if you can, a 4 pound, 12 ounce bluegill. A day dream you say. Think
again, because that is the current world record for bluegill, Lepomis
macrochirus. It probably represents the maximum size for bluegill;
at least no one has caught a larger one in the 31 years since T.
B. Hudson caught the world record from Alabama's Ketona Lake. Any
bluegill over one pound or ten inches is a trophy. I consider a
large bluegill anything over eight inches. Any way you look at it,
big bluegills are a unique resource, just as valuable and scarce
as trophy bass or trout.
Bluegill Biology: Ready or Not
What does it take to produce big bluegill? I've been trying to answer
this question for the last three years, while studying bluegill
populations throughout Missouri. In the article that follows, I'll
describe a few early findings that will probably be of interest
to anyone, like me, who likes to cast flies at big bluegills. Unfortunately,
blue- gills don't spring to life at eight inches, so to understand
the big ones, we will have to talk about the small ones first.
While big bluegills are in short supply, small ones aren't. In Missouri,
a female can spawn as many as nine times between May and September.
When ready, female bluegills enter a spawning colony, which may
contain 300 or more males. Each "bedding" male guards
his nest from other fish. Males do all the work. They build the
nest and care for the young. Males locate the spawning colonies
in protected areas like the back of a cove, in shoreline notches,
or pond dam corners. Colonies are frequently located under overhead
cover, like the branches of an overhanging willow. The males build
the nests at a variety of depths (1 to 16 feet) on all kinds of
bottom (bedrock to loose organic silt) and a variety of water temperatures
(63° to 86°F). In Missouri, the heaviest spawning takes
place in late May and June. Once the best is built the male bluegill
defends the nest, eggs, and young vigilantly, aggressively at tacking
anything that comes near.
The young bluegill feed almost exclusively on microscopic zooplankton...
small animals about the size of a pinhead. As they grow larger,
blue- gills switch to insects. Sometimes, big bluegill eat small
fish, but they re ally aren't designed to pursue fast moving prey.
Their deep-bodied, long- finned, "pie-plate" shape helps
them capture prey that demand quick turns, maneuverability, or careful
searching of the vegetation or bottom, like the in sects found in
aquatic plants. As they feed on these insects, bluegills will of
ten accidentally consume plants, but they're not able to use them
Food availability determines how fast bluegills grow, and ultimately,
how good the bluegill fishing will be. While growth rates of bluegill
vary tremendously, it always takes several years to produce catchable
size fish. How many years depends on how, much food is available
for each fish. Usually, in populations with large fish, bluegills
grow faster. Even in the best populations, however, it usually takes
at least four years to grow to eight inches.
Usually poor populations, dominated by small, slow growing fish
have too many young bluegills; not enough young blue die. Due to
their prolific nature, bluegills nearly always produce more young
than most lakes and ponds can support, If too many young survive,
they compete among themselves for the limited food supply. Biologists
describe such populations as "stunted". Nearly all bluegills
in these populations die of natural causes (predation or old age)
before they reach a desirable size - 8 or 8 inches.
The best way to reduce the number of small bluegills is by protecting
largemouth bass. Bass eat small bluegills, thus reducing the competition
among survivors. The relatively few remaining young can then grow
to rod-bending size.
In contrast, angling generally removes only the largest bluegills
with little effect on the small fish (less than 5 inches). This
requires that we need to question the idea that you can "fish
your way" to better bluegill populations. In fact, as I will
show, recent evidence suggests that harvest may re duce to the numbers
of large fish.
Does Angling Impact Bluegill Populations?
It happens every spring. I'll pick up a copy of a fishing magazine
or look at an outdoors column in a newspaper to find the author
extolling the joy of fishing for bedding bluegill. After describing
all the rod bending action the author will point out that bluegills
are good to eat and because of their prolific nature, "anglers
need not apologize for taking home a stringer full".
Over the last two years, as part of a research study, I've tried
to determine the impact of angling and decide whether anglers should
apologize for harvesting a limit of bluegills, or be en courage
to take more. To date, over 2,500 catchable-size bluegills have
been tagged in four impoundments in central Missouri. The tags are
numbered and are worth $5 to $100 to any angler who returns one.
Since tagged and untagged fish are equally likely to be caught,
the percentage of tags that are returned gives an estimate of the
percentage of the total population that are caught. This is an old
method of determining angler harvest rates or "exploitation",
but applying it to bluegills is new.
The first year's results should make you think twice about loading
the boat with bluegills. In a public fishing lake, anglers returned
54% of the tags in a single fishing season! That is, over 50% of
the adult bluegills were caught that year. In contrast at a private
lake with limited fishing, only 2 percent of the tags were returned.
The second year's returns were quite different. Returns at the public
fishing lake declined from 54 to 25 per cent. Why the change? Possibly,
the depletion of large bluegills (over 8 inches) the first year
discouraged anglers from fishing the second year. Also, despite
heavy harvest of large fish, the numbers of five to six inch bluegills
increased greatly. The tagged fish might have been diluted in this
larger population of small bluegills.
