Multi-species fish stock assessment by acoustic method in the South China Sea Area I: Gulf of Thailand and east coast of Peninsular Malaysia

Acoustic resource surveys were conducted by M/V SEAFDEC in the Gulf of Thailand and off the east coast of Peninsular Malaysia from September 5 to 28, 1995 for pre-NE monsoon season and from April 24 to May 17, 1996 for post-NE monsoon season, using the scientific echosounder FQ-70 (Furuno Electric Co.). Collected raw values of backscattering strength (SV) from the 200 kHz were carefully corrected and filtered to eliminate the influence of plankton. These corrected SV values were classified into pelagic and demersal fish, and were used to estimate the biomass of pelagic and demersal multispecies fish. Biomass of pelagic and demersal fish for each season was only estimated in the east coast of Peninsular Malaysia within Malaysian EEZ waters due to the availability of previous fisheries statistics and biological data. Dominant species were selected based on the fisheries statistics and landing place survey. Length (L) and weight were obtained from previous literatures. Target strength (TS) of these dominant species were calculated as TS =20 log (L) -66. The distribution of the SV values for pelagic fish showed a distinct difference between preand post- monsoon seasons. Greater concentrations of SVs were observed from offshore compared to the nearshore waters in pre-monsoon season. The distribution for the demersal fish showed that there was no clear difference between pre- and post-monsoon. The estimated biomass of multi-species fish off the east coast of Peninsular Malaysia within Malaysian EEZ for the pre-and post-monsoon seasons was 4.4x105 tonnes (2.3x105 tonnes of pelagic fish and 2.1x 105 tonnes of demersal fish) and 3.1x105 tonnes (1.9x105 tonnes of pelagic fish and 1.2x 105 tonnes of demersal fish), respectively

Stock assessment by hydro-acoustic method in the South China Sea Area II: Sabah, Sarawak, Brunei Darussalam

Acoustic resource surveys were conducted by M/V SEAFDEC off Sarawak, Brunei and the east coast of Sabah from July 10 to August 2, 1996 for pre-NE monsoon season and from May 1 to May 24, 1997 for post-NE monsoon season, using the scientific echo sounder FQ-70, developed by Furuno Electric Co. Japan. Collected raw values of backscattering strength (SV) from the 200 kHz transducer were carefully corrected and filtered to eliminate the influence of plankton. These corrected SV values were divided into pelagic and demersal fish, and were used to estimate the biomass of pelagic and demersal multi-species in the limited coastal waters off Sarawak. Decapterus macrosoma for pelagic fish and Priacanthus macracanthus for demersal fish were selected as representative species, based on the fisheries statistics, landing place survey, and research vessel survey in order to estimate biomass. The standard length (SL) and weight of these representative species were obtained from research vessel survey and supported by previous literatures. Target strength (TS) of these representative species were calculated using formula TS = 20 log(SL) - 66. The distribution of the SV values for pelagic fish showed distinct difference between pre and post Northeast (NE) monsoon seasons along the coastal waters. Greater concentrations of SVs were observed from depth 100 and 200m on the continental shelf along the survey area for both the seasons. The estimated biomass of multi-species fish off coastal Sarawak waters for the pre and post NE monsoon seasons was 120,000 tonnes (100,000 tonnes of pelagic fish and 2x105 tonnes of demersal fish) and 470,000 tonnes (360,000 tonnes of pelagic fish and 110,000 tonnes of demersal fish), respectively. Estimated Maximum Sustainable Yield (MSY) was 83,000 tonnes for pelagic fish and 31,000 tonnes for demersal fish when using Cadima’s model

Field Guide to Sharks of Malaysia and Neighbouring Countries

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Field Guide to Rays and Chimaeras of Malaysia and Neighbouring Countries

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Multi-species Fish Stock Assessment by Acoustic Method in the South China Sea Area I: Gulf of Thailand and East Coast of Peninsular Malaysia

Acoustic resource surveys were conducted by M/V SEAFDEC in the Gulf of Thailand and off the east coast of Peninsular Malaysia from September 5 to 28, 1995 for pre-NE monsoon season and from April 24 to May 17, 1996 for post-NE monsoon season, using the scientific echosounder FQ-70 (Furuno Electric Co.). Collected raw values of backscattering strength (SV) from the 200 kHz were carefully corrected and filtered to eliminate the influence of plankton. These corrected SV values were classified into pelagic and demersal fish, and were used to estimate the biomass of pelagic and demersal multispecies fish. Biomass of pelagic and demersal fish for each season was only estimated in the east coast of Peninsular Malaysia within Malaysian EEZ waters due to the availability of previous fisheries statistics and biological data. Dominant species were selected based on the fisheries statistics and landing place survey. Length (L) and weight were obtained from previous literatures. Target strength (TS) of these dominant species were calculated as TS =20 log (L) -66. The distribution of the SV values for pelagic fish showed a distinct difference between preand post- monsoon seasons. Greater concentrations of SVs were observed from offshore compared to the nearshore waters in pre-monsoon season. The distribution for the demersal fish showed that there was no clear difference between pre- and post-monsoon. The estimated biomass of multi-species fish off the east coast of Peninsular Malaysia within Malaysian EEZ for the pre-and post-monsoon seasons was 4.4x105 tonnes (2.3x105 tonnes of pelagic fish and 2.1x 105 tonnes of demersal fish) and 3.1x105 tonnes (1.9x105 tonnes of pelagic fish and 1.2x 105 tonnes of demersal fish), respectively