2004 Manatee Mortality Figures Released

For further information, contact: Nancy Sadusky Communications & Outreach Director Phone: 407-539-0990 E-mail: nsadusky@savethemanatee.org

Date: January 5, 2004

The 2004 manatee mortality statistics were released this week by the Florida Fish and Wildlife Conservation Commission (FWCC). A total of 276 manatees died last year, compared to 380 in 2003.

According to the FWCC, 69 manatees, or 25% of the total, were killed by watercraft collisions in 2004. This figure is nothing new. Statistically, since records have been kept, watercraft-related mortality, on average, has accounted for about 25% of all manatee mortalities. “That means that one in four manatees are still being killed by boats,” said Patti Thompson, SMC Director of Science and Conservation. “That’s unacceptable, and our challenge is to get those numbers down.”

Three manatees were killed in flood gate/canal lock structures in 2004, and four manatees died as a result of other human-related activities such as entanglement in monofilament line, fishing nets, or ingestion of fishing hooks or litter. This compares to three flood gate/canal lock and seven other human-related deaths in 2003.

There were 72 perinatal mortalities in 2004 compared to 71 in 2003. It is important to note that ”perinatal” is not a cause of death but a category that includes all calves that measure150 cm or less in length that were not determined to have died from human-related causes. “All wild populations of animals have an inherent, and relatively high, rate of perinatal death, but absent human-caused influences on the general population, they can usually overcome these losses.” said Thompson. “However that does not mean that researchers are not looking for the causes of these deaths and trying to find ways to bring these numbers down as well.”

While there was a large drop in total number of manatees killed in 2004 as compared to 2003, the FWCC figures show that red tide events in 2003 largely account for the difference. In 2003, 96 manatees were determined or suspected to have died because of red tide while only four manatee deaths were attributed to red tide in 2004.

As for Hurricanes Charley, Frances, Ivan, and Jeanne, which swept through Florida in 2004, “we can’t say at this point whether they had an effect on the population or not,” said Thompson. “It’s too soon to tell.” A scientific paper written by Catherine A. Langtimm and Cathy A. Beck of the U.S. Geological Survey Sirenia Project and published in 2003 showed that manatees’ mean survival during years with major storms was significantly lower than years without them. Scientists use sighting-resighting methods to track the annual survival rates of individual manatees (in other words, whether manatees showed up at the same warm water gathering areas this year) and then use statistical analysis to determine the survival rate of the whole population.

“Clearly, we can’t do anything about the weather when it comes to manatees,” said Thompson. “But this is another reason why it is so important to address human-caused threats, because these are the types of injuries and mortalities we can do something about.”

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