This has been a very tough winter for manatees in Florida.

According to the Tampa Bay Times, the record for manatee deaths caused by Red Tide will likely be broken sometime this weekend.

A Red Tide bloom has been killing 10 or more manatees a day, and experts say the deadly algae isn't going away anytime soon.

The record for manatees killed by Red Tide was set in 1996, when 151 perished from a toxin in the bloom. Entering the weekend, 149 manatees had died this year.

Eleven manatees have been rescued and taken to Lowry Park Zoo in Tampa. But the animals are so sick, zookeepers have to stand in a water tank with them and hold their heads up so they can breathe.

Red Tide has been a problem for Florida's beaches for centuries. There are many years when it doesn't cause much harm, but every now and then, the algae population just off shore explodes into a bloom, staining the water a rust color and releasing toxins.

This year's Red Tide bloom affects about 70 miles of the southwest Florida coast, from Sarasota County south through the middle of Lee County. It has been floating off the coast since last fall, but it did not begin killing off manatees in large numbers until last month, the Times reports.

It's believed there are about 5,000 manatees living in Florida, about 40 percent of which live in southwest Florida from Tampa Bay to Ten Thousand Islands. Almost all of those killed by the Red Tide have turned up in the center of the stretch, in Lee County.

Experts say 392 manatees died last year from all causes.