How do you keep turtles from crossing the road? You fence them in.

A temporary barrier built alongside the guard rail near Spencer’s Creek Thursday prevents turtles from crossing the busy stretch of road to lay eggs.

"We’re trying to get the turtles to follow the creek under the bridge, rather than over top the road," said Tys Theysmeyer, head of natural lands for the Royal Botanical Gardens.

Royal Botanical Gardens staff and volunteers are digging up invasive plants and shrubs cluttering Cootes Paradise to create a more hospitable environment. They want to encourage turtles living in the marshland to reproduce without crossing Cootes Drive.

The RBG believes the barrier saved about 125 turtles last year, the first time a barrier was built.

About 15 years ago the RBG noticed turtles were crossing the road and being run over.

"Certainly as the population increases and more and more cars are going up and down this road, its been a point of issue [for the turtles] figuring out how to get around it," said Theysmeyer.

Cootes Paradise is home to five species of turtles, including the snapping turtle and the midland painted turtle. Four out of the five species are at-risk or rare. The RBG believes about 200-300 turtles remain in Cootes Paradise. It’s a crucial environment for the Great Lakes.

"It connects into Lake Ontario and is the largest remaining coastal marsh in the area. It’s a very important wetland habitat for a lot of species including turtles," said Kathryn Harrison, biologist for the RBG.

The big problem is mature, female turtles cross the road and get killed, said Harrison.

The RBG wants to build a permanent barrier along the guard rail but doesn't have the $50,000 - $100,000 it will take to build one.

"It’s expensive," said Theysmeyer. "If you’re going to keep them, you better keep them here."