• Bacon, G.B.
  Aquaculture and Fisheries Development
  

The analytical benefits, derived from species diversity in benthic diatom community structure, were used to asses the impact of experimentally-applied Aminocarb Flowable and Aminocar in 585 Oil on the microphytic component of stream vegetation. In addition samples of periphyton were analyzed chemically for the presence of aminocarb residues.

Glass plate collectors were deployed in stretches of Manzer Stream to permit colonization during the two weeks prior to the days of experimental applications (82-06-01; 82-06-15).

Samples collected from control and treatment stretches of the stream at t = -1h, 1h, 3h and 6h, and prepared with acid fuchsin stain indicated that 70-90% of colonized diatoms were alive during the experiment. Samples of drift periphyton collected at t = 1h and 7h indicated that 40-50% of these specimens were alive during the experiment.

Samples from colonized plates and from drift which were analyzed using the Coefficient of Community and Percentage Similarity of Community, also revealed no evidence of an impact, since shifts in species diversity and dominance amongst controls was as great or greater than that amongst treatment samples.

Analyses of periphyton samples collected immediately following spray application and at 7h post spray in effect indicated no accumulation of aminocarb had occurred. However, ppm levels of fenitrothion were discovered in some samples and are thought to have been present in others.