Reproduction survey shows excellent numbers of young fish
The North Dakota Game and Fish Department's annual fall survey shows exceptional numbers statewide of young-of-the-year walleye, perch and northern pike, according to Scott Gangl, fisheries management section leader.
"The end result is a combination of our stocking efforts and excellent natural reproduction," Gangl said, noting that a record number of lakes were stocked this year.
The Missouri River from Garrison Dam to Lake Oahe led the way with outstanding natural walleye reproduction. "This stretch was phenomenal, and this is noteworthy because it is all natural," Gangl said. "Nothing is stocked in the Missouri River."
Lake Oahe and Devils Lake also showed excellent numbers of young fish during the survey. "This was one of the best years ever for Lake Oahe, definitely a top five year," Gangl said. "Devils Lake was off the charts, with numbers six times greater than the long term average."
Game and Fish did not stock walleye in Lake Oahe or Devils Lake in 2009.
Lake Sakakawea wasn't nearly as good as the other larger systems, but it was better than the last few years. "There was some natural reproduction, and numbers were similar to the end of the last drought in the early 1990s," Gangl said.
Many of the smaller lakes had good numbers of young fish as well. "Whether it was because of stocking efforts or on lakes with natural reproduction, it was pretty standard across the state with a really good take of fish this year," Gangl said. "Flooding across much of the state provided excellent fish habitat conditions."
In general, fisheries crews saw good numbers of early spawning species, such as walleye, pike and perch, Gangl said. "Pike and perch take advantage of flooded vegetation and with the large amount of water this year we saw good natural reproduction," he said.
Statewide, Gangl said forage species did really well. "Fathead minnows in smaller lakes were very abundant," he added. "On some of the bigger systems, there was really good reproduction of white bass, crappies, and other minnow and sucker species."
Gangl said a disappointment from this fall's sampling was the lack of gizzard shad in the Missouri River and Lake Oahe. "Shad can't tolerate cold water for long periods, and the severity of last winter appears to have depleted much of the adult population, as few young-of-the-year shad were collected this year," he said.
Fall reproduction sampling provides biologists with an index that measures natural reproduction and stocking success. It allows biologists to see if fish did spawn, and how fingerlings survived the summer. All large and mid-sized reservoirs are sampled every year, and many small lakes are targeted as well. Survey nets are designed for small, young fish, which allows biologists to assess reproduction and status of both game and forage fish species.
"Good reproduction or stocking success is certainly the first step to good fishing, but those little fish have to survive their first couple of winters before they get to a size that anglers can catch," Gangl said.