Monitoring Tilapia (Tilapia spp.) Population in Köyceğiz Lake of Turkey by Thermal Bands of LANDSAT-5 TM and LANDSAT-7 ETM+ Satellite Images

Abstract

Invasive Tilapia fish (Tilapia spp.) numbers in Köyceğiz Lake of Turkey were monitored in 1993, 1999 and 2012 by utilizing the thermal bands of LANDSAT-5 TM and LANDSAT-7 ETM+ images. Geo-referenced archival field data, collected from 4 stations on Köyceğiz Lake between January and December of 1993, was used to develop a model. Detecting significant positive correlation (0.88) between fish numbers and water temperature, polynomial regression analysis with the second order was conducted to develop a model. Obtained model was applied to the thermal bands of a LANDSAT-5 TM image taken in 1995, and two LANDSAT-7 ETM+ images taken in 1999 and 2012. Consequently, the fish numbers and Catch Per Unit Effort (CPUE) in those three years were mapped and monitored. Overall results showed that Tilapia fish populations tend to be increase with increasing water temperature in Köyceğiz Lake.