Accuracy of Low-Cost Depth Sounding Device for Sea Surface Temperature: A Case Study of Songkhla Lake.

Abstract

The Sea Surface Temperature (SST) map serves as a tool to identify areas with suitable water temperatures for cultivating different aquatic species. Temperature directly influences the growth, health, and reproduction of marine organisms. Therefore, it is essential to monitor and plan aquaculture activities in specific areas to maximize efficiency and prevent the occurrence of "fish kill," which results from severe oxygen depletion in the water, causing large-scale fish mortality within a short period. The SST map can be created using satellite data combined with field data analysis. Furthermore, it can be integrated with bathymetric maps in real time through the application of low-cost echo sounders. The objective of this study is to assess the accuracy of low-cost echo sounders and use them to map the distribution of sea surface temperatures in the study area. This was achieved by comparing the measurements obtained from the echo sounder with reference thermometer values. The results indicated that the standard deviation (SD) was 0.194°C and the root mean square error at a 95% confidence level (RMSE95) was 0.776°C. These results conform to the World Meteorological Organization (WMO) standards, which specify that the allowable error should not exceed ±1.0°C. This demonstrates that the instrument used in this study provides acceptable accuracy, even though it was not specifically designed for creating SST maps. Additionally, the study found that the sea surface temperature has a significant correlation with water depth and sediment layers.