A 4-year-old endangered right whale that became entangled in nearly 300 feet of fishing line was partially freed Monday after biologists pursued it and removed some of the heavy rope from its mouth.

The 30-foot whale was spotted in the waters near Jacksonville, Fla., during Navy aerial surveys. Biologists from the Georgia Department of Natural Resources and the Florida Fish and Wildlife Conservation Commission were alerted to the distressed whale’s predicament, and quickly sprang into action to free the giant.

According to Associated Press, the rescue crew was able to remove about 280 feet of the heavy commercial fishing rope, but had to leave some of it inside the whale’s mouth.

“We feel like what we did gives the whale a fighting chance to shed the remainder of the rope on its own,” Clay Georgia, a marine mammal biologist for the Georgia Department of Natural Resources, told AP. “The real take-home message here is, we can't just go out and save and fix every whale that shows up entangled. In some cases it's just completely impossible to disentangle that whale.”

Experts say that encounters with commercial fishing gear and accidents with ships off the East Coast are the biggest threats right whales face in the wild.

Right whales, which can reach 50 feet in length and are identified by their enormous heads, are the rarest of all large whales. According to National Geographic, right whales were hunted nearly to extinction by 17th-, 18th- and 19th-century whalers. The whales were especially valuable for their abundant oil and baleen, the row of keratin bristles used to filter krill through their mouths. Baleen was used to make corsets, buggy whips and other popular items.

Northern right whales, which are found in the Atlantic along the eastern coast of Canada and the U.S., are the most endangered of all the right-whale species. There are only about 450 northern right whales left in the wild. Each winter, the whales migrate to warmer waters off the coasts of Georgia and Florida to give birth to their calves.

Watch a video of the right whale rescue here:

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