Headwater Lakes Research Articles

Vegetation, soils, and ion transfer through the forest canopy in two Nova Scotia lake basins

Characterization of the forest vegetation and soils in two adjacent; contrasting headwater lake basins located in Kejimkujik National Park, Nova Scotia was completed in 1980. Precipitation chemistry was studied during May to November, 1981–83 at two forested plots in each basin. There were 2012 stems ha-1 in Beaverskin basin and 1816 stems ha-1 in Pebbleloggitch basin. Beaverskin species composition was predominantly coniferous (72% of stems) while Pebbleloggitch was predominantly deciduous (52% of stems). Thickness and mass of organic soil layers were greater in Beaverskin. Mineral soil cation concentrations were similar. There were no differences between the basins in mean incident bulk precipitation pH. Mean volume-weighted pH for the period (73 collections) was 4.80. Sixteen percent of collections had a pH < 4.25. Sulphate deposition in incident bulk precipitation (May – November) ranged from 5.4–8.5 kg ha-1 during 1981–83 while NOinf3sup-ranged from 0.04–0.93 kg ha-1. The partitioning of incident precipitation into throughfall varied considerably (69%–38%) year-to-year. Temporal flux of ions did not differ significantly. Amounts of all major ions in throughfall especially SOinf4sup2-and base cations(Ca2+ + Mg2+ + K+ + Na+) were enriched.

Comparison of the macrophyte communities of a clearwater and a brownwater oligotrophic lake in Kejimkujik National Park, Nova Scotia

Beaverskin and Pebbleloggitch Lakes are small, proximate, acidic, oligotrophic, headwater lakes located in southwestern Nova Scotia. Beaverskin Lake has clear water, its euphotic zone is deep, and it has extensive beds of macrophytic vegetation that cover most of its bottom to a depth of 6.5 m. In contrast, the water of Pebbleloggitch Lake is highly colored by dissolved humic substances, and macrophytes are restricted to a narrow littoral fringe in depths of less than about 1.8 m. The most widespread macrophyte community in Beaverskin Lake occurs at depths of 2.0–6.5 m and is dominated by Sphagnum macrophyllum and Utricularia vulgaris, while the second most prominent community is littoral and is dominated by Eriocaulon septangulare, Lobelia dortmanna, and Eleocharis acicularis. The most prominent community in Pebbleloggitch Lake is dominated by the floating-leaved Nuphar variegatum rooted as deep as 1.8 m, while communities dominated by E. septangulare and Sphagnum spp. occur in water less than about 0.7 m deep.

Hydrology of Two Headwater Lakes in the Adirondack Mountains of New York

Cranberry Pond and Woods Lake are small, acidic headwater lakes in the west-central Adirondack region of New York State. The lakes differ in size and depth but have similar watershed characteristics. Both watersheds contain thin eolian and sandy till deposits overlying granitic gneiss and have limited capacity to store and transmit groundwater. Total lake inflow was calculated as a residual of a monthly hydrologic balance based on measured precipitation, lake outflow, change in lake storage, and estimated evaporation; surface-water and groundwater inflow to each lake also were estimated. Results indicate that the lakes are hydrologically similar and are dominated by surface-water systems with highly variable runoff that responds rapidly to precipitation. Groundwater, which constituted about 16% of the total inflow to Cranberry Pond and from 31 to 38% of the total inflow to Woods Lake in 1984–86, moves through a shallow flow system that provides little stabilizing influence on the hydrology or water chemistry of the lakes. Error analysis of the hydrologic balance indicated that total annual inflow, calculated as a residual of the hydrologic balance, is accurate to within 12%. Calculated monthly inflow values are subject to greater potential error that ranges up to 46%.

Accumulation of Trace Metals in Three Species of Fish from Lakes in New Brunswick and Nova Scotia (Canada): Influence of pH and Other Chemical Parameters

Abstract Brook trout (Salvelinus fontinalis), white sucker (Catostomus commersonii) and yellow perch (Perca flavescens) from headwater lakes in New Brunswick and Nova Scotia (Canada) were analyzed for whole body concentrations of Pb, Cd, Hg, Cu and Zn. Fish from western New Brunswick generally had lowest concentrations of metals. Mercury concentrations were highest in fish from lakes close to urban centers on the leeward side. Only trout were collected from lakes in Cape Breton Island, and these were characterized by high Cd and Zn concentrations. The only consistently strong correlation between metal concentration and any lake chemistry parameter was a negative correlation between Pb concentration and lake pH. Copper and Zn were consistently positively correlated for all three species, perhaps due to their common existence in mineral deposits.

