Last week I had an interesting natural resource adventure.
If you are a regular reader of my columns, you will have read about some of the projects the Okabena/Ocheda watershed has been involved with over the past 20 years. I am a chairman of the watershed advisory committee.
The advisory team is members of the public that advise and share information with the watershed district managers to help them formulate and prioritize their watershed programs.
They are entrusted with the goal of improving and protecting the surface and subsurface water quality within the boundaries of the Okabena/Ocheda watershed. They have done extensive above the waterline projects to help clean up the water that runs into Lake Okabena. With the help of other partners, they are undertaking a project that happens below the waterline or actually in the lake itself.
It was determined, with the use of some consultants and testing done prior, that the number of common carp that live in the lake might be one of the issues that adds to less than desirable water quality in the lake.
The problem is how do you find a concentration of these invasive fish and successfully remove them. The program I was involved with last week included the capture and release of 16 common carp that have been radio tagged. This was done last summer.
The process involves catching the carp, inserting a transmitter inside the fish and then releasing it. The transmitter battery lasts two years and can be found with a locator and a handheld antenna if you can get within 600 feet of the fish.
The tagged fish is referred to as judas fish.
The goal of the program is to see where these fish spend their winter days. Winter is a time where, when conditions are right, that carp will gather in large schools. By being able to monitor the location of the tagged fish it would help the commercial fisherman target the fish in sufficient numbers that removing them might help improve water quality.
Carp are bottom feeders and have a mouth that sucks up the bottom and filters it to provide the food they need to survive. It is the feeding action that stirs up the water, reduces light penetration and uproots aquatic vegetation needed to secure bottom sediments.
Dan Livdahl and I took my tracked Polaris Ranger and made a slow trip around the lake, stopping about every 1,000 feet. With a 600-foot location range scanning forward and backward, we should have had a signal strong enough to locate the fish if they were present.
We located 10 of the 16 tagged fish. The unfortunate problem is that they were not at all grouped up. We found one here and another over there. A significant concentration of these fish was non-existent. We could not in any reliable way tell the commercial fishermen where any large groups of fish might be found.
Dan Livdahl, the watershed manager, will try again in a few weeks to see if the fish might have grouped up by then.
Because the carp numbers in Lake Okabena are not nearly as high as other shallow lakes and wetlands in southwest Minnesota, the commercial fisherman cannot justify an attempt based solely on the sale of a small number of carp he might capture.
The watershed is adding a subsidy to each pull in the lake to make such an effort financially feasible for the commercial fisher. The watershed is not going to expend that subsidy unless they can feel confident that they can find a concentration of carp large enough that their removal might help improve water quality.
This project is by no means a slam dunk which guarantees success, but it is one more arrow in the quiver that the watershed district is using to achieve goals of better overall water quality.
We will have to wait and see how the winter progresses and if the carp with school up in a more concentrated area. If and when a commercial attempt is made, I will cover that and report the outcome to you. Please stand by.