Perching

The following data ( fable 1) for niolcctilcs, including hydrocarbon s, strained ring system s. molecn les with heieroatom s, radicals, and ions conies from a review by Stewart. For most organic molecules,, YM 1 reports heals of formation accurate to within a few kilocalories per rn ol. bor soni e molecules (particularly inorgari ic compoun ds wdth several halogens, such as perch loryl fluoride, even the best sem i-em pineal method fails completely. 

R. D. Stewait, ia J. C. Schumachei, ed., Perch/orates, Reinhold Publishing Coip., New York, 1960, Chapt. 5. 

Sensitive insects, phytoplankton and zooplankton die Whitefish and grayling die Perch and pike die Eels and brook trout die... 

Barre, /., Barren, m. bar ingot. Barren-elnguss, m., -form, /. ingot mold. Bmch, m. perch (fish). 

Perch lo rat its or Perchloratitas. Industrial blasting expls, based on perchlorates, used in Ger before and after WWI. Naoum (Refs 1 2) lists the compns shown in Table 1 ... 

Perchlorit (Perch lor ites). A type of Ger perchlorate mining expl used prior to and during WWI. Two typical formulations are shown in... 

Perch loro cellulose, Perchloronitrocellulose, Perch jo roglycerin and Ferchloronitroglycerin. A series of expls prepd by Alvisi (BelgP 141582 of 1899)... 

Perch ramie and Per poly perchromic Acids and Their Salts... 

Exposure of two species of freshwater fish to 0.106 ppb of a commercial formulation containing 50% methyl parathion increased serum levels of T3 and reduced T4 (Bhattacharya 1993). This effect was attributed to inhibition of acetylcholinesterase activity in the fish brain, but no direct evidence was presented. Similar treatment of freshwater perch for 35 days resulted in decreased release of progesterone from the ovaries (Bhattacharya and Mondal 1997). Also, treatment of freshwater perch for up to 90 days with methyl parathion induced a decrease in the gonadosomatic index (not defined) after day 15 of... 

Choudhury C, Ray AK, Bhattacharya S, et al. 1993. Non lethal concentrations of pesticide impair ovarian function in the freshwater perch, Anabas testudineus. Environ Biol Fishes 36 319-324. 

One study conducted in Britain between 1983 and 1989 was of barn owls found dead in the field 10% of the sample of 145 birds contained anticoagulant rodenticide residues in their livers, and difenacoum and brodifacoum were prominent among them (Newton et al. 1990). In another study, barn owls were fed rats that had been dosed with flocoumafen. It was found that a substantial proportion of the rodenticide ingested by owls was eliminated in pellets (Eadsforth et al. 1991). The authors suggest that exposure of owls to rodenticides in the field may be monitored by analysis of pellets dropped at roosts or regular perching places. 

Prey fish are here defined as small, usually short-lived, finfish. In North American fresh waters, many are members of the cyprinid (minnow), percid (perch), and centrarchid (sunfish) families. Prey fish are widely distributed, common, and important in the transfer of MeHg to higher trophic levels, such as piscivorous fish and many fish-eating birds. MeHg concentrations in prey fish of uniform age are less... 

Example of a Prey-Fish Indicator Yellow Perch Analyses of total mercnry in whole bodies or axial muscle tissue of age-1 yellow perch have provided a useful measure of MeHg concentrations in food webs of many North American lakes. This widely distributed species inhabits lakes and reservoirs across mnch of the north-central, northeastern, and eastern United States and across the central and eastern provinces of Canada (Scott and Crossman 1973 Becker 1983). An ecologically similar congeneric species, the Eurasian perch Perea fluvi-atilis), is distribnted across much of Europe and northern Asia (Thorpe 1977). 

Cope WG, Wiener JG, Rada RG. 1990. Mercury accumulation in yellow perch in Wisconsin seepage lakes relation to lake characteristics. Environ Toxicol Chem 9 931-940. 

Haines TA, Komov VT, Matey VE, Jagoe CH. 1995. Perch mercury content is related to acidity and color of 26 Russian lakes. Water Air Soil Pollut 85 823-828. 

Hammerschmidt CR, Wiener JG, Frazier BE, Rada RG. 1999. Methylmercury content of eggs in yellow perch related to maternal exposure in four Wisconsin lakes. Environ Sci Technol 33 999-1003. 

Metsaelae T, Rask M. 1989. Mercury concentrations of perch, Perea fluviatilis L., in small Finnish headwater lakes with different pH and water colour. Aqua Fennica 19 41 6. 

---