Most recent figures show the Thai marine catch to be 2.65 million mt in 2003, valued at USD 1.6 billion. 70% of this catch was sourced from the Gulf of Thailand while the Andaman Sea accounted for the remainder. The industry is characterized by both smallscale and large-scale or commercial fisheries. Demersal fish resources in coastal waters have been severely depleted and are mainly caught by otter-board trawls, pair trawls, beam trawls and push nets.

Several factors may have contributed to over-fishing, notably increasing human population, increased pressure from Thai trawlers who lost access to foreign fishing grounds after neighbouring countries declared EEZs, developments in processing techniques for turning low-priced demersal fish into human food, increasing numbers of animal feed plants that utilise trash fish, and trash fish itself. Trash fish is currently around 60% of the total trawl catch. Between 18% and 32% of trash fish are juveniles of commercially important fish species.