Biologists on Friday examined the carcasses of 25 dead pilot whales found off the coast of southwest Florida, collecting samples from the animals to try to determine the cause of a recent spike in whale deaths.

 

Wildlife officials completed necropsies on six whales among the group of 16 females and 9 males a day after they were spotted by boaters near Kice Island, Florida, said Kim Amendola, a spokeswoman for the National Oceanic and Atmospheric Administration (NOAA).

 

The whales were part of a pod originally seen swimming in shallow waters near the city of Naples on Sunday, prompting a team of wildlife officials concerned about a spate of stranded whales, to mark the animals to better identify them.

 

Earlier this week, eight other whales were found dead after they swam into shallow waters near Fort Myers, Florida.

 

The group of 25 whales were found to be thin and showed no signs of having interacted with humans, Amendola said.

 

Biologists have said the whales' close-knit social structure may be playing a role in the deaths. Pilot whales are a social, deep-water species. They live in pods of 20 to 90 whales and typically will not leave ailing or dead members behind.

 

The bonds are so strong that dead whales have to be cleared from beaches before others swimming in shallow waters can be guided out to sea.