A Case for Selective Bluegill Harvest
February 28, 2017
Do you remember the last time you saw a bluegill so big it curled up in the bottom of a 5-gallon bucket? Neither do I. Consequences of killing such exceptional fish notwithstanding, any sunfish over 10 inches today is as valuable and perhaps even scarcer than a Master Angler Award sized walleye, muskie, or bass. When was the last time you filleted a 10-pound walleye or an 8-pound largemouth, or made steaks from a muskie? Yet even today, many anglers don't give a second thought to harvesting an entire limit of giant bluegills.
If you're much over the age of 30, you likely have memories of unbelievably large bluegills caught from public waters. These were thick, heavy, impressive fish that despite their relatively giant dimensions didn't seem all that uncommon at the time.
Among my clearest early recollections are winter catches of massive blue and orange sunfish — fish my grandfather called two-pounders — from Mississippi River backwaters in Iowa and Minnesota. I also recall running across pods of plate-size, dark-bodied bluegills in busy southwestern reservoirs during the late 1980s. During a 15-year stretch when I was ice fishing almost daily, friends and I would discover one or two lakes with monster sunfish every winter. Inevitably, inside a season or less, as word spread, we'd return to a hollow fishery — once-numerous 9-inch-plus sunfish replaced by swarms of 5-inchers. We never measured bluegills in those days, nor do I recall harvesting the giant ones, seeing little point in sticking dead fish on our walls.
Anyone who visited bait shops during this era witnessed another form of sunfish slaughter — colossal frozen bluegills on display during then-popular big-fish contests. At Marv Koep's famed shop in Nisswa, Minnesota, the real jaw-droppers were always plate-sized sunfish, rather than big walleyes, bass, or pike.
When I moved to central Minnesota in the mid-90s, pound-plus bluegills had already been more or less exterminated from local lakes — a distressing trend that has continued across the species' range, leaving pockets of big fish isolated in private ponds, large lakes, and remote river backwaters. Fishery managers as well as anglers have realized — oftentimes, too late — that 25- and 50-fish limits are not sustainable, if healthy, balanced bluegill populations are the goal.
We've been losing stocks of top-end-size sunfish for over half a century. Moreover, the slaughter of big bluegills in a particular lake can happen within a single fishing season. When word of a newly discovered lake or a torrid bite reaches the wrong ears, greed often runs rampant, particularly given a lack of progressive regulations limiting the harvest of big bluegills. The psychology of gluttony and hoarding are whole other topics. Suffice to say, for every angler ticketed by conservation officers for over-limits, assume that dozens of others are stocking freezers and "double dipping" panfish limits every day without recrimination. You know who you are and you're only shooting yourself, the fishery, and your fellow fishermen in the gut.
So even while attitudes on catch and release and selective harvest remain the norms for other species, many anglers continue to harvest big sunfish with impunity and with little thought to the future. It doesn't help that most state fishery agencies allow the harvest of 25 to 50 sunfish daily, with some imposing no limit at all. Yes, licensed anglers are completely within their rights to harvest up to a limit. But even with liberal possession limits, realize anglers aren't harvesting small bluegills; they're targeting and taking the largest fish.
In the absence of progressive management strategies, anglers must look inward and self-impose the appropriate selective-harvest ethic on each lake we fish. In most states, a single licensed angler can legally harvest enough panfish to feed an entire family, or even enough to supply a neighborhood fish fry. The reality is, a half dozen 7-inch sunfish or as few as two or three 11-inch crappies are enough for one dinner. A single deep-fried bluegill fillet can contain in excess of 200 calories. Run the numbers and you realize how much food value lies in a limit of 25 sunfish.
Perspectives from the Past
If only we'd known then how rare those big old bluegills would become. It's eye opening and disheartening to read accounts of fish populations, and net and creel survey data from the period between 1950 and 1990. But the data also give us a glimpse of what healthy, balanced bluegill populations look like. Given sufficient spawning habitat, predator abundance, and adequate bluegill growth rates, fisheries are meant to contain multiple year-classes, including plenty of mature fish over 8 and 9 inches. With a few steps in the right direction — the right panfish regulations blended with voluntary selective harvest — we can return to the good old days within our lifetimes. If not, the data merely become a footnote in the history of fishery management.
Two previous studies from Michigan and Wisconsin show how vulnerable sunfish can be to angler exploitation. Just one month after a new Michigan lake (Third Sister) was opened to angling, 24 percent of legal-sized (6-inch) sunfish were harvested. In another lake newly opened to the public in 1976 — Mid Lake, Wisconsin — anglers harvested 13 percent of bluegills greater than 6 inches within the first three days, and 35 percent by the end of the third month.
