Nuevos registros de crinoideos (Echinodermata: crinoidea) en el talud continental de chile

Indexación: Scopus.The presence of Solanometra antarctica has been reported in the continental slope of central Chile, however, some studies suggest that this species could have been confused with Florometra magellanica. In this study, 11 crinoid specimens obtained in the continental slope of Central Chile were analyzed and compared with other specimens previously collected in that same region and catalogued as Florometra magellanica. The morphological and meristic characteristics confirm that the crinoids collected in Central Chile, off Concepción and Los Vilos, correspond to Florometra magellanica.https://revistas.uv.cl/index.php/rbmo/article/view/239

Man and the Last Great Wilderness: Human Impact on the Deep Sea

The deep sea, the largest ecosystem on Earth and one of the least studied, harbours high biodiversity and provides a wealth of resources. Although humans have used the oceans for millennia, technological developments now allow exploitation of fisheries resources, hydrocarbons and minerals below 2000 m depth. The remoteness of the deep seafloor has promoted the disposal of residues and litter. Ocean acidification and climate change now bring a new dimension of global effects. Thus the challenges facing the deep sea are large and accelerating, providing a new imperative for the science community, industry and national and international organizations to work together to develop successful exploitation management and conservation of the deep-sea ecosystem. This paper provides scientific expert judgement and a semi-quantitative analysis of past, present and future impacts of human-related activities on global deep-sea habitats within three categories: disposal, exploitation and climate change. The analysis is the result of a Census of Marine Life – SYNDEEP workshop (September 2008). A detailed review of known impacts and their effects is provided. The analysis shows how, in recent decades, the most significant anthropogenic activities that affect the deep sea have evolved from mainly disposal (past) to exploitation (present). We predict that from now and into the future, increases in atmospheric CO2 and facets and consequences of climate change will have the most impact on deep-sea habitats and their fauna. Synergies between different anthropogenic pressures and associated effects are discussed, indicating that most synergies are related to increased atmospheric CO2 and climate change effects. We identify deep-sea ecosystems we believe are at higher risk from human impacts in the near future: benthic communities on sedimentary upper slopes, cold-water corals, canyon benthic communities and seamount pelagic and benthic communities. We finalise this review with a short discussion on protection and management methods

Late Cretaceous (Maastrichtian) shallow water hydrocarbon seeps from Snow Hill and Seymour Islands, James Ross Basin, Antarctica

Fossil hydrocarbon seeps are present in latest Cretaceous (Maastrichtian) volcaniclastic shallow shelf sediments exposed on Snow Hill and Seymour Islands, James Ross Basin, Antarctica. The seeps occur in the Snow Hill Island Formation on Snow Hill Island and are manifest as large-sized, cement-rich carbonate bodies, containing abundant thyasirid bivalves and rarer ammonites and solemyid bivalves. These bodies have typical seep cement phases, with δ13C values between 20.4 and 10.7‰ and contain molecular fossils indicative of terrigenous organic material and the micro-organisms involved in the anaerobic oxidation of methane, including methanotrophic archaea and sulphate-reducing bacteria. On Seymour Island the seeps occur as micrite-cemented burrow systems in the López de Bertodano Formation and are associated with thyasirid, solemyid and lucinid bivalves, and background molluscan taxa. The cemented burrows also have typical seep cement phases, with δ13C values between 58.0 and 24.6‰. There is evidence from other data that hydrocarbon seepage was a common feature in the James Ross Basin throughout the Maastrichtian and into the Eocene. The Snow Hill and Seymour Island examples comprise the third known area of Maastrichtian hydrocarbon seepage. But compared to most other ancient and modern seep communities, the James Ross Basin seep fauna is of very low diversity, being dominated by infaunal bivalves, all of which probably had thiotrophic chemosymbionts, but which were unlikely to have been seep obligates. Absent from the James Ross Basin seep fauna are ‘typical’ obligate seep taxa from the Cretaceous and the Cenozoic. Reasons for this may have been temporal, palaeolatitudinal, palaeobathymetric, or palaeoecological

A new species of Munida Leach, 1820 (Crustacea: Decapoda: Anomura: Munididae) from seamounts of the Nazca-Desventuradas Marine Park

Este artículo contiene 18 páginas, 5 figuras.Munida diritas sp. nov. is described for the seamounts near Desventuradas Islands, in the intersection of the Salas & Gómez and Nazca Ridges, Chile. Specimens of the new species were collected in the summit ( 200mdepth) of one seamount and observed by ROV at two nearby ones. This species is characterized by the presence of distinct carinae on the thoracic sternites 6 and 7. Furthermore, it is not related with any species from the continental shelf nor the slope of America, while it is closely related to species of Munida from French Polynesia and the West-Pacific Ocean (i.e., M. ommata, M. psylla and M. rufiantennulata). In situ observations indicate that the species lives among the tentacles of ceriantarid anemones and preys on small crustaceans. The discovery of this new species adds to the knowledge of the highly endemic benthic fauna of seamounts of the newly created Nazca-Desventuradas Marine Park, emphasizing the relevance of this area for marine conservation.This work was supported by grants (CONA C22 16-09, FONDECYT 1181153, FONDEQUIP EQM 150109) and ANID-Millennium Science Initiative Program-ESMOI. Beca Magister Nacional CONICYT # 22190560 (now ANID) to Jan M. Tapia Guerra, Beca Postdoctorado Universidad Católica del Norte No 003 to María de los Ángeles Gallardo.Peer reviewe

