CIAA fish ladder allows salmon to colonize Paint River system

Nearly every stream connected to the ocean in Alaska has native salmon. Each summer, they make their way up to their birthplaces, homing in using instincts researchers are still investigating.

Some systems have roadblocks, though, courtesy of waterfalls or natural dams. Even if the area upstream is perfect for salmon, if there’s a 40-foot waterfall in the way, there won’t be any salmon there.

However, if the stream layout changed, like a dam bursting or a navigable side route appearing, then wild salmon could push on upstream and create a new population, one that imprints on and returns for years to places no salmon have gone before. That’s what the Cook Inlet Aquaculture Association is trying do with the Paint River system.

The remote river system, emptying from the Alaska Peninsula into Cook Inlet’s Kamishak Bay, has just such a set of approximately 40-foot high barrier falls. Though there’s plenty of good upstream habitat for salmon, they haven’t had a way up past the falls until recently.

CIAA built its fish ladder on the Paint River in the summer of 1991. What looks like a long concrete hallway, roofed by steel grate, stretches the length of a city block through a side channel of the river alongside the falls. After more than two decades of planning, permitting and building, the ladder opened for the first time in 2011, and CIAA is finally seeing some salmon successfully climbing through the ladder.

“Last year, we found some fish carcasses in the ladder,” said Gary Fandrei, executive director of CIAA. “(In 2014,) we found a live silver salmon. That one we tossed into the river above the ladder.”

The Kenai-based nonprofit, which operates hatchery and weir programs throughout the Cook Inlet region, records the fish passing through the ladder from a video weir positioned at the top of the ladder.

This year, the organization installed a video system to document individual salmon passing through the weir. Throughout the summer, CIAA workers have flown to the site to download the video from the solar- and wind-powered camera to watch for fish. In the footage reviewed so far, staff have seen adult chum and pink salmon passing through. Salmon naturally stray. Although salmon have an uncanny ability to find their way back to their birthplaces, they may not always be able to make it all the way because of outside forces acting on their natal streams. Straying allows them to seek out new habitat.

“Otherwise, they’d be extinct,” Fandrei said.

The Paint River fish ladder is a system of locks that guide fish the way ships move through the Panama Canal. Fish enter below the falls and encounter a series of chambers full of water with openings on either side of a concrete wall that allow them to pass into the next chamber. The wall breaks the current, giving the fish a rest as they progress upward, Fandrei said.

The ladder itself works like a spiral staircase, with five flights stacked atop one another for fish to climb the falls. Once they round the final corner, they work their way up a long corridor into the final chamber, where they are cordoned off by a weir and have to pass through a narrow passage to make it out again. This is where the video camera is positioned. They pass between the camera and a wall with a set of measuring marks on it, allowing the viewer to take an easy measurement of the fish.

There are ladders all over Alaska allowing fish to access new habitat. One successful example is the Margaret Creek fish ladder, built in Southeast Alaska near Ketchikan in 1989. It allowed anadromous fish to populate a river system previously blocked by an approximately 23-foot waterfall. Sockeye salmon fry were stocked into lakes above the falls, but wild pinks and cohos colonized the new habitat more than the returning sockeye, along with cutthroat trout, Dolly Varden and steelhead, according to a study published in a January 2011 edition of the North American Journal of Fisheries Management. The discovery of the silver salmon in 2014 marked the first time a salmon had been documented passing through the ladder. Last year, staff found 10 salmon carcasses and two rainbow trout inside the ladder, and on a September aerial survey noted two small groups of 10–12 fish each above the ladder.

This year, the biologists think the salmon returning may be the descendents of those in previous years, finally learning to call the Paint River home.

The Paint River fish ladder only took a summer to construct but more than two decades to accomplish its purpose.

Work on populating the river originally began in 1975, when the Alaska Department of Fish and Game identified it as a potential enhancement site in a statewide plan. Commercial fish harvests had hit an all-time low, and the state launched into salmon enhancement projects, including building fish ladders, to supplement stocks.

