RIVERDALE It is all good news for area lakes, according to recent tests for dissolved oxygen content conducted by the North Dakota Game and Fish Department. The amount of dissolved oxygen in water is critical to fish survival under the ice.
A heavy snowpack, or snow that sticks to ice and further limits the amount of sunshine that can penetrate an ice pack, often kills plants. When plants die underwater they consume oxygen, thereby lowering the amount of dissolved oxygen critical for fish survival. If the dissolved oxygen level gets too low, fish kills result.
Unlike our previous three winters, this winter's snowpack has been virtually nonexistent. The result has been one of the best winters ever for dissolved oxygen readings on area lakes. Jason Lee, N.D. Game and Fish Department fish biologist at Riverdale, does winter oxygen sampling every year at lakes in the Minot area. He called this winter's results extremely good with no winter-kill situations expected.
"Everything is looking real good," Lee said. "In a winter like this we check out those lakes where we have had problems in the past. They were all higher in (dissolved oxygen) than general. All had at least 5ppm."
Less than 5 parts per million of dissolved oxygen is considered a warning level for fish survival. Anything less indicates that a fishery is flirting with trouble. Fish kills are inevitable at 1 ppm or less.
"Rice Lake looks good with 8 ppm at a meter down," Lee said.
Rice Lake has been particularly prone to fish kills in past years. However, with no snow cover to choke out sunshine, this winter has reversed the odds for fish survival in area lakes.
"Nelson-Carlson have 16 ppm at the surface with lots of good water there," said Lee. "Buffalo Lodge looked good. Crooked Lake had high (dissolved oxygen) levels. Antelope Lakes and Clear Lake in Pierce County all had adequate oxygen levels."
Crooked Lake is among those bodies of water that has experienced more than its share of winter kills, the most recent just two winters ago. Since then the fishery has been staging a comeback.
Lee also checked the Arroda Lakes near Washburn, Lake Audubon and the McClusky Canal Chain of Lakes. Again, no dissolved oxygen problems were discovered.
"We did the Canal Lakes Feb. 13 and they all looked good," Lee said. "Actually, some had open water. If they've got open water there's exchange from the surface, too."
Lake Metigoshe, Strawberry Lake and Carbury Dam were among those lakes northeast of Minot tested by Lee.
"It was the same in Bottineau County. At Strawberry Lake, which is normally is pretty terrible for (dissolved oxygen) in winter, had pretty good oxygen this winter. There likely will be some carryover trout in that lake."
Lee emphasizes that the winter is not over and that there is still time for snowfall to coat area lakes. However, he adds, spring is close enough that even a late snowfall should not create big problems for fish survival. Another plus has been the number of fishermen taking advantage of near ideal conditions for ice fishing.
"It was was real neat to see was the amount of activity on the lakes this winter with an open winter with little or no snow," Lee said, noting that ice fishermen have had to contend with too much snow for three years running. "All the lakes had some type of activity. Even if we get some snow on the lakes now, I think we're far enough along that we should be all right."