Palau does not produce enough food to support itself, mainly because the cost of doing so is higher than the cost of importing needed items. The main crops are coconuts, bananas, root crops such as taro (similar to the potato), vegetables, and tropical fruits. Poultry, pigs, and dairy cows are the main livestock. Crops and livestock generated only about 2 percent of GDP in 1998. Since Palau cannot incorporate any economies of scale in agricultural production, the likelihood of significant increases in the sector are slim. Fisheries generated about 3 percent of GDP in 1998, but output from the fisheries sector appears to be in a steady decline—in 1992, the value of fish landed was almost 4 times greater, and the fishing fleet has halved to 150 vessels in 1998.