• Holmes, S.B.
  Canadian Forestry Service
  
• Kingsbury, P.D.
  Canadian Forestry Service
  

The effects of three matacil field formulations and some of their components on the invertebrate fauna of a cold water trout stream were studied near Searchmont, Ontario. Treatments were made by hand, applying the test material to a section of the stream using a Micron ULVA sprayer. Applications of Matacil 1.8D + ID58 and Matacil 1.8F + Atlox 3409F + invertebrate taxa. Collembra and Gerridae appeared to be most affected by the MATACIL 1.8Î ≠ ID 585 treatment and Simuliidae, Lecturidae, Baetidae, Philopotamidae, and Hydroptilidaeby the Matacil 1.8 F + Atlox3409 + water treatment. Peak aminocarb levels in water following these treatments (35.4 and 256.1 ppb respectively.) were higher than those measured following the application of matacil in Quebec and Newfoundland. N0 impacts were evident following application of Matacil 1.8F + ID 585 and impacts were evident following applications of matacil 1.8f + ID585 and Matacil 1.8 + Atlox 3409F + water, for which peak levels of aminocarb in water were 127.2 and 29.2 ppb respectively. Although an application of Sunspray 7-N + ID 585 resulted in increased drifts of Collembola and Leuctridae, no impactts were associated with an application of sunspray 7-N + Atlox 3409F + water, even though applied at a higher dosage rate. There was no mortality of rainbow trout fingerlings held in cages in the treated stream sections. Fish did accumulate aminocarb residues in their tissues., however, bioaccumulation ratios were .48 for the Matacil, 1.8D+ID 585 treatment, 0.25 for the Matacil 1.8F + ID585 treatment, and 0.50 for the Matacil 1.8F + Atlox 3409 F +water treatment.