Physical, Chemical, and Biological Characteristics of the Turkey Lakes Watershed, Central Ontario, Canada

The Turkey Lakes Watershed (TLW) in central Ontario was selected for intensive research into the effects of the long-range transport of air pollutants (primarily acidic deposition) at a site on the Canadian Shield having both vulnerable terrain and an undisturbed Great Lakes forest type. The terrestrial and aquatic resources within the basin are representative of the surrounding region of Algoma, although for Ontario, it does have high relief (290 m) and high annual precipitation (&gt;1200 mm). The TLW contains a chain of four lakes (five distinct lake basins) that range from 5.8 to 52.0 ha in area and 2.2 to 12.2 m in mean depth. The lakes are dimictic and, except for the deepest lake, experience dissolved oxygen depletion in undisturbed bottom waters. There is a gradient in the major ion composition of lakes within the TLW, the most dilute waters occurring at high elevations. Calcium levels increase from 55 to 138 μmol∙L−1 down the chain. Sulphate is the dominant lake water anion in the headwater lake, while alkalinity dominates in the lowest lake. Phosphorus is the limiting nutrient in these lakes; NO3-N levels are relatively high (7.9–16.4 μmol∙L−1) because the terrestrial basin exhibits low utilization of this nitrogen species. Seasonal and episodic variations in surface water composition can be large. The headwater lake contains no fish; however, fish communities in the lower three lakes (composed of 8-11 species) are typical of the Algoma region. The distribution of benthic organisms is primarily a function of lake depth and presence/absence of fish rather than variations in water chemistry. Zooplankton species composition is similar across all lakes, and cyanophytes are the dominant algae throughout. The forest is an uneven-aged, mature-to-overmature, old-growth tolerant hardwood stand. The principal tree species is sugar maple (90%) with lesser amounts of other hardwoods (9%, usually yellow birch) and various conifers (1%). Production is typical of forest at this northerly latitude (47°N). Foliar bioelement concentrations are generally similar to those observed at Hubbard Brook, New Hampshire.

Risk to Salmonids of Water Quality in the Turkey Lakes Watershed as Determined by Bioassay

Batchawana Lake, the headwater lake in the Turkey Lakes Watershed, was devoid offish. Although a number of factors could cause this fishless state, we conducted in situ studies to partially address conditions related to lake acidification. The spring pH depression did not induce significant, consistent mortality to rainbow trout (Salmo gairdneri) or lake trout (Salvelinus namaycush) caged in situ. In 1981, however, considerable mortality occurred to fish caged in Batchawana Lake during or immediately following the maximum spring pH depression. In the remaining lakes, mortality occurred later in the exposure period. Whole-body concentrations of Na+, Ca2+, and Mg2+ in rainbow trout caged (1980) in three lakes of the watershed were similar; however, K+ appeared slightly higher (but not statistically different) in fish held in the headwater lake. Static bioassays indicated that the 96-h pH-LC50 for brook trout (Salvelinus fontinalis) was 3.80–4.09, considerably lower than the lowest pH, 4.66, observed during spring. Brook trout corralled in Batchawana Lake grew slightly faster and accumulated more Pb and Hg than fish held in a downstream lake. Although pH and trace metal levels in Batchawana Lake may at times be inhospitable to fish, other factors likely contributed to the fishless condition of this lake.

Fish Community Structure, Biomass, and Production in the Turkey Lakes Watershed, Ontario

The Turkey Lakes Watershed contains four lakes, and the headwater lake (Batchawana Lake) consists of two distinct basins, neither of which supports a native, reproducing fish stock. Fish biomass varied by a factor of 3.3 among the other three lakes in the watershed. Fish flesh production varied by a factor of only 1.5 in the system. Salmonid and small cyprinid contribution to biomass and production increased with progression downstream. Both fish biomass and production per unit surface area decreased with increasing lake depth. The fish biomass and production in the watershed was strongly influenced by depth, but alkalinity and phytoplankton carbon assimilation also were related to stock and production. Wishart Lake, immediately below Batchawana Lake, has a fish stock with restricted recruitment, and cyprinids make only a limited contribution to the observed production. Although both these conditions may be symptomatic of lake acidification, it is unclear whether the situation in this watershed results from lake acidification or biogeographic factors.

