Seining to Check Lake Balance

Managers should assess fish populations in ponds every 1 to 2 years. More detailed information is given in assessment and Corrective Management for Fish Populations in Small Impoundments,” Special Publication No. 2 of the Texas Chapter of the American Fisheries Society. Private fisheries consultants also can evaluate fish populations.

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 (at least 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 the presence of unwanted species.

Sampling with a 30-foot or larger (1/2-to l-inch mesh) seine will provide further data for evaluating pond balance. Seine one or two 50-foot areas in the pond. Record the number of bluegill captured in groups: less than 3 inches; 3 to 5 inches; and longer than 5 inches. Also look at bass condition (that is, plumpness) and for unwanted species.

Seining a pond in early June to check pond balance.  Refer to Table 3 to analyze pond balance from seine and catch data. 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 bluegill are caught your pond is
probably out of balance. If you find undesirable species, it is time to poison and restock.  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.

Evaluation of Pond Balance Using 15-foot Seine and Catch Data

 Type of Fish Caught — Conclusion and Recommendation

Seine Data– fish populations in balance no additional management small and intermediate necessary
bluegill and young of the year (YOY) largemouth bass

Angler Catch Data — bass and bluegill of various sizes

Seine Data –- Many intermediate bluegill and bluegill-crowded remove intermediate bluegill by few or no young of the year bass shore line rotenone in fall

Angler Catch Data –or few harvestable size bluegill; stock 20-30 adult (>12”) bass large bass per acre

Seine Data –- Few intermediate bluegill; many bass-crowded remove 50-75 (35 lbs.) bass recently hatched bluegill per acre
numerousbut smalland thin; stock 200, 3-5”bluegillper acre
bluegill, few but large and robust
Seine Data-
unwanted species, no recent bluegill fish populations dominated rotenone and start over
hatch, few intermediate bluegill by unwanted species
Angler Catch Data-
few harvestable size bluegill and
unwanted species (crappie, bullhead,
green sunfish, shiners, etc.)

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