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7582697 
Journal Article 
Recording Fathometer Techniques for Hydrilla Distribution and Biomass Studies 
Shireman, JV; Maceina, MJ 
1983 
English 
Quantitative vegetation parameters are presented to calculate hydrilla cover and biomass. It is recommended that several of these parameters be utilized to describe hydrilla relationships in a lake. Predictive equations were formulated for the three study lakes and it was concluded that the independent values taken for biomass did not indicate similar relationships in each lake. Differences in subsurface light intensity water chemistry, and substrate types may cause differences in hydrilla growth patterns which are not detectable with the fathometer. Plant density appears to be a major variable in determining plant biomass using fathometer tracing characteristics. Studies were conducted to document temporal changes in white amur and native fish populations and aquatic plant distribution associated with the introduction of white amur. White amur capture techniques including electroshocking, block netting, gill netting, and haul seining were investigated in Lake Baldwin. Although white amur were collected by all methods, none was considered effective. Hydrilla consumption rates were determined for Lake Baldwin white amur. Effective control was obtained with 185 kg fish/ha of hydrilla. Data indicate that Lake Baldwin has a harvestable bass population of 30.5 kg/ha. Condition factor analysis of largemouth bass, bluegill, and redear sunfish indicates that condition values are lower than the national average and are related, to some extent, to the amount of hydrilla present. (Author 's abstract) 
Water Resources Abstracts; Aquatic plants; Hydrilla; Ecosystems; Biomass; Distribution patterns; Fathometers; Ecology; Distribution; Plant populations; Sport fishing; Lake Baldwin; Orange Lake; Lake Pearl; Florida; SW 0850:Lakes; SW 2010:Control of water on the surface