A broad overview is given of research and information on aquaculture economics in Asia and the Pacific. Following a description of the general state of aquaculture in the region, an examination is made of the available research and information on the various aquaculture systems: inland/freshwater aquaculture; brackishwater /coastal aquaculture; and, marine aquaculture/sea farming. Studies on post-harvest handling, processing, transportation and marketing, and market analysis and development are discussed. Environmental issues and concerns, social equity and women's issues, community-based coastal resources management, technology transfer and macro-economic policies and institutional structures are also analysed. Aquaculture economics research is also assessed, highlighting thrusts, priorities, constraints and needs.

The aim of the present study was to use three PCR-based techniques for the analysis of genetic variability among Vibrio parahaemolyticus strains isolated from the Philippines. Seventeen strains of V. parahaemolyticus isolated from shrimps and from the environments where these shrimps are being cultivated were analyzed by RAPD, ERIC and REP-PCR. Antimicrobial susceptibility of these strains to selected compounds was investigated using broth microdilution method. Results of this work and analysis of similarity among strains using Dice coefficient and unweighted average pair group method have demonstrated genetic variability within the V. parahaemolyticus strains. The RAPD, ERIC and REP-PCR were found to be suitable typing methods for V. parahaemolyticus. They have good discriminative ability and can be used as rapid means of comparing these strains for epidemiological investigation. However, the REP-PCR analysis yielded a relatively small number of products suggesting that the REP sequences may not be widely distributed in the V. parahaemolyticus genome. Results of antimicrobial susceptibility revealed that resistance among the strains was rare. In conclusion, RAPD, ERIC and REP-PCR techniques are useful methods for molecular typing of V. parahaemolyticus strains. To our knowledge this is the first study of this kind carried out on V. parahaemolyticus strains isolated from the Philippines.

The improvement of existing immunoassay techniques, development of monoclonal antibody technology and the development of new immunoassay approaches are all working together to provide new tools for the detection of disease-causing organisms in fish and crustaceans. Following the introduction of nucleic acid hybridization technique and PCR, it was recognized that the methods offered a sensitive approach to the detection and identification of specific microorganisms as in the case of a bacterial or viral infection in a variety of sample types. Potentially, a characteristic DNA sequence from a single virus particle or cell of a particular organism can be amplified to detectable levels within a short period of time. Conventional diagnostic methods that involve the culture of microorganisms can take days or weeks to complete or very tedious to perform. PCR offers a rapid, very sensitive, very specific and simple alternative. Further developments in immunodiagnostics and emerging technologies such as DNA-based tests will revolutionize the detection and identification of infectious disease agents.

A wide variety of parasites have been identified as causing significant economic losses in fish and shrimp culture. Most of these parasites are difficult to control effectively with a single measure. The control of parasites is dependent on culture systems of the host fish, knowledge of the life cycle of the parasite, and the availability of effective treatment methods.