110 research outputs found
Schroederichthys bivius, Narrowmouth Catshark
The Narrowmouth Catshark (Schroederichthys bivius) is a small (to 82 cm total Length) catshark that occurs in the Southeast Pacific and Southwest Atlantic from Valdivia, Chile, south around Cape Horn and north to southern Brazil. It is demersal on the continental shelf and upper slope at depths of 12-359 m (mostly <130 m). It is occasionally caught as bycatch of industrial and artisanal trawlers in Chile, Uruguay, Argentina, and the Falkland Islands (Malvinas). It is not typically utilized and is usually discarded dead. Overall, this catshark is caught throughout most of its range in small numbers. Its small size and presumably productive life history, combined with a lack of evidence of a population reduction, indicates that it is likely able to withstand limited exposure to fishing pressure. The population is suspected to be stable, therefore, the Narrowmouth Catshark is assessed as Least Concern.Fil: Dulvy, N. K.. University Fraser Simon; CanadáFil: Acuña, E.. Universidad Católica del Norte; ChileFil: Bustamante, C.. Universidad de Antofagasta; ChileFil: Chiaramonte, Gustavo Enrique. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia". Estación Hidrobiológica de Puerto Quequén (sede Quequén); ArgentinaFil: Cuevas, J. M.. Wildlife Conservation Society; Estados UnidosFil: Herman, K.. Georgia Aquarium; Estados UnidosFil: Pompert, J.. Georgia Seafoods; PaÃses BajosFil: Velez Zuazo, X.. Smithsonian Conservation Biology Institute; Estados Unido
Amblyraja georgiana, Antarctic Starry Skate
The Antarctic Starry Skate (Amblyraja georgiana) is a medium-sized (to 115 cm total length) deepwater skate that occurs in the Southeast Pacific Ocean off southern Chile, in the Southwest Atlantic Ocean off southern Argentina and the Falkland Islands (Malvinas), in the Atlantic and Pacific Antarctic Oceans from South Georgia Island and the Antarctic Peninsula to the Ross Sea, and in the Indian Antarctic off the Crozet Islands. It is demersal on continental and insular slopes at depths of 20?1,255 m, and is captured as bycatch in trawl and longline fisheries, particularly those targeting Patagonian Toothfish (Dissostichus eleginoides). There are no population size estimates for this skate, and it is not clear what the current population trend is. Although estimates of bycatch around South Georgia and the Ross Sea are comprised of a low percentage of overall estimated stock biomass, the demographic consequences are unknown and require further research. Furthermore, catch levels in other areas are unknown, and some specimens previously referred to as this species may include cryptic individuals of a yet-to-be-described species. Overall, it is not clear what level of fishing mortality this species is exposed to across its range, and further research is needed on distribution, population size and trend, and threats. Therefore, the Antarctic Starry Skate is assessed as Data Deficient.Fil: Pollom, R.. University Fraser Simon; CanadáFil: Acuña, E.. Universidad Católica del Norte; ChileFil: Bustamante, C.. Universidad de Antofagasta; ChileFil: Chiaramonte, Gustavo Enrique. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia". Estación Hidrobiológica de Puerto Quequén (sede Quequén); ArgentinaFil: Cuevas, J.M.. Wildlife Conservation Society; Estados UnidosFil: Herman, K.. Georgia Aquarium; Estados UnidosFil: Pompert, J.. No especifÃca;Fil: Velez Zuazo, X.. No especifÃca
Bathyraja meridionalis, Darkbelly Skate
The Darkbelly Skate (Bathyraja meridionalis) is a large (to 158 cm total length) that occurs in the Southeast Pacific Ocean off Magallanes Province, Chile, in the Southwest Atlantic Ocean from Buenos Aires to Tierra del Fuego, Argentina and westward to the Falkland Islands (Malvinas), and in the Antarctic Atlantic Ocean around the Shag Rocks and South Georgia. It is demersal on continental and insular shelves and slopes at depths of 65?2,240 m, and is captured in demersal trawl and longline fisheries targeting skates, Patagonian Toothfish, and other finfishes. It has substantial refuge at depth and its population is suspected to be stable. Therefore, the Darkbelly Skate is assessed as Least Concern.Fil: Pollom, R.. University Fraser Simon; CanadáFil: Dulvy, N. K.. University Fraser Simon; CanadáFil: Acuña, E.. Universidad Católica del Norte; ChileFil: Bustamante, C.. Universidad de Antofagasta; ChileFil: Cuevas, J. M.. Wildlife Conservation Society; Estados UnidosFil: Chiaramonte, Gustavo Enrique. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia". Estación Hidrobiológica de Puerto Quequén (sede Quequén); ArgentinaFil: Herman, K.. Georgia Aquarium; Estados UnidosFil: Pompert, J.. No especifÃca;Fil: Velez Zuazo, X.. No especifÃca
