The maximum sustainable yield of demersal fishery resources in the Gulf of Thailand to a depth of 50 m is estimated to be 750,000 tonnes. On this basis the Gulf has been overfished since 1973. There were over 4,000 trawlers registered in the Gulf in 1972; over 10,000 in 1982. The total catch of food fish has increased only slightly since 1963, most increases being of trash fish. However, the trash fish component includes increasing numbers of juvenile food fish. Trash fish are now mostly processed into fish meal. The number of fish meal factories has increased from six in 1967 to 95 in 1980. The total quantity of trash fish has been declining since 1978. The Thai Department of Fisheries proposed controlling trawler numbers in 1969, but received Goverment approval only in November 1979. The Department issued licences for trawlers until September 1982.