Biologists Report 453 Fla. Manatee Deaths in 2011

State wildlife officials are reporting the third straight year with high numbers of manatee deaths.

The Florida Fish and Wildlife Conservation Commission reported Wednesday that 453 manatee carcasses were documented in state waters in 2011.

That's the second-highest number on record. Biologists reported 766 in 2010 and 429 in 2009.

Biologists say the past three years also had the highest numbers of cold-related manatee deaths. Before 2009, cold stress accounted for an average of 30 manatee deaths a year. That number jumped to 56 in 2009, 282 in 2010 and 112 last year.

The director of the conservation commission's Fish and Wildlife Research Institute says officials are concerned about the number of manatee deaths since 2009 and will do more research to understand any long-term implications for the protected species.