Nearly 100 false killer whales recently were stranded in the mangroves in the Everglades in South Florida. The beached whales were first spotted near Hog Key on the morning of Jan. 14 by the U.S. Coast Guard, according to the National Oceanic and Atmospheric Administration National Marine Fisheries Service. Rescuers tried to herd the animals back into deeper waters, but were unsuccessful.

So far, 82 of the animals have been reported dead and 13 are unaccounted for.

The Coast Guard was joined by a team from NOAA and the Florida Fish and Wildlife Conservation Commission, reports the Miami Herald. They tried for two days to herd the whales away from the shore, but their rescue efforts were stalled in the remote location due to issues with shallow muddy flats and mangrove-laced shorelines. Rescuers also had to deal with the threat of sharks. In addition, the lack of cell service made communication among rescuers difficult.

False killer whales are actually large members of the dolphin family. They resemble killer whales, except they are black with lighter patches near the throat and chest. The stranded whales included adults, calves and juveniles.

Of the 95 animals that were located, rescuers had to euthanize 10 that were too ill to survive, according to CNN. In addition, 72 died on their own.

The National Park Service closed the area around the stranding and asked boats and planes to avoid the area while the search continues.

According to NOAA, false killer whales are known to strand in large groups. However, this is the largest recorded stranding of false killer whales in Florida history. The largest stranding on record occurred in 1946 when an estimated 835 whales beached themselves in Argentina.

Researchers don't know what caused this group of whales to strand, but biologists have taken samples from the dead whales, hoping to learn more.

Mary Jo DiLonardo covers a wide range of topics focused on nature, health, science and anything that helps make the world a better place.

Mysterious stranding kills dozens of false killer whales
Nearly 100 false killer whales were stranded in the Everglades and more than 80 died as rescuers tried to save them.