Vincent Williams

Fish Population Responses to Improved Lake Habitat Utilizing an Extreme Drawdown

An extreme drawdown conducted on Lake Tohopekaliga rejuvenated littoral substrate, stimulated development of desirable aquatic plants and increased macroinvertebrate production. As a result of these beneficial changes standing crops offish in littoral areas increased from a high of 191 pounds per acre before the drawdown to 455 pounds per acre within two years after reflooding. Limnetic standing crops increased from 59 pounds per acre to 127 pounds per acre during the same period. Biomass of sportfish neady doubled, although forage fish accounted for a higher percentage of the population...

Aquatic Macroinvertebrate Responses to an Extreme Drawdown

An extreme drawdown conducted on Lake Tohopekaliga, Florida. improved littoral substrate. stimulated development of aquatic macrophytes and increased invertebrate standing crop. Benthic macroinvertebrates increased from 98 to 244 organisms per square foot in limnetic areas after reflooding; littoral benthos rose from 154 to 250 organisms per square foot. Phytomacrofauna increased from a predrawdown high of304. to 1364 organisms per sample unit after reflooding, Standing crops decreased to predrawdown estimates within two years following peak production periods. These decreases were...

Sampling Shallow Water Fish Populations Using the Wegener Ring

The Wegener Ring was designed to sample fish populations of shallow, vegetated habitats in Lake Tohopekaliga, Florida. The sampler is portable and simple to use. Ten transects in water 0-18 inches deep were sampled within consecutive 3 inch contours. As depth of water increased, non-centrarchid forage fish decreased while numbers of centrarchids increased. Total numbers of fish decreased from an average of 216,042 per acre in 0-3 inches to 20,326 per acre in 15-18 inches of water. Standing crop was relatively constant, averaging 91 pounds per acre for all water depths. The monetary values...