INFLUENCE OF CHANNEL TRAFFIC AND KOYCEGIZ LAKEON THE WATER QUALITY OF DALYAN CHANNEL NETWORK

Abstract

Koycegiz-Dalyan Lagoon is situated in the southwestern region of Turkey. The area between the K ycegiz Lake and the seais covered with four small lakes and numerous canals. The Dalyan Channel network connects lake to the Mediterranean Seais one of the most important reproduction areas for Mediterranean Sea turtles. The objectives of the present study are toevaluate the influence of channel traffic and K ycegiz Lake on the water quality of Dalyan Channel by evaluating historicalwater quality data from 2007 to 2011 at three monitoring sites; two located at Dalyan Channel and one in K ycegiz Lake. Specific objectives are to perform trend analysis for; (i) concentration trends; (ii) load estimation (mass of pollutantsdelivered); (iii) TN:TP Ratio (trophic status trends); (iv) TSI (eutrophication trends); and (v) the WQI (environmental quality trends) for K ycegiz Lake. Results showed that TSI (trophic state index) values of both SD (secchi depth) and TP (total phosphate) remained within the range of eutrophic category for the lake from 2007 to 2011. The calculated TN/TP ratios suggest that K ycegiz Lake can be considered to be P limited with a few exceptions. The lake has poor water quality index (POOR WQI) between 2007 and 2011. This is mainly due to land-based fish farm located on Yuvarlak ay Creek which born within the K ycegiz-Dalyan SEPA and drains directly into K ycegiz Lake. In addition to change in water quality class of the creek before and after fish farming, TP concentration incidence also increased after fish farming from 2008 to 2011. This study also revealed that activities like touristic boat trips performed in Dalyan Channel didn t significantly affect the water quality class of channel in terms of NO2 N, TP concentrations and the number of total coliforms.