Limnology of 46 lakes and ponds on Banks Island, N.W.T., Canadian Arctic Archipelago (original) (raw)

Physical and chemical limnological characteristics of lakes and ponds across environmental gradients on Melville Island, Nunavut/N. W. T., High Arctic Canada

Fundamental and Applied Limnology / Archiv für Hydrobiologie, 2007

The limnological features that characterize the shallow ponds (<2 m deep) and lakes (> 2 m deep) on Bathurst Island, Nunavut, Canada were examined through chemical analyses and multivariate statistical methods as part of a larger ongoing survey to document and monitor environmental changes in these remote and sensitive areas. All sites were relatively oligotrophic and alkaline. Nutrient ratios indicated that nitrogen could be limiting algal growth to a greater degree than phosphorus in over 63 % of the sites. Principal components analysis (PCA) was used to explore the patterns of variation in the limnological dataset. The three dominant limnological gradients were: major ion content and dissolved organic carbon (DOC) levels along Axis 1; and pH along Axis 2.

Patterns in the limnology of lakes and ponds across multiple local and regional environmental gradients in the eastern Canadian Arctic

2012

This study examined water chemistry from 113 lakes and ponds across the eastern Canadian Arctic to address the lack of limnological data and understanding of relationships among limnological variables across key local and regional gradients. Environmental and geochemical variables were compared at both the local and regional scale with the use of multivariate analysis. A principal components analysis indicated that there was a primary gradient in temperature, nutrients, and conductivity between sampled regions. In addition, there were significant regional differences observed for nutrients total nitrogen (TN) and total phosphorus (TP), chlorophyll a, and dissolved major ions determined via canonical variates analysis. Across all regions TN:TP ratios were high, indicating phosphorus limitation, and midsummer surface water temperature was strongly correlated to dissolved nitrogen concentrations. Local landscape characteristics were also examined, with multiple samples from lakes of varying elevations, surface area, and depth within the same area. Shallow pond systems (<2 m depth) were found to have significantly higher variability for major ions, especially in areas with influences from local geology. Likewise, the concentration of nutrients and ions in ponds were strongly correlated to concentrations of dissolved organic carbon, likely indicating the influence of watershed inputs and resuspended sediments on the limnology of ponds. Although there was higher regional variation in the limnology of pond systems than lakes, the general patterns within each region were similar.

Physical and chemical limnology of 204 lakes from the Canadian Arctic Archipelago

Hydrobiologia, 2001

The physical and chemical limnology of 204 lakes from across the Canadian Arctic Archipelago was examined. Mean summer air temperature did not correlate well with lake chlorophyll levels due to the predominance of ultra-oligotrophic hard-water lakes located in a polar climate. Local geology influences ion budgets and is an important factor in determining pelagic phosphorus availability, carbon cycling and metal concentrations. Ratios of particulate carbon, particulate nitrogen and chlorophyll a indicate that planktonic microorganisms are not always the major producers of organic carbon in arctic lakes. Allochthonous particulate matter contributes significantly to the carbon and phosphorus budgets of small and mid-sized lakes across the Arctic, although the availability of these elements is controlled by many interacting geochemical and biological factors. Phosphorus is generally limiting, however, increases in available phosphorus, nitrogen and carbon are all required to make significant long-term differences in lake productivity. Particulate phosphorus levels can be high in lakes where phosphorus-rich shales or carbonatite bedrock are present. These phosphorus-enriched lakes are found in several areas across the midarctic islands, however, only small amounts of this nutrient are available as soluble reactive phosphorus. Although lakes throughout the Arctic are typically ultra-oligotrophic, they still represent an important sink for allochthonous nutrient deposition.

Limnological Characteristics of 22 Lakes and Ponds in the Haughton Crater Region of Devon Island, Nunavut, Canadian High Arctic

Arctic, Antarctic, and Alpine Research, 2003

BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access titles in the biological, ecological, and environmental sciences published by nonprofit societies, associations, museums, institutions, and presses.

Differences in Riverine and Pond Water Dissolved Organic Matter Composition and Sources in Canadian High Arctic Watersheds Affected by Active Layer Detachments

Environmental science & technology, 2018

Regional warming has caused permafrost thermokarst and disturbances, such as active layer detachments (ALDs), which may alter carbon feedback in Arctic ecosystems. However, it is currently unclear how these disturbances alter DOM biogeochemistry in rivers and ponds in Arctic ecosystems. Water samples from the main river channel, ALD-disturbed/undisturbed tributaries, and disturbed/undisturbed ponds within a catchment in the Canadian High Arctic were collected and analyzed using carbon isotopes and spectroscopic methods. Both river and pond samples had large variations in dissolved organic carbon (DOC) concentrations. Ponds, particularly ALD-disturbed ponds, had much older C DOC ages than rivers. Results from δC and absorption and fluorescence analyses indicate higher autochthonous contributions in ponds than rivers and increasing autochthonous contributions from upper to lower reaches of the main channel. The disturbed samples had less carbohydrates but more carboxyl-rich alicyclic ...

