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Historical aerial applications of the insecticide Matacil 1.8D provide an opportunity to look for potential effects of the endocrine disrupting compound 4-nonyiphel (4-NP) on Atlantic salmon (Sdlmo slar) populations. Matacil 1.8D contained the carbamate insecticide aminocarb, with 4-NP as primary solvent Between 1975 and 1985 Matacil 1.8D was applied to forests in Atlantic Canada to control damage from the spruce budworm (Cboristonerafumiferana). After spraying, estimated concentrations of 4-NP in water fell within a range in which estrogenic effects might be anticipated. The spraying coincided with final stages of smolt development in salmon. Salmon catch data were evaluated considering effects on survival of the smolt stage. There wa siificant negative. r ionship between the returns of salmo and the proportion of tributaries sprayed within. the Restigoudhe River drainage basin in 1977. There was also a broader event of unusually heavy salmon smolt mortality in 1977, which contains a significant relationship indicating that where Matacil 1.8D spraying occurred, the smolt mortality increased. For 16 rivers exposed to spraying between 1973 and 1990, a significant proportion (0.005) of the lowest salmon catches coincided with Matacil 1.8D spraying. A decline coinciding with the use of Matacil 1.8D1 was also apparent in: blueback herring (Alsa aestiva) catches in New Brunswick Because similar relationships were not evident for Matacil 1.8F or fenitrothion, neither of which were formulated with 4-NP, we hypothesize that the 4-NP in Matacil 1.8D was the causal agent. Concentrations of 4-NP described here are within current ranges encountered in industrial effluents and municipal sewage outfalls.

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Emerging insects are a potential biotic transport route for export of contaminants sequestered in lake sediments to surrounding aquatic and terrestrial ecosystems Emerging insects (mainly Diptera) were collected from four lake mesocosms treated with 10 pg of sediment-sorbed 2,3,7,8tetrachlorodibenzofuran Insects emerging from the mesocosms had a mean contaminant concentration of 228 pg/g wet weight Contaminant export by emerging insects was from 0 2 to 2 1% of the total sediment contaminant content annually

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