Environmental protection officer Manuel de Jesus Solis says his agency found 12 dead turtles bearing marks apparently caused by fishing nets. It was unclear which fishing boats were involved.
Victor Berdejo says another 47 dead turtles were found by personnel at a turtle-protection area he supervises.
The sea turtles, once hunted in Mexico for their meat and eggs, were declared a protected species in 1990. Fishermen are required to include turtle escape devices in their nets.