From Nafff

[Phil Lilley]

Below are two notices from Jeff Williams at AGFC that might be of interest.

1) Disolved Oxygen Update

All,

I just wanted to provide you all with an update on our monitoring of the dissolved oxygen (DO) levels on Bull Shoals and Norfork. As of today the breaker vents are blocked open on the turbines at all the White River project dams (Bulll Shoals, Norfork, Greers Ferry, and Beaver). Recommended maximum generation rates have been in place since August 18th and currently Bull Shoals is being operated at 85% of nameplate capacity and Norfork at 73%.

On August 18th I recommended to implement stocking restrictions on the upper portion of the Norfork Tailwater. This means that no trout are being stocked at Quarry Park or Gene’s Trout Dock. Field measurements on that day indicated that the dissolved oxygen did not recover to 6 mg/l until nearly a mile above the Bill Ackerman/River Ridge Access. Trout that were scheduled to be stocked at the two upper locations will be placed at downstream locations until conditions improve.

On September 2nd field measurements indicated that the dissolved oxygen on Bull Shoals Tailwater did not recover to 6 mg/l until about Bruce Creek. At that time I recommended stocking restrictions for upper Bull Shoals, which meant that trout would not be stocked at State Park, Gunga La, or Gaston’s.

The dissolved oxygen levels have continued to decline since that time and last Friday (September 9th) I checked the DO levels on Bull Shoals and Norfork again. Although the location of recovery to 6 mg/l on Norfork has moved downstream somewhat, there was no need to adjust the stocking restrictions. On Bull Shoals, however, the dissolved oxygen now does not recover to 6 mg/l until below the White Hole Access. As a result earlier today I submitted a recommendation to extend the stocking restrictions to include Sportsman’s and the White Hole Access until conditions improve.

Also, last Friday I received notification from the Corps of Engineers that they intend to maintain the current maximum generation levels for the next week even as DO levels are expected to drop into the 3.8 – 3.5 mg/l range. The Reservoir Control folks cited a reduced capacity to evacuate remaining flood waters as a result of the maximum generation restrictions. Although the lake elevations are well down from what they have been, I think they are trying stay ahead of any tropical storms that may come our way.

Fortunately, we have not observed any evidence of a large-scale trout kill on Bull Shoals or Norfork and there is plenty of good fishable water remaining. We will monitor the situation closely and implement additional measures as needed. Please let me know if you have any questions. Thanks.

Jeff

2) Trout Marking

All,

We are scheduled to mark approximately 8,000 11-inch rainbow trout on September 22nd and 23rd at our Jim Hinkle/Spring River Hatchery in Mammoth Spring. This is the last cohort of rainbow trout that will be marked as an ongoing growth and mortality study on the Spring River. Since our district biologists are busy with their fall sampling we are in need of some volunteer help to complete the marking. Volunteers can ride with us to and from the hatchery so you don’t have to use any of your own gas. Anyone that is willing and able to help please let me know as soon as possible and I will provide additional details. Thanks.

Jeff