A warming climate has dried out some of the nearby ponds and shallow waterways in which frogs and salamanders have typically sought refuge, new research shows.
Exotic trout dominate the West's high-mountain lakes after being introduced for recreational fishing, forcing the aforementioned amphibians and their young to survive in these precarious waters. With climate change thrown into the mix, they are stranded.
"Amphibians in the West's high-mountain areas find themselves in a vice, caught between climate-induced habitat loss and predation from introduced fish," lead author Maureen Ryan, a University of Washington postdoctoral researcher in environmental and forest sciences, said in a statement.
Via new techniques and currently used hydrologic technology, scientists can project river flows in wetland areas as a way to evaluate the effects of foreseen climate change.
In combination with assessing which native wetland areas are most at risk of drying out, researchers can simply eliminate the enemy, so to speak.
"In these regions, fish removal from strategic sites can be used to restore resilience to a landscape where inaction might lead to tipping points of species loss," Ryan and her co-authors report.
In some parts of the West fish removal programs are already in place. Jack Oelfke, a manager at North Cascades National Park in Washington state, said that his crew cleared lakes in the region of trout, allowing long-toed salamanders, northwestern salamanders and tailed frogs to return. The park began trout removal at eight lakes in 2009 after it banned fish stocking.
Frogs and salamanders once flourished in these high elevation habitats when the last Ice Age left behind thousands of isolated high mountain lakes and ponds free of fish. But in the late 1800s fisherman brought in trout and with it a loss of a safe haven for these amphibians.
Those most at risk now are Cascades frogs found only at high elevations in Washington, Oregon and California.
"We hope newly developed wetland modeling tools can improve climate adaptation action plans so ecosystems can maintain their resilience in the face of a changing climate," Ryan added.