The US Forest Service, which manages the weir at Redoubt, reports almost 22,000 fish have returned to freshwater so far, and the run is not expected to peak for another week or two. Biologists project that the total run this year could reach 80,000.
Two commercial seine openings have been held, and more are likely.
Chris Leeseberg is the district wildlife biologist in Sitka. He oversees the Redoubt lake fertilization project.
Redoubt Lake is an unusual body of water.
“The top one-third of the lake is freshwater, and the bottom two-thirds are saltwater.”
This happens because saltwater is denser than freshwater. The technical term for a lake like Redoubt is “meromictic.” In some meromictic systems, the different layers of water might mix at times, but not so at Redoubt.
The freshwater lens at the top of the lake supports the reproductive cycle of the sockeye. The bottom of the lake is a sort of no man’s land.
“They come back. They spawn. They die. Their carcasses provide these great nutrients. Well, we’re losing a lot of that to the bottom of the lake. It gets into this anoxic saltwater environment, and we lose it.”
As a result, the Redoubt Lake sockeye system is deceptively small, given the overall size of the lake. Leeseberg says the optimum capacity for Redoubt is from 7,000 to 25,000 returning fish. Anything more does not really contribute to larger runs.
So this year, with a projected return of 80,000 fish, the Alaska Department of Fish and Game has already held two commercial seine openings. Leeseberg says commercial fisheries are written in to the sockeye management plan created by the state, the Forest Service, and other stakeholders over ten years ago.
“When we get a year like this we have options to open up more fish for subsitence fishermen, and potentially commercial fisheries as well.”
The subsistence bag limit has also been raised this year to 25 fish per day, or 100 per household for the season.
Additionally, the Forest Service has for the second year in a row issued an emergency order banning dogs from coming ashore within a half-mile of the falls. The six Forest Service employees working on the weir have established a strict bear hazing protocol. Loose dogs upset that discipline, and can antagonize bears.
Leeseberg says the weir crew has, over the course of several years, trained the Redoubt bear population to respect air horns.
“So when you’re out there dipnetting or fishing, it’s one of two things: A crew coming to the weir. We notify the bears that we’re coming to the weir with air horns. It is our time to be on the weir. We’re trying to be the dominant species out there at that point. I don’t want my crew out there working with bears five or ten yards away. And if we’re on the weir and a bear does pop out, we blow air horns and shoot them in the rump with a rubber slug, and blow the air horns again. And that usually does the trick.”
And the trick for fishermen, says Leeseberg, is to take advantage of this pattern.
“Bring an air horn with you. These bears see an air horn and they get scared, because they associate it with a rubber slug to the rump, which is not very pleasant.”
One wild card in the Redoubt formula this year is the massive landslide in May, which blocked the inlet stream — prime spawning ground for sockeye.
A 55-acre lake has formed behind the slide. Leeseberg says this is not necessarily bad news for fish. He says the downed old-growth timber resembles a huge beaver dam.
“There’s a lot of fear from people who really don’t understand how fish migrate that beaver dams can create migration barriers. In a lot of cases that’s not true. In fact, beaver dams can create great fish habitat, and fish will find their way through, even big fish. And I think that’s going to be the case with this slide.”
A Forest Service team will conduct surveys of spawning activity in the lake, to confirm this idea.
Leeseberg says state wildlife troopers have been more active at Redoubt than in past years, and several people have already been cited for failing to obtain their free subsistence permits at the local ADF&G office. He also doesn’t think fishermen need to be overly competitive looking for good spots on the falls. Leeseberg says he’s no expert dipnetter by any means, but there are so many fish around that he’s managed to get a few anyway.