The biomass of the submersed macrophytic vegetation in four hydrilla (Hydrilla verticillata Royle) infested lakes in central Florida was monitored for one year. Lake Orienta and Little Lake Fairview received 2,320 and 960 grass carp, respectively, while Clear Lake and Lake Mann did not receive grass carp. Hydrilla was eliminated in Lake Orienta within six months of stocking; the lake was stocked at 19 grass carp/mt hydrilla (45 fish/ha). Hydrilla was not eliminated from Little Lake Fairview which contained 9 grass carp/mt hydrilla (30 fish/ha). The growth of hydrilla was restricted in Little Lake Fairview which produced 0.380 mt hydrilla, dry organic wt., in contrast to Clear Lake and Lake Mann in which annual net primary production was 0.728 and 0.880 mt organic matter/ha, respectively. The rate of hydrilla growth was greater in the two unstocked lakes. Clear Lake produced 0.31 g/m2/day, dry organic wt., while the net primary productivity of hydrilla in Lake Mann averaged 0.38 g/m2/day. The net primary productivity of hydrilla in Little Lake Fairview was 0.14 g organic matter/m2/day. Three species (in addition to hydrilla) were common to Little Lake Fairview and Lake Mann and provided the only data upon non-target species. Pondweed (Potamogeton illinoensis Morong.) and stonewort (Nitella sp.) were more abundant and more widely distributed in Little Lake Fairview than in Lake Mann. The poor representation of pondweed and stonewort in Lake Mann was attributed to competitive pressure exerted by hydrilla which comprised 83%, by weight, of the annual mean biomass of submersed macrophytic vegetation. In comparison, hydrilla comprised 74% of the annual mean biomass in Little Lake Fairview. The effect of the grass carp in Little Lake Fairview may have been to ease the competitive pressure exerted by hydrilla, allowing pondweed and stonewort to remain well established. The percentage frequency of occurrence was concluded to be a poor criterion for measuring changes in the hydrilla population. Changes in biomass as great as 900% resulted in no change in the percentage frequency of occurrence of hydrilla in Lake Mann.

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Epibenthic marine fish populations were sampled in order to establish quantitative base-line data for use in long term monitoring of the northern Indian River lagoon system, Florida. Fish samples were taken by trawling monthly at 8 fixed stations from June through September, 1979 and 1980. Fifty-seven fish species representing 29 families were collected. The fish community was numerically dominated by a very few species. Anchoa mitchilli alone accounted for 87% of the 105,853 individuals collected. Abundance, domin ance, and species diversity were compared among the three lagoon subdivisions, Mosquito Lagoon, Indian River, and Banana River. Greater numbers of fishes were collected in the Indian River, while the highest diversity levels were in the Banana River. Although most species were collected in all three subareas, gross inequities occurred in the numbers of individuals taken. For example, Mosquito Lagoon produced significantly more Micropogonias undulatus and Leiostomus xanthurus than either the Indian or Banana rivers. Significantly more Syngnathus scovelli and Anchoa mitchilli were collected in the Indian River than in the Banana River, and the Banana River produced significantly more Lagodon rhomboides than the Indian River. The only measured environmental parameters that appeared to play significant roles in determining fish populations were vegetative cover and salinity. An importance value (IV) index, combining relative abundance, relative frequency of capture, and relative size (biomass) per individual, was calculated for each species in the community. Dominance ranking by IV has advantages over dominance ranking by relative abundance alone and is calculable for making comparisons in a long-term monitoring study.

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Zooplankton abundance, hydrilla biomass, and physicochemical parameters were sampled for one year in a small central Florida lake. Annually, rotifers comprised most of the species collected and were the most abundant zooplankton group. Hydrilla biomass was lowest during winter and spring while orthophosphate and phtoplankton concentrations were highest. Zooplankton densities were highest when hydrilla biomass was low. Small-bodied limnetic herbivores comprised most of the zooplankton during the spring. Zooplanton abundances were lowest during summer and fall and may have been either directly or indirectly related to the hydrilla growth. Factors, such as lower phytoplankton and dissolved oxygen concentrations, possible increased predation by fish, and substances that may have been secreted by the hydrilla may have had a negative effect on the lake's zooplankton density. Littoral zooplankton species were frequently collected from the lake when hydrilla biomass was high. Species diversity (─æ) was lowest during winter and spring and ranged from 1.69 to 2.11; species diversity peaked during the summer reaching 3.04.

This study was conducted to determine whether there were significant factors contributing to a teacher's ability to perform effectively in the classroom. An approximate 5% stratified random sample was selected from 9,401 possible subjects in Florida's Beginning Teacher Program between 1982 and 1985. A comparison of descriptive and reportive data was performed for teachers who completed and teachers who did not complete the program. Statistical measures included the use of contingency tables, chi-square statistic, frequency distributions and t-tests. Results suggested that a teacher's possibility of successfully completing Florida's Beginning Teacher Program was influenced by the participant's age, grade point average, type of university, college of education background, student teaching experience and teaching field. Of the teachers surveyed, those teachers who completed the Beginning Teacher Program reported significantly higher levels of performance in competencies dealing with discipline and motivation. All teachers cited peer teachers and coaching as the most common methods of assistance. Teachers who did not complete the program were more likely to lack student teaching and education background, to teach in critical shortage areas and to receive more assistance from principals than more successful teachers.

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