Invasive plants threaten BC’s western painted sea turtles

Invasive plants are infiltrating the nests of British Columbia’s rare western painted sea turtles, putting the population at serious risk.

These weeds colonize the habitats of the painted sea turtles, the only native freshwater turtle species in the province, by colonizing the loose gravel where female turtles like to lay their eggs.

Now, local biologists are organizing weed-pulling events to prevent the pesky plants from disrupting the environment further.

“These non-native plants choke out potential nesting sites and their roots have been shown to grow through the developing eggs,” says wildlife biologist Leigh Anne Isaac in an interview with CBC.

“[The hatchlings are] very much confined to its nest, so anything that does happen while it’s in its nest, they are quite vulnerable, including roots growing through their nest,” said Isaac.

Known for the bright yellow stripes on its head, neck, legs and tail, and the red marking on its belly shell, the painted sea turtle lays around six to 18 eggs, which are the size of a toonie, in June or July. If the hatchlings survive the summer, they break out of the eggs around September. They stay in the nest until the following spring. Because sea turtles only reproduce every second year, only a few baby turtles survive each year.

And along with predators like raccoons and skunks, the eggs are now facing the threat of invasive plants.

Isaac hopes that pulling out the weeds will restore the habitat, noting that a long-lasting effort will be needed to protect the turtles in the future.

“[Invasive plant] seeds can last a long time in soil. These weed pulls will have to have regularly and frequently, so we can knock back this impending front of invasive plants,” said Isaac.

In British Columbia, most painted sea turtles are located in pockets throughout the southern interior, including the Okanagan Valley, Kamloops Lakes and the Creston area, where Isaac was heading up the weed pull.

The western painted sea turtle is currently on the province’s Blue List, which means the species is considered vulnerable to habitat loss and particularly sensitive to human activities or natural events.