Fossil Midge Associations in Relation to Trophic and Acidic State of the Turkey Lakes

Most changes in profiles of relative abundance of Chironomus, Sergentia, Procladius, Heterotrissocladius, Micropsectra, Tanytarsus, and other taxa in dated sediment cores suggested a trend to more oligotrophy conditions at present in four dimictic lakes, but not in the single polymictic lake in which species composition was least variable temporally. Decreased numbers of chironomids and chaoborids toward the present indicated declining productivity in all five lakes. Total phosphorus concentrations in sediments declined through these periods of inferred greater oligotrophy. Most of these trends were probably not caused by anthropogenic acidification because they began up to 130 yr B.P. and they were sometimes duplicated even deeper in sediment cores. Furthermore, taxa common in acidified lakes elsewhere did not increase in these lakes. Recent acidification may have affected taxonomic composition and diversity of chironomids in the headwater lake, the only lake which showed a near-surface reduction in members of the tribe Tanytarsini, and the ratio of taxa to individuals. Chaoborus americanus occurred at high densities throughout the cores from the two upper lakes, indicating that these lakes probably never had fish communities.

Natural and anthropogenic acidity sources for Finnish Lakes

The headwater lakes in peat-rich areas in Finland commonly have high organic matter concentrations and are surrounded by soils and bedrock poor in bases. As a result the organic acid load on the watercourses is generally high. The significance of the organic vs anthropogenic acidity in 78 moderately acid lakes (pH range 4.3 to 7.1, TOC range 0.6 to 33.9 mg L−1) was evaluated in areas receiving different levels of acid deposition. The lakes were sampled during autumn overturn, and their water quality (mean TOC = 10.9 mg L−1, mean pH = 5.9) represents rather well the average water quality in small lakes in Finland. According to the correlation and regression analyses, TOC is a better predictor of pH than non-marine sulfate. Base cation concentrations are important in determining the sensitivity of the lakes to organic and anthropogenic acidity. The highest minerogenic acid contribution is found in high-deposition areas, while the percent organic acid contribution is greater in low deposition areas although TOC levels are comparable in both areas. It would appear that the pH of humic lakes is determined to a greater extent by individual watershed characteristics than by their geographical location at the present atmospheric loadings received in Finland.

Response of Headwater Lakes to Varying Atmospheric Deposition in North-Central Ontario, 1979–85

Between 1976 and 1985, loadings of SO42− to the Algoma district (north-central Ontario) varied from a low of 47 (1980) to a high of 84 meq∙m−2 (1978) and was low in years of low annual precipitation. The mean and median lake concentrations of H+ and SO42− in 54 lakes declined between 1979 and 1982 following the period of lowest annual deposition and declined further between 1982 and 1985. Overall, mean lake pH increased 0.35 unit between 1979 and 1982 and an additional 0.07 unit over the next 3 yr. Lake concentrations in the Turkey Lakes watershed exhibited a similar trend. Two lakes without fish in 1979 and with pH's &lt; 5.5 developed white sucker (Catostomus commersoni) populations by 1986 with ages indicating that survival began after 1980. This apparent invasion from downstream populations probably occurred when lake pH's neared 5.5. Although a direct link has not been established, these lakes appear to be extremely responsive to changes in atmospheric deposition. The "recovery" of water quality clearly extends beyond that locally documented at Sudbury, Ontario, yet it remains to be determined to what degree the responses relate to differences in continental deposition and/or responses within the watershed.

Genetic Identification of Cutthroat Trout, Salmo clarki, in Glacier National Park, Montana

Trout populations in 29 lakes in Glacier National Park were identified by meristic and electrophoretic analyses to assess the extent of introgressive hybridization between introduced nonnative trout and the indigenous cutthroat trout, Salmo clarki lewisi. Native cutthroat trout remain in 16 lakes draining to the North and Middle forks of the Flathead River; no native trout were found east of the Continental Divide. Introduced Yellowstone cutthroat trout, Salmo clarki bouvieri, occur in six headwater lakes. Hybrid populations, including both S. c. lewisi × bouvieri and S. clarki × S. gairdneri, inhabit six lakes. Hybridization between native and introduced trouts has been minimal, apparently due to strong selective pressures favoring the indigenous genotype. Close agreement was observed between the meristic and electrophoretic results.

