FRESHWATER ALGAL DIVERSITY AND PHYSICO-CHEMICAL CHARACTERISTICS OF DAM WATER BODIES IN KARJAT TAHSIL, AHILYANAGAR DISTRICT, MAHARASHTRA, INDIA

Freshwater algae are important primary producers and sensitive biological components of aquatic ecosystems. Their occurrence and distribution are influenced by water chemistry, nutrient availability, temperature, light, water movement and human activities. The present investigation was undertaken to document freshwater algal diversity and selected physico-chemical characteristics of dam water bodies in Karjat Tahsil, Ahilyanagar District, Maharashtra. Algal samples were collected from ten dam-water localities and preserved for microscopic examination. Identification was carried out using a digital compound optical microscope and standard algal literature. Water samples were examined for physical and chemical parameters including temperature, pH, electrical conductivity, calcium, magnesium, sodium, potassium, bicarbonate, chloride and sulphate. A total of 48 algal species were recorded from the ten sampling sites. Green algae were dominant, while cyanobacteria and diatoms were also well represented. Frequently recorded genera included Chlorella, Scenedesmus, Pediastrum, Spirogyra, Zygnema, Cosmarium, Anabaena, Nostoc, Oscillatoria, Navicula, Pinnularia and Synedra. Water samples were generally neutral to slightly alkaline, with pH values of 7.0 – 8.1, while recorded temperatures ranged from 15 – 29 °C. Electrical conductivity showed variation among sites, reflecting differences in ionic concentration. The coexistence of pollution-tolerant and relatively pollution-sensitive algal groups suggests spatial variation in ecological conditions among the dam sites. The study demonstrates that algal diversity, when interpreted together with physico-chemical characteristics, can provide useful information about the ecological status of freshwater bodies in the Karjat region.