Hundreds of Animals Mysteriously Dead in Florida Lagoon [PHOTOS]

Indian River Lagoon in Florida has become a mysterious mass grave for hundreds of animals as experts struggle to determine what is prolifically killing marine life in one of America's most biologically diverse estuaries.

At least 111 manatees, 300 pelicans and 46 dolphins have been reported dead in the water along the northern stretches of the lagoon. Marine biologists are trying to figure out what could possibly be going wrong in the water. The animals were all found emaciated to the point of skin and bones, according to a report by Discovery News, which said the lagoon ecosystem contains more species than anywhere else in the country.

The lagoon, which stretches across 40 percent of Florida's eastern coast, has reportedly long been polluted by nutrient and fertilizer runoff from lawns and farms, but in recent years the effects of the pollution may be coming to a tipping point. Florida does not have strict laws regulating the amounts of nutrients such a nitrogen and phosphorous allowed to run off the land into its surrounding waters.

"The lagoon is in a full collapse, it is ongoing," Marty Baum of the Indian Riverkeeper told Discovery News.

Since July of last year 111 manatees have died in the lagoon, with 43 of the creatures reported dead in just one month. Kevin Baxter, spokesman for Florida Fish and Wildlife Conservation Commission (FWCC) told Discovery News that their deaths could be linked to a diet change. While they usually feed on sea grass, a lack of availability forced the manatees to switch to feeding on sea algae, which may be a contributor to their deaths.

The FWCC reports as many as 300 dead pelicans in the lagoon since January. The birds were reportedly emaciated and overrun with parasites.

Dolphins were reported similarly emaciated, with at least 46 of the mammals reported dead since January. Marine life experts have called the dolphin deaths an "unusually high mortality event" because the number of dead is double the average record for previous years.

So far the exact source of the deaths remains undetermined, making the incident of mass death similar to others which offered in the same waters in 2001 and 2008. It's probable that the precise cause of all the deaths will never be known, as it's likely a number of factors are in play.

Megan Stolen, a marine life researcher, told Disvocery News, "If lots of bad things are happening all at once, we may not find a consistent cause of death."

The Daily Mail obtained a number of photos documenting the extent of the loss of marine life, which can be seen here.