Abstract

The Katalalixar National Reserve (KNR) is located south of the Penas Gulf in central Patagonia (47,5°S - 48,5°S), and in longitudinal direction extended between the Pacific Ocean and glaciers belonging to the southern Patagonian ice field. The reserve and its surrounding channels and fjords represent one of the few remaining pristine areas of Patagonia without any significant human intervention. The composition of invertebrates from 10 to 220m depth of the sublittoral from selected sectors located in the central and eastern part of the reserve was investigated by means of biological samples and underwater video obtained with a remotely operated vehicle. A total of 72 taxa was registered in shallower waters above 20m and 143 taxa were found at greater depths. Polychaetes and gastropods were the most divers taxa above 20m with19 and 11 species, respectively, whereas sponges and cnidarians were most divers in the deeper sublittoral with 37 and 28 taxa. The highest species richness of the shallow sublittoral was registered in the southern limit of the reserve, close the oceanic entrance of the del Castillo channel (19,4 ± DE 8,9 taxa). The highest richness of the deeper sublittoral was observed in the north of the reserve, south of the islands adjacent to the Penas Gulf (42,5 ± DE 0,7 taxa). A decreasing diversity and a change in species composition of the fauna of the deeper sublittoral was observed towards the interior of the reserve where input from melting glaciers results in high sedimentation rates and less salinity. About 90% of the invertebrates found in the deeper sublittoral are distributed all over Patagonia, underlining the reserve as important and representative place for any future conservation of the marine diversity of Chilean Patagonia.