p .. KU 40(5)

ABSTRACT Loi Island is connected with Sri Racha, Chonburi Province by a bridge. The fishermen and tourists use this island in many purposes. This research was investigated during September 2004-June 2005. Many kinds of data resource were used in this study such as geoinformatic system data and seawater current. From the final result showed that coastline is dynamics changed in every years and sensitive for protecting. The unique image in year of 2001 depicted a new bridge. Abandon of suspended solid was distribution around the coast. From human activity, size of Loi Island nowadays bigger than in year 1997 about 1.4 times, this was easy to interpret by remote sensing data. Although shape of new bridge was changed but seawater movement still having the same direction and speed have a little bit changed less than 10 % since under the bridge was still shallow. The seawater could not move in easy way

Verification Experiments of Aerators in Aquacultural Ponds

An aerator, which can induce circulation, supply dissolved oxygen and improve bottom mud conditions, is one of the important equipment for aquaculture. Many of the aquacultural farmers have installed and utilized the aerator to keep better aquacultural ponds conditions and products growth. However, most of the farmers operate the aerator empirically due to lack of the criteria for usage, setting and operating of the aerator. Such empirical operation might immiserate the farmers because the management expense of the aerator must be costly. In addition, the empirical operation might impact the nature environments. Therefore, systematic operation of the aerator might be required from both economic and environment points of view. In order to perceive the usage tendency and clarify the performance of the aerator we conducted survey on the usage of the aerator at Samut Songkram Province, Thailand. After the survey we conducted operation experiments of the aerator at Samut Songkram Fisheries Research Station, Faculty of Fisheries, Kasetsart University to verify the impacts of the aerator on water temperature and dissolved oxygen (DO) level in the ponds. From the survey results, it was clarified that most of the farmers didn’t know operation way of the aerator and run the aerator continuously. However the operation experiments of the aerator indicated that the performance of the aerator was not necessarily lead the better impact for the water quality. In this paper we discuss and propose the better operation method of the aerator based on both survey and experiments results

Development and Improvement of Acoustic Equipments and System for Fisheries Resources Survey in shallow Area

The acoustic data collection system including equipment modification were conducted for coastal area survey around set-net fishing ground in Rayong province, Thailand. An analysis methodology is also developed and will be using as a tool for acoustic survey methodology education for young scientist in Thailand. The project modified acoustic device with composed of GPS Plotter Fish-Finder (FURUNO GP1670F), Interface unit and personal computer (PC) for using as acoustic data collection system. The equipment modification was performed by importing the echo-sounder transmitting and receiving signal from transducer cable to newly designed data collection system. The data collection system were composed of Pre-Amplifier and Band Pass Filter, Interface unit, Analog to Digital Converter, and PC computer system. The digital hydro-acoustic data were collected to PC hard disc by using “FishFinder” software program. The GPS position data was transfer from GP1670F to PC Computer pass through standard NMEA to USB port. The GPS position data were recorded to PC by using Windows Hyper-terminal program. The data collection system was design to record the echo-sounder signal of 50 kHz only. The recorded data in “.csv” file format were analyzed by Microsoft Excel Program. The data collection system was calibrated by standard target ball (Tungsten carbine, 38.1 mm) in the acoustic experimental water test tank of TUMSAT, Japan. The experiment survey cruise for investigated on the comparison of abundance of fisheries resources during set-net fishing operation season and off season were conducted during December 2013 and April 2014, respectively. Total survey area covering for 16.25 km2 of set-net fishing ground with running distant of 38.5 km. The survey results shows a satisfied system performance

Education Study of Acoustic Surveys in Coastal Shallow Area at Southeast Asia

This is abstract on Educational Study of Acoustic Surveys in Coastal Shallow Area at Southeast Asi