Is everyone a fisheries expert?

Are you satisfied with the fishing on your lake? Is it as good as it used to be? Is there talk about a need to stock more fish? Or change bag and size limits?

Many lake associations and friends groups want to improve the fishing, and that is certainly the case here on Birch Lake, near Harshaw, Wis., where I live. Here, the fishing most certainly is not what it used to be. Years ago, this was, in the words of one long-time cottage owner, a “dummy lake,” meaning any dummy could catch fish. Bluegills and crappies abounded. Perch could be caught at will. Walleyes grew to trophy sizes. Largemouth bass and northern pike were available, as were muskies.

Then about a dozen years ago, rusty crayfish invaded and mowed down the cabbage weed beds that created much of the fish habitat. Fishing was bleak for a few years until the lake Friends group began trapping the crayfish, smallmouth bass moved in, and they and other fish began feeding on the invaders. Now we have trophy smallmouths, abundant walleyes, (though on the small side), and a good musky population, but panfish are about nonexistent. People long for the old days, as do I, since my family vacationed here for about 20 years and we saw the before and after of the crayfish explosion.

At meetings of Friends of Birch Lake, someone almost inevitably brings up the fishery and how we can improve it. The group has placed a couple dozen cribs in recent years, five last year alone. Some members want to petition the DNR for a special walleye regulation that would let us keep fish below the statewide legal size limit of 15 inches. Others want the DNR to stock fish here. The latest idea to surface, in the newsletter of the Friends group (of which I am treasurer), is to have people start keeping (instead of catching and releasing) smallmouth bass. The thought is: The bass are abundant and we need to “balance the species.”

Now, this informal fishery management practice has no scientific foundation – no lake survey, no assessment by an aquatic biologist. I am fully sensitive to the concern about the lake and its fishery. I’ve had ideas of my own on how to improve things. But I must admit my ideas have no more scientific merit than anyone else’s, so I have largely kept them quiet. I might suggest that, if we can afford it, our Friends group commission a lake study by an independent biologist. Then we might know where the fishery stands and be able to propose changes that have a reasonable chance of success.

In the meantime, I am going to release smallmouth bass – anything that eats rusty crayfish is my friend. In fact, I imagine most other anglers feel the same. Anyway, the catch-and-release ethic is strong, and most would be about as likely to start keeping bass as to quit brushing their teeth.

The point is that we all care about our lakes and the fisheries, and we’re all willing to invest time and to some extent money to make them better – but we need to build our actions on a foundation of knowledge. If we do just a little research, we find that stocking fish is rarely a long-term solution. Lakes prove out Aldo Leopold’s findings about carrying capacity: It’s habitat that decides which fish species thrive and in what numbers and sizes. We also find that usually cribs do more to concentrate fish already there than to expand their populations. And we find that tinkering with size and bag limits and changing the catch-and-release ethic are at best exercises in guesswork, unless we know through research what we’re doing.

So if we care as deeply about our lakes as we claim to, perhaps we need to put our money where our passions are and learn what’s happening under the water before we start trying to change things to suit our wishes.