Isolation and characterization of toxic Cyanobacterial Communities distribution in Lake Tana, Amhara Regional state, Ethiopia

Abstract

Lake Tana is the second largest lake next to Victoria Lake in Africa. This Lake is exsposed to agriculture run off, industrial and Urban waste since it has not buffer zone to protect any invading materials to the water body. The accumulation and growth of blue-green algae in water body call public attention because of its health concern. Some cyanobacterial species produce toxin microcystins and anatoxin molecules can affect the liver, kideney and nervous system of animals because the toxic molecules of released from some toxic cyanobacteria may lead the organs to fail the metabolice system. The major exposure pathways of these toxins are through drinking water and recreations including swimming. In addition, these problems happen through food web. Those cyanobacteriaa are spread and growth in diffrent water body via agriculture run off, industrial and urban wastes and other nutrient source of N and P. The main goal of this scientific study was to assess the distribution of potential toxic cyanobacteria in Lake Tana. Cyano bacterial distributions were studied in different water bodies of Lake Tana. From the water bodies that have visible algal blooms and not observed algal blooms were investigated. Identification of cyano bacteria was conducted using microscope by following appropriate procedures. In the present studied area Anabaena sp, Nostoc sp., Chlorella sp., and Microcystis aeruginosa sp. were dominantly exist. Therefore, Maybe the numbers of fishe depleted in Lake Tana due to the presence of microcystine molcule source, those are Anabaena sp.,Nostoc sp. and Microcystis aeruginosa sp.