Turkey Lakes Watershed Study reference list: 1986

Report presents an evaluation of long term changes in lake pH for Batchawana L using sediment diatoms. Most of the small changes recorded over the past several hundred years are attributed to climate.

Report presents the evaluation as in 86-01 and extensive data summaries in appendices.

The groundwater contribution to springmelt runoff in the TLW was evaluated using the ¹⁸O technique. At peak runoff, 50-60% is derived from premelt groundwater stored in the surficial deposits. Shallow groundwater on hillslopes is susceptible to episodic acidification; hence first order streams experience the greatest pH depressions.

Report presents the results of an evaluation of the effect of lake acidification on bacterial numbers and organic biodegredation rates in sediments. Samples from Turkey L were included in the study.

The effect on phytoplankton production of extremely low concentrations of metals derived from contaminated incubation equipment was evaluated. Samples from Little Turkey Lake (among others) were used in the study.

The composition and deposition of major ions in the TLW is evaluated using weekly bulk precipitation samples. Seasonal variations in concentrations are discussed and overall deposition compared to other locations.

Report describes development of a prototype expert computer system for the analysis of watershed acidification. Data from the TLW was extensively used in the development and testing of the system. The temporal and spatial changes in both terrestrial characteristics and aquatic chemistry are readily represented in the new system. 

Metal concentrations in lake sediment cores were evaluated to assess their source. Variations in the profile of Pb, Cd, Hg and Zn concentrations (evaluated relative to ²¹⁰Pb activity) showed that these metals had a significant anthropogenic origin. The inferred metal loadings to the sediments was compared to atmospheric loadings.

Paper presents an analysis of the reductions in ANC, base cations, and SO₄ in lakewaters that occur during spring melt using a 30-lake survey conducted within and around the TLW. A simple model is developed that predicts changes in lake chemistry during spring melt given a few chemical and morphometric variables.

In-lake ANC production occurring at the sediment-water interface was evaluated using sediment peepers in several lakes including Batchawana and Little Turkey L. Calcium and NH release and SO₄ consumption are the most important contributors to ANC production in non-acidic lake sediments. Large ANC gradients in the sediments may or may not indicate a large source of ANC for the lake depending on the fate of co-diffusing Fe, Mn, and NH.

Concentrations and annual (1983) fluxes of Fe, Al, Mn, Cu and Pb in bulk precipitation, throughfall, stemflow, forest floor percolate, mineral soil solution and streamflow are presented. The biogeochemical cycling of these metals is discussed. Atmospheric inputs and watershed outputs are low; however, intermediate portions of the cycle do exhibit higher concentrations for some metals.

The contribution of anthropogenic (SO₄ and NO₃) and natural organic acids to cation leaching from a podzolic soil is examined. Soils exhibit little SO₄ adsorption in the TLW. Current atmospheric inputs of SO₄ and NO₃ contribute significantly to cation leaching. Areal weathering rates needed to maintain soil base cation content at current levels are calculated.

Trace metal (Cu, Fe, Mn, Ni, Cd, Pb, Zn,) content of the various components of the forest phytomass in the TLW is evaluated. Relative concentration levels are presented and discussion of metal sources and availability are included. Some metals are lower than those reported for similar forests in the NE USA.

Interaction of springmelt runoff with the terrestrial ecosystem is examined using an extremely large, hill-slope snow lysimeter. Formation of ice lenses in the snowpack are responsible for lateral movement of meltwaters prior to contact with the ground. Subsurface waters are much more acidic in the lower portion of the hill-slope than at the top.

Report presents results obtained by interfacing a hydrological (see 86-16) and hydrogeochemical model using TLW data. The model simulated the progressive downstream increase in pH, Ca²⁺ , and ANC observed in the TLW by varying the proportion of groundwater to the total runoff. The model adequately reproduces episodic events.

The hydrological model developed for the TLW was applied to the Lac Laflamme and Harp Lake watersheds to test its accuracy and portability. Model performance is reasonably good. Differences in calibration coefficients among the watersheds are discussed.

The chemistry of the snowpack and snowmelt was investigated in 1985. Ion concentrations were 2- to 10-fold higher in early meltwaters compared to the pre-melt snowpack. Fifty percent of the ions were lost during the first 30% of melting. Rain events exerted a major influence on meltwater composition.

The deposition of major ions across eastern N. America is presented using data from several sources including the TLW (i.e. CAPMoN Algoma site). Variability, seasonal cycling, deposition episodicity, and relative contributions from wet and dry components are all discussed.

Relative quantities of the wet and dry components of SO₄ and NO₃ deposition are assessed at 6 eastern Canadian locations including the TLW. Dry deposition is approximately 20% of total. Seasonal variations and episodicity are discussed.

Ion mass budgets for Batchawana L. South and Turkey L. are presented for the 81-83 water years. Atmospheric deposition is the primary input pathway for H⁺ and NH. The lakes strongly retain H⁺, weakly retain N species, and are in balance for other ions except Ca²⁺ and ANC. Excess output of Ca²⁺ and ANC (over input) is attributed to unmeasured groundwater inputs.

The abundance and composition of benthic fauna in 41 lakes of central Ontario (including those in the TLW) was evaluated. No correlation with pH or ANC was observed. Other factors such as lake depth and sediment nature appear to be important factors governing benthos distribution.

Report presents a summary of the results from the GLFC intensive biogeochemical studies conducted in the TLW. Information on throughfall, forest floor percolate, mineral soil solution, till composition, vegetation and litter composition are included. Some differences were observed between the 2 sites of intensive study in the watershed; however, both still contain a large reserve for neutralization of present levels of acidic deposition.

Report summarizes daily wet-only precipitation data for stations in CAPMoN. TLW data are found in Appendix 3 for 1984.

Bogs and fens at an area northeast of Sudbury (Wanapitei Lake area) were compared to those at Ranger Lake (TLW). Sulphate was the predominant anion at Wanapitei, while organic acids were more important at Ranger. No direct influence on mat vegetaion was observed at either site. Aquatic organisms were negatively affected by low pH's. Wildlife inhabiting the peatlands was documented, and Tree Swallows were studied for the possible indirect effects of acid deposition on insectiverous species. More study is needed, but the potential for negative impact on wildlife by acidic deposition is indicated.

In a study on the effects of aquatic acidification on waterfowl (including the Ranger Lake area near the TLW in Algoma) it was found that the populations of certain fish and other waterfowl food were reduced in the stressed areas, resulting in smaller broods for piscivores in those areas. Some macroinvertebrates flourished with the absence of fish, causing a change in customary diet for the waterfowl. Long-term biomonitoring is recommended on loons and selected duck species to generate trend data for acidification effects.