Bathyraja magellanica, Magellan Skate
The Magellan Skate (Bathyraja magellanica) is a medium-sized (to 105 cm total length) skate that occurs in the Southeast Pacific Ocean from Puerto Montt, Chile to Cape Horn and in the Southwest Atlantic Ocean from San MatÃas Gulf to Tierra del Fuego, Argentina, off the Falkland Islands (Malvinas), and on the Burdwood Bank. It is demersal on the continental shelf and slope at depths of 30?600 m. It is captured in demersal trawl fisheries, however it has some refuge at depth and the population trend is suspected to be stable. Therefore, the Magellan Skate is assessed as Least Concern.Fil: Pollom, R.. University Fraser Simon; CanadáFil: Dulvy, N. K.. University Fraser Simon; CanadáFil: Acuña, E.. Universidad Católica del Norte; ChileFil: Bustamante, C.. Universidad de Antofagasta; ChileFil: Chiaramonte, Gustavo Enrique. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia". Estación Hidrobiológica de Puerto Quequén (sede Quequén); ArgentinaFil: Cuevas, J. M.. Wildlife Conservation Society; Estados UnidosFil: Herman, K.. Georgia Aquarium; Estados UnidosFil: Pompert, J.. Georgia Seafoods; PaÃses BajosFil: Velez Zuazo, X.. Smithsonian Conservation Biology Institute; Estados Unido
Bathyraja griseocauda, Graytail Skate
The Greytail Skate (Bathyraja griseocauda) is a large (to 157 cm total length) skate that occurs in the Southeast Pacific and Southwest Atlantic Oceans from Coquimbo, Chile south around Cape Horn and north to Uruguay, including the Falkland Islands (Malvinas), and is demersal on the mid-continental shelf and upper slope at depths of 30?1,010 m. It is captured in trawl and longline fisheries targeting skates, squid, shrimp, scallops, hake, and Patagonian Toothfish (Dissostichus eleginoides) that are inadequately managed and together operate throughout its range. Its large body size and relatively unproductive life history make it particularly vulnerable to overfishing. In the Southeast Pacific, this skate is captured and discarded dead in inadequately managed fisheries that operate throughout that portion of its range. In the Southwest Atlantic, where large skates are typically utilized or exported for human consumption, the catch-per-unit-effort (CPUE) for this skate in the Falkland Islands (Malvinas) multi-species skate fishery declined consistently and substantially from 120 to 23 kg/hr between 1994 and 2006, and increased to 70 kg/hr in 2013 due to a change in the area fished. Although no later data are available, this fishery continues and is still not managed at the species level. In Argentina, there are no species-specific data, but rays in general declined in CPUE in the 1990s and early 2000s. Overall, due to the level of inadequately managed fishing pressure it is exposed to across its range, its large size and relatively unproductive life history, the decline in CPUE of rays in general in some areas, and the noted decline in CPUE (although succeeded by an increase) of this species in the Falkland Islands, it is suspected that this skate has undergone a population reduction of 50?79% over the past three generations (69 years). Therefore, the Greytail Skate is assessed as Endangered A2bd.Fil: Pollom, R.. University Fraser Simon; CanadáFil: Dulvy, N. K.. University Fraser Simon; CanadáFil: Acuña, E.. Universidad Católica del Norte; ChileFil: Bustamante, C.. Universidad de Antofagasta; ChileFil: Chiaramonte, Gustavo Enrique. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia". Estación Hidrobiológica de Puerto Quequén (sede Quequén); ArgentinaFil: Cuevas, J. M.. Wildlife Conservation Society; Estados UnidosFil: Herman, K.. Georgia Aquarium; Estados UnidosFil: Paesch, L.. Direccion Nacional de Recursos Acuaticos ; UruguayFil: Pompert, J.. No especifÃca;Fil: Velez Zuazo, X.. No especifÃca
Amblyraja doellojuradoi, Southern Thorny Skate
