WAPOA and MN DNR work on project to improve walleye spawning in Hay Creek
In late September 2011 WAPOA and the Brainerd area fisheries office of the MN DNR worked together on a project to improve walleye habitat on the Whitefish Chain.
Walleye mothers-to-be don’t behave like human mothers. A human mother would likely look for a comfy mattress for her newborn.
Curiously, walleye mothers think rocks are the best place.
So they place their eggs on beds of rock and gravel.
The fertilized eggs are slightly adhesive and stick to the side of the rocks.
What is so good about using rocks for a nursery?
The survival of the eggs depends on the type of bottom surface they land on.
Rock and gravel are the best surface for protecting the eggs. The eggs are protected from being washed away and are protected from predators.
However if the eggs land on a silty or mucky bottom survival of the eggs is much reduced.
Hay Creek, looking upstream from the walleye habitat restoration site
Two years ago a neighbor called WAPOA’s attention to walleye spawning in Hay Creek.
A key to restoring walleye habitat is to provide rocks and gravel for the eggs to attach to.
The rock structure also has to be designed to promote water flow fast enough so that the rocks are not eventually covered by silt.
Ed Egan, WAPOA Director of Natural Resources, went to Hay Creek that year, obtained photographs of walleye moving upstream in the creek, and shared them with the DNR.
The DNR was aware that fish were spawning in the creek, and the photographs verified that they were there.
But the place they had picked for spawning was not very good because there was little rock on the bottom.
Over the years, upstream development and human activities have not been kind to Hay Creek.
Sixty years ago it was possible for a kid in a wooden fishing boat with a small motor to go upstream from Lower Hay to Upper Hay. Now an unimpeded trip is impossible.
Gradually, as upstream development occurred, the water quality deteriorated. The stream became obstructed with native plants and the water flow was further slowed by beaver dams.
The rocky stream bottom became covered with silt and mud. This was not good for the development of walleye eggs.
Ed Egan of WAPOA contacted Marc Bacigalupi, Brainerd DNR Fisheries Supervisor, to review his pictures and discuss the potential for a walleye spawning habitat improvement project.
After discussion the walleye habitat improvement project was agreed to and Owen Baird, a Fisheries Specialist, in the Brainerd office of the DNR was assigned as the DNR project lead.
WAPOA, represented by Ed Egan, was the sponsor for the project and coordinated the purchase and delivery of the required materials, the required machinery, and the required labor.
MN DNR Fisheries Specialist, Owen Baird, right, describing walleye habitat project to Conservation Corps workers
Baird said that walleyes tend to release eggs and sperm at the first good rocky area they come to as they swim upstream. So it is not necessary to add rocks all along the stream.
The DNR fisheries expert suggested placing rocks in a carefully selected portion of the stream bed of Hay Creek. The rock needed to be placed in a shape that would help them stay clean by the action of the water flow.
Baird designed the self-cleaning rock bed. His design sped up water flow so that silt could not accumulate on the rocks.
A foggy day.
Truck with rocks barely visible on right side of road.
At the beginning visibility was not more than 150 feet at the site.
Unloading the Bobcat by hand
Rocks carried and placed by hand
Jens Bach was responsible for delivering the rock to the water’s edge. The rocks came by truck and then were downloaded onto a “really big” Bobcat which carried the rocks to the stream edge.
On the day of construction Baird smoothly coordinated the placement of the rocks in the inverted “U” shaped form he designed.
From the water’s edge every single rock had to be hand-carried to its place in the stream.
An incredible 35,000 pounds of rocks were placed by hand by a hard working six-member crew during the day.
The work in the water was done by the young members of Conservation Corps Minnesota from the Brainerd and Bemidji offices.
Large rocks, 12-18 inches, were first placed, followed by 3-6 inch rocks, followed by a final top layer of 1-3 inch rocks.
Conservation Corps workers passing and placing rocks by hand
At the end, the configuration of the rock barrier was carefully measured and documented.
Laser-operated surveying instruments were used. The crew worked in the water to make the measurements.
Fortunately the stream flow on construction day was only an estimated 5 cubic feet per second. Baird estimated that at peak spring flows the stream would have flows of 20 times that— 100 cubic feet per second.
Baird’s rock structure had to be designed to withstand that tremendous flow.
Taking final measurements of completed rock habitat. Notice the inverted “U” shape. All the rocks are under extremely clear water. This is the area on which spawning is expected to occur.
Now walleyes swimming upstream will find a good rocky surface to place their eggs.
Next spring will be an exciting time to see the results of the improved spawning area.
Ed Egan from WAPOA and Owen Baird from the MN DNR were present during the installation.
Ed Egan, left, WAPOA Director of Natural Resources
WAPOA arranged and paid for all the materials and labor for the project as described in the article above.