TN00206 BLUEGILL LEPOMIS MACROCHIRUS
| Result | Management Action | ||
| Existing | Other management practices [specified in comments] |
| References/Result | Reference Numbers |
| Adverse | TN5388, TN5394 |
| Beneficial | TN5383, TN5388, TN5389 |
Comments on Management Practices
CONTROL OVER ABUNDANT AQUATIC VEGETATION, AS FEEDING AND GROWTH ARE OVER HARVEST OF LARGEMOUTH BASS WILL REDUCE PREDATION PRESSURE AND ALLOW BLUEGILLS TO OVERPOPULATE *TN5394,TN5388* MAXIMIZED AT INTERMEDIATE STRUCTURE LEVELS *TN5389*; OVER ABUNDANT VEGETATION ALSO LEADS TO STUNTING DUE TO DECREASED PREDATION PRESSURE *TN5383,TN5388*; MAINTAIN GOOD PREDATOR POPULATION TO KEEP BLUEGILL POPULATIONS IN CHECK *TN5388* Largemouth bass and bluegill are a good predator-prey combination in many states, although questionable in others. Relatively large population of predators must be introduced before bluegills *1200*. Bluegills tend to overpopulate and must be controlled to maintain good fishing for both species *1178,1584,1200*. In a Kansas study, moderately acid strip-mine lakes which had been neutralized with agricultural lime appeared to have good sport fisheries potential *6635*. In an Alabama study, potassium permanganate at 3 mg/L significantly reduced mortality due to external bacterial infections *6614*. In an Alabama pond study, bluegill in grass carp and carp ponds had standing crop decreases of 52% and 67%, respectively *67*. Beds of pondweed in Clearwater Lake favored bluegill survival *68*. Characteristics of balanced bass/bluegill ponds in Missouri included small to intermediate size bluegill with a relatively high mortality rate, and adult bluegill with a relatively low mortality rate with consistent and uniform recruitment of young fish. Charactoristics of unbalanced ponds includes small to intermediate size bluegill with low a mortality rate, and adult bluegill with mortality rates that increase with increasing size as the dominant year classes *6638*. In one Missouri study, growth was considered satisfactory if bluegills attained a length of 5.5 inches or weighed .1 pound by age IV *6634*. Management recommendations in large Missouri impoundments to decrease the population density include: 1. Educate anglers to keep all bluegill caught, regardless of size. 2. Use poison along shorelines at a time when a minimum of other species will be affected. 3. Fluctuate water levels at critical spawning and nesting periods *6626*. In Illinois, early fall drawdowns greatly reduced the numbers of small bluegills and allowed an increase in the number of large bluegill *6625*. In one Missouri lake, an 8 foot drawdown in July seemed to reduce the density of fry and intermediate- size bluegill due to: 1. Stranding small sunfish in weedbeds and shallow pools. 2. Increased predation by bass on small sunfish. 3. Nest exposure due to decreased water levels. *6644*. In Missouri, aquatic weed control is used as a means of reducing the numbers of small bluegill *6637*. In an Indiana study, channel catfish and Northern pike showed some potential as a prey species for bluegill control *69*. When bluegills in Oklahoma were treated with 5-10 ppm of 2,4-D spawning was delayed about 2 weeks *70*. In Ohio, chemical control of algal mats increased nesting surfaces *6623*. In a Missouri study, fish in fertilized ponds grew significantly faster than fish in unfertilized ponds during the first summer after stocking. However, fertilization may accelerate the process of overpopulation *6628*. In an Indiana study, bluegill exposed to high levels of trace metals took up substantial quantities of trace metals *71*. Split-stocking is recommended in Missouri with bluegill and channel catfish stocked in the fall, and largemouth bass the following June. Stocking rates in low fertility ponds are - 50 largemouth bass, 250 bluegill, and 50 channel catfish. In ponds with intermediate fertility - 75 bass, 375 bluegill, and 75 channel catfish. In high fertility ponds - 100 bass, 500 bluegill, and 100 channel catfish. Bluegill should be stocked at 1.5-2.0 inches, andnever less than 1.2 inches *6616*. It is generally agreed that fingerlings have the best survival and give a better chance for pond balance than do fry. It is also, agreed that stocking adults will produce an unbalanced situation very quickly *72*. Stocking objectives are - 2 years after stocking, you should have 2 age groups of bass, 3 age groups of bluegill, plus good growth and abundance *6616*. In Indiana, male bluegill X female redear hybrids appeared to be excellent for stocking if no other species were present. Hybrids had good growth rates, and though reproduction occurred it was at a very slow rate, so there was little danger of overcrowding *73*. For other references see *67,68,6625,6644,6637,69,70,71,72,73,6628*.