The Southern Thorny Skate (Amblyraja doellojuradoi) is a small (to 69 cm total length) deepwater skate that occurs in the Southeast Atlantic Ocean from Uruguay to Southern Argentina and the Burdwood Bank, including the Falkland Islands (Malvinas). It is demersal on the mid- and outer continental shelf and upper slope at depths of 50?1,000 m. This skate is captured as bycatch in demersal trawl fisheries and possibly on longlines targeting hake, squid, and Patagonian Toothfish (Dissostichus eleginoides), and is increasingly retained for human consumption. It has some refuge at depth and is not suspected to be undergoing a reduction in population size at this time. Therefore, the Southern Thorny Skate is assessed as Least Concern.Fil: Pollom, R.. University Fraser Simon; CanadáFil: Dulvy, N. K.. University Fraser Simon; CanadáFil: Acuña, E.. Universidad Católica del Norte; ChileFil: Bustamante, C.. Universidad de Antofagasta; ChileFil: Chiaramonte, Gustavo Enrique. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia". Estación Hidrobiológica de Puerto Quequén (sede Quequén); ArgentinaFil: Cuevas, J. M.. Wildlife Conservation Society; Estados UnidosFil: Herman, K.. Georgia Aquarium; Estados UnidosFil: Paesch, L.. Direccion Nacional de Recursos Acuaticos ; UruguayFil: Pompert, J.. No especifÃca;Fil: Velez Zuazo, X.. No especifÃca
Bathyraja macloviana, Patagonian Skate
The Patagonian Skate (Bathyraja macloviana) is a small (to 71 cm total length) skate that occurs in the Southeast Pacific Ocean off Magallanes, Chile and in the Southwest Atlantic Ocean from Uruguay to Tierra del Fuego, Argentina and the Falkland Islands (Malvinas) and is demersal on the inner continental shelf and upper slope at depths of 50?515 m. It is captured in demersal trawl fisheries targeting skates, finfish, and squid. Skates are typically not recorded or managed at the species level. For example, in Argentina, there are no species-specific data, but catch-per-unit-effort of rays, in general, declined in the 1990s and early 2000s. In the Falkland Islands (Malvinas) target skate fishery, this species increased in relative abundance in catch compared to other larger species, but there are no data on absolute changes in density or biomass from that area. Little is known about the Chilean portion of the population, but it is captured there and is typically discarded dead. Overall, due to the level of inadequately managed fishing pressure it is exposed to, declines in skates in general in some parts of its range, and its relatively small size that likely makes it productive enough to withstand some fishing pressure, it is suspected that this skate has undergone a population reduction of 20?29% over the past three generations (28.5 years). Therefore, the Patagonian Skate is assessed as Near Threatened, nearly meeting the threshold for Vulnerable A2bd.Fil: Pollom, R.. University Fraser Simon; CanadáFil: Dulvy, N. K.. University Fraser Simon; CanadáFil: Acuña, E.. Universidad Católica del Norte; ChileFil: Bustamante, C.. Universidad de Antofagasta; ChileFil: Chiaramonte, Gustavo Enrique. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia". Estación Hidrobiológica de Puerto Quequén (sede Quequén); ArgentinaFil: Cuevas, J.M.. No especifÃca;Fil: Herman, K.. Georgia Aquarium; Estados UnidosFil: Paesch, L.. No especifÃca;Fil: Pompert, J.. No especifÃca;Fil: Velez Zuazo, X.. Smithsonian Conservation Biology Institute; Estados Unido
Dinitrogen emissions: an overlooked key component of the N balance of montane grasslands
While emissions of nitric oxide (NO), ammonia (NH₃) and nitrous oxide (N₂O) from grassland soils have been increasingly well constrained, soil dinitrogen (N₂) emissions are poorly understood. However, N₂ losses might dominate total gaseous nitrogen (N) losses. Knowledge on N losses is key for the development of climate-adapted management that balances agronomic and environmental needs. Hence, we quantified all gaseous N losses from a montane grassland in Southern Germany both for ambient climatic conditions and for a climate change treatment (+ 2°C MAT, - 300 mm MAP). Monthly measurements of soil N₂ emissions of intact soil cores revealed that those exceeded by far soil N₂O emissions and averaged at 350 ± 101 (ambient climate) and 738 ± 197 lg N m¯²h¯¹ (climate change). Because these measurements did not allow to quantify emission peaks after fertilization, an additional laboratory experiment was deployed to quantify the response of NH₃, NO, N₂O, and N₂ emissions in sub daily temporal resolution to a typical slurry fertilization event (51 kg N ha¯¹). Our results revealed that total N gas losses amounted to roughly half of applied slurry-N. Surprisingly, N₂ but not NH₃ dominated fertilizer N losses, with N₂ emissions accounting for 16–21 kg or 31–42% of the applied slurry-N, while NH₃ volatilization (3.5 kg), N2O (0.2–0.5 kg) and NO losses (0–0.2 kg) were of minor importance. Though constraining annual N₂ loss remained uncertain due to high spatiotemporal variability of fluxes, we show that N₂ losses are a so far overlooked key component of the N balance in montane grasslands, which needs to be considered for developing improved grassland management strategies targeted at increasing N use efficiency
