DARRINGTON – In the springtime, frogs and salamanders busily lay eggs in a 5-acre wetland behind tribal members’ homes on the Sauk-Suiattle reservation.
Tribal natural resources staffers have been monitoring the hundreds of egg clusters, along with the live amphibians they find in the wetland, between February and May for the past four years.
Because amphibians are thin-skinned and sensitive to disturbances in their habitat, they are good indicators of wetland health. The tribe’s survey could reveal a pattern of mutations or changes to amphibian populations that indicate increased pollution or effects of climate change.
The most common species in the wetland are Pacific tree frogs, red-legged frogs and northwestern salamanders. Surveyors also have seen eggs of long-toed salamanders and a few western toads.
Each week, the survey team marks the locations of new egg masses and checks the status of the older ones, noting larvae that have grown tails and those that have floated to the surface or hatched.
Last year, the team found and flagged 1,500 egg clusters. “It was a two-day event to monitor them last year,” said Kevin Lenon, natural resources technician.
“We bit off more frogs than we could chew,” joked Scott Morris, watershed manager for the tribe.
About a month into the survey this year, Morris and Lenon, along with natural resources technicians Eugene Edwards and Michael Wolten, had flagged about 350 egg masses.
By mid-morning on a mild day in late March, Pacific chorus frogs, also known as tree frogs, broke into a desperate symphony for a couple of minutes, then quieted. Studies have shown that one male frog acts as chorus master, leading the others to join in, Morris said.
“It can be kind of peaceful out here,” Lenon said. “Last week, the Pacifics in that pond were making all kinds of noise.” A quick check of the pond confirmed what he expected – many new egg masses waiting to be counted.
The Sauk-Suiattle reservation, at the foothills of the Cascade Mountains, is far from the large cities where water quality has been degraded. The amphibian survey is one way to make sure the wetland remains uncontaminated.
“If anything, this survey will show that we have a healthy wetland,” Morris said.