Nearly 10 miles down a gravel road in the thick of the southern Kenai Peninsula near Happy Valley, Syverine Bentz lead two scientists wearing thick boots to a shallow stream of water draining from nearby Stariski Creek. It was nearly obscured by shrubbery and trees.
The group deployed about a dozen backpack sized, collapsable fish traps to test the effectiveness of a nearby, man-made beaver dam made of sticks and dirt. If the traps catch baby salmon, that means the dam is working.
Bentz coordinates coastal training and engagement programs for the Kachemak Bay National Estuarine Research Reserve. That’s an environmental research institution operating under the University of Alaska Anchorage.
She and her team are working to keep wetlands wet.
“Everyone has something to thank a wetland for, whether that's keeping your basement dry, keeping your roads from eroding,” Bentz said.
But she said healthy wetlands don’t only benefit salmon. Beaver dams also extend wetland habitat that’s important to spawning salmon.
“Providing that cold water and nutrients to salmon stream for adult salmon returning, as well as providing juvenile salmon habitat throughout their early life stages,” Bentz said.
Baby salmon often swim through small streams, like those found in peatlands.
Peatlands are a type of wetland made up of decaying plants, and make up a portion of the southern Kenai Peninsula. But those swampy areas are drying up due to a warmer, dryer climate. Bentz says that’s drying the associated critical salmon habitat at a rate of about 10% per decade.
Drying conditions are compounded by a dwindling beaver population.
“Without beavers, obviously there are fewer beaver ponds, and so less kind of standing water on the landscape,” said Kachemak Bay National Estuarine Research Reserve ecology technician Spencer Johnson. “And so, you know, less rearing habitat for juvenile salmon, potentially.”
But the implications of dried-out wetlands are broader than salmon. Moose feed in marshy areas. And wetland plants have long been used by Alaska Native tribes for berries.
Peatlands also store carbon — more than all other vegetation types in the world combined, according to scientists.
Some of the research reserve’s data show that carbon in the soil of peatlands has higher levels of dissolved organic matter in the nearby water. This improves stream productivity, which can be good for salmon habitat.
The team said restoring peatlands can offset greenhouse gas emissions, like those that come from cars. So, the project also measures carbon exchange rates in the peatlands. In short, healthy wetlands means a healthier environment.
“If we can keep our wetlands as like, good areas of carbon sequestration, then that'll help us mitigate the effects of climate change,” Johnson said.
Johnson said healthy wetlands mean healthy salmon. And on the Kenai Peninsula, healthy salmon means a healthy economy.
“Obviously, salmon are really important. I mean, they're really important for many reasons, you know, really important economically for the state. A lot of people fish for salmon for subsistence,” Johnson said.
Right now, Bentz’ team has a small number of dams and testing sites installed. But they hope to expand and leverage their research for the health of wetlands, salmon and Alaskans alike.