Bathyraja multispinis, Multispine Skate
The Multispine Skate (Bathyraja multispinis) is a medium-sized (to 126 cm total length) skate that occurs in the Southeast Pacific Ocean from Coquimbo, Chile to Cape Horn and in the Southwest Atlantic Ocean from Santa Catarina, Brazil to Tierra del Fuego and the Falkland Islands (Malvinas) and is demersal on the continental and insular shelves and slopes at depths of 70-740 m. It is captured in demersal trawl and longline fisheries that operate throughout its range and there is little refuge at depth; it is likely to be retained for sale for human consumption in the Southwest Atlantic, but is discarded dead in the Southeast Pacific. Across its range, skates are typically not recorded or managed at the species level, and there are no estimates of population size. In Argentina, there are no species-specific data, but rays in general declined in catch-per-unit-effort (CPUE) in the 1990s and early 2000s. In the Falkland Islands (Malvinas) target skate fishery, this species showed an either stable or increasing trend in CPUE over the time-series from 1994 to 2013. Overall, due to the level of inadequately managed fisheries it is exposed to, general declines of skates in some parts of its range, and its lack of refuge at depth, balanced with the increase in CPUE in the Falkland Islands (Malvinas), it is suspected that this skate has undergone a population reduction of 20-29% over the past three generations (45 years). Therefore, the Multispine Skate is assessed as Near Threatened, nearly meeting the threshold for Vulnerable A2bd.Fil: Pollom, R.. University Fraser Simon; CanadáFil: Dulvy, N. K.. University Fraser Simon; CanadáFil: Acuña, E.. Universidad Católica del Norte; ChileFil: Bustamante, C.. Universidad de Antofagasta; ChileFil: Charvet, P.. Universidade Federal do Paraná; BrasilFil: Chiaramonte, Gustavo Enrique. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia". Estación Hidrobiológica de Puerto Quequén (sede Quequén); ArgentinaFil: Cuevas, J. M.. Wildlife Conservation Society; Estados UnidosFil: Herman, K.. Georgia Aquarium; Estados UnidosFil: Paesch, L.. Dirección Nacional de Recursos Acuáticos; UruguayFil: Pompert, J.. No especifÃca;Fil: Velez Zuazo, X.. Smithsonian Conservation Biology Institute; Estados Unido
Dipturus trachydermus, Roughskin Skate
The Roughskin Skate (Dipturus trachydermus) is a large skate (to 265 cm total length) that occurs in the Southeast Pacific and Southwest Atlantic from Coquimbo, Chile (31°S), south around Cape Horn and north to RÃo de la Plata, Uruguay, including the Falkland Islands (Malvinas). It is demersal on the outer continental shelf and upper slope at depths of 85–480 m, but is most commonly found at 200–350 m in Chile and shallower (80–150 m) in Argentina. It is captured in industrial trawl fisheries for hake (Merluccius spp.), and artisanal bottom longline fisheries that encompass nearly the entire geographic and depth range of this species in Chile and Argentina. In Chile, it was a secondary catch of the target skate fishery which ramped up in 1993 as a direct result of the arrival of Korean skate traders who provided a market that incentivised fishers to target and retain this species for international trade.Fil: Dulvy, N. K.. University Fraser Simon; CanadáFil: Acuña, E.. Universidad Católica del Norte; ChileFil: Bustamante, C.. Universidad de Antofagasta; ChileFil: Chiaramonte, Gustavo Enrique. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia". Estación Hidrobiológica de Puerto Quequén (sede Quequén); ArgentinaFil: Concha, F.. Universidad de ValparaÃso; ChileFil: Cuevas, J. M.. Wildlife Conservation Society; Estados UnidosFil: Herman, K.. Georgia Aquarium; Estados UnidosFil: Paesch, L.. Dirección Nacional de Recursos Acuáticos; UruguayFil: Pompert, J.. No especifÃca;Fil: Rincon, G.. Universidade Federal Do Maranhao.; BrasilFil: Velez Zuazo, X.. Smithsonian Conservation Biology Institute; Estados Unido
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