Processes and Causes of Lake Acidification during Spring Snowmelt in the West-Central Adirondack Mountains, New York

The surface and outlets of two headwater lakes acidified during the 1978, 1979, and 1980 spring snowmelt periods. The decrease in pH was accompanied by an increase in nitrate whereas the other strong acid anion, SO42−, remained relatively constant. Chemical mass-balance calculations, using data from the Integrated Lake–Watershed Acidification Study, indicate that the peak in acidification observed in the Adirondack Mountains in the spring is caused by (1) a dilution of base cations (Ca2+, Mg2+, Na+, and K+) and associated alkalinity by snowmelt, (2) an increase in NO3− concentration in the acidified portion of the lakes, and (3) the constant elevated concentration of SO42−. At Woods Lake, the NO3− that accumulated in the snowpack plus that deposited from the atmosphere during snowmelt was sufficient to account for the increased NO3− in and transported from the lake. At Panther Lake, an additional source of NO3− was needed and was believed to be contributed by nitrification in the upper soil horizons. If atmospheric deposition of sulfur is reduced, low-alkalinity systems like Woods and moderate-alkalinity systems like Panther will be less likely to develop strong acidity during spring acidification.

Organochlorine Residues in Brook Trout and Yellow Perch From New Brunswick and Nova Scotia (Canada) Lakes

Abstract Brook trout and yellow perch collected while surveying New Brunswick and Nova Scotia headwater lakes were analyzed for DDT metabolites, chlordane, hexacyclohexane isomers, hexachlorobenzene, toxaphene and PCB’s. Concentrations of DDT metabolites were much higher from fish taken from lakes in north-central N.B. (200-700 ng/g wet wt) than from fish taken elsewhere (&amp;lt;10 ng/g). Seventy to 90% of the DDT metabolites was DDE. Chlordane (3-13 ng/g) was analyzed in seven trout, six of them from central N.B. areas with intensive agriculture. Isomers of hexachlorocyclohexane were in highest concentration from north-central N.B. (10-20 ng/g), eastern N.S. (5-15 ng/g) and southern N.B. (5-20 ng/g). In most cases, alpha-hexachlorocyclohexane (lindane) was the isomer in highest concentration. Concentrations of hexachlorobenzene in fish tissues was highly variable with no obvious geographic bias. PCB’s were detected in very few fish, and no toxaphene was detected.

Environmental status of several Shubenacadie River headwater lakes, Nova Scotia, Canada

The Shubenacadie River basin is the largest watershed in Nova Scotia, Canada, encompassing an area of approximately 2,800 km2 and supporting one of the most rapidly expanding populations in Atlantic Canada. A comprehensive study was carried out to assess the effect of recent development in the basin on the headwater lakes. Information on the environmental status of the lakes can be further used in the development of a management framework for the basin with respect to water quality and quantity objectives.

Factors Influencing the Distribution of Phytoplankton in 97 Headwater Lakes in Insular Newfoundland

Phytoplankton samples collected from 97 headwater lakes throughout insular Newfoundland were analyzed and used as a basis for a statistical evaluation of the environmental factors influencing species distributions. A selected subset of 77 taxa were clustered using a complete-linkage cluster analysis. The final 12 clusters represent the associations of species found occurring together in insular Newfoundland. Physical, chemical, and morphometric data collected with the phytoplankton served to characterize the environment. Factor analysis simplified the original variables, many of which were highly correlated and uninterpretable, into seven derived environmental factors: dystrophy, hardness, salinity, lake size, season, watershed influence, and orthophosphate enrichment. The resulting orthogonally rotated (VARIMAX) scores comprising these seven factors were correlated with species abundances. Spearman correlations showed several relationships between species distributions and the seven derived environmental factors. Although the analysis identified a subset of naturally acidic, dystrophic lakes, it failed to reveal any evidence of anthropogenic acidification in the lakes studied. For the most part, the members from each of the cluster groups demonstrated similar relationships with the derived environmental factors. The evidence suggests that the cluster groups may represent species associations; groups of species that co-occur because of their common requirements for specific environmental conditions. Phytoplankton autecological findings resulting from this study of insular Newfoundland lakes correspond well with conclusions derived independently from a comparable study of 95 headwater lakes in Labrador.

