Link River ladder ready for migration

Published April 6, 2005 by DYLAN DARLING

	The new Link River Dam fish ladder could soon have endangered sucker fish swimming up it, federal scientists say.

Water is now tumbling down the Link River fish ladder and soon endangered sucker fish will be swimming up it, federal scientists say.

"The migration is just beginning now," said Rich Piaskowski, a U.S. Bureau of Reclamation fisheries biologist.

If successful, the migration will be the first since the Link River dam was put in from 1920 to 1921. The dam, on the river that links Upper Klamath Lake to Lake Ewauna, blocked suckers that swam down from going back up.

The new fish ladder will fix that, Piaskowski said. "I expect they are going to run right through this thing," he said.

The ladder, the second-flattest in the United States with a 10-foot climb over a 300-foot run, has a smooth grade created by 33 baffles with slots in them.

Until recently it was unconfirmed whether Lost River and shortnose suckers, both federally protected species, swam through the murky waters of Lake Ewauna, still cloudy from decades as a log storage pond. However, for three years, federal scientists have been catching suckers in the lake, putting electronics in them and then their monitoring the movements.

Scientists slid two kinds of hardware into the fish - "pit" tags and radio tags. The pit tags are like giant grains of rice, stuck into the flesh at the bottom of the fish, while the radio tags are larger and are put into the fish's abdomen.

The radio tags can be detected from afar while the pit tags need to be scanned from a caught fish or a fish that passes by checkpoints.

Scientists are now setting up five such checkpoints, made by a ring of wire strung through plastic pipe, in the fish ladder. The checkpoints will detect any of the 100 suckers scientists plan to tag with pit tags in the coming months.

Another 30 suckers will also get radio tags, Piaskowski said.

The migration should be heaviest this month and next, when the suckers are looking for spawning ground, he said.

With the new electronics in the fish ladder, scientists will get an idea of how many suckers use it, when, and if they come back through. But other questions will be left to linger, including why suckers that are radio tagged have a high mortality rate.

Piaskowski said more than half of the fish radio tagged in the last three years have died, but it's unclear if it is water quality, the radio tagging process - a type of minor surgery - or something else that is causing their deaths.

He is confident that the fish ladder will help suckers that want to go up to Upper Klamath Lake get to their goal.

The easy grade of the new fish ladder will also be inviting for other species of fish, said Chuck Korson, Bureau fish passage manager, including redband trout, lampreys and salmon if they are reintroduced to the area.

"The design is fish friendly for multiple species," he said.

Unlike the old-style fish ladder still on the west side of the Link River, the new ladder doesn't have rungs or steps for the fish to jump in order to get over the dam.

While salmon and trout could make the leap up the steps, there was a problem.

"Suckers can't jump like a salmon or trout," Piaskowski said.

The tagging program has been going on for three years, but most the fish already tagged won't be detected. After 12 to 14 months the radio tags lose their charge and the older pit tags aren't picked up by the new rings.

Across the river from the new fish ladder is the old ladder, which fits the name more. Now unused, the old ladder had a series of small walls fish needed to vault over to get past the dam.

Research into the tagged fish in the last three years showed some of the suckers wanted to migrate up the Link River, but couldn't get up the ladder, Piaskowski said.

The construction of the new fish ladder should end up costing the Bureau $2.5 million, Korson said, well below its original budget $3.2 million.

Workers are still waiting for electronic motors to put on the gates that control the flow of water through the ladder, and for weather to warm up to put down a new parking lot at the Link River nature trail head off of Lakeshore Drive.

The project should be done in June and the Link River trail should reopen, officials said.