Salmon From Idaho Hatchery Also Endangered Fish Tanks Stand Empty Because Not Enough Adults Returning From Ocean To Provide Eggs Needed To Fill The Tanks
The Sawtooth Fish Hatchery, ringed by Idaho’s most impressive mountains, has a suitably impressive display of fish-rearing technology.
The centerpiece is 14 204-foot long concrete tanks, each capable of rearing 170,000 young chinook in fast-flowing water pumped from the nearby Salmon river.
But most of the tanks are empty. Not enough chinook salmon are returning from the Pacific Ocean to provide eggs needed to fill the tanks.
“It’s a disturbing feeling to see those tanks empty like that,” said Brent Snider, who manages the hatchery for the Idaho Department of Fish and Game.
In 1985, the year the hatchery opened, 1,344 adult chinook returned to site. Only 19 adult fish made it back in 1995.
Idaho’s hatchery program has plummeted into jeopardy.
Many experts fear that Idaho’s hatchery spring/summer chinook - the world-famous fish that migrate up to 900 miles to the state’s alpine meadows - are following wild fish on the path toward extinction.
A total of 460 adult chinook returned to the Idaho hatcheries this year, down from a peak of 18,390 in 1986.
The Idaho Fish and Game department, which designed the hatchery program to fill Idaho’s rivers and streams with fish for anglers, has been forced to change goals. Now it’s struggling to simply produce fish to keep the hatcheries alive.
“Trying to produce large number of smolts isn’t on the table - we’re in the emergency mode,” said Ed Bowles, anadromous fisheries coordinator for Idaho Fish and Game. “We’re to the point to where we’re concerned about losing the patient, not getting him ready to run a marathon.”
Of the 19 fish that arrive this year, only four were females. Two are wild fish, so will be released to spawn and die.
Two, recognizable as hatchery fish by their clipped dorsal fins, will be kept in pools until their egg sacs fill. They will then be killed and their eggs - neatly removed with sharp knife - will be fertilized with sperm taken from the males. Each female has about 4,000 eggs.
Those 8,000 eggs should translate into 6,000 to 7,000 six-inch smolt ready for release in early 1996. That does not sound like a small number, but the Sawtooth Hatchery was designed to produce 2.4 million smolt a year.
About one adult chinook can be expected to return to Idaho for every 1,000 smolt that head to sea.
The problem, experts say, aren’t the hatcheries themselves, which have pumped out nearly 60 million young salmon - called smolts - over the past decade. Hatcheries cannot overpower the eight federal dams on the lower Snake and Columbia, which devastate runs of smolt migrating to sea.