Dipturus trachydermus

DULVY, N.K.; ACUÑA, E.; BUSTAMANTE, C.; CHIARAMONTE, GUSTAVO ENRIQUE; CONCHA, F.; CUEVAS, J.M.; HERMAN, K.; PAESCH, L.; POMPERT, J.; RINCON, G.; VELEZ-ZUAZO, X.

The IUCN Red List of Threatened Species

IUCN

Año: 2020

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 Río 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. Despite quota management since 1997, the fishery peaked in around 2003 and landings started to decline until the target fisheries were closed in 2016. There may be some refuge for the species in the extensive coastline of southern Chile which consists of many fjords and canals where fishing activities are not operating at present. The current skate fishery in Chile is considered to be ?fully exploited? and the high percentage of juveniles present in catches and the decreasing trend of the catch size are symptoms of a fishing collapse. The stock assessment of the target Yellownose Skate (Dipturus chilensis) indicated a reduction of 73.1% over three generation lengths for that species (52.5 years), with the highest probability (95%) of 50?79% reduction over three generation lengths. In Argentina, reported landings of skates in general increased from 900 t in 1993 to a peak of 28,000 t in 2007, due to export demand from Korea. Whole small specimens and wings of larger Roughskin Skate are landed, frozen, and traded to Korea for the ?Hongeo? market. There is no local consumption. Overall, this skate is subject to intense and inadequately managed fishing pressure throughout most of its range, there is little refuge at depth, it has limiting life history characteristics, and other similar species in the region have exhibited substantial population reductions. As a result, it is suspected that the Roughskin Skate has undergone a population reduction of 50?79% over the past three generations (64.5 years), and it is assessed as Endangered A2bd.