Not everyone loves mayonnaise. It’s a controversial condiment that doesn’t have quite the same widespread appeal as ketchup or mustard. But if you ask animal conservationists, there’s no debate: Mayonnaise has become an unlikely ally in the fight to save endangered green sea turtles.

According to the Associated Press, a recent oil spill on Israel’s coast has created an environmental crisis for wildlife. More than 1000 tons of tar have washed ashore over 120 miles. Sea turtles native to the region are being subjected to the toxic substance that covers their bodies and enters their digestive systems. Rescued turtles have been moved to the Sea Turtle Rescue Center in Michmoret to receive treatment.

“They all got here with a coat of tar on their heads, and in their eyes, nostrils, mouth, digestive system, and stomach,” Yaniv Levy, founder of the center, told Israel news outlet Haaretz.com. “With this kind of damage they have no chance to survive without treatment. We removed the tar from their nostrils and eyes so they could breathe and see.”

To flush the tar out, conservationists have found that mayonnaise is an effective solution. First, vegetable oil is used to thin the tar. Then, turtles are fed the condiment via a syringe, which dilutes the tar and allows it to be flushed out of their digestive tract.

Because mayonnaise has proteins and fats, it’s also nourishing for the turtles, who are right now subsisting almost exclusively on an all-mayo diet.

Currently, 27 turtles are being treated. Though the turtles begin to respond to care within days, it could be weeks or months before they’re ready to be released back into the wild, pending results of their bloodwork. Israel’s Environmental Protection Ministry is still investigating the cause of the spill.

[h/t Food & Wine]