SCHIESS: Polygamist fish at Henrys Lake
Polygamist arranged marriages are alive and well – at least for the fish at Henrys Lake. Seven female and seven male cutthroat trout are being linked together as families by the Idaho Department of Fish and Game with the help of volunteers.
These families will answer a lot of questions for the department that will hopefully end up improving the fishery for fishermen.
“All of our cutthroats that we will create in the hatchery this year will be genetically included in the “Parental Base Tagging (PBT) system,” Damon Keen, manager of the Henrys Lake Fish Hatchery said as he helped volunteers from North Fremont High School take eggs from the females.
“We take eggs from seven females and fertilize them with milt from seven males that will make about 22,000 in each family. Each family will be identified genetically different from all others,” Keen said.
From each of the 14 “parents” a portion of a fin is clipped that will be preserved and sent to Eagle Genetics Lab that will create the genetic makeup of each family. Then for the next four years (the life expectancy of Henrys Lake cutthroats) a genetic sample of each fish captured during the spawning and gill netting will determine which family the fish comes from and which are wild fish.
“There are a lot of important data that can come from this program,” Keen said. “Some of the ones we are really interested in are the ratio of natural and hatchery production, the difference between the early and late spawning success, our success of feeding in the hatchery while they are young and to check how accurate our aging process has been.”
With all that is going on during a spawning day, many hands make for a smooth and quick egg take, hence the need for volunteers.
On March 10, Karl Dahle’s Fish and Wildlife class from North Fremont High School scheduled a work day at the hatchery. They were taught how to correctly hold and strip the eggs and milt from the fish while others netted the fish in the holding tanks in the hatchery.
“This was awesome,” said senior Seth Bell. “I have never fished Henrys and did not realize what it took to produce fish and how many different fish there are. I mostly signed up for the class because we are going to build a fly rod and I am looking forward to that.”
Last season the fishing during the summer was not very good, which concerned Keen. “I don’t know what happened; we knew the numbers were lower than what we want, but the fishing picked up the last week of August and was good during September,” he said.
This year 3,300 cutthroats have ran into the hatchery compared to 2,200 for the same period last year, but the spawning run is not a population indicator as Keen believes it does not factor in the wild fish.
“We don’t stock hatchery fish in the tributaries anymore and this genetic testing will help us find out if any wild fish are using the hatchery,” Keen explained. “Our population estimate of fish in the lake comes from our gill netting in the spring and hopefully this year we will see better numbers than last year.”
Not only are the fish more numerous running into the hatchery this spring, but the cutthroats are also running larger with a good mix of different age classes of fish. But the population estimates of the lake will have to wait until early May when the gill netting is done.