Although many disease and environmental problems are bothering cage fish farmers
in the Upper Ping River, tilapia remains to be the most popular species for culture. This is
because of its fast growth and high market value. However, the lack of regulations in public
rivers has resulted in the uncontrolled proliferation of cage farms. High farm stocking densities
leads to rapid infection transmission and predisposes to clinical disease. Pathogens can
spread in the water column between cages. Preventive measures are needed to mitigate the
risk of disease emergence, establishment and spread. All fish being introduced into cages
must undergo a health exam and must be disease free. The aquaculture industry,
governments and international organizations must face up to the challenge of emerging
diseases to ensure that fish cage culture development is efficient economically, sustainable,
and has a minimal environmental impact.