Captain Mike Ellis said in an interview posted on YouTube that the boats were conducting controlled burns to get rid of the oil, myFOXtampabay.com reported.
"They drag a boom between two shrimp boats, and whatever gets caught between the two boats, they circle it up and catch it on fire. Once the turtles are in there, they can’t get out," Mr Ellis said.
Mr Ellis said he had to cut short his three-week trip rescuing the turtles because BP quit allowing him access to rescue turtles before the burns.
"They're pretty much keeping us from doing what we need to do out there," he said.
Other reports corroborate Captain Ellis' claims. A report in the Los Angeles Times described "burn fields" of 500 square miles in which 16 controlled burns will take place in one day.
"When the weather is calm and the sea is placid, ships trailing fireproof booms corral the black oil, the coated seaweed and whatever may be caught in it, and torch it ... " the report said.
Mr Ellis said most of the turtles he saw were Kemps Ridley turtles, a critically endangered species. Harming or killing one would bring stiff civil and criminal penalties and fines of up to $50,000 against BP.