(February 01, 2022) --
Cold stress is the leading cause of death for manatees in Alabama and Mississippi, and cold-weather-related manatee strandings happen almost every year along the northern Gulf of Mexico coast. The death of a potentially cold stressed manatee last week, however, turned out to be more unusual than researchers expected.
The manatee was first reported by a local fisherman in the Theodore Industrial Canal off Mobile Bay, Alabama on Monday, January 24. Staff from the Dauphin Island Sea Lab’s Manatee Sighting Network (DISL/MSN) and the Alabama Marine Mammal Stranding Network immediately responded to assess the animal’s condition.
“The animal had some skin discoloration that can be a sign of cold stress and was actively swimming, but failed to leave the area, making rescue a good option,” said DISL/MSN Director Dr. Ruth H. Carmichael. “We are always concerned about cold-stress-related mortality this time of year when water temperatures can be too cold for manatees to survive in Alabama.”
Under the direction of the U.S. Fish and Wildlife Service, DISL/MSN staff and partners from SeaWorld Orlando and the Florida Fish and Wildlife Conservation Commission coordinated a rescue on Wednesday, January 26. The nine-foot-long, male manatee was successfully captured and attended by a veterinarian, but was too sick to survive, and died during transport to a rehabilitation facility.
During a post-mortem examination (also known as a necropsy) the following day, the manatee was found to be suffering from multiple stressors.
“While cold stress alone could have been enough to cause the manatee’s death, in this case, there was more to the story. The manatee also had chronic heart failure that led to severe lung disease,” explained DISL veterinarian, Dr. Jennifer Bloodgood. “This condition would have made it very difficult for the manatee to breathe and may have been exacerbated by the cold water temperatures. In addition, a plastic bag was found blocking the animal’s esophagus and likely prevented the animal from being able to swallow food.”
Additional tests are pending to determine how long the plastic bag may have been lodged in the esophagus and whether it may have contributed to the animal’s death. Plastic debris, including monofilament fishing line and small unidentifiable plastics, are occasionally found in the digestive tracts of stranded marine mammals in Alabama, but this is the first case in which the debris has been large enough to cause an impaction and may have contributed to death.
DISL/MSN stresses the importance of reporting manatee sightings to the network year-round, but especially during winter months when animals are at greater risk of becoming distressed and sick.
“In this case, rapid reporting allowed us to quickly get on the scene with the manatee and work with our partners to launch a rescue effort,” said Carmichael. “While this is not the outcome we hoped for, our rapid response was able to give this animal the best possible chance of survival.”
Please report manatee sightings as soon as possible to DISL/MSN by dialing 1-866-493-5803. If animals appear sick or in distress, choose the emergency reporting option when prompted. Non-emergency sightings can also be reported online at manatee.disl.org.
For more information on manatees in our area and recommendations on how to safely share our local waterways with these protected marine mammals, visit manatee.disl.org.