Let the big boys go...

[Renneberg]

New Information Could Mean Bigger Bluegills

ST. PAUL, MN--Recently released information by the Minnesota Department of Natural Resources (DNR) delivers an important message to anglers: When fishing bedded 'gills, keep some females but throw males back!

Brady Becker, assistant DNR area fisheries manager, says that while this might seem contradictory to typical fish management strategies, which almost exclusively protect females, there is good reason for releasing male bluegills.

"The males play a critical role during the spawn," Becker explains. "They fan out the nests for females and guard the eggs and fry. But most importantly, by keeping small, genetically inferior male bluegills away from the nest, they may actually help prevent stunting."

Bluegills, Minnesota's largest and most popular sunfish, are notorious for becoming stunted in certain lakes. "While there are a number of factors that can lead to stunting, it basically comes down to over-population," Becker said.

"Bluegills are more prone to over-produce than to under-produce," Becker explained. "When you have a lake with lots of bluegill, the bluegill can eat all the available forage. Then they grow very slowly. A bluegill that typically matures at 6 to 7 inches will mature at five inches in lakes where there are too many bluegills."

One means for keeping the population under better control, while at the same time protecting a more genetically superior strain of 'gills, is to leave those larger males on their nests, letting them "do their thing" of protecting their nests during the spawn, explained Cindy Tomcko, a DNR fisheries research biologist in the Grand Rapids fisheries office.

"Smaller, inferior males (called cuckolders) swarm around the nests of large males and try to spawn while the large males do their best to keep the cuckolders away from their nests," Tomcko said. "If large males are fished off of their nests, the result is the production of too many, slow growing offspring - stunted bluegills.

Tomcko said there are usually more than enough females and eggs to produce plenty of young fish. "But it's the large males that may be the key to quality in bluegill populations," Tomcko noted. "Well-meaning anglers think they are doing the right thing by keeping the males and putting the females back, when in fact they should be doing just the opposite." Tomcko also pointed out that because of their aggressiveness during the spawn, the males are considerably more vulnerable to hook and line at that time.

"Anglers usually aren't going to keep four-and five-inch bluegills but they will keep those six inches and larger," Tomcko said. "Yet it's the larger, male bluegills that prevent cuckolders from spawning and give you the genetic pool you want to produce large bluegill. Leave more of them in the lake and you stand a much better chance of eventually having a good, healthy crop of large bluegills."

Other factors, such as the effects of predation (or lack thereof) and the presence of submerged aquatic vegetation also affect the size of bluegills. Tomcko said, "If there aren't enough predators, particularly northern pike and bass, in a lake, bluegills are much more prone to become stunted. And we're still studying just how much submerged aquatic vegetation along shorelines is best.

We know that clearing shorelines of vegetation is bad news, but it appears too much vegetation can also be detrimental."

The DNR has been working on improving the size of bluegills in Minnesota lakes for nearly a decade. A study by Peter Jacobson, a DNR fisheries researcher in Detroit Lakes, involved lowering the bag limit to 10 bluegill on eight similar lakes. Some lakes with the lower daily limit began to grow bigger bluegills.

The DNR continues to experiment with different daily bluegill limits in an effort to determine which lakes are most likely to respond positively to lower limits. A few lakes, such as Annie Battle Lake in Ottertail County, Mink, Somers and Crawford lakes in Wright County, and Bass and Grave lakes in Itasca County, currently have a five-fish limit. Most lakes have a 20-fish limit.

"We're looking for a good balance," Tomcko said. "Not all lakes have the food, habitat, and abundant predators to produce bluegills larger than 8 inches. But if bluegills in a lake grew large in the past, we may restore those bluegill populations by lowering the bag limit of bluegill.

In the end, we hope to restore quality bluegill populations to those lakes. "Releasing those larger males during the spawn and keeping the females all year round is may be one way to start growing bigger 'gills in other lakes."

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"Study to be quiet"

[B. Amish]

How do you tell the difference between a male and a female sunnie?

Is it purely on size or what?

[steve schmidt]

to my knowledge, the females are brightly yellow colored on the belly...the males range from blueish to orange or redish.

Also if you see a school of bluegills that "appear lost", the lead ones are males....they like other male species refuse to ask directions!

[CrappieJohn]

Renneberg....Good post and excellent documentation! I simply don't like cleaning the sharp gilled devils and keep only a few each spring. Rick got a dandy this morning and dropped it on the dock....thought he was going to have to do mouth to mouth on that animal for a little while, but after forcing some water thru the gills it took off. That was one of those fish that needs to be set free. Again, good post!

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Plastics...making better fishermen without bait! Good Fishing Guys! CrappieTom

Culprit Tackle Crappie Pro Staff
[email protected]

[CrappieMagnet]

Another point worth noting is most sunfish in this region don't usually spawn till the water temperature reaches between 68 and 72 degrees.So i would encourage my friends to release all but a few fish during this time.(gotta let them keep a select few)
At least thats what i tell most people i fish with.Other than a few...we C&R.

CM

[Renneberg]

The big males have a small bump on the head.

That's why some people call them bull gills.

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"Study to be quiet"

[RHW]

Renneberg, thanks, excellent and useful information. I will have to start paying more attention to difference in the sexes.
Even when I lift their tails to take a look, I still can't tell which is which 8-). I was lead to believe that it was the males that were the ones that were colored the brightest and the females had the least or none.

[JiggingSpoon]

Great Post guys
I was fishing up at Bemidji this winter and we ran into a bunch of 1/2 up to 3/4 lb gills, it was just awesome, a true 3/4 lb gil is just huge, anyways, we caught many 3 to a lb fish also, we just kept some of those to eat, it is great to hear other people do this also,

The females usually have a yellow belly while the males while spawning are really dark orange, purple, or sometimes they literally appear almost black, that is what i have found through my experience

JS