A creel survey from 1961 showed that 40 percent of harvested bluegill from Lake Andrew, Minnesota, measured 225 mm (nearly 9 inches) or larger. In 1995, only 1 percent the entire bluegill population from this same lake measured this size or larger.
In another study on four Minnesota lakes, fishery biologists Brad Parsons and Jeff Reed found that during the four-year evaluation, average total mortality was 75 percent for bluegills and 59 percent for black crappies. Rates of angler exploitation averaged 25 to 35 percent for each lake, each year, with average sizes declining rapidly.
If it isn't already obvious that current harvest levels can be excessive and that existing regulations often aren't working, you need only experience the phenomenon on a personal level. If you're no longer catching big bluegills in your lake, it likely isn't because they've suddenly become harder to catch. Big bluegills typically are the most aggressive and first fish to be removed from a population. Rather, it's likely the fish no longer exist in that system.
Balanced Bluegill Fishery
In waters biologists refer to as "balanced," bluegills larger than 8 or 9 inches can be abundant, with at least several strong year-classes present in the population. Healthy fisheries house smaller populations of sunfish, with lots of top-end-size spawning males as well as moderate numbers of large, yellow-orange females. (Compare that to overly abundant populations of stunted, slow-growing bluegills). Individual growth rates vary, based on latitude, water temperature, and forage. In Minnesota, it can take 10 years or more to grow a 9-inch bluegill under nearly optimal conditions. In a fertile pond in the South, a bluegill can reach 8 inches or more within 3 years.
Some lakes lack the ingredients necessary to grow large numbers of big bluegills. When lake fertility is low, and biomass (particularly zooplankton) is lacking, bluegills grow slowly. In many shad-based reservoirs, for example, big bluegills often are rare because shad outcompete bluegills for available zooplankton — a key forage for both species.
Outside remote lakes and private ponds that lack fishing pressure, prime big-bluegill fisheries contain limited areas of optimal spawning habitat — often hard bottom, sand/rubble shallow flats peppered with hardstem bulrush and a variety of other plant species. Water clarity is often stained, limiting growth of vegetation, which can shelter small sunfish from predation. Invasive macrophytes, such as Eurasian milfoil, provide excessive refuge, promoting numbers of small sunfish. Also, dark water often indicates high fertility, which means abundant zooplankton and invertebrates. Largemouth bass can be important to balance fisheries, keeping bluegill numbers in check through predation. Studies in Missouri, South Dakota, and Nebraska have shown that lakes with high numbers of bass less than 12 inches tend to produce larger bluegills.
Fast-growing bluegills often possess thick, burly midsections, with relatively short, stout bodies. Older, slower-growing 'gills or those from stunted populations can appear more streamlined and thinner across the chest. Even mature male bluegills may lack a pronounced hump, indicating prematurely spawning fish known as "sneakers," a phenomenon that occurs when too many alpha male bluegills are removed from a population. The removal of large alpha males is particularly damaging to a fishery because as sneakers begin to infiltrate spawning beds and displace absent alphas, the trend can quickly become an epidemic that's nearly impossible to reverse.
Heavy Harvest Seasons
Two distinct seasons account for a lionshare of the year's bluegill harvest. In the ice belt, primarily the Upper Midwest, Northeast, and Great Plains, bluegills become highly susceptible to winter harvest, especially in smaller, remote lakes that can only be reached by ATV or snowmobile. When harvest-minded anglers eradicate a fishery's biggest bluegills — which can easily happen in weeks — it may take decades to restore the population, and only then if harvest diminishes.
Throughout the rest of the bluegill's range — to say nothing of other sunfish species, such as redear and pumpkinseed sunfish — anglers target and remove more big fish during the extended spring-summer spawning season than any other period. The fish are shallow, visible to anglers, and aggressive. But removing the large alpha males at this time can be damaging for the reasons stated earlier. Each alpha harvested is likely to be replaced by several smaller males that mature earlier and produce offspring with their same genetics. Once a male bluegill matures, its growth slows greatly, as energy goes toward spawning. So you see why it's in a fishery's best interest to maximize the abundance of later-maturing, alpha males.
In scattered lakes across the U.S., fishery managers have closed panfish nesting sites during the Spawn Period. In Minnesota, several lakes I fish have posted spawning areas off limits to fishing from April 15 to June 15. I've enjoyed catching and releasing a few nesting fish in the past, as these resplendent males make for beautiful photographs. But pulling such sunfish off their nests, even temporarily, can be a bad idea. Smaller sunfish and other predators can swarm and vacuum a nest clean within seconds, effectively erasing a throng of baby bluegills with potentially grand genetics.
