Biomass Estimation by Hydro-acoustic Methods in the South China Sea, Area II: Sarawak, Sabah and Brunei Darussalam

The abundance of fisheries resources and their structure off shore of Sarawak, Sabah and Brunei Darussalam were investigated under the SEAFDEC Collaborative Research Survey. Hydro-acoustic surveying by using a scientific echo sounder model FQ-70 was conducted for estimating the fish abundance and biomass. Two survey cruises were carried out by M.V. SEAFDEC during 10 July to 2 August 1996 and 1 to 24 May 1997 for pre and post-northeast monsoon seasons, respectively. The scientific echo-sounder was equipped with an echo-integrator and two quasi-ideal beam transducers with operating frequencies of 50 and 200 kHz. For pre and post-northeast monsoon season was 1,717,852 tons and 956,397 tons, respectively. The maximum fish abundance were found at the water depth between 100 to 200 m was 92.4% and 49.8% of total abundance for pre and post-northeast monsoon season, respectively

Auxiliary Sail for Small/Medium Scale Fishing Boat

In the long history of mankind, there was no machinery, Since wind is an abundant power resource in the open sea, vessels and boats in fisheries, trade, and warfare were installed with sails for propulsion. For several hundred years, humans had always applied wind energy in most of their water-related activities. In the last hundred years, technologies on internal combustion engine have been enhanced. Promoted for active propulsion in water cruising, the engine practically replaced the functions of the sail, until the sails have become less visible especially in fisheries activities

Biomass estimation by hydro-acoustic methods in the South China Sea, Area II: Sarawak, Sabah and Brunei Darussalam

The abundance of fisheries resources and their structure off shore of Sarawak, Sabah and Brunei Darussalam were investigated under the SEAFDEC Collaborative Research Survey. Hydro-acoustic surveying by using a scientific echo sounder model FQ-70 was conducted for estimating the fish abundance and biomass. Two survey cruises were carried out by M.V. SEAFDEC during 10 July to 2 August 1996 and 1 to 24 May 1997 for pre and post-northeast monsoon seasons, respectively. The scientific echo-sounder was equipped with an echo-integrator and two quasi-ideal beam transducers with operating frequencies of 50 and 200 kHz. For pre and post-northeast monsoon season was 1,717,852 tons and 956,397 tons, respectively. The maximum fish abundance were found at the water depth between 100 to 200 m was 92.4% and 49.8% of total abundance for pre and post-northeast monsoon season, respectively

Biomass estimation by hydro-acoustic methods in the Gulf of Thailand and Peninsular Malaysia

The abundance of fisheries resources and their structure in the Gulf of Thailand and East coast of Peninsular Malaysia were investigated during the SEAFDEC Collaborative Research Survey. Hydro-acoustic surveying using a scientific echo sounder model FQ-70 was conducted to estimate the fish abundance and biomass. Two survey cruises were carried out by M.V.SEAFDEC during the pre and post-northeast monsoon seasons. The scientific echo-sounder was equipped with an echo-integrator and two quasi-ideal beam transducers with operating frequencies of 50 and 200 kHz. The volume back scattering strength (SV) of the fish schools were collected from the layer of water at a depth from 10 m to the bottom along the track of survey cruise. The estimated biomass measured by high frequency shows clearly that a high concentration is observed at the upper and middle part of the Gulf of Thailand and the border area between Thailand and Malaysia waters during the pre-northeast monsoon season. Whereas, high biomass concentration shows only in the middle part of the Gulf of Thailand during the post-northeast monsoon season

The experiments on turtle excluder devices (TEDs) for shrimp trawl nets in Thailand

The purpose of this paper is to determine a suitable type of Turtle Excluder Device (TED) attached to the body of a shrimp trawl to avoid inflicting harm on marine turtles. Seven types of the TEDs were tested; three brought from U.S.A. namely the Anthony Weedless, the Super Shooter and the Bent Pipe, two brought from Mexico namely the Georgia Jumper and the Mexican, and two were designed by Kasetsart University and SEAFDEC/TD, Thailand, namely the Thai-KU and Thai Turtle Free Device (TTFD), respectively. No turtles were caught in any of the areas off Chumporn and Songkhla during a total of 120 hauls. The escape rate by weight of the Super Shooter and TTFD were found to be 2.67% and 1.80% for day-time operation and 1.91% and 1.04% during the night, respectively, this indicated that they were the most efficient TED. The fuel consumption for all TEDs showed little difference. In terms of convenience in operation, the TTFD was found to be the best and the most suitable TED for the use by Thai fishermen

Biomass Estimation by Hydro-acoustic Methods in the South China Sea, Area II: Sarawak, Sabah and Brunei Darussalam

The abundance of fisheries resources and their structure off shore of Sarawak, Sabah and Brunei Darussalam were investigated under the SEAFDEC Collaborative Research Survey. Hydro-acoustic surveying by using a scientific echo sounder model FQ-70 was conducted for estimating the fish abundance and biomass. Two survey cruises were carried out by M.V. SEAFDEC during 10 July to 2 August 1996 and 1 to 24 May 1997 for pre and post-northeast monsoon seasons, respectively. The scientific echo-sounder was equipped with an echo-integrator and two quasi-ideal beam transducers with operating frequencies of 50 and 200 kHz. For pre and post-northeast monsoon season was 1,717,852 tons and 956,397 tons, respectively. The maximum fish abundance were found at the water depth between 100 to 200 m was 92.4% and 49.8% of total abundance for pre and post-northeast monsoon season, respectively