Evidence of eutrophication in Arctic lakes

Arctic Science

Lakes and ponds are dominant components of Arctic landscapes and provide food and water for northern communities. In the Greiner Lake watershed, in Cambridge Bay (Nunavut, Canada), water bodies are small (84% <5 ha) and shallow (99% <4 m deep). Such characteristics make them vulnerable to eutrophication as temperatures rise and nutrient concentrations from the greening landscape increase. Here, we investigated and compared 35 lakes and ponds in the Greiner watershed in August 2018 and 2019 to determine their current trophic states based on their chemical composition and phytoplankton communities. The ponds had higher trophic status than the lakes, but overall, most sites were oligotrophic. Lake ERA5, located upstream of any direct human influence was classified as eutrophic due to high total phosphorus (32.3 μg·L−1) and a high proportion of Cyanobacteria (42.9% of total phytoplankton biovolume). Satellite imagery suggests the lake may have been eutrophic for the last 30 years....

Local physiographic controls on the responses of Arctic lakes to climate warming in Sirmilik National Park, Nunavut, Canada

Journal of Paleolimnology, 2011

Twenty high Arctic lakes and ponds were sampled for water chemistry and modern diatom assemblages in two distinct physiographic sectors of Sirmilik National Park, Nunavut, Canada. Sites on southwestern Bylot Island were warmer, more alkaline, less dilute, and had higher concentrations of nutrients, DOC and Chl-a (mesotrophic to oligomesotrophic), whereas sites on Qorbignaluk Headland on northern Baffin Island were deeper, very dilute, mostly oligotrophic and had lower pH. Diatom assemblages differed markedly between these two regions as a consequence of limnological differences between them. Paleolimnological records, spanning [ 200 years and dated by 210 Pb activity, were produced from each region to compare biological responses to recent warming inferred from glaciological studies on Bylot Island and regional syntheses for the Arctic. Diatom assemblages began to change around AD 1900 at both sites. At Qorbignaluk Headland, marked shifts in diatom community composition occurred during the twentieth century, with large increases in the abundance of planktonic diatoms. At Bylot Island, diatom community changes began around the same time, and involved modest decreases in planktonic diatoms and increases in inferred specific conductance, likely because of a decrease in the areal extent of the small lake as a response to warming. The study confirms that responses of freshwater ecosystems to climate warming vary depending on local physiographic factors.

Nutrient limitation of phytoplankton communities in Subarctic lakes and ponds in Wapusk National Park, Canada

Polar Biology, 2012

We determined the limiting nutrient of phytoplankton in 21 lakes and ponds in Wapusk National Park, Canada, using nutrient enrichment bioassays to assess the response of natural phytoplankton communities to nitrogen and phosphorus additions. The goal was to determine whether these Subarctic lakes and ponds were nutrient (N or P) limited, and to improve the ability to predict future impacts of increased nutrient loading associated with climate change. We found that 38% of lakes were not limited by nitrogen or phosphorus, 26% were co-limited by N and P, 26% were P-limited and 13% were N-limited. TN/TP, DIN/TP and NO 3 ¡ /TP ratios from each lake were compared to the RedWeld ratio to predict the limiting nutrient; however, these predictors only agreed with 29% of the bioassay results, suggesting that nutrient ratios do not provide a true measure of nutrient limitation within this region. The N-limited lakes had signiWcantly diVerent phytoplankton community composition with more chrysophytes and Anabaena sp. compared to all other lakes. N and P limitation of phytoplankton communities within Wapusk National Park lakes and ponds suggests that increased phytoplankton biomass may result in response to increased nutrient loading associated with environmental change.

Limnological features and models of chlorophyll-a in 30 lakes located in the lower Mackenzie River basin, Northwest Territories (Canada)

Journal of Limnology, 2009

Limnological variables from 30 lakes situated along the proposed Mackenzie Gas Project pipeline route in the Canadian Northwest Territories were examined. Sampled lakes were shallow (Z max = 1.5-30 m; mean depth = 6.6 m), generally nutrient poor (TP often ≤10 µg L -1 ), and alkaline (mean pH = 8.2). Floodplain lakes located within Arctic-tundra watersheds tended to have higher conductivity and major ions (Na, Cl, Ca, SO 4 ) concentrations relative to non-flooded Arctic-tundra or forest-tundra lakes, reflecting differences in vegetation, elevation and most importantly, proximity to the Mackenzie River. The first two axes of a principal component analysis explained 56.1% of the variance in the environmental data. Variables most strongly associated with the first principal component axis were latitude, elevation, dissolved oxygen, temperature, conductivity and turbidity while the second principal component axis represented gradients of nutrients and Chlorophyll-a (Chl-a). Factors affecting Chl-a varied among the different ecological zones. This study provides reference data for future monitoring of potential effects of development and warming in the Arctic.