Perch Lake

Ground Water Geochemistry. Ground water from the lower aquifer in the lower Perch Lake Basin at the Chalk River Nuclear Laboratories, Figure 2, was used for field elution studies to provide water of different redox characteristics. Water from piezometer "0" in the transition area, and from KNEW in the discharge area was used as being representative of "neutral" and... 

Figure 2. The lower Perch Lake basin. Chalk River Nuclear Laboratories, showing the location of piezometers HA, O, and KNEW. The screens of these piezometers are 60 cm long and are located at the bottom of the piezometer, adjacent to the numbers on the figure.

Investigations on the transfer of l e04 from surface water to organic-rich bottom sediments in the freshwater Perch Lake, located on the Canadian Shield, revealed very low transfer rates of only 1.4 to. 1.3 % of radioactivity per day. The same range of transfer rates was found for - I and [32]. 

Chalk River Nuclear Laboratory, lower Perch Lake Basin, Ontario, Canada... 

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. 

Roseman EF, Mills EL, Forney JL, Rudstam LG. 1996. Evaluation of competition between age-0 yellow perch (Perea flavescens) and gizzard shad (Dorosoma cepedianum) in Oneida Lake, New York. Can J Fish Aquat Sci 53 865-874. 

Simonin HA, Gloss SP, DiiscoU CT, Schofield CL, Kretser WA, Karcher RW, Symula J. 1994. Mercury in yellow perch fromAdirondack drainage lakes (New York, U.S.). In Watras CJ, Huckabee JW, editors. Mercury pollution integration and synthesis. Boca Raton (FL) Lewis Pubhshers, p. 457-469. 

Yellow perch, Perea flavescens Michigan 1993 Torch Lake (34 pg Cu/L) vs. reference site (10 pg Cu/L) Ovaries Testes... 

Ellenberger, S.A., PC. Baumann, and T.W. May. 1994. Evaluation of effects caused by high copper concentrations in Torch Lake, Michigan, on reproduction of yellow perch. Jour. Great Lakes Res. 20 531-536. Elsenhans, B., W. Forth, and E. Richter. 1991. Increased copper concentrations in rat tissues after acute intoxication with 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin. Arch. Toxicol. 65 429-432. 

Perch, Perea fluviatihs Norway 1991 lake near highway vs. reference lake ... 

Lake Paijanne (estimated 137Cs Chernobyl loading of 20,000 Bq/m2) 137Cs whole fish three species (northern pike, Esox lucius] yellow perch, Perea flavescens roach, Rutilus rutilus) 1986 pre-Chernobyl vs. post-Chernobyl 580 FW vs. 1250 FW 6... 

Driscoll et al. (1994) have studied the mercury species relationships among water, sediments, and fish (yellow perch) in a series of Adirondack lakes in New York state, USA. In most lakes, approximately 10% of the total mercury loading was in the form of C2HsHg+. Mercury concentrations increased as pH fell, but the best correlation was found between [dissolved Al] and [dissolved Hg] suggesting that the same factors are responsible for mobilizing both these metals. Methylmercury concentrations correlated strongly with the dissolved organic carbon content in the water. Fish muscle tissue was analyzed for mercury and showed an increase with age. However, the study was unable to resolve the question of whether the principal source of mercury to these lakes was atmospheric deposition or dissolution from bedrock due to acid rains. 

LC50 (24-h) for rainbow trout 850 pg/L, brown trout 842 pg/L, lake trout 164 pg/L, fathead minnow 883-2,240 pg/L, channel catfish 372 pg/L, bluegill sunfish 101 pg/L, yellow perch 407.50 pg/L (Mayer and Ellersieck, 1986). 

LC50 (96-h) for Pteronarcella badia 610 pg/L, Atlantic salmon 134 pg/L, bluegill sunfish 460 pg/L, brown trout 138 pg/L, brook trout >800 pg/L, channel catfish 440 pg/L, lake trout 480 pg/L, longnose sucker 330 pg/L, rainbow trout 135 pg/L, white sucker 435 pg/L, yellow perch 240 pg/L (Johnson and Finley, 1980). 

Anthoni U, Christophersen C, Nielsen PH, Gram L, Petersen BO (1995) Pseudomonine, an Isoxazolidone with Siderophoric Activity from Pseudomonas fluorescens AH2 Isolated from a Lake Victorian Nile Perch. J Nat Prod 58 1786... 

The DMT universe can overlap ours in various ways. For example, a DMT psychonaut, with his eyes open, may see a being perched on a tree in our world. This is a level 1 merging of realities, with the being from the DMTverse superimposed on the tree from our universe. In a level 2 blending, the psychonaut can walk through a forest and around a lake in the real world and see an unrelated forest and lake in the DMTverse, with no correspondence to the real universe except that a forest and a lake exist. In this level 2 blending, it s as if the subconscious brain sees our traditional world but creates a DMT metaphor for it. A lake in one world is a lake in the world beyond. 

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