Las áreas de filtración de metano constituyen zonas de agregación del bacalao de profundidad (Dissostichus eleginoides) frente a Chile central?

Se presenta los resultados de dos campanas (invierno y verano) de pesca de bacalao de profundidad (Dissostichus eleginoides), realizadas sobre un área de filtración de metano (AFM) y un sitio aledano utilizado como control. Estas fueron desarrolladas con el objetivo de determinar si las AFM constituyen sitios de agregación de D. eleginoides. Para cada área se registró la captura promedio, el rendimiento de pesca y se determinó índices de abundancia y diversidad incluyendo la fauna capturada incidentalmente. Los ejemplares de bacalao de profundidad capturados en ambos sitios fueron sexados, medidos y pesados. Adicionalmente, se presentan imágenes tomadas in situ, dentro del AFM, que documentan la presencia tanto de D. eleginoides como aparejos de pesca perdidos utilizados en su captura frente a la costa de Concepción. Las mayores capturas y rendimientos fueron observadas en el AFM, con valores promedio de 56,2 kg por lance de pesca y rendimientos promedios de 80,3 g/anzuelo, siendo significativamente mayores en comparación al sitio control. La campana de pesca realizada en invierno registra mayores capturas y rendimientos en ambas áreas. La composición faunística evaluada a través de los índices comunitarios, indica diferencias significativas entre sitios, registrándose un mayor número de especies de fauna acompanante en el AFM, en comparación con el sitio control (18 y 14 especies, respectivamente). Se hipotetiza que la mayor abundancia de bacalao de profundidad en el AFM, estaría relacionada tanto con la mayor heterogeneidad espacial, dada por la presencia de arrecifes de carbonatos autigénicos, como con la disponibilidad de presas, constituyendo estos sitios como zonas de alimentación. El presente trabajo entrega información tendiente a establecer el rol ecológico de las AFM y la fauna asociada a ellas en ambientes batiales frente a Chile

Anatomy of Zetela alphonsi Vilvens, 2002 casts doubt on its original placement based on conchological characters (Mollusca, Solariellidae)

Zetela is a genus of marine gastropods belonging to the family Solariellidae (Vetigastropoda, Trochoidea). The species Zetela alphonsi Vilvens, 2002 was originally described using classical conchological characters from samples obtained from deep water off Chiloé, Chile, but no other features were recorded in the original description. In the present paper, taxonomically relevant characters such as the operculum, radula, and soft part anatomy are illustrated and described for the first time from a specimen of Zetela alphonsi from a new locality, a methane seep area off the coast of central Chile. We find that many features differ substantially from other members of the genus, including several which deviate from characters that are diagnostic for Zetela. Zetela alphonsi also lacks retinal screening pigment, giving the appearance of eyelessness from gross examination. Although pigmentation loss has been reported in other deep sea genera, this feature has not been reported in any other members of Zetela. We reconstructed a tomographic model of the eye and eyestalk, and demonstrate that a vestigial eye is still present but externally invisible due to the loss of pigmentation. Based on these new morphological characters, particularly observations of the radula, we suggest that the current placement of this species in the genus Zetela should be reconsidered

Meiofaunal distributions on the Peru margin: relationship to oxygen and organic matter availability.

A quantitative study of metazoan meiofauna was carried out on bathyal sediments (305, 562, 830 and 1210m) along a transect within and beneath the oxygen minimum zone (OMZ) in the southeastern Pacific off Callao, Peru (128S). Meiobenthos densities ranged from 1517 (upper slope, middle of OMZ) to 440– 548 ind. 10 cm2 (lower slope stations, beneath the OMZ). Nematodes were the numerically dominant meiofaunal taxon at every station, followed by copepods and nauplii. Increasing bottom-water oxygen concentration and decreasing organic matter availability downslope were correlated with observed changes in meiofaunal abundance. The 300-m site, located in the middle of the OMZ, differed significantly in meiofaunal abundance, dominance, and in vertical distribution pattern from the deeper sites. At 305m, nematodes amounted to over 99 % of total meiofauna; about 70 % of nematodes were found in the 2–5 cm interval. At the deeper sites, about 50 % were restricted to the top 1 cm. The importance of copepods and nauplii increased consistently with depth, reaching 12 % of the total meiofauna at the deepest site. The observation of high nematode abundances at oxygen concentrations 50.02ml l1 supports the hypothesis that densities are enhanced by an indirect positive effect of low oxygen involving (a) reduction of predators and competitors and (b) preservation of organic matter leading to high food availability and quality. Foo

Las áreas de filtración de metano constituyen zonas de agregación del bacalao de profundidad (Dissostichus eleginoides) frente a Chile central? Do the methane seep areas constitute aggregation spots for the Patagonian toothfish (Dissostichus eleginoides) off central Chile?

