As much as 75 percent of the population of Tuvalu is involved in agricultural production of some sort. Subsistence farming is the main source of both food and income for many Tuvaluans. Agriculture, in the form of the production of copra, also provides the nation's only true export. Total agricultural exports in 1998 amounted to US$400,000, and agriculture accounted for 25 percent of the nation's total GDP.
The main crops include copra, taro (a large tuber), bananas, and sugarcane. There is little or no livestock production, although many families keep small numbers of pigs and chickens for personal consumption. While copra is harvested from coconut trees, the other crops are planted according to traditional practices. The islands receive about 2,500 millimeters (100 inches) of rainfall per year, but the porous, volcanic nature of the soil means that islanders have to use cisterns to collect rainwater as the water rapidly soaks through the ground and there are no natural springs or wells on any of the islands. Because there is little fresh water, islanders often use coconut milk in place of drinking water. Water constraints have also led to the evolution of a distinctive form of planting. Crops are planted in trenches that are 3 to 6 meters (10 to 20 feet) wide and dug down to the water table (usu-ally a depth of between 2 to 4 meters or 6 to 12 feet). In order to compensate for the nation's poor soil, these trenches are filled with leaves and natural fertilizers to produce a mulch capable of sustaining the crops. Indigenous foodstuffs such as breadfruit (a round seedless fruit from the mulberry family the texture of which resembles bread when cooked) are often cultivated on the banks and edges of the trenches for local consumption.
Most farms are small (less than an acre in size) and communally owned. The Agriculture Division has been implementing programs designed to join together communal lands into larger farms in order to increase efficiency with the ultimate goal of ensuring that no land capable of agriculture remains unproductive. As the communal farms are joined together, profits from production would be divided into 3 parts: one-third for the original land owners; one-third for the agricultural workers; and the final third would be deposited in a communal fund in a bank. This group fund would serve as a resource for future land improvements or to offset periods of underproduction or price declines.
Fishing is done extensively throughout the islands, but the majority of the catch is used for local consumption. Tuvalu allows other nations, including South Korea, Taiwan, and the United States, to fish for tuna in its territorial waters in exchange for license fees that totaled US$5.5 million in 1998. In addition, small quantities of sea cucumbers are harvested by Tuvaluans for export to China.