Beyond the joy of simply watching the antics of nesting sunfish, closing spawning sites has other benefits. It's compelled friends and I to seek new patterns — targeting prespawn or postspawn females on adjacent structures as well during summer and autumn, when big 'gills can be wholly underfished and intensely active, once found.
Reduced Limit Model
Given a general lack of regulations limiting the harvest of large bluegills, anglers must continue to rely on personal restraint and selective harvest. Meanwhile, some fishery agencies have been experimenting with special regulations for at least a decade. Some, such as reduced bag limits, are showing promise.
In Minnesota, Wisconsin, and some other states, certain lakes identified for their propensity to grow large bluegills have received 5- or 10-fish limits, where statewide limits are 25. One promising study, by Andrew Rypel of the Wisconsin DNR, has evaluated the effects reduced daily bag limits (from 25 to 10) have on bluegill size structure in 7 Wisconsin lakes over the past 15 years. Rypel identified and selected lakes based on bluegill size and growth. Problem lakes were identified as those with good growth rates but poor size structure, where angler exploitation was identified as the main culprit for the lack of larger fish.
The study showed that mean and mean maximum length of bluegills increased in five of the seven 10-fish limit lakes. On average, bluegills in all lakes increased by an average of a half inch. Rypel noted that over time, greater gains in bluegill size can be expected. By contrast, in another study lake, where the bag limit increased from 25 to unlimited, mean total length decreased substantially, dropping from over 8 inches to under 6.
Rypel added that the next stage of the project — which will run another 10 years — is to add new management strategies on an additional 100 lakes — some with 10-fish limits, some with 5, and others with reduced limits only during the spawning season.
Length Limits and the Future
Bringing the management of bluegills into the realm of selective harvest strategies for larger predator species, several studies have also examined bluegill length limits. At Nebraska's Sandhill lakes, biologist Dr. Craig Paukert analyzed an 8-inch minimum length limit for its effectiveness in increasing population size structure. In these lakes, bluegills attained 8 inches between years 4.3 and 8.3. Unlike other areas where anglers have not supported bluegill length limits, 100 percent of anglers surveyed in this study favored the new regulation, if it increased the number of larger bluegills, even though the size restriction meant a reduction in the number of fish they were legally able to harvest.
The length limit increased bluegill size structure on all 18 study lakes. The populations with the lowest natural mortality and fastest growth had the highest increase in size structure. Where bluegill growth was slower, gains in size structure were smallest.
In Bluegills — Biology and Behavior, author Stephen Spotte notes that maximum size limit to 175 mm (6.8 inches) have been tested and have failed to significantly increase mean size. He also notes that to achieve populations of quality bluegills, the goal should be to reduce recruitment (number of surviving fish) and to increase juvenile mortality — principally through predation.
To my knowledge, neither bluegill slot limits nor a "one fish over" a given size daily been attempted in public fisheries. Also, although we've primarily examined bluegill here, size limits — particularly minimum size limits, as opposed to maximum sizes or slot limits — have a longer history in crappie management. While populations of large crappies can certainly be damaged by harvest, crappies seem capable of replenishing themselves faster in many waters, given good growth rates.
In my experiences across the country and with other species, minimum size limits often result in a fishery rife with specimens just below the legal size limit, and very few larger individuals. Instead, protected slot limits and limiting harvest to one fish over a certain length per day, may be much more effective tools if the goal is larger fish.
Dr. Michael S. Allen, University of Florida fishery professor and veteran bluegill biologist says: "One of the keys to quality bluegill management is high mortality rates of smaller, juvenile sunfish — both through predation and exploitation by anglers. A slot limit that perhaps protects those valuable 8-, 9-, and 10-inch bluegills would allow anglers to continue harvesting ample numbers of the more numerous medium-sized fish. Folks could also continue to experience the thrill of trophy fish — whether they're fishing in Florida or Minnesota."
As complicated as the big-bluegill issue often appears, it actually couldn't be simpler. Harvest selectively, gently, wisely. Understand that it's our own individual actions — more than any rule, regulation, or management tool — that helps shape fishing's future. Keep enough medium sunfish for a meal — these are the most numerous, easy to replace, and delicious. Catch, admire, and release the rest. â–
In-Fisherman Field Editor Cory Schmidt, Brainerd, Minnesota, contributes to all In-Fisherman publications and along with his angling expertise often covers conservation issues affecting fishing.