Lake variables

Rowan, DJ. and J.B. Rasmussen. 1992. Why don t Great Lakes fish reflect environmental concentrations of organic contaminants An analysis of between-lake variability in the ecological partitioning of PCBs and DDT. Jour. Great Lakes Res. 18 724-741. 

I. Laurion, M. Ventura, J. Catalan, R. Psenner, R. Sommaruga (2000). Attenuation of ultraviolet radiation in mountain lakes Factors controlling the among- and within-lake variability. Limnol. Oceanogr., 45,1274-1288. 

The following lake variables were determined (monthly samples from central lake sites) for pH, Secchi depth, temperature, alkalinity, total-P, chlorophyll-a, conductivity, Fe, Ca, hardness (= Ca+Mg concentration) and color. 

In summaiy, periphyton are present in all lakes, easy to sample, and would respond rapidly to changes in the abundance of MeHg. Periphyton are sometimes eaten directly by fish. The diverse, complex, and variable nature of the periphyton community, however, would complicate interpretation of mercury concentrations in periphyton in a monitoring program. 

Rusak JA, Yan ND, Somers KM, Cottingham KL, Micheh F, Carpenter SR, Frost TM, Paterson MJ, McQueen DJ. 2002. Temporal, spatial, and taxonomic patterns of crustacean zooplankton variability in umnanipulated north-temperate lakes. Limnol Oceanogr... 

Weigel BM, Wang LZ, Rasmussen PW, Butcher JT, Stewart PM, Simon TP, Wiley MJ. 2003. Relative influence of variables at multiple spatial scales on sheam macro invertebrates in the Northern Lakes and Forest ecoregion, USA. Freshwat Biol 48 1440-1461. 

The model is composed by different equations which in all cases can be used in unsubscribed format in a basic language program. An important point to highlight is that Qwasi takes into account both steady and unsteady state solutions for the equations for systems involving contamination of lakes (or rivers). The equations considered by Qwasi involve more than 15 physicochemical processes (such as partitioning, sediment transport, deposition, etc.) to estimate the fate of the studied system. These processes and the main involved variables and parameters are summarized in Fig. 2. 

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