Karasu (Fırat) nehri alg florası üzerinde bir araştırma

Abstract

Algal composition of the river Karasu (F~rat) and its seasonalvaria-tons `ere first studied in the sarnples collectedfrom six seleted stations be-tl,een Harcl:l1988-Junuary 1989.In addi tiOIl, some physical and chewical analysis of thewater were carried out. It was observed that Bacillariophytawas dominant in the phytoplanl(ton. The generaCyclotella` Fragilaria, §.Yn~d.E.g, t1~losira, Nitzschia,Diato..!!§, £y!nbella, ~ra-tq..I1_eis and Chlor~lla were COl1U11onin the phytoplankton at various stations. The members ofChlorophyta, Cyanophyta and Euglenophyta were rarelyencountered. The algae except diatom were not importantas composi tion and number of species. In the seasonalvariation ',hich currents and temperature were effective,phytoplanlcton was generally increased in July 1988 andSepternber 1988 decreased in the o-the;:- terms. In the regionswhich water pollution Ivas observed the algal speciesaccepted pollution indicator Here seen also.In the epipelic algal flora of tre river Karasu(F~rat) ,145species were found belonging to Bacillariophyta, Chlorophyta,Cyanophyta and Euglenophyta divisions. Bacillariophytawas dominant algal group in the epipelic communi teoIn this groLp Navic;.ula £FyPtocephala, Nitzschia palea,~ella affinis, ~)ella verrtricosa, §.Ynedrq ul_n~,Arnppo:C:g _9./C.a_lis 'vere observed as dominant species. Theother algae except Stigeoclonium sp., Oscillatoria tenuis,Closterium ll!.nula, and Euglena spathirhyncha were seenrarely and in lesser nunlber. Seasonal vc'.riations of epipelicflora were incrased in summer and early Autumn anddecreased in winter.In the bentic algal communite, epifitic and epiliticalgae such as Cyftlbel}. affinis, Ceratoneis ¥cus, Cymbellaventricosa, Cocconeis plac.§lntula, Gomphonema olivaceum,Nitzschia fonticola were found as dominant species.Hi tzschia palea, Diatoma vulgar~ var. vuJ,gare, Fragilaria~heria, Helosira vari2ns, Surirella ovata, Cymbellalanceolata `lere observed as next common. The most encounteredspecies except diatom Here Ulothrix zonata, Ulothrixtenuis, Oscill~toIia limnetica, Oscillatoria limosa,Spirogyra .9vae - anqliae, Spirogyra sp., Schizotrhrixsp., Micr9.cy_t~ aeruginosa and StiBeoclonium sp.In the algal flora of the river Karasu (Fırat), totally182 species were found. It was seen that the speciesbelong to phytoplankton and bentic algal societies wereintermixed. This is a general feature of short an fastrivers.The physcial and chemical analysis shovled that the riverwater was hard and alkaline. The poIlu tion of the riverby sevage and otl1ers was supported by physical, chemicaland biological findings.