the humboldt current system of northern and central chile - figema

MARTIN THIEL ET AL.speared large fish and marine mammals such as sea lions (Otaria juvata and O. flavescens) (Santoroet al. 2005). A report on the navigation off the west coast of South America carried out by Lothrop(1932) showed artifacts used by aboriginal people of northern Chile. Most remarkable was a raftcomposed of two cylinders of seal hides tied together to support a small platform on top, and whilevoyages out of sight of land were rarely attempted, it was not uncommon to remain at sea for 2 or3 days (Lothrop 1932).Llagostera (1979), working between 21°S and 25°S, found evidence of groups of people withthe ability to exploit natural resources from coastal waters ~10,000 yr BP, and he found remainsof molluscan species such as Concholepas concholepas, Fissurella spp., Tegula atra, Choromytiluschorus, several species of fishes (e.g., Isacia conceptionis and Trachurus murphyi), and semifossilisedbones of sea lions and dolphins. Reports from southern Peru suggest specific sites wheremainly fish and seabird resources were exploited (Keefer et al. 1998), while at other (more ephemeral)sites they processed mainly molluscs (Sandweiss 2003). Studies from southern Peru andnorthern Chile demonstrated that the resources exploited by early coastal settlers of the HCSchanged with time (Llagostera 1979, Sandweiss et al. 2001), which is taken as an indication ofclimate change and EN events, causing gradual or abrupt changes in available resources. Similarobservations were made in central Chile near 32°S (Báez et al. 2004). For the late Holocene(4000–2000 BP) Méndez & Jackson (2004) reported a high degree of mobility of coastal peoplein central Chile, who apparently moved between different sites in a region, exploiting the accessibleresources at a given site in an opportunistic manner.A systematic study of remains of marine invertebrate fauna from central Chile (Curaumilla,33°S) defined the ecological role of early inhabitants as shellfish gatherers (Jerardino et al. 1992).According to these authors, they probably modified areas of the rocky intertidal, causing decreasesin mean sizes of Concholepas and Fissurella. Interestingly, Llagostera (1979) suggested that theappearance of larger shells of Concholepas in shell heaps is indication of an increasing radius ofaction and the exploitation of new fishing grounds. This author also remarked that the appearanceof some fish species (e.g., cusk eels, locally called ‘congrio’, from the genus Genypterus, whichcan only be fished at greater depths) around 3000 BP is indication that coastal fishermen startedto venture farther out to sea during that time period.In general, prehistoric people used littoral resources in an opportunistic manner, and duringthe past millennia they increasingly widened their radius of action, improved their navigating skills(rafts) and developed their fishing techniques (fishing nets, hooks). Extraction of marine resourceswas not only for subsistence of local groups, but also for an intensive transfer of fish toward inlandsites (Briones et al. 2005). Local people persisted and exploited marine resources until well afterthe appearance of the Spanish (Llagostera 1979). The resources collected and captured by prehistoricpeople are the same that still today play an important role in the fisheries of northern and centralChile.Artisanal benthic fisheriesThe present artisanal fisheries in the HCS between 18°S and 35°S are very diverse, comprising~13 species of algae, ~45 species of invertebrates (molluscs, crustaceans, echinoderms, tunicates)and ~68 fish species (SERNAPESCA 2005). Before the 1980s, fisheries in general were of lowlevel and stable since products only went to local markets and the intensity of exploitation wascomparatively moderate (Stotz 1997, González et al. 2006). During the mid-1980s the export ofmost of the resources was initiated, producing increases in captures, and once the accumulatedbiomass was used up, the resources remained at low and fluctuating levels (Figure 22). In general,these fluctuations have been interpreted as the classical signs of a badly regulated fishery, as278