Trout, pesticide

Jaensson, A., Scott, A.P., and Moore, A. et al. (2007). Effects of a pyrethroid pesticide on endocrine responses to female odours and reproductive behaviour in male parr of brown trout (Salmo trutta L.). Aquatic Toxicology 81, 1-9. 

Davies, P.E., L.S.J. Cook, and D. Goenarso. 1994. Sublethal responses to pesticides of several species of Australian freshwater fish and crustaceans and rainbow trout. Environ. Toxicol. Chem. 13 1341-1354. 

Macek, K.J., C. Hutchinson, and O.B. Cope. 1969. The effects of temperature on the susceptibility of bluegills and rainbow trout to selected pesticides. Bull. Environ. Contam. Toxicol. 4 174-183. 

Other studies further indicate that the occurrence of endrin in the U.S. food supply is very low. In a 1990-91 FDA survey of pesticide residues in milk representing most of the U.S. supply consumed in metropolitan areas, endrin was detected at trace levels (0.0005-0.001 ppm [0.5-1.0 ppb]) in only 2 of 806 composite samples (one sample each from Atlanta, Georgia and Dover, Delaware) (Trotter and Dickerson 1993). In another statistically based FDA study in 1992-93, endrin was not found as a violative residue in any of 710 domestic or 949 imported pear samples (Roy et al. 1995). Endrin was not reported among the pesticides detected in a 1994 FDA survey of pesticide levels in 160 samples of catfish, crayfish, shrimp, trout, salmon, oysters, and various other species from important aquaculture areas of the United States (FDA 1995). Comparable results were found in similar studies conducted by the FDA in 1990-93 (FDA 1995). 

Petty et al. (1998, 2000) used a vitellogenin (VGT) assay to assess the endocrine disrupting potential of contaminants in purified SPMD extracts. VGT is an egg yolk phosphoprotein precursor that is synthesized in the liver of female teleosts in response to estrogen from the ovary (Bailey, 1957). A wide variety of environmental contaminants have been shown to have estrogenic activity (Colborn et al., 1993). Equal portions of purified extracts from SPMDs, exposed in the Missouri River after the flood of 1993 and from the IWWTP at the Nogales Wash deployment were individually injected into immature rainbow trout (Oncorhynchus mykiss) as described in Section 6.4. The SPMD extracts contained elevated levels of complex mixtures of contaminants, including PAHs and pesticides. The fish injected with these sample extracts exhibited VGT induction, while no induction was observed in fish injected with any of the blank sample extracts. 

Lu, Y. and Wang, Z. 2003, Accumulation of organochlorinated pesticides by triolein-containing semipermeable membrane device (triolein-SPMD) and rainbow trout. Water Res. 37 2419-2425. 

Zabik, M.E., Booren,A., Zabik, J., Welch, R. and Humphrey, H. (1996). Pesticide residues, PSBs and PAHs in baked, charbroiled, salt boiled and smoked Great Lakes lake trout, Food Chem., 55, 3, 231-239. 

Environmental. The high lipophilicity of the cydodienes and the prolonged persistence of dieldrin and heptachlor epoxide (soil half-lives 2—10 yr) have resulted in severe environmental contamination. These compounds are bioaccumulated from water to fish up to 100,000- to 300,000-fold and are ubiquitous in human fat and milk. Oxychlordane [26880-48-8], mirex, and chlordecone are also bioaccumulative. The cydodienes are extremely toxic to fish with LC5Qs (ppm) to trout and bluegill of endrin, 0.001-0.002 endosulfan, 0.001-0.003 diddrin, 0.003-0.015 aldrin, 0.006-0.01 heptachlor, 0.03-0.026 and chlordane, 0.022—0.095. The LD5Qs to pheasant and mallard are aldrin 16.8 and 520, dieldrin 79 and 381, and endrin 1.6 and 5.6 mg/kg. As indicated by their rat oral LD - s, they are also extremdy toxic to small mammals in fact, endrin has been used as a rodenticide (see Pesticides). Compounds, eg, aldrin and heptachlor, which have unsubstituted double bonds, readily add oxygen to form epoxides in plant and animal tissues and are preferentially concentrated and stored in animal fats. Aldrin epoxide (dieldrin) and heptachlor epoxide are more stable (half-lives on alfalfa of seven to eight days) than aldrin and heptachlor (half-lives on alfalfa of less than one day). 

