Two pilot whales died and two more were euthanized, off the coast of southwest Florida Tuesday, day after four others died in the area, officials said.
A total of four whales have been euthanized around Lover's Key near Fort Myers in Lee County, which is the same area where four whales died, NOAA spokeswoman Kim Amendola said.
Six whales who were spotted there on Monday were not found in an aerial survey Tuesday and are unaccounted for, Amendola said.
Two of the eight whale carcasses are being brought to the Florida Fish and Wildlife Conservation Commission's pathobiology lab in St. Petersburg, where necropsies will be done on them, Amendola said.
Necropsies will be carried out on the other six on scene, and afterward they will be buried there, she added.
Meanwhile, the U.S. Coast Guard has reopened boat traffic in the area.
On Monday, the two whales had to be euthanized after they beached themselves south of Lover's Key, according to NOAA.
A total of 14 pilot whales had been spotted in the area earlier Monday but by Monday evening, a group of seven were stranded on a sandbar and appeared to be in poor condition, NOAA said.
The dead or euthanized whales and the animals who could not be located Tuesday all came from that group, Amendola said.
She said it's too soon to tell why the whales died, and that it could be months before officials get the necropsy results.
Pilot whales live in deep water, so when they swim inland it's usually a sign of toxicity or disease.
Separately, none of the 23 whales that were spotted swimming around Gordon Pass in Naples in Collier County on Sunday were stranded or died, Amendola said.
Biologists marked those whales, which were spotted again off Marco Pass near Marco Island on Monday. A FWC boat stayed with the 23 whales for much of Monday, when they were two miles off-shore, and officials are no longer monitoring them because they were offshore, Amendola said.
She added that another 12 whales were seen swimming two miles off of Fort Myers Beach on Monday morning, but officials did not respond to that situation because they were offshore.
In December, more than 50 pilot whales stranded in Everglades National Park, some of whom died.