In 1978, Fish and Game and then-two-year-old CIAA started feasibility studies on a potential enhancement program on the Paint River system. Upper and Lower Paint lakes, located in the uplands, were stocked with sockeye fry beginning in 1986 and 10 more times throughout the years until 2002. Although adult sockeye were returning to the mouth of the Paint River by 1994, there were never enough to open the fish ladder, according to a 1996 enhancement report from Fish and Game.

CIAA picked up some of the state hatchery operations and was financially stretched to operate them all. That delayed further work on the Paint River project, and then there were challenges to its permit. The Paint River system is close to the McNeil River, famous for its abundant bears. Because of concerns that bears could be attracted to the fish ladder and either fall into it or over the steep falls at the Paint River, Fish and Game’s Division of Wildlife Conservation requested that CIAA add grating above where the fish swim, which took time and money.

Bear conservation advocates were concerned that the increased fish stocks at the Paint River would draw the abundant bears at the McNeil River to the Paint River, which was not part of the game sanctuary where hunting was prohibited. The plan for the ladder kicked off plans to annex some additional territory into the sanctuary in 1993.

“There was concern about the ladder going in and drawing bears off, or bears getting over there and either falling into the ladder or falling into the falls, or being drawn over there outside the sanctuary and being hunted by hunters in the fall,” said Ed Weiss, the lands and refuge manager for the McNeil River State Game Sanctuary and Refuge. “So I think that was part of the impetus behind the movement to expand the sanctuary to include the ladder.”

At this point, CIAA has addressed the major concerns, he said. CIAA also has to obtain research permit to operate in the sanctuary and file an annual report each year about bear sightings and interactions, Fandrei said. Each year, they attend a meeting with concerned agencies about the ladder’s operations, he said.

“We try to work very closely with (Fish and Game) to make sure what their requirements are,” he said.

The organization is allowed to run the video weir until Sept. 30 this year. When workers take the video system out, they will close the ladder, allowing it to go completely dry until next year.

It takes maintenance. On their Sept. 2 trip out to the weir, biologist Rodney Hobby went about downloading the video to a hard drive while Fandrei went down to examine a potential leak. The river is also highly dynamic system — depending on the day, the river can fill the entire fish ladder, about 10 feet tall, or be so low that no fish can physically swim through, Fandrei said.

“Sometimes the water comes up so high that it would lift these grates up,” he said. “So we learned we had to bolt them down.”

Fish and Game keeps an eye on the ladder and will watch the area in the future for potential effects on bears, Weiss said.

“At this point we’re just having a wait and see attitude,” Weiss said. “We don’t do regular surveys or anything. We do have (CIAA), when they go over there, let us know if they spot bears using the stream.”

The video weir costs less to run over time, though it comes with startup expenses. Fandrei estimated that after the initial expenses, the ladder with the video system will cost approximately $15,000 to run each year. The organization has talked about establishing a cabin there for a researcher to mind the weir, but no decision has been made, he said.

The organization has not decided whether to use the fish returning to the system for cost recovery yet. In addition to the fish required for broodstock to keep the population going, CIAA harvests a certain number of the fish returning to some of its hatchery systems as a way to fund itself before making the rest available for commercial and sport fishermen. Setting up a cost recovery harvest would require a terminal harvest area designation through the state, like those the organization operates elsewhere, Fandrei said.

“Those conversations are ongoing,” he said.

After the successful documentation of returning salmon in 2014, CIAA stocked 1 million pink salmon fry into Upper Paint Lake, allowing them to imprint before heading out to ocean. Pink salmon immediately head out to sea after hatching, so the fish returning this year could be the fish from the stocking, Fandrei said. If there comes a day CIAA won’t operate the ladder anymore, it can be shut down at any time, Fandrei said — they’ll simply not open it. Fish can’t climb the ladder without water in it, and if the bottom is blocked off, everything will return to the way it was, the waterfall cascading down, any fish that return stuck into the pool and lagoon below.

 

Reach Elizabeth Earl at elizabeth.earl@peninsulaclarion.com.