Determination of trophic status and potential of fish production in lake Choghakhor
Subject Areas : New Technologies in Aquaculture Developmentرضوان موسوی ندوشن 1 , محمدرضا فاطمی 2 , عباس اسماعیلی ساری 3 , غلامحسین وثوقی 4
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Abstract :
Lake Choghakhor is a shallow ecologically and economically important water body in eastern part of Iran. During last decade Lake Choghakhor has been influenced by some man-made impacts such as water level fluctuation, agricultural discharge and fish (Cyprinids) introduction causing a serious problem in its trophic states. So in this study water quality for physical, trophic state indicators, total phosphate, algal chlorophyll, Secchi disk transparency, biomass of macrobenthose (seasonal) was studied monthly between May 2004 to April 2005. Now submerged plants especially Myriophyllum spicatum have covered almost the entire lake and dense macrophyte beds (Polygonom amphibium), located on the south east end of the lake appear to act as a sink for these nutrients. Lake Choghakhor appeared to be in a macrophyte dominated clear water state with low TP (annual mean: 24± 15µg.l-1) and chlorophyll a (annual mean: 3±1.28 µg.l-1) and very high Secchi depth. Fish yeild potential was estimated according to TP model as 34.4 kg.ha-1, production value for macrobenthose was 4.7 mg DM m-2yr-1 and annual fish production obtained by macrobenthose was about 282 to 376 kg.ha-1yr-1.