Transport of arsenic and mercury from gold mining activities through an aquatic system

Past gold mining pracerties in the Waverley area of Nova Scotiaa, Canada, have left wastes containing arsenic and mercury which are affecting water and sediment in the Shubenacadie River headwater lakes. The concentrations of arsenic and mercury in sediments decreased gradually from 1500 μg g −1 near the Waverley mine site to 120 μg g −1 and 0.5 μg g −1, respectively, in a downstream lake. The concentrations of arsenic and mercury were determined in water from the lakes and connecting streams and in suspended solids collected from the connecting streams in the spring, summer and fall of 1983 to investigate means of transport within the headwater lakes. The greatest quantity of arsenic (7.1 kg) was transported by suspended solids in November, while most of the mercury was transported by suspended solids during spring and fall, although the concentration of mercury in all water samples was below the detection limit of 0.0005 mg 1 −1. A significant increase of dissolved iron and manganese concentration was found during summer anoxic conditions in lake bottom waters and in the water of connecting streams. Calculations show that arsenic is most likely associated with iron oxides precipitated after the mixing of iron-rich hypolimnetic water with oxygenated surface lake water, and is transported further downstream by suspended solids.

Sulfur and oxygen isotopes of sulfate in precipitation and lakewater, Quebec, Canada

Stable isotope ratios of sulfur and oxygen of sulfate ion in precipitation and lakewater were monitored in six headwater lakes in Québec, Canada. The lakes studied are oligotrophic and located over a wide area (350 km) on the Canadian Shield, which is known to be sensitive to acidification. The δ 34S of the sulfate ion in precipitation ranges from 3.1 to 6.7‰ for all locations during the sampling period, which is very close to the values found for the lakes, from 3.5 to 6.7‰. Moreover, the δ 34S of sulfate showed seasonal variations which are parallel in time for all stations. This strongly suggests that precipitation is a major source of sulfate in the lakes that were investigated. However, the δ 18Ovalues of precipitation sulfate are close to each other between stations and are consistently higher (+ 8.3 to 13.5‰) than that of the lakes (+ 1.7 to 8.5‰). In addition, there is no spatial or temporal trend in lake δ 18O sulfate, suggesting that a transformation occurs to sulfate in the watersheds. We suggest the hypothesis that sulfate ion is reduced and reoxidized in the runoff and lake waters so that it acquires an oxygen isotopic label different from precipitation.

Sources of mercury contamination in the sediments of small headwater lakes in south-central Ontario, Canada

To determine the significance of mercury contamination of remote lakes in three regions of south-central Ontario, Canada, sediment cores were collected at several stations in each of fourteen lakes. Profiles of Hg concentration with depth were similar to those found in many parts of the world and indicate a substantial increase in Hg loading to these lakes in recent decades. Surficial sediment concentrations (0–2 cm) ranged from 120 to 700 ng/g dry matter.

Interactive Toxicity of Aluminum and Acidity to Early Life Stages of Brook Trout

Abstract The influences of exposure to aluminum and increased acidity on mortality, growth, behavior, and biochemical responses of brook trout Salvelinus fontinalis were evaluated as a function of developmental stage. Eyed eggs and young brook trout were exposed until 30 d after hatching in proportional diluters to pHs of 4.5, 5.5, and 7.2, with and without aluminum (300 μg/L); 37-d-old brook trout that had been held in experimental control water since hatching were exposed to these same conditions for 30 d. Exposure conditions (i.e., aluminum and calcium concentrations and pH) simulated conditions in some headwater lakes and streams in the northeastern United States. Adverse effects on exposed brook trout generally increased as pH decreased from 7.2 to 4.5 and potentiation of effects by aluminum occurred at pHs of 5.5 to 7.2. However, embryos and fish older than 36 d were more tolerant of acidic conditions and aluminum than were larvae less than 15 d old. We conclude that the adverse effects on mortality...

Headwater lake chemistry during the spring freshet in North-Central Ontario

From data on 30 headwater lakes in north-central Ontario we found that, during the spring snow melt of 1981, all lakes underwent serious declines in alkalinity. Generally, SO42−, alkalinity, Ca+ and Mg2+ concentrations were reduced by runoff and rain then recovered to intermediate levels after the major inputs declined. As expected, a range in responses was evident with lower alkalinity systems showing the greatest changes. The observed changes, however, were consistent with acid loading having depleted alkalinity.