Firefighters and volunteers are searching the mud and grass around the lake, which is situated in Irsee, about 100 kilometres east of Munich.
Experts have deemed the bite marks to be that of an alligator snapping turtle, a species not native to the region. Found almost exclusively in the southern U.S., they are among the largest freshwater turtles in the world, with some known to weigh over 100 kilograms.
Authorities believe that a pet owner must have released the turtle into the lake, a notion that outrages locals.
“We the people of Irsee, are annoyed by whoever has done all of this because this here is one of our nicest lakes for swimming,” Guenther Oberweiler told Reuters Monday. “I think that it is simply grotty and irresponsible of whoever did this,” he added.
The turtle, now nicknamed "Lotti," is now featured in warning signs plastered around the lake. The town’s mayor, Andreas Lieb, has offered a reward of €1,000 ($1,370) to the person who finds the turtle, according to local media.
Irsee folk are afraid that the popular summer spot might never be the same for famlies if Lotti is not found.
Oberweiler’s wife, Gisela, told Reuters her children would be too afraid to swim in the lake again. “My children would no longer want to come themselves because they will be scared about what could happen,” she said.
Experts from Munich are expected to arrive Tuesday to help find the turtle. Meanwhile, the lake will be fenced off to prevent further incidents, while Lotti could be sinking deeper into the mud, as turtles are wont to do.