Biology and conservation of elasmobranchs: an introduction to the collection

Elasmobranchs, the taxonomic group comprising sharks, skates and rays, play important roles in society and marine ecology but several species in this subclass are under threat. This collection aims to be an open access hub for articles concerning all areas of elasmobranch biology and conservation. The collection is indefinitely open to further submissions and so will continue to grow as additional articles are added

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 Científicas 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; Países BajosFil: Velez Zuazo, X.. Smithsonian Conservation Biology Institute; Estados Unido

The role of marine reserves in achieving sustainable fisheries (One contribution of 15 to a Theme Issue 'Fisheries: a Future?')

Many fishery management tools currently in use have conservation value. They are designed to maintain stocks of commercially important species above target levels. However, their limitations are evident from continuing declines in fish stocks throughout the world. We make the case that to reverse fishery declines, safeguard marine life and sustain ecosystem processes, extensive marine reserves that are off limits to fishing must become part of the management strategy. Marine reserves should be incorporated into modern fishery management because they can achieve many things that conventional tools cannot. Only complete and permanent protection from fishing can protect the most sensitive habitats and vulnerable species. Only reserves will allow the development of natural, extended age structures of target species, maintain their genetic variability and prevent deleterious evolutionary change from the effects of fishing. Species with natural age structures will sustain higher rates of reproduction and will be more resilient to environmental variability. Higher stock levels maintained by reserves will provide insurance against management failure, including risk-prone quota setting, provided the broader conservation role of reserves is firmly established and legislatively protected. Fishery management measures outside protected areas are necessary to complement the protection offered by marine reserves, but cannot substitute for it

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 Matías 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 Científicas 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; Países BajosFil: Velez Zuazo, X.. Smithsonian Conservation Biology Institute; Estados Unido

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 Científicas 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 especifíca;Fil: Velez Zuazo, X.. No especifíca

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 Científicas 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 especifíca;Fil: Herman, K.. Georgia Aquarium; Estados UnidosFil: Paesch, L.. No especifíca;Fil: Pompert, J.. No especifíca;Fil: 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 Científicas 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 especifíca;Fil: Velez Zuazo, X.. No especifíca

Squalus acanthias, spiny dogfish

While there are reported subpopulations of Squalus acanthias (Linnaeus, 1758) elsewhere in the world, the North Pacific subpopulation is now considered a separate species, Squalus suckleyi (Girard, 1854) (see Ebert et al. 2010). Further taxonomic studies on this genus are required, including in relation to Mediterranean and Black Sea subpopulations. In Europe, three subpopulations are inferred to occur.Fil: Finucci, B.. National Institute of Water and Atmospheric Research; Nueva ZelandaFil: Cheok, J.. University Fraser Simon; CanadáFil: Chiaramonte, Gustavo Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia". Estación Hidrobiológica de Puerto Quequén (sede Quequén); ArgentinaFil: Cotton, C. F.. Florida State University; Estados UnidosFil: Dulvy, N. K.. University Fraser Simon; CanadáFil: Kulka, D. W.. No especifíca; ArgentinaFil: Neat, F. C.. No especifíca; ArgentinaFil: Pacoureau, N.. University Fraser Simon; CanadáFil: Rigby, C. L.. James Cook University; AustraliaFil: Tanaka, S.. No especifíca; ArgentinaFil: Walker, T. I.. University of Melbourne; Australi

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 Científicas 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 especifíca;Fil: Velez Zuazo, X.. No especifíca

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 Científicas 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 especifíca;Fil: Velez Zuazo, X.. Smithsonian Conservation Biology Institute; Estados Unido