DDT was the major pesticide found in fish and birds in the Great Lakes. On a by-lake basis, lake trout from Lake Michigan contained the highest concentrations of DDT [32,33] (Fig. 4), followed by those from Lake Ontario. Fish from Lakes Erie and Superior contained the lowest DDT concentrations. No major reduction in DDT concentrations was observed in lake trout col-... 

Fig. 4 Concentrations of organochlorine pesticides in lake trout and walleye (Lake Erie only) collected in 1988 and 1998. For mirex and toxaphene, 1991 concentrations are presented instead of 1988 values. From [32,33]...

Stored DDT and dieldrin present in lake trout eggs at spawning time can affect the ultimate survival of the young (ref. 82c). Oyster growth is inhibited even at low concentrations of DDT. This characteristic growth sensitivity of a number of mollusks to DDT, and the rates at which DDT is flushed out when the mollusk is transferred to fresh water, has been used as a pesticide monitoring tool (Butler, ref. 82d). 

Bioaccumulatlon of some pesticides (fenitrothion, aminocarb, permethrin) with real or potential application in forestry in Canada has been examined in laboratory experiments using larval rainbow trout and common duckweed. Bioaccumulation of an aromatic hydrocarbon, fluorene, has also been examined since some commercial formulations employ hydrocarbon solvents. Laboratory exposures of fish or plants were carried out by placing the organisms in dilute aqueous solutions of C labelled pesticide or hydrocarbon, and by measuring transfer of radioactivity from water to fish or plants. After transfer of fish or plants to untreated water, loss of radioactivity was measured similarly. These measures allowed calculation of uptake and depuration rate constants which were used to predict residue accumulations under various exposure conditions. Predicted residue accumulations agreed substantially with other predictive equations in the literature and with reported field observations. 

The intent of this study was to derive rate constants describing uptake and depuration of some forest pesticides using fish (rainbow trout, Salmo gairdneri) and an aquatic macrophyte (duckweed, Lemna minor) in laboratory tests. Since some formulations of forest pesticides also contain solvents of petroleum distillates, experiments were also carried out with a hydrocarbon, fluorene, which is a component of fuel oil (16). 

Table I. Bioconcentration factors (BCF) for rainbow trout in laboratory exposures to several pesticides and a hydrocarbon.

The DEMETRA project [20, 26] represents the first important case of a European project to develop QSAR models for regulatory purposes. DEMETRA developed five free models to determine the ecotoxicity of pesticides using endpoints that include trout, daphnia, bees, and quails (oral and dietary exposure). Since the target was to develop models for the user, these five endpoints were decided by them, not by the developers. 

The use of the pesticide DDT has been banned in Canada since 1969 because of its damaging effect on wildlife. In 1967, the concentration of DDT in an average lake trout, taken from Lake Simcoe in Ontario, was 16 ppm. Today it is less than 1 ppm. What mass of DDT would have been present in a 2.5 kg trout with DDT present at 16 ppm ... 

T ichlobenil (2,6-dichlorobenzonitrile) is used for weed control in cranberry marshes, in nursery stock and woody plants, for pre-emergent control in crops, and for aquatic weed control. The acute toxicity of dichlobenil to fish has been measured at the Fish-Pesticide Research Laboratory in Denver the 24-hour-LC50 values are 22 p.p.m. active ingredient to bluegills (Lepomis macrochirus Rafinesque) at 24 °C. and 23 p.p.m. to rainbow trout (Salmo gairdneri Richardson) at 13°C. 

Konwick, B.J. Garrison, A.W. Black, M.C. Avants, J.K. Eisk, A.T, Bioaccumulation, biotransformation, and metabolite formation of fipronil and chiral legacy pesticides in rainbow trout Environ Sci. Technol. 2006, 40, 2930-2936. 

In addition, important detoxification enzymes such as cytochrome P450 monooxygenases and glutathione S-transferases can be used as biomarkers for monitoring pesticide pollution. For example, Jensen et al. (1991) showed that treatment of rainbow trout (Onco-rhynchus mykiss) with endosulfan (as low as 8.3 ppb) induced two microsomal monooxygenase activities (7-ethoxyresorifin O-demethylase and aldrin epoxidase). Martinez-Lara et al. (1996) found that dieldrin and malathion induced individual isozymes of GST in the gilthread seabream, Sparus aurata. 

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