Airdate: Jun 07, 2010
Scientist: Heidi Golden
Science Diary: Grayling - Weir
Scientists use a river fence to help monitor Arctic Graylings, the only fish found in Alaska’s Kuparik River.
music; ambience: moving water
"Down in here, I know there's fish."
We're on the Kuparik River in the Alaskan tundra, in the Brooks Mountain Range, fishing for science. And yes, it's catch and release. Welcome to Pulse of the Planet's Science Diaries, a glimpse of the world of science from the inside.
"These fish that reside in the Kuparik River are exclusively Arctic Grayling. And what they tend to do is, around noon, when the mayflies start hatching and things start warming up in the river bed a little bit, they'll start moving up and feeding. But they move up and they catch the weir there, they bump into the weir and then they'll sidle back down into this pool."
Heidi Golden is a research assistant to Linda Deegan at Alaska's Toolik Lake Field Station. Climate changes in the Arctic mean changing conditions for the Alaskan tundra ecosystem. Deegan and Golden's work will help monitor the effects of these changes on the fish known as the Arctic Grayling.
"A weir is a special kind of a fence that we put into the river to keep the fish from moving around too much. We don't want them to migrate upstream before we can tag and weigh and measure them, so we place the fence or the weir into the river and it stops their migration. And all the fish that we capture we place in this holding pen, and we do this so that they can stay for twenty-four hours to clear their gut. And by doing that, we get a much more accurate weight on the fish, when we weigh and measure them the next day. And then we tag them, and we then let them recover and we place them back in the river."
The way scientists tag fish nowadays will likely surprise you. We'll find out in our next program. Our thanks to the Marine Biological Laboratory in Woods Hole.
Pulse of the Planet's Science Diaries are made possible by the National Science Foundation. I'm Jim Metzner.