Determination of selected chemical parameters in surface water samples collected from the Revelva catchment (Hornsund fjord, Svalbard)

Enrichment, Isolation and Characterization of Heavy Metal-Tolerant Bacteria from Polar Lacustrine Sediments

Polar areas are not exempt from anthropogenic pollution. Heavy metals have been detected in Arctic and Antarctic lakes. Bacteria, at the base of the food web, can possess the ability to adsorb or immobilize heavy metals in the environment and reduce their concentration in the water column. However, several gaps exist in our knowledge of bacterial tolerance to heavy metals in polar systems, especially in lakes. Heavy metal-tolerant bacteria from polar lacustrine sediments were selectively enriched and subsequently isolated and identified. Their growth at increasing concentrations of different heavy metals (iron, copper, and mercury) was evaluated. Selected isolates were tested for sequestration of iron and mercury. A total of 101 bacterial isolates were obtained from metal-enriched cultures. Gammaproteobacteria and Actinomycetota isolates were most abundant in Arctic and Antarctic enrichments, respectively. Iron was the most tolerated metal. Mercury and iron were sequestered by the isolates by up to 14.2 and 13.4%, respectively. The results from this study contribute to our understanding of heavy metal-tolerant bacteria from cold environments and their potential use in biotechnological applications.

Arctic Freshwater Environment Altered by the Accumulation of Commonly Determined and Potentially New POPs

Chemical composition of Arctic freshwater ecosystems depends on several factors. They include characteristics of the surrounding landscape, its lithology, geomorphology, vegetation, and hydrological features, as well as accumulation of anthropogenic pollution. In the Arctic, the problem of environmental contamination is widespread. That is why research on lakes and river catchments in terms of their chemical composition has enjoyed increasing interest among scientists worldwide. The freshwater reservoirs of the Arctic are fragile and particularly vulnerable to the uptake of pollutants that become trapped in the water and sediments for an extended period. This review summarises selected studies of freshwater bodies in the Arctic to highlight the problem of the accumulation of pollutants in these reservoirs. Moreover, it emphasises the possible negative impact of chemical pollutants on both animal and human health.

Evaluation of Water Quality in Ialomita River Basin in Relationship with Land Cover Patterns

The paper reviews the state of water quality in Ialomita River Basin (IRB), Romania, between 2007 and 2018 using the land use/land cover and basin-specific conditions effects on sediments and nutrients load. On-site monitoring was performed in two control sections of the Ialomita River, one in the upper part of the basin (near Targoviste city) and the second near the discharge into the Danube (downstream of Tandarei town). The statistical averages of water parameters for 10 years’ monitoring in the control section that is close to the Ialomita River discharge in Danube were pH = 7.60 (range: 6.41–8.40), NH4-N = 1.20 mg/L (0.02–14.87), alkalinity = 4.12 mmol/L (1.34–6.27), NO3-N = 2.60 mg/L (0.08–17.30), PO4-P = 0.09 mg/L (0–0,31), dissolved oxygen (DO) = 8.87 mg/L (2.72–15.96), BOD5 = 5.50 mg/L (0.01–74.71), suspended solids (TSS) = 508.32 mg/L (15.2–4457), total dissolved salts (TDS) = 733.69 mg/L (455.2–1053), and river discharge = 38.60 m3/s (8.22–165). Expected mean concentration and soil and water assessment tool (SWAT) modeling have been employed in the GIS environment to extend the approach to large spatial patterns within the basin. The estimated average specific emission on the total area for nitrogen was 3.2 kg N/ha, and 0.3 kg P/ha for phosphorus highly influenced by the agricultural activities. The results are useful to raise awareness regarding water-quality degradation and the need to stop and even reverse such trends for local and national sustainable development.

Water chemistry of tundra lakes in the periglacial zone of the Bellsund Fiord (Svalbard) in the summer of 2013

Climate changes observed in the Arctic (e.g. permafrost degradation, glacier retreat) may have significant influence on sensitive polar wetlands. The main objectives of this paper are defining chemical features of water within six small arctic lakes located in Bellsund (Svalbard) in the area of continuous permafrost occurrence. The unique environmental conditions of the study area offer an opportunity to observe phenomena influencing water chemistry, such as: chemical weathering, permafrost thawing, marine aerosols, atmospheric deposition and biological inputs. In the water samples collected during the summer 2013, detailed tundra lake water chemistry characteristics regarding ions, trace elements, pH and specific electrolytic conductivity (SEC₂₅) analysis were determined. Moreover, water chemistry of the studied lakes was compared to the water samples from the Tyvjobekken Creek and precipitation water samples. As a final step of data analysis, Principal Component Analysis (PCA) was performed. Detailed chemical analysis allowed us to conclude what follows: (1) Ca²⁺, Mg²⁺, SO₄^2-, Sr are of geogenic origin, (2) NO₃^- present in tundra lakes and the Tyvjobekken Creek water samples (ranging from 0.31 to 1.69mgL^-1 and from 0.25 to 1.58mgL^-1 respectively) may be of mixed origin, i.e. from biological processes and permafrost thawing, (3) high contribution of non-sea-salt SO₄^2->80% in majority of studied samples indicate considerable inflow of sulphate-rich air to the study area, (4) high content of chlorides in tundra lakes (range: 25.6-32.0% meqL^-1) indicates marine aerosol influence, (5) PCA result shows that atmospheric transport may constitute a source of Mn, Co, Ni, Cu, Ga, Ba and Cd. However, further detailed inter-season and multi-seasonal study of tundra lakes in the Arctic are recommended. Especially in terms of detailed differentiation of sources influence (atmospheric transport vs. permafrost degradation).