Investigation of the effects of anthropogenic activities on the water quality and macroinvertebrates in Karacaoren I Dam Lake (Burdur).

The water quality of Karacaören I Dam Lake, a vital irrigation and hydropower source and a potential source of drinking water for the inhabitants of the Antalya province, is under significant threat from human activities in and around the dam lake. Therefore, this study aimed to determine the status of the water quality of the dam lake by investigating some physicochemical and nutrient parameters, heavy metal concentrations in the sediments of the dam lake, and the macroinvertebrates community in the dam lake. Samples were collected from seven strategic stations in Karacaören I Dam Lake for one year (January- December 2022). The Water Quality Index (WQI) and Water Pollution Control Regulation (SKKY) criteria were used to classify the dam lake's water quality. The Contamination factor (CF), pollution load index (PLI), geo-accumulation index (Igeo), and enrichment factor (EF) indices were used to ascertain and assess the degree of potential sediment contamination with heavy metals/metalloids by anthropogenic activities. Family Biotic Index (FBI), Biologic Monitoring Working Party Score System (BMWP), Average Score Per Taxon (ASPT), and Ephemeroptera, Plecoptera, and Trichoptera (EPT) biotic indices were employed to determine the pollution level of Karacaören I Dam Lake. Some physicochemical parameters such as dissolved oxygen (DO), temperature, salinity, total dissolved solids (TDS), chemical oxygen demand (COD), biochemical oxygen demand (BOD), electrical conductivity (EC), transparency, and nutrients like phosphate, sulfate, nitrite, and nitrate were analyzed by standard methods across seven sampling points on the dam lake. The X-ray fluorescence spectrometry (XRF) method was used to analyze the heavy metals in the sediments of the dam lake. The mean values of 8.0, 9.18 mg/l, 21.3, 0.18 ppm, 177.99 ppm, 354.29 µs/cm, 206.35, 18.24 mg/l, 0.128 mg/l, 4.67 mg/l, 0.23, 3.20 mg/l and 15.5 for pH, DO, temperature, salinity, TDS, EC, Secchi disc length, SO42−, NO2−, NO3−, PO₄³⁻, BOD and COD respectively. All the examined physicochemical parameters except PO₄³⁻, BOD, and COD showed significant changes from season to season (p ≤ 0.05). The Pearson Correlation Analysis revealed a positive correlation between salinity, TDS, and EC; the relationship was significant (p ≤ 0.05). According to the SKKY criteria, the PO₄³⁻ value was at a critical level (Class III), which is unsuitable for human consumption. The WQI results revealed that the water of the dam lake is in fair condition but not excellent for human consumption. Karacaören I Dam Lake was classified as eutrophic and mesotrophic lake based on the Secchi disc length. The results of the heavy metals studied showed that Karacaören I Dam Lake was polluted with Al, Co, Cr, Ni, and Pb, as the recorded mean values for these metals were higher than their background shale values and some sediment quality guidelines (SQGs) values. This study identified 39 macroinvertebrates belonging to 24 families in Karacacaören I Dam Lake. The most dominant families were Chironomidae, Palaemonidae, Notonectidae, and Corixidae. This result is the first record of Palaemon sp. in Karacaören I Dam Lake. The results of Margalef, Shannon-Weiner, and Simpson diversity indices revealed that Karacaören I Dam Lake had a higher abundance and diversity of macroinvertebrates in the hot seasons (spring and summer). The results of Margalef and Shannon-Weiner (H′) diversity indices and BMWP, ASPT, and FBI biotic indices in this study revealed that Karacaören I Dam Lake possessed Class II water quality. It can be inferred from the results of this study that anthropogenic factors impacted the water quality of Karacaören I Dam Lake. Furthermore, the negative relationships between the biotic indices with NO3-, PO₄³-, EC, TDS, and salinity showed that the sources of pollution of the water of Karacaören I Dam Lake are not natural but caused by anthropogenic factors. Therefore, realizing the planned use of Karacaören I Dam Lake water as a potential source of drinking water is related to adopting protection measures to prevent further deterioration of the water quality.