Fish is a major protein element in the Thai diet. Freshwater fish, abundantly found in rivers and canals, and marine fish (from the waters along the lengthy coastline) produced a catch of 2,923,579 tons in 2000 (9th in the world), as compared with 846,600 tons in 1967. Leading marine species in the 2000 harvest included (in tons): sardines, 187,772; anchovies, 158,833; Indian mackerels, 152,564; and threadfin breams, 95,500. Thailand exports cured fish to neighboring countries, and frozen shrimp and prawns mainly to Japan. In 2000, Thailand accounted for7.9% of the world's exports of fish and fish products, valued at over $4,367 million. Giant tiger prawn, tilapias, hybrid catfish, and green mussels accounted for most of the aquacultural volume.