About 26 whales ran aground this week in Georgia – and 16 of them died – in the second mass stranding this year in the state, said the Georgia Department of Natural Resources.
The pilot whales with short fins were arrested Wednesday on or nearby St. Catherines Island, south of Savannah, the department said in a press release.
It is unknown why whales run aground. This species is the most common mass-chain species in the southeastern US, DNR said.
Necropsies are being performed on the carcasses to try to determine why the whales ended up on the beach.
Whales are highly social and travel in cocoons.
"They are highly cohesive animals, and when one is sick or sick, others can be around, even if it means reaching the shore and getting sick, weakening or running aground," says the state DNR.
Other possibilities for stranding include biotoxins, underwater noise, tides and extreme weather conditions, says DNR.
This week's beaching "is clearly not related to" a capsized freighter in St. Simons Soundmore than 30 miles away, said Clay George, senior wildlife biologist at DNR.
In July, dozens of bathers came in to help at least 47 stranded pilot whales on the island of St. Simons in southern Georgia. No cause for this mass beaching has been determined, DNR said, and it is not known if any of the same whales were in St. Catherines this week.
St. Catherines is privately owned and not open to the public.
Short fin pilot whales can weigh over 3 tons and reach 24 feet in length.