Se presenta los resultados de dos campanas (invierno y verano) de pesca de bacalao de profundidad (Dissostichus eleginoides), realizadas sobre un área de filtración de metano (AFM) y un sitio aledano utilizado como control. Estas fueron desarrolladas con el objetivo de determinar si las AFM constituyen sitios de agregación de D. eleginoides. Para cada área se registró la captura promedio, el rendimiento de pesca y se determinó índices de abundancia y diversidad incluyendo la fauna capturada incidentalmente. Los ejemplares de bacalao de profundidad capturados en ambos sitios fueron sexados, medidos y pesados. Adicionalmente, se presentan imágenes tomadas in situ, dentro del AFM, que documentan la presencia tanto de D. eleginoides como aparejos de pesca perdidos utilizados en su captura frente a la costa de Concepción. Las mayores capturas y rendimientos fueron observadas en el AFM, con valores promedio de 56,2 kg por lance de pesca y rendimientos promedios de 80,3 g/anzuelo, siendo significativamente mayores en comparación al sitio control. La campana de pesca realizada en invierno registra mayores capturas y rendimientos en ambas áreas. La composición faunística evaluada a través de los índices comunitarios, indica diferencias significativas entre sitios, registrándose un mayor número de especies de fauna acompanante en el AFM, en comparación con el sitio control (18 y 14 especies, respectivamente). Se hipotetiza que la mayor abundancia de bacalao de profundidad en el AFM, estaría relacionada tanto con la mayor heterogeneidad espacial, dada por la presencia de arrecifes de carbonatos autigénicos, como con la disponibilidad de presas, constituyendo estos sitios como zonas de alimentación. El presente trabajo entrega información tendiente a establecer el rol ecológico de las AFM y la fauna asociada a ellas en ambientes batiales frente a Chile.We report results of two seasons (winter and summer) fishing for Patagonian toothfish (Dissostichus eleginoides), performed on a methane seep area (AFM) and a nearby place used as a control. These campaigns were developed with the aim of determining whether the AFM are sites of aggregation of D. eleginoides. For each area, the average catch was recorded, fishing performance and, abundance and diversity of wildlife indexes were determined, including incidentally caught fauna. Patagonian toothfish caught at both sites were sexed, measured and weighed. Additionally, there are images taken in situ, within the AFM, documenting the presence of both D. eleginoides as well as lost fishing gear used in their capture off the coast of Concepcion. The largest catches and yields were observed in the AFM, with average values of 56.2 kg per fishing haul and average yields of 80.3 g/hook, being significantly higher compared to the control site. In the winter fishing season higher yields and catches were recorded in both areas. The faunal composition, evaluated through community indices, indicate significant differences between sites, with the greater number of bycatch species in the AFM, compared with the control site (18 and 14 species, respectively). We hypothesize that the greater abundance of toothfish in the AFM would be related to both the greater spatial heterogeneity, given by the presence of authigenic carbonate reefs, and with the availability of prey, constituting these zones into foraging sites. This paper provides information aimed at establishing the ecological role of the AFM and associated fauna bathyal environments off Chile

Unexpected death of the scleractinian Desmophyllum dianthus in northern Patagonian Fjords, Chile

Fiordo Comau in Northern Patagonia, Chile, is home to a wide range of unique habitats and diverse communities of many new and little understood species. At one site in the fiordo, XHuinay, H2S seeps allow for the formation of filamentous chemosynthetic bacteria mats. Here, two scleractinians, Desmophyllum dianthus and Caryophyllia huinayensis, were once abundant on hard substrate below 18m depth. However, a recent mass mortality of D. dianthus occurred while C. huinayensis continues to survive. This pilot study investigates whether the presence of H2S seeps and their associated bacteria have an affect on D. dianthus mortality. We fixed nine D. dianthus individuals and nine C. huinayensis individuals at 25m depth at two sites: XHuinay and Isla Lilihuapi (control) to monitor their survival under actual conditions. If H2S seeps negatively affect Desmophyllum dianthus survival, then we expect to observe deaths of individuals of D. dianthus at XHuinay and the survival of individuals at Isla Lilihuapi. We also expect C. huinayensis to survive at both sites. This experiment is still in progress. However, this preliminary study emphasizes the need for and seeks to prompt further investigation into these scleractinians, their relationship with both biotic and abiotic environmental factors, and specifically their role within the fragile web of Chilean Fiord ecology