Humboldt (Southern) - Ecology

In terms of biological components, the southern Humboldt sustains a diverse food web. Large diatoms dominate the phytoplankton group most of the year, while the zooplankton is dominated by herbivorous copepods and euphausiids. Jellyfish also constitute an important group in the plankton domain. Macrocrustaceans are significant benthic components and some species such as red squat lobster (Pleuroncodes monodon), yellow squat lobster (Cervimunida johni) and pink shrimp (Heterocarpus reedi) are important fishery resources. The fish community is dominated by pelagic species. Small pelagic fishes such anchovy (Engraulis ringens) and the endemic Araucanian herring, also known as common sardine, (Strangomera bentincki) are present at high biomasses in the southern Humboldt and dominate landings. These species feed on phytoplankton and zooplankton. Although horse mackerel (Trachurus symmetricus) performs large-scale migrations in the Pacific Ocean, it is a major fishery resource off Chile, where it feeds mainly on euphausiids. The demersal fish community is dominated by the Chilean hake (Merluccius gayi) both in biomass and landings. Hake inhabits mid-depth waters (200-400 m) and feeds on euphausiids, galatheid crustaceans and small pelagic fishes. This species also exhibits a highly cannibalistic behaviour. The current status and basic ecology of top predators such as marine birds, sea lions and cetaceans are poorly known, but it is likely that their abundances are low compared to those at the start of the industrial fisheries in Central Chile.