Oza dos Rios, Spain ? More than 15,000 minks are on the loose in Spain. And conservation officials say they likely won’t survive long.

Vandals – believed to be environmental activists – broke into three mink farms late Saturday and opened the gates. They propped boards on walls to help the prized animals scale them and placed fish outside as bait to keep them going.

The biggest raid was at a farm in the town of Oza dos Rios, where about 5,000 of the animals were freed. The farm’s owner, Charo Carrillo, said the raid meant “20 years of work to create a high-quality product have been ruined.”

Carrillo said the mink likely will starve to death in days because they were raised in captivity and don’t know how to hunt or fish. Jose Benito Reza, a conservation official with the Galician regional government, said whoever freed the mink “did them no favor whatsoever” because they cannot survive in the wild.