Pull up a chair, let me use my blog today to crawl up on a soap box for a little bit. There is a little issue that has come to my attention; let me address it and try to do a little edumacating in the process.
What do we mean when we talk about a population of fish that is “stunted”? Let me answer that–a population of fish that is stunted simply has slow growth rates; fish are not growing to their potential because there is not enough food. Typically this occurs in panfish populations where reproduction produces more small panfish than there is prey to feed them all.
From a fisheries management standpoint, what is the solution for a population of stunted fish? Well, ultimately there needs to be enough prey to feed them all. So, the solution can either be increasing the amount of food or prey resources available for those fish (e.g. supplemental feeding) OR the population needs to be reduced so there are not as many mouths to feed.
Now some of you are nodding your heads in agreement and thinking that YOU will help by whacking some of those over-abundant small panfish. In fact this time of year you will see some “anglers” throwing small bluegills, crappies or yellow perch on the ice and leaving them there because “they are stunted and need to be thinned out”.
“Not so fast my friend”–Lee Corso
How does one know that those small fish are “stunted”? Is every small panfish “stunted”? The only way to answer that question is to determine the age of those fish. Small panfish may be stunted and have grown very little over a period of years OR SMALL PANFISH MAY SIMPLY BE YOUNG FISH! This is where the “burr” gets under my “tail”! Once again this winter we have had reports of “anglers” throwing a bunch of small panfish on the ice and simply leaving them. Apparently those anglers are much better fisheries biologists than I am because they can tell the age and growth rates of those small panfish simply by looking at them. I am saying that in many cases those small panfish are not stunted at all; they are small simply because they are young. Those fish need to be left in the lake so they can grow!
By the way, did I mention that leaving a bunch of small panfish on the ice would be considered “wanton waste” of those fish and would earn a nice little citation from the local conservation officer?
Furthermore, would anglers whacking a bunch of small panfish really help the situation? I admit, I have to cut folks some slack here. Years ago the common knowledge was that anglers needed to whack panfish in order to maintain “balance” in their fishery, in order to prevent the over-population and stunting of panfish. Over the years we have learned that is NOT necessarily the case. Panfish are very prolific and can reproduce at very young ages and small sizes. In fact panfish can reproduce at sizes much smaller than anglers catch and certainly much smaller than anglers can harvest and utilize. The control of panfish numbers needs to occur when the panfish are relatively young and small–smaller than anglers typically catch and much smaller than anglers can utilize.
Let me illustrate this by telling a story. My son and I harvested a few yellow perch from a sandhill lake a couple of weeks ago. I am a biologist, any fish that I clean has its stomach contents analyzed. We found a variety of food items in the perch we cleaned, but you want to know what the most common food item was? Young-of-the-year (YOY) green sunfish and bluegills were found in more stomachs than any other prey item. Research has shown that yellow perch can be significant predators of sunfish in natural lakes. How big do you suppose those YOY sunfish were that the perch were eating? I will show you, they were this long, ———– . Now those perch were preying on YOY sunfish reducing their numbers so the surviving sunfish would be less likely to become stunted. Those perch were doing the job as predators and providing some control of sunfish numbers when the sunfish were WAY smaller than any angler would even catch! Largemouth bass, and other predators operate in a similar manner. The key to preventing the over-population and stunting of panfish is healthy populations of predator fish, not angler harvest of panfish!
While I am on the subject of sandhill lakes; those waters are some of the fisheries where you will likely see some “anglers” helping us out by throwing a bunch of small panfish on the ice. Afterall, they know that those panfish are stunted. Again, I would point out that there is no way of knowing that without aging those fish, but I will tell you that research on Nebraska’s sandhill lakes has shown that those habitats are so productive that in most cases there is more than enough prey for all the panfish in those waters! Seldom do we see “stunting” of panfish in sandhill lakes; there is enough productivity to feed all of the panfish at the densities of panfish we typically see in those waters!
I hope all of that makes sense. If you see some anglers throwing small panfish on the ice this winter because they are “stunted” stroll on over and see if you can learn their technique for aging fish. In the conversation maybe you can remind them that what they are doing is not only illegal, but most likely misguided.
OK, I am crawling off the soap-box now, thank you for listening.