Humboldt (Southern) - Exploitation

Regarding human exploitation of marine resources, four main periods are identified in the history of the southern Humboldt system. a) Pristine Period (<1900): characterized by a small-scale survival fishery extending from the Pleistocene-Early Holocene period (i.e., 10400 to 9000 years BP) up to the starting point of the first big-scale fisheries in central Chile exploiting large marine mammals; b) Period altered by removal of large marine mammals (1900-1950): characterized by industrial whaling and hunting of sea lions. Whaling mainly occurred from 1920 to 1982 (about 40 thousand individuals caught), but was halted in central Chile in 1983 when the authority passed a total ban due the poor condition of exploited stocks, many of which were seriously depleted. The hunting of sea lions (Otaria flavescens) may have started as early as 1825. However, the first records seem to indicate that this was a very intensive activity during early 1990s. For example, in just one site (Santa Maria Island, 37°S; 73°30W), around 52 thousand individuals were caught only between 1921 and 1922. Nowadays, the common sea lion population in central Chile is estimated in only 17 thousand individuals; c) Period altered by heavy industrial fishing (1950 to mid 1990s). The Industrial fisheries on fish and crustacean species started in the decade of 1940s, when demersal trawlers targeted Chilean hake (Merluccius gayi). However, landings of this fleet were significant only from the mid 1950’s onwards. By the early 1960´s, an industrial pelagic fishery developed, targeting small pelagic fish, mainly Araucanian herring (Strangomera bentincki) and anchovy (Engraulis ringens). At the same time, an industrial fleet operated on medium-sized pelagic fish, namely horse mackerel (Trachurus symmetricus), landings of which were globally significant only from 1975 onwards; d) Significantly altered period (2000s-present): total landings in central Chile reached a peak in mid 1990s with a historical maximum landing of over 4.5 million tons in 1997, after which, total landings have consistently decreased. This is explained by serial stock declines in important fisheries such as horse mackerel (1998), red squat lobster and yellow squat lobster (1999) and Chilean hake (early 2000s). Since the early 1990s, all these fisheries have been managed by means of total allowable catches (TACs) set by the National Fisheries Council, following the technical advice of the Undersecretary of Fisheries. TACs are calculated following detailed analyses of the state of each fishery resource, based on fishery-independent (annual survey data) and fishery-dependent global or structured (by age or size) models. Other management measures include minimum legal size and reproductive (seasonal) bans.