About 2,500 manatees have perished in Florida over the last four years, heightening tension between conservationists and property owners as federal officials prepare to decide whether to down-list the creature to threatened status.
Conservationists say the deaths are evidence of the vulnerability of the walrus-like mammals, which were included on the endangered species list in 1967 because of boat collisions and destruction of sea grasses in the shallow coastal inlets they inhabit.
But owners of waterfront property and businesses filed a lawsuit in April in federal court accusing the U.S. Fish and Wildlife Service of failing to adhere to its own 2007 recommendation that down-listing is warranted because there are now more manatees than ever.
Most of the 4,800 pudgy sea-grass-munching mammals in the U.S. gather in each year in Florida, where warm, temperate coastal water, power plant discharges and warm-water springs act as buffers to the lethal effects of icy winters.
The agency's delay in implementing the recommendation prompted the Pacific Legal Foundation to sue on behalf of a group called "Save Crystal River Inc."
The group takes its name from the Crystal River, a destination about 100 miles north of Tampa, known for sport fishing and manatee tours in the vicinity of its headwaters.
"Environmentalists want to turn the entire Crystal River into a sanctuary, which would hurt our clientele," said Christina Martin, a Pacific Legal Foundation lawyer representing property owners in the case. "Our clients simply want the federal government to pay attention to what its own biologists are saying and down-list."
Opponents of down-listing argue that the agency's recommendation came before two major mortality events. They also fear that decreasing protection would leave manatees more vulnerable to potentially catastrophic die-offs.
In 2010, 766 of an estimated 5,077 U.S. manatees died, largely due to cold stress. In 2013, 830 manatees died amid red tide blooms. In the meantime, dozens of manatees are killed each year in boat collisions, despite rules and regulations enacted to safeguard the animals.
"We're up against an antigovernment group that wants to roll back the very protections that have prompted a comeback of a species once hunted to near extinction," said Pat Rose, executive director of the nonprofit Save the Manatee Club. "Then they could run their boats where they want, when they want and as fast as they want.
"We're trying to get as many people as possible to put pressure on the Fish and Wildlife Service before the public comment period on this matter ends," he said. "We want the agency to base its final decision on the most up-to-date scientific information available."
The Fish and Wildlife Service is expected to take comments until Sept. 2, then make a final decision with a year.