Citing a need to protect sturgeon amid abnormally low dissolved oxygen levels and high water temperatures on a portion of CJ Strike Reservoir, Idaho Fish and Game Director Ed Schriever on Wednesday, Aug. 24 signed a conservation closure order for sturgeon fishing in the portion of the Snake River arm between Canyon Creek and Rattlesnake Creek, effective Friday, Aug. 26 until Sept. 25, unless reservoir conditions improve sooner.
The purpose of this closure is to minimize additional stress and mortality while these environmental conditions in the reservoir exist. In recent weeks, Fish and Game has verified about 20 reports of dead sturgeon found within the closure area, ranging in size between 5 and 9 feet. While these 20 fish constitute just a sliver of the total sturgeon population between CJ Strike Dam and Bliss Dam — Idaho’s second largest, which is estimated to be in the neighborhood of 4,000 fish — the mortality event is unprecedented for sturgeon at CJ Strike.
Fisheries managers cannot say definitively whether angling effort, combined with the environmental conditions, directly contributed to the mortalities they have documented so far at CJ Strike. That is something that warrants — and will receive — further study going forward. Idaho Fish and Game is a science driven agency and does not take restrictions that reduce opportunity for anglers lightly, particularly when they cannot draw a direct link to angling activities and fish mortality as is the case in this instance. However, fisheries biologists have data that shows that current water temperatures and dissolved oxygen levels within this segment of the reservoir are currently near or at levels that are lethal to white sturgeon, even without additional stressors. Out of an abundance of caution to protect these important fish, Fish and Game has chosen a temporary closure as the prudent course of action pending further scientific analysis.
“With the current water conditions in this segment of the reservoir, the sturgeon here are already teetering on the edge of what is survivable,” said Art Butts, Regional Fisheries Manager. “Fighting one of these fish could potentially be the thing that tips them over that edge, and it is one potential stressor we can control.”
At the population level, the 20 sturgeon mortalities Fish and Game has documented in recent weeks is not a major concern, according to regional fisheries biologists. However, given the extraordinary nature of this mortality event, and the fact that these fish are nearly irreplaceable — taking between 50 and 70 years to reach a length of around 9 feet — the closure of this portion of the sturgeon fishery was necessary to conserve a resource treasured by Idaho anglers.
“Given that this closure impacts both fishing opportunity and, potentially, the livelihood of people who guide sturgeon trips at CJ Strike, this decision was not made lightly,” said Art Butts, regional fisheries manager for Idaho Fish and Game’s Southwest Region. “But it is the right decision based on the circumstances.”
Idaho Fish and Game will be posting signs at access points on the Snake River arm of CJ Strike Reservoir to notify anglers of the closure, and working closely with Idaho Power Company to monitor water conditions in the closure area on a weekly basis.