Salmon to hatch soon
RIVERDALE – Tiny eyes can be seen inside the first salmon eggs gathered by North Dakota Game and Fish Department biologists this fall. The eggs are in incubating jars located in the Salmon Building at the Garrison Dam National Fish Hatchery.
Each fall biologists extract eggs from spawning-age salmon taken from Lake Sakakawea and the Missouri River. North Dakota’s land-locked salmon cannot successfully spawn naturally, meaning the salmon captured and the eggs extracted are vital to sustaining a salmon population within the state.
This year, the salmon egg-taking operation took on even greater importance because South Dakota and Montana were in need of eggs too.
“South Dakota didn’t have a very good run,” said Russ Kinzler, NDG&F Missouri River System fisheries biologist at Riverdale. “Part of it is that they are still suffering from losing salmon through the dam on Lake Oahe in 2011. They also got hit with a loss of smelt. They have a real forage problem down there.”
Kinzler estimated about 550,000 North Dakota salmon eggs were transported to South Dakota. Montana will get salmon eggs in a few weeks after the “eye up” in jars at the Garrison Dam Hatchery. Fortunately, North Dakota’s salmon egg quota was easily met. That left plenty of eggs for other locations on the Missouri.
“As far as I know they are the only disease-free chinook salmon in North America,” said Sean Henderson, Garrison Dam National Fish Hatchery. “They are completely isolated from the ocean and are a distinct stock now.”
According to Kinzler, the state plans on stocking 200,000 salmon back into Lake Sakakawea next June. The salmon will grow in the hatchery throughout the winter and are expected to be about 6 inches long when released. The 200,000 will come from more than 1 million eggs gathered during this year’s spawn.
“We ended up with more than we needed,” said Kinzler. “A saving grace for us this year is that about a third of our females have come out of the river.”
Many of the river salmon ran up a man-made flow toward the hatchery where they were raised and became impounded in holding basin. Retrieving the salmon from the basin is a much faster and simpler process than standard electroshocking.
“We got over 200 females out of that kettle,” said Kinzler.
The average size of the female salmon was about 7 pounds, but a number of 10-15 salmon were captured daily.
Inside the hatchery, it is Henderson’s responsibility to care for the eggs and young salmon that will be produced. Henderson speculated that the total amount of eggs under his care will number about 875,000. That amount includes a significant number of eggs that will not hatch.
“Yes, it includes the bad eggs,” explained Henderson. “We’ll pick through them, we’ll hatch them in the hatching jars. Then they’ll swim out as yolk sac fry into the troughs. It’ll take about two weeks for them to swim up into the water column. Then we’ll begin feeding them. It is pretty labor-intensive until they are stocked out in June.”
Henderson estimated that all of the salmon eggs in the hatchery this past week would be hatched out within three weeks. Based on past survival history, reaching a goal of 200,000 salmon for stocking is within reach.
“We are raising them bigger than we have in the past,” noted Kinzler. “That should mean better survival. Last spring they were about 20 to the pound. That is probably a 6-inch fish.”
According to Kinzler, goldeyes in Lake Sakakawea were an effective predator on salmon when stockings were made of smaller fish. It is believed goldeye predation of salmon is virtually eliminated by stocking older salmon, meaning more salmon have the opportunity to live until breeding age. Most female salmon spawn in their second or third year and then die. Males join the spawn no later than their second year.