Biotopes of the intertidal zone in Clarence Island (south of the Strait of Magellan).

Background: The characteristics of the Strait of Magellan promote the formation of unique environments, with diverse habitats and marine organisms. This fragmentation of the landscape generates diverse little-explored ecological associations, especially in the zone of sub-Antarctic islands of the Tierra del Fuego archipelago. One way to address this lack of knowledge is through the biotope characterization methodology, with ecological units composed of the habitat and the communities associated with these environments, obtaining data and information on the dominant and incidental taxonomic groups. This is a good research model to conduct baseline studies in coastal benthic marine environments. New information: A data set in Darwin Core standard is presented of the species that make up the intertidal biotopes of Clarence Island (Tierra del Fuego Archipelago, south of the Strait of Magellan). This includes 50 identified species and the specific coordinates for each sampled location, with a total of 1400 georeferenced records. Mollusks were the most diverse taxon with 21 species, followed by algae (14 species). Sessile organisms such as the barnacles Elminiuskingii and Austromegabalanuspsittacus predominate in these ecosystems, followed by bivalve mollusks such as Choromytiluschorus and Mytiluschilensis, which together with Nacellamagellanica and the alga Hildenbrandia sp. make up more than 50% of the total records. The inclusion of biotope patterns in this study complements the information on benthic marine flora and fauna in the intertidal zone, including new records for the coast in the Clarence Island area, which is within the boundary of the Kawésqar National Park.

Benthic biota of Chilean fjords and channels in 25 years of cruises of the National Oceanographic Committee.

The CIMAR program (Marine Research Cruises to Remote Areas) run by the Chilean Navy through the National Oceanographic Committee has been developed since 1995, focused on Chilean fjord and channel zones (~41-56°S; "CIMAR-Fjords") and Chilean remote islands ("CIMAR-Islands"). Samples and data was collected on biotic and abiotic variables on all these cruises, both from the water column and benthos. Our work standardizes, compiles, and summarizes the published information on benthic organisms for twenty-one CIMAR-Fjords cruises developed in the first 25 years of the program, plus the Southern Ice Fields Cruise 1995 (precursor of the CIMAR program), which includes the distribution, abundance and geographic location of cruises sampling stations. The data set includes 8,854 records from 880 different localities, corresponding to 1,225 species from 24 different phyla (four kingdoms) and more than 150,000 individuals. Only two cruises did not record any benthic sampling. The fjords and channels of Chilean Patagonia have high biodiversity, so we hope that our data set will serve as a baseline for ecological studies and ecosystem conservation.

Diversity of benthic marine mollusks of the Strait of Magellan, Chile (Polyplacophora, Gastropoda, Bivalvia): a historical review of natural history.

An increase in richness of benthic marine mollusks towards high latitudes has been described on the Pacific coast of Chile in recent decades. This considerable increase in diversity occurs specifically at the beginning of the Magellanic Biogeographic Province. Within this province lies the Strait of Magellan, considered the most important channel because it connects the South Pacific and Atlantic Oceans. These characteristics make it an interesting area for marine research; thus, the Strait of Magellan has historically been the area with the greatest research effort within the province. However, despite efforts there is no comprehensive and updated list of the diversity of mollusks within the Strait of Magellan up to now. This study consisted of a complete bibliographic review of all available literature that included samples of mollusks in the Strait of Magellan. More than 300 articles were reviewed, covering 200 years of scientific knowledge. There were 2579 records belonging to 412 taxa, of which 347 are valid species. Of the total valid species, 44 (~13%) are considered of doubtful presence in the Strait. This work increases the known richness of mollusks of the Strait of Magellan by 228%; it is also the first report that integrates all available diversity studies of the three most speciose classes of benthic mollusks (Gastropoda, Bivalvia and Polyplacophora) from the Strait of Magellan.