Low Specific Phosphorus Uptake Affinity of Epilithon in Three Oligo- to Mesotrophic Post-mining Lakes

Epilithon contributes to phosphorus (P) cycling in lakes, but its P uptake traits have been rarely studied. We measured the chemical composition of epilithon and its inorganic P uptake kinetics using isotope 33P in three deep oligo- to mesotrophic post-mining lakes in April, July, and October 2019. Over the sampling period, epilithon biomass doubled, while the P content in biomass dropped to 60% of the April values, and the seasonal changes in P content expressed per epilithon area were only marginal and statistically not significant. High epilithic C:P molar ratios (677 on average) suggested strong P deficiency in all investigated lakes. Regarding the kinetic parameters of phosphorus uptake, maximum uptake velocity (Vmax, seasonal range 1.9–129 mg P g OM–1 h–1) decreased by an order of magnitude from April to October, while half-saturation constant (KS, seasonal range 3.9–135 mg P L–1) did not show any consistent temporal trend. Values of epilithic specific P uptake affinity (SPUAE, seasonal range 0.08–3.1 L g OM–1 h–1) decreased from spring to autumn and were two to four orders of magnitude lower than the corresponding values for seston (SPUAsest), which showed an opposite trend. Considering our results, we suggest a possible mechanism underlying a stable coexistence of planktonic and epilithic microorganisms, with plankton prospering mostly in summer and autumn and epilithon in winter and spring season. Additionally, a phenomenon of reversible abiotic P adsorption on epilithon was observed.

From Extremely Acidic to Alkaline – Diversity of Aquatic Invertebrates in Forest Mining Lakes Under the Pressure of Acidification

Human activities, including mining industry, have considerably degraded the water habitats worldwide. Acidification has severely affected aquatic environments with acidifying pollutants and constitute threat to freshwater biodiversity. The study area is unique for addressing the effects of mining-related acidification on biodiversity in freshwater ecosystems along a pH gradient (2.4-9.6). Using multivariate ordination techniques, we analysed taxa distribution to determine how variations in invertebrate composition correlated with environmental factors. The results revealed differences in pH of water, salinity indicators, hardness, and content of calcium, nitrites, and iron. The highest iron content, relatively high values of conductivity and chlorides was found in the extremely acidic mining lakes. A clear decreasing tendency was observed for the number of taxa with increasing acidity (Oligochaeta, Chironomidae, Glossiphonidae). The density of Hirudinidae, Lestidae, Libellulidae, Caenidae, Sialidae, Dytiscidae, Helodidae, Hydrophilidae and Polycentropodidae increased along with decreasing pH. Specific communities were found with increasing acidity, therefore a progressive increase in acidity will probably have further influence on biological life and water chemistry. The data yielded offer an opportunity to fill knowledge gaps concerning less-studied aquatic environments and links environmental pollution with communities, which is especially important because forest habitats are especially exposed to different climatic factors and threats.

Uptake of phosphorus by epilithon in three oligo- to mesotrophic post-mining lakes

Epilithon contributes to phosphorus (P) cycling in lakes, but its P uptake traits have been rarely studied. We measured the chemical composition of epilithon and its inorganic P uptake kinetics using isotope 33P in three deep oligo- to mesotrophic post-mining lakes in April, July, and October 2019. Over the sampling period, epilithon biomass doubled, while the P content in biomass dropped to 60% of the April values. High epilithic C:P molar ratios (677 on average) suggested strong P deficiency in all investigated lakes. Regarding the kinetic parameters of phosphorus uptake, maximum uptake velocity (Vmax, seasonal range 0.9–101 mg P g OM–1 h–1) decreased by an order of magnitude from April to October, while half-saturation constant (KS, 1.6–103 mg P L–1) did not show any consistent temporal trend. We found a general decrease in the specific P uptake affinity (0.1–2.2 L g OM–1 h–1) and the estimated in-situ P uptake (0.04–2.3 µg P g OM–1 h–1) of epilithon over the season, which might have resulted from changes in epilithon community composition, a decreasing ratio of living biomass to extracellular polymers and detritus, rapid internal recycling, and/or thickening of the epilithic biofilm. Additionally, we observed a phenomenon of reversible abiotic P adsorption on epilithon.

Geochemical Variability of Surface Sediment in Post-Mining Lakes Located in the Muskau Arch (Poland) and Its Relation to Water Chemistry

Water and sediment chemical compositions were investigated in 75 post-mining lakes in the eastern part of the Muskau Arch region (Western Poland, Central Europe). The lakes, originating from lignite and clay surfaces and underground mining activity, exhibited a wide gradient of physical and chemical water parameters. The most pronounced variability in water parameters was observed in pH values, conductivity, and oxygen concentration in the mixolimnion and monimolimnion. In addition, the lakes varied in terms of their trophic status, indicated by their dissolved organic carbon (DOC) and phosphorous concentrations. In general, lakes with higher pH values had higher trophic states, and some even exhibited hypertrophic conditions. The Monte Carlo test indicated that the water pH, phosphorus, DOC, and silicon concentrations could significantly explain the chemical characteristics of sediments.

Water Quality Assessment of Former Tin Mining Lakes for Recreational Purposes in Ipoh City, Perak, Malaysia

A study of the water quality of the former tin mining lakes in Ipoh City was carried out to determine the Water Quality Index (WQI) and classification based on the Malaysia National Water Quality Standards, in order to determine its suitability to be developed as a water recreation area. Five former mining lakes were chosen: Gunung Lang, Taman Indah, Kg. Temiang, Lahat and Kg. Engku Husin. The parameters measured were pH, dissolved oxygen, suspended solids, biochemical oxygen demand, chemical oxygen demand and ammonical nitrogen (NH3N), while the heavy metals measured were lead (Pb), copper (Cu), zinc (Zn) and arsenic (As). The analytical study shows that four former mining lakes in this research are suitable to be developed for water recreation purposes as they are classified under class II with a WQI greater than 81, which holds a clean status. Only one lake, Kg. Engku Husin, is categorised as class III, which requires an intensive treatment before it can be used for recreational purposes. Meanwhile, heavy metals such as Zn, As and Cu were at the standard level except for Pb, which exceeded the set guidelines. The local authorities and project developers should take appropriate measures to ensure that this former mining lake is well maintained and managed so that it is preserved and suitable to be developed as a recreational area.

EVALUASI KEGIATAN AKUAKULTUR DI KOLONG PASCA TAMBANG : ANALISIS PENCEMARAN AIR KOLONG

Ex-tin mining lakes are commonly used by many people in Bangka Island for fish farming activities. The water logs of post mining lakes have been used for fish farming activities. We hypothesized possibly environmental pollution related to the water quality. This paper aimed to evaluate fish farming activities by the local communities using the waterlogs of post mining lakes. The evaluation was based on heavy metals extent in the water using survey method with purposive sampling in order to determine which extin mining lakes would be feasible for aquaculture activities. The data of the content of heavy metals and water qualities were analyzed using the method of Pollution Index (PI). According to the age of mining lakes, the five ex-tin mining lakes which has been observed. The results showed one new aged, two middle aged, and one old age; meets the quality standard eligibility for fish farming activities, while the middle aged was low polluted. The age of ex-tin mining lakes not affected nor the extent of the pollution levels or water qualities.Keywords : ex-tin mining, lakes, aquaculture, water qualities, pollution index, fish