Do you love big bluegill?
Why Everything You Know About Bluegill Management is Wrong
BY MATT MILLER
OCTOBER 15, 2015
Bluegills are prone to overpopulation. This is accepted knowledge among many anglers.
If you don’t catch and keep a lot of bluegills out of a pond, you’ll often hear a fisherman say, the bluegills will overrun the place. You’ll soon have a pond full of runty, stunted fish.
This is why the bag limits for bluegills are typically very liberal – it is not unusual to be able to keep 25 fish a day. It’s the angler’s duty to catch and eat as many as possible – keep the herd in check, if you will.
It sounds good, but current research suggests it’s wrong.
In fact, research conducted by Andrew Rypel, research biologist with the Wisconsin Department of Natural Resources, suggests the opposite: that liberal harvest limits on bluegills actually decreases the size of fish.
“Fish Here Aren’t As Big As They Used to Be”
Bluegills are often the first fish many anglers encounter (including me). They are common in farm and urban ponds. They’re the fish kids catch with a Mickey Mouse rod, a bobber and worms.
In the spring, many anglers target them on their spawning beds, where the biggest males are often easy to catch (see yesterday’s blog for the full details on this spectacle).
Bluegills are also popular because they’re tasty. Anglers call them and similar-sized species – crappies, perch, other sunfish – panfish. They’re the perfect size to fit in a frying pan.
Rypel and his colleagues in Wisconsin noticed something over the years: Anglers reported decreasing size of bluegills and other panfish. Of course, conventional angling wisdom would suggest the solution to this would be to harvest even more bluegills. After all, decreasing size is a sign of overpopulation.
Research tells a different story.
Rypel analyzed size trends going back to the 1940’s, and found that bluegills (and other panfish species) steadily declined in size over a 70-year period.
Researcher Andre Rypel (right) first encountered bluegills as many of us do: as a young kid, fishing.
“The regulations are relatively liberal,” he says. “I thought one possibility might be that we were fishing them too hard. As we looked at the data, we found that evidence of bluegills becoming stunted because they were overpopulated was not as common as previously thought.”
Fishing pressure, particularly on spawning beds where bluegills are most vulnerable, can be intense. And that pressure may be decreasing the size of fish.
In response to the trend, the Wisconsin DNR reduced the bag limit to 10 fish on 10 lakes as a test. Researchers, including Rypel, analyzed fish size before and after the regulation.
They found that fish size increased on average a half-inch on maximum size and .8 inch on mean size.
That may not sound like much, but consider that a typical bluegill is six or seven inches, and a really large one is ten inches.
Rypel published the findings in the North American Journal of Fisheries Management.
A New Experiment in Bluegill Management
The next phase of the project is to implement new management strategies on 100 Wisconsin lakes. One third will have a reduced limit of 10, one third will have a reduced limit of 5, and one third will have a reduced bag limit only during the spawning season.
The management regimes will run for ten years. “We’re going to find out what different regulations can do for panfish size,” says Rypel.
The good news is that bluegill size rebounds when fishing pressure decreases. A study by Rypel in collaboration with researchers at the University of Wisconsin-Milwaukee, School of Freshwater Sciences found that the reduction in size was not likely due to a shift in genetics, as has been shown to be the case in some other prominent studies on fishing pressure.
Anglers have, in general, been reluctant to embrace size limit reductions. Rypel points out that the limit reductions may actually result in more meat harvested. That may seem counterintuitive, but it’s true. “As bluegills get bigger in length, they get exponentially bigger in weight,” he says. “So if you catch a few larger bluegills, you often get more meat than if you caught a bunch of smaller ones.”
There is still a lot biologists don’t know about bluegills. New research will likely call for more changes in fishing regulation, but Rypel acknowledges that science is only one part of fisheries regulation.
“Regulations are a blunt instrument,” he says. “They cannot account for all aspects of fisheries management. If they get too complicated, they become much more difficult to enforce. We want regulations that are easy to understand and easy to enforce. There are trade-offs. In this case, reducing the bag limit could help the resource tremendously while still meeting the expectations of anglers.”
And while the bluegill may seem an unlikely symbol for global fisheries management, what Rypel says applies to large commercial fisheries as surely as it does the local farm pond. Regulations are only ever partly about science, and they can never fully account for the complexity of a fishery.
