Spring spawning on Lake Sakakawea confirms healthy fishery
PARSHALL, N.D. (AP) — It happens every spring but, my oh my, it’s definitely not always like this.
North Dakota Game and Fish biologists have been conducting their annual spring walleye spawning operations on Lake Sakakawea in recent days and the results have been extremely good, maybe the best ever in the history of the state’s biggest body of water.
“Overall the fishery has probably never been in better shape,” Dave Fryda, NDG&F Missouri River System fisheries supervisor, told the Minot Daily News. “There’s record abundance, good size structure and strong, young year classes. There’s lots of nice, big fish in good condition. Egg quality is good.”
Good egg quality is important. Fryda credits low water temperatures on Lake Sakakawea, still in the mid-40′s recently, as a main reason for good egg quality. Sometimes temperatures during the spawning season rise into the 60′s and 70′s and warm up lake water. Warmer water usually equates to less than ideal egg quality. It’s not something biologists can control. The walleye spawn is primarily driven by the amount of daylight, not water temperature.
The annual process of egg taking involves the setting out of capture nets which are pulled daily so that fish do not undergo undue stress. Walleyes are taken from the nets and then to a crew of biologists waiting on shore. There the male and female fish are separated and placed in holding tanks in preparation for artificial spawning.
Females that are ready to release their eggs do so with the careful help of biologists. The eggs are streamed into a bowl where they are fertilized by milt from male fish. The eggs then undergo a thorough cleaning by fresh water circulating through holding jars. After the cleaning process is complete the eggs are poured into coolers.
“Then they are transported to the Garrison Dam National Fish Hatchery. We hand them off to the Fish and Wildlife Service,” explained Fryda. “They do the hatching and rearing of the fish, stock them into their outdoor ponds and raise them to fingerling size. Game and Fish will come back and do the distributing throughout the state.”
According to Fryda, the goal this year is to raise over 10 million young walleye. It’s a big undertaking that will push the production capabilities of the Garrison Hatchery to the limit.
“We have a high demand across the state because we have a record number of walleye fisheries. The vast majority of them rely on annual stocking to maintain them so there is a high demand for fingerlings,” said Fryda.
All of the eggs sent to the hatchery this year will be taken from Lake Sakakawea walleyes. The artificial spawning process usually results in hatching success of 50% or better. In the wild hatching success is thought to be approximately 5%, even less depending upon conditions.
Many of the fingerlings raised from eggs taken from Lake Sakakawea walleyes will be returned to the reservoir later this summer. Stocking efforts have proven to be quite a success story. Lake Sakakawea’s walleye population is very high and fishermen have been enjoying the results.
“Last summer was exceptional fishing throughout the reservoir,” said Fryda. “The last three years our abundance of walleyes is higher than it has been since Garrison Dam went in and we have good size structure.”
Construction of Garrison Dam was completed in 1955.
Last summer a creel survey was conducted on Lake Sakakawea that revealed the average walleye caught by fishermen measured nearly 18 inches long. An 18 inch walleye weighs about two pounds.
“That’s off the charts for a creel survey,” remarked Fryda. “The average angler caught 3.3 fish per trip and there’s always some blanks. You’ve got to make up for that so the survey results were pretty impressive.”
Judging by the walleyes taken from nets this spring it looks like it will be another banner year for walleye fishing on Lake Sakakawea. The fish were fat and healthy with an abundance of fish in the four to five pound range. Biologists reported netting several walleyes exceeding 10 pounds, whopper fish by anyone’s standards.
With angler success running high Game and Fish determined it was an excellent time to start a four-year fish tagging project. Angler reporting of tagged fish will supply vital information for future management of the fishery.
“Tagging gives us an idea on mortality, exploitation and movements,” said Fryda. “We haven’t done a significant study in 12 or 13 years.”
The walleye tagging goal, which was obtained, was for three thousand fish to be tagged; one thousand in each of the eastern, central and western portions of the reservoir.
Northern pike are also being tagged this year, for the third consecutive year. Even though Lake Sakakawea pike numbers have declined slightly in the past few years, the sprawling reservoir still has good numbers of northern pike.
“There’s a lot of nice fish and the amount of big fish is there,” responded Fryda when asked about northern pike. “It looks like last year was a pretty good year class. We are seeing those little guys in the nets. This year might be another good year too because we got early high water. Overall our pike abundance is good.”
Biologists have not been tagging every pike that turns up in their nets, but rather targeting pike generally considered to be of trophy size, 40 inches or longer. Forty-inch pike tip the scale in the mid-teens or better. One of the largest pike captured, tagged and released by fisheries crews this spring was a post-spawn female that weighed over 27 pounds.
Information from: Minot Daily News, http://www.minotdailynews.com