FIGURE 2-1 Total production by principal (mainly marine) species in 1994. Production includes mariculture and aquaculture, but represents catch for most species. Source: Redrawn from FAO (1996b).

1997a). Approximately 31.5 million t (28 percent) of world fish production was used for animal feed—including feed for mariculture—and other products that do not contribute directly to the human food supply in 1995.

In addition to fish that are caught and processed, a substantial number of fish and other organisms are caught and discarded—usually dead—at sea. Discards are a result of bycatch, which results because fishing gear and methods are not selective enough to catch only the target species, and of high grading, the discarding of smaller or less desirable fish in favor of larger or more desirable fish that are caught later. Some bycatch is retained, but the remainder is discarded when