicated, and not always the most appropriate course of action. These response efforts require careful planning. They often draw on the expertise, personnel, and resources of local and state agencies, as well as other regional Stranding Network partners. To safely relocate a trapped or out-of-habitat animal, responders may need to herd, catch, handle, and/or transport the dolphin. The rescue attempt can sometimes lead to the injury and death of the dolphin, as well as injury to responders. Depending on the species and the circumstances, the animal may require treatment and care at an authorized rehabilitation facility. If they are severely ill or injured, they may require euthanasia. If rescue and relocation are not urgent, safe, or feasible, experts may monitor the animal to determine whether a rescue may be possible at a later date.

Case Study: Hurricane Ida

Hurricane Ida was the second-most damaging hurricane in history to make landfall in the United States. In 2021, the hurricane left behind a trail of destruction and caused severe flooding in many low lying areas. As the storm waters began to recede, a bottlenose dolphin was found swimming in a small, 10-foot-deep drainage pond in Slidell, Louisiana. 

NOAA coordinated with trained responders from local Stranding Network partners who monitored the trapped animal’s behavior and health daily. The animal was observed feeding on wild fish; however, there was no clear path for the animal to leave the pond on its own. During the monitoring effort, skin lesions associated with freshwater exposure began to appear on the dolphin’s body, suggesting its health was in decline.

Within a week of Hurricane Ida, the area was deemed safe enough for a rescue attempt. Stranding Network members—with assistance from local and NOAA law enforcement agencies—successfully caught, medically assessed, transported, tagged, and released the animal back into the Gulf of Mexico near Waveland, Mississippi. 

What You Can Do?

If you see a trapped, injured, or dead marine mammal, please immediately call trained and authorized marine mammal Stranding Network responders. Do not attempt to move, feed, or intervene with dolphins in any way. You can also download the Dolphin and Whale 911 Stranding App in the Apple Store to help report a stranding. 

If you find a stranded or out-of-habitat dolphin (or other marine mammal) following a large storm or at any other time, put human safety before animal safety. 

Immediately call trained responders for help and guidance on how to safely assist a stranded animal. Across the Southeast, (877) WHALEHELP (877-942-5343) will connect you with a local responder. Or you can reach a responder by state: 

• Louisiana: 504-235-3005
• Mississippi: (888) 767-3657
• Texas: (800) 9MAMMAL (800-962-6625)
• Florida: (888) 404-FWCC (3922)
• Other regions in the United States

If possible, wait with the animal at a safe distance until a trained responder returns your call. Be prepared to provide a photo taken from a safe distance, to describe the animal’s size, color, and physical characteristics, and to describe the animal’s exact location.