But what about the private lake, you ask? Returns increased significantly
from 2 percent to 10 percent. It seems a new, apparently very effective,
bluegill angler began fishing this 37 acre lake during the second
year of the study. In one season, he returned more than twice as
many tags as all other anglers in both years combined.
Now lets step back and review a few facts about bluegill biology.
Bluegills are very prolific - a single female may spawn as many
as nine times a year in Missouri. Growth rates depend on the amount
of food available per fish; if too many young survive, growth declines
and "stunting' occurs. In typical Missouri populations, it
takes about 6 or 7 years to grow an 8- inch bluegill and at least
four years in the best populations.
Yes, angling can impact bluegill populations by reducing the number
of large fish, but no, you cannot "fish your way" to a
better bluegill population. It only takes a few spawners to produce
a tremendous number of off spring and anglers cannot remove enough
small bluegills to reduce the risk of "stunting". The
tagging study has shown that anglers can harvest a high percentage
of the largest fish. Also , many of the large bluegills can be harvested
by a small number of skilled anglers, even a fairly large impoundment.
Since it takes 4 to 7 years to grow an eight-inch bluegill in Missouri,
a 50% harvest rate is not sustainable here. At this rate, a dramatic
decline in the number of large bluegills result, with no effect
on the small fish.
I'm not suggesting a ban on bluegill harvest. In most waters, surplus
fish exist and anglers need not apologize for harvesting them. Besides,
a platter of fried bluegill fillets fresh out of the pan is truly
a sensational delight. However, we shouldn't let our appetites influence
our perspective too much, because bluegill are capable of providing
more than just meat fishing. Under optimum habitat conditions and
light harvest, trophy bluegills - over a pound or 10 inches - are
How to Find Big Bluegill
As a fisheries biologist, anglers often ask me where they can catch
big bluegills. Since "big" is defined in the eyes of the
beholder, I usually ask them to describe "big." They'll
usually stretch out the palm of their hand and mark a spot somewhere
on their wrist. I've measured many such "hand-sized" bluegills
and found they've usually somewhere around eight inches in length.
After I've established what the angler considers big, I can get
to the business of helping them find the bluegill of their dreams.
Bluegills can grow large in good habitat that contains the proper
density of bass and other fish and where fishing pressure is light.
In Missouri, this combination is most often found in privately-owned
impoundments, and anglers willing to do some scouting and obtain
fishing permission usually have the best bluegill fishing.
What does the perfect bluegill habitat look like? I would concentrate
your search on ponds and lakes with relatively clear, fertile, and
weedy water. Sunlight penetrates the water of such ponds easily
and stimulates the growth of algae and aquatic plants. These stimulate
the production of zooplankton and aquatic insects that are important
bluegill food How ever, you should avoid impoundments where vegetation
covers much more than a quarter of the surface area.
Fertile water is a basic ingredient that many waters lack. Like
the bountiful harvest produced from rich soil, fertile water has
the capacity to grow bluegill food and seems to be a common characteristic
of the places where truly large bluegills are found. The easiest
way to recognize rich water is by the greenish tint that an abundance
of algae produces. Rich water is usually found in areas with high
soil fertility or in impoundments that receive nutrients from human
activities - farming operations, septic tank leaks or residential
or golf course fertilizer run off. The problem with human Inputs
that they may become too much of a good thing, initially charging
the system with fertility, hut eventually leading to over-enrichment
and fish kills.
When searching for big bluegill, try to locate waters containing
high densities of largemouth bass. Heavy predation by bass is a
critical component in the production of big bluegills - preventing
overpopulation and the stunted fish that result. Lakes with high
densities of 8 to 12 inch bass are common in Missouri, and they
often produce good fishing for bluegills up to 8 inches and occasionally
larger. However, impoundments with trophy bluegill more often have
many bass in the 12 to 16 inch range.
If you have a source of information on the bass population in a
prospective impoundment, learn as much as you can about other fish
that may be present. In Missouri, the biggest bluegill usually come
from small impoundments with few fish other than large- mouth bass
and bluegill. Impoundments with large populations of gizzard shad,
channel catfish, bullheads or carp rarely produce big bluegills.
An abundance of crappie usually means poor bluegill populations,
but big bluegills can coexist with low numbers of large crappie.
Big redear sunfish are often found in the same impoundments with
Anglers searching for big bluegills should find ponds or lakes with
the above characteristics and try the most lightly-fished ones first.
Trophy blue- gills are unlikely in heavily-fished bodies of water.
In all my searching, I know of only a few Missouri impoundments
that regularly produce bluegills over ten inches and they're all
privately-owned with tightly controlled access. Sorry, I'm sworn
If any of this information helps you find some big bluegills, treat
them with respect. Such populations don't necessarily last forever
- overharvest of largemouth bass or bluegill, introduction of new
fish species, excessive inputs of nutrients or siltation can all
ruin a fishery. Like blue ribbon trout streams, big bluegill impoundments
are a reflection of good land use and a respect for fish and their