The key for resource managers is to use sound science to create regulations that work best – for fish and for people.
“Bluegills have the opportunity to get bigger with a relatively minor shift in fishing regulations,” says Rypel. “Our research is providing the evidence that it benefits anglers, too. The findings seem counter-intuitive to many anglers, who have long believed that smaller bluegills was a sign of overpopulation. But perhaps our long-term studies can convince them that lower bag limits can mean better fishing, and bigger panfish fillets for the fish fry.”
TAGS: Field Notes, Fish, Fisheries, Nature + People, NaturePop, Weird Nature
Matt Miller is director of science communications for The Nature Conservancy and editor of the Cool Green Science blog. A lifelong naturalist and outdoor enthusiast, he has covered stories on science and nature around the globe. Matt has worked for the Conservancy for the past 14 years, previously serving as director of communications for the Idaho program. More from Matt
I really appreciate this thread! I am replying to your addition Jim as your thought process best suits my mind set. I limit how many fish I keep and which size on every body of water I fish. With every lake having a little different mind set for what size I keep to eat (if any) and what size goes back. I think we should become as knowledgeable as possible on our local lakes. Change will take time in most of our areas when it comes to implementing better state wide and lake specific limits (and slots if necessary) with intentions to help Blue gills flourish. We should be on the front lines educating the public as we continue to learn more from studies, other great fisherman and our own experience.
I think it is great that this thread is the first someone will see when visiting our web site. It is a good read and has a lot of helpful information. This web site is becoming a wonderful forum for the ideas and studies that not only make great fisherman but also help make for a better fishery. Lets keep the conversation going!
here is the results of a 40% creel reduction study showing positive results in Minnesota
This article and many others I've read are very interesting but I contend the overall results to a particular body of water are relative.........I've searched a lot of the North Carolina data and it appears that the majority of the general public are comfortable with the overall 30 fish limit on Bluegill.......studies seem to suggest that the fish are doing well in most waterways as compared to harvest surveys........Although not the largest nationally, I do fish a region with 2,900 square miles of surface water with 1.5 million acres of that being brackish water thus the amazing sunfish fishery. I do clean a lot of bluegill and crappie every year but I'm also selective and tickle both my thrill to catch trophy gills and my taste buds that say panfish are my favorite food........ I do stuff that may seem silly to others in that I will rest a certain location for an entire year before I return to fish despite most of the water I cover being public. So is it doing anything! I think so and for me that matters and I will continue to follow these patterns. But anglers with less water available may not be able to employ a similar approach. It was just something that came with age and understanding for me..........I don't target largemouth anymore but love to eat 12" class bass and below........That hurts bass angler's feelings but I also release hundreds of big bass every year because I just prefer the smaller fish.........I have a harder time cutting into a trophy sunfish than I did as a young angler.........I've released many trophy sunfish in recent years and even if I never see them again it makes me feel a little better about the water I fish.........just my two cents.......lot of great points by the members as always........
Excellent report, I have always heard and read in other reports on bluegills right the opposite from this report. I fish a small pond with my grandson in the summer that has nothing but small bluegills, and we have never caught anything larger than five or six inch gills. I do agree with the bag limit of 10 or 15 per day. Thanks for sharing
Hey guys maybe this as a thought for trophy BG. If one has the time, money land and desire, one could build 5 or 6 small ponds, fill one stock it with quality genetics BG.. Once or twice first year seine out smaller fish during fall and fill a second pond and stock with seined small BG. No fish out of the 1st pond for 3 or 4 years. 2nd year seine 1st and second pond and use small fish to stock 3rd and or 4th pond. See where I am going?!. After the 5th or final pond is stocked, one could fish the 1st pond when the BG are mature and closer to death than life. My understanding is a 5 and especially a 6 year old BG is getting out there as far a longevity is concerned.That would be the reason to have 5 or 6 smaller ponds with different year class fish. Kinda like one poster said if you leave the old trees and not harvest what a waste.
With multi ponds, aeration systems, feeders and all the chemical analysis,etc. if would be a labor of love for sure and probably costly.
I do not have the land for it but would think that is a interesting idea to have(after 5 or so years a pond to fish Big BG out of and just rotate a pond every year and restock the one that is the oldest and depleted of most of the old BG. I may try that if I win the lottery!
So in essence it's, "Keep Fewer, Keep Fewer Big One's."