Bluegill

Lepomis macrochirus

While some anglers go on to chase trophy muskellunge or cast tiny flies to rising trout, most begin their love of fishing with the aggressive nibble of the bluegill. The bluegill is small, but curious and notoriously spirited in nature. Many an angler has commented that, “if bluegill weighed 10 pounds, no one would fish for anything else.”

Etymology

The lower portion of the bluegill’s gill cover is often light powder blue. This can be somewhat confusing since the closely related pumpkinseed and longear sunfish can also display vibrant blue markings on the gill cover. In pumpkinseed and longear sunfish, however, these blue markings take the form of wavy lines and appear on much of the gill cover.

Life History

One of the first studies involving bluegill in Michigan took place on Walnut Lake in Macomb County in 1906 and was published by the American Fisheries Society in 1911. The author, Thomas L. Hankinson, observed:
• Bluegill use shallow bulrush flats for spawning.
• They build dish-shaped nests and aggressively defended their eggs from minnows.
• In the bulrushes and over deeper vegetation, bluegill feed on aquatic invertebrates including midge and mayfly larvae.

In the hundred-plus year since Hankinson’s early bluegill observations, scientists have learned more about the ways vegetation can affect their growth, survival and predator-prey relationships. The influential work of Werner and Hall at MSU’s Kellogg Biological Station included a 1977 study that found small bluegill stay confined to areas with dense plant growth because in open areas they are exposed to predators like largemouth bass. Once bluegill grow large enough to present more than a mouthful for bass, they stray from weed cover and feed on a wider range of food.

Diet

Bluegill can and do eat almost anything they can fit in their small mouths, including small fish and fish eggs, amphibian larvae and eggs, and algae and aquatic plants. Invertebrates are most often on the menu, though. Grasshoppers, spiders, ants, dragonfly and damselfly larvae, midges, snails, scuds, water fleas, and a long list of other insects, zooplankters and bottom-dwelling organisms (benthos) are fair game.

Size and Master Angler Entries

The Michigan State Record bluegill weighed in at 2.75 pounds and measured 13.9 inches long. Bluegills weighing more than 1 pound (or longer than 10 inches – if released) qualify for a Master Angler Award from the Michigan Department of Natural Resources. Since 2005, 844 bluegill from more than 300 inland lakes, impoundments, bayous and rivers have been entered in the program.

Although anglers around the state can probably find big bluegill in local waters, two lakes that offer a good chance of catching trophy-sized fish are Houghton Lake and Long Lake (in Grand Traverse County). Houghton Lake has been the top producer of Master Angler bluegill since 2005.

Management Issues

The density, species and patchiness of vegetation can greatly influence they type of food available to bluegill and their risk of predation. In some lakes, extremely high weed density covering a high percentage of the lake can lead to stunting — meaning the fish grow slowly and mature at a small size. In some cases, this is linked to the inability of predators to effectively limit the number of small bluegill competing amongst their own kind for limited food. In short, vegetation is important for protecting young bluegill but too much protection can harm growth rates. However, there are exceptions to this.

In 1999, James C. Schneider with the Michigan Department of Natural Resources demonstrated that weedy lakes can grow large bluegill under certain conditions. One of his study sites was a private lake with 83 percent of the surface area covered with vegetation. Despite this, big bluegill (larger than eight inches) numbered more than 1,200 per acre. Schneider’s work suggested that low angling pressure, high numbers of small-sized largemouth bass, and abundant food can result in large numbers of large bluegill in weedy lakes.

Importance to Fishery

Anglers often target bluegill along with other sunfish. Close relatives including pumpkinseed, green sunfish, and hybrids of the species can all be caught using the same methods — most often while fishing with a worm or piece of night crawler fished under a bobber. Other panfish including rock bass, crappie, and yellow perch can also be caught using simple tackle and techniques, but the bluegill is the most abundant panfish in many Michigan lakes.