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ANR-577 MANAGEMENT OF RECREATIONAL FISH PONDS IN ALABAMA/Eight

Management Of Recreational Fish Ponds In Alabama


Evaluation Of Pond Balance

Managers should check ponds for balance every 1 to 2 years if fishing quality is perceived to be unsatisfactory. The district fisheries biologist with the Alabama Department of Conservation and Natural Resources --Fisheries Section may be able to assist you in checking pond balance. Call the district office well in advance to schedule a visit. Private fisheries consultants are also available to evaluate pond balance. For a list of fisheries consultants in Alabama contact your county Extension office.

Pond balance can be checked by using a 15-foot minnow seine (1/4-inch mesh). The best time to check is early June. Seine several (a minimum of three) shallow areas of the pond that are clear of brush and weeds. Allow the seine to arch or cup slightly as it is pulled, so that fish cannot easily swim around it. Samples from seining provide information on reproductive success and presence of unwanted species.

Sampling with a 30-foot or larger (1/2- to 1-inch mesh) seine will provide further meaningful data to evaluate pond balance. Seine one or two areas in the pond. Record the number of bluegill captured in groups: less than 3 inches; 3 to 5 inches; and greater than 5 inches. Also look at bass condition (that is, plumpness) and look for unwanted species.

Refer to Table 5 to analyze pond balance from seine and catch data.

Table 5. Evaluation of Pond Balance Using 15-Foot Seine And Catch Data.

Type of fish caught
Conclusion
Recommendation
Seine data--small and intermediate bluegill and young of year largemouth bass  
fish populations in balance
no additional management necessary
Angler catch data--bass and
bluegill of various sizes
Seine data--many intermediate bluegill and few or no young of the
year bass
bluegill-crowded
remove intermediate bluegill by shore line rotenone in fall
or
stock 20-30 adult bass (12" or larger) per acre
Angler catch data--few harvestable size bluegill; few large
bass
Seine data--few intermediate bluegill; many recently hatched bluegill
bass-crowded 
remove 50-75 (35 lbs.) bass per acre
Angler catch data--bass, numerous but small and thin; bluegill, few, but large and robust
stock 200, 4-5" bluegill per acre
Seine data--unwanted species, no recent bluegill hatch, few intermediate bluegill
fish populations dominated by
unwanted species
retenone and start over
Angler catch data--few harvestable size bluegill and unwanted species (crappie, bullhead, green sunfish, shiners, etc.)


If fishing is adequate and seine data show both young bass and recently hatched bluegill fry, the pond is probably in balance. If no young bass and bluegill fry are found but many 3- to 5-inch intermediate-size bluegill are caught, your pond is probably out of balance. If you find undesirable species, it is time to poison and restock. Tadpoles in large numbers indicate that few bass are present.

(Photo right) A balanced pond means that bream are available and abundant in sizes that allow for bass predation. As a bass grows it preys on larger bream.

 

If an over-population of bream is the problem, trying to fish, trap, or seine enough bream to restore balance may not be practical or possible. A slow growing and stunted bream population can be corrected by applying rotenone along the margins of the pond in the early fall to achieve a partial kill. Apply rotenone when the water temperature drops below 80 º F, so that surviving bream will not reproduce until the following spring. Water temperatures, however, should not be below 70 º F, as the rotenone will remain toxic too long. In this procedure rotenone is applied to the margin of the pond at a distance of approximately 20 to 30 feet from the shore, but not in water deeper than 5 feet. Usually rotenone is applied at mid-day when the sun is shining and applied so the drift is toward the shore.

(Photo left) Seining a pond in early June to check pond balance.

 

The amount to be applied can be determined by calculating the amount of rotenone formulation (5 percent) required to kill all the fish in the pond and then divide that amount by 4. Then apply half this amount to approximately half of the shoreline area on one day; return 2 days later and apply the remaining rotenone to the other half of the shoreline area. For example, a 2-acre pond with an average depth of 6 feet requires 8 gallons of liquid 5 percent rotenone to get a concentration of 2 ppm (see Removal of Fish). A partial rotenone of this pond would require 2 gallons (8/4 = 2). The rotenone would be applied in two treatments, 2 days apart, and each treatment would use one gallon of rotenone.

The rotenone formulation can be diluted and poured into the prop wash of an outboard motor. Be careful to avoid skin contact. The objective is to remove approximately half the bluegills in the pond. A partial application of rotenone can be a tricky procedure; pond owners may want to contact a state fisheries biologist, fisheries specialist, or fisheries consultant for assistance.


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