Turkey Lakes Watershed Study reference list: 1987

The isotopic composition of SO₄ in bulk precipitation at the TLW was used to infer that up to 30% of the acidifying sulphur burden in remote areas of Canada may originate from biogenic sources. The importance of biological re-emission of previously deposited S is discussed.

The occurrence of Chernobyl-derived radionuclides in TLW precipitation is documented. Use of the radionuclides for delineating tropospheric transport processes is also discussed.

Water quality in various compartments of the Wishart L. terrestrial basin is evaluated. Shallow groundwaters are dominated by Ca²⁺ and SO₄, while deeper groundwaters and streams by Ca²⁺ and ANC. Geochemical weathering of CaCO₃ in the till is the major reaction controlling ANC levels. Hydrological pathways are important.

Water and chemical budgets were examined for 3 undisturbed, forested catchments in northern Ontario (TLW, Nipigon, and ELA). Precipitation inputs and basin outputs are compared and specific watershed characteristics that control responses are noted. The results are compared with other catchments in Ontario, New Brunswick, and New Hampshire.

The current knowledge concerning ground-water studies in the acid rain program (including the TLW) is summarized in 13 points. Further work is required to understand the mechanisms of ground water acidification on both the large and small scale, to document/confirm trends, and to determine the spatial extent of acidification.

Report presents results of the application of time series methods (for developing stochastic models) to ion data from the TLW and the Norwegian Project RAIN. The univariate models explained 80% of the total variability. Runoff is a significant explanatory variable in the TLW.

Report documents historical and chronological land use changes in the 5 calibrated watersheds of eastern Canada including the TLW. It notes "the TLW offers a well documented, relatively undisturbed natural environment in which to perform monitoring of long-term deposition and impacts of acid precipitation."

Report presents an evaluation of the effects on waterfowl due to ecological changes in aquatic ecosystems associated with acid precipitation. Aerial surveys of waterfowl were used including lakes in the Ranger Lake area of Algoma just south of the TLW.

Paper presents an overview of mass budgets determined for the 4 lakes in the TLW. It discusses the relative importance of various acidifying species, dominent input pathways, and biogeochemical processes (see 88-25).

Report presents an overview of snowmelt studies conducted in the TLW to determine the physical and chemical processes that control the occurrence of episodic acidification in the TLW. (see 86-14, 86-17, 87-11)

This paper examines methodology involved in intensive snowmelt runoff studies in the TLW. These studies focus on understanding the pathways of snowmelt water within the snowpack and through the terrestrial portion of the ecosystem. Mixing of snowmelt or snowmelt induced runoff water and lakewater is investigated.

Report presents a statistical summary and data listing of the major ion chemistry and instantaneous discharge at 6 NWRI steam stations in the TLW for January 1980 to May 1986. Some data for a headwater stream draining into Turkey L is also included. Sampling, analytical and data processing methods are briefly discussed.

Report presents a statistical summary and data listing for lakes in the TLW. This is a companion to 87-12.

Undisturbed soil cores from the TLW and Montmorency Forest (Quebec) were treated to 10m of simulated rain at 3 pH levels. Effects on cation leaching, base saturation, organic C, nitrogen, and others are described. The soils from the 2 sites behaved similarly. XRD analysis of the clay minerals was also performed.

An overview of GLFC research on evaluation of LRTAP effects on forests is presented. Among others, biogeochemical studies in the TLW are described. A short discussion of findings is included.

2 sets of lakes, one near Sudbury and one near Ranger Lake (south of the TLW) were sampled to examine insect assemblages. Fishless lakes were found to contain a greater variety and abundance of insects. Fish predation is seen as the most important factor structuring aquatic insect assemblages and is responsible for changes coincident with acidification.

Cyprinids from 58 lakes in the Algoma district were sampled. Common shiner, creek chub and blacknose dace tended to occupy lakes with larger than average drainage areas. Pearl dace and fathead minnow occurred commonly in lakes with smaller drainage areas. Lakes without cyprinids were those more sensitive to acidification.

The chemical variation of peatland waters in samples taken from the acidic Sudbury area and the less acidic Ranger Lake district (near the TLW) was statistically separated into 3 components related to nautral organic, mineral and deposition sources. H⁺ variation was related to organic C concentration, while sulphate was positively associated with acidity and Ca was negatively associated with acidity.

An acid-stressed lake in northeastern Ontario, (Wanapitei) and a non-stressed lake (Ranger Lake, near the TLW) were studied to monitor and compare the effects of high acidic deposition on waterfowl. The breeding success of the Common Loon and the Common Merganser is less at Wanapitei in direct response to a depletion in fish stocks due to low pH. The Common Loon and selected duck species should become part of a long-term biomonitoring program, since a decrease in breeding success is a good indicator of the negative impact of acidic deposition.