info:eu-repo/semantics/article
Bottom-trawling along submarine canyons impacts deep sedimentary regimes
Fecha
2017-02-24Registro en:
Paradis, Sarah; Puig, Pere; Masqué, Pere; Juan Diáz, Xènia; Martín de Nascimento, Jacobo; et al.; Bottom-trawling along submarine canyons impacts deep sedimentary regimes; Nature Publishing Group; Scientific Reports; 7; 24-2-2017; 1-12
2045-2322
CONICET Digital
CONICET
Autor
Paradis, Sarah
Puig, Pere
Masqué, Pere
Juan Diáz, Xènia
Martín de Nascimento, Jacobo
Palanques, Albert
Resumen
Many studies highlight that fish trawling activities cause seafloor erosion, but the assessment of the remobilization of surface sediments and its relocation is still not well documented. These impacts were examined along the flanks and axes of three headless submarine canyons incised on the Barcelona continental margin, where trawling fleets have been operating for decades. Trawled grounds along canyon flanks presented eroded and highly reworked surface sediments resulting from the passage of heavy trawling gear. Sedimentation rates on the upper canyon axes tripled and quadrupled its natural (i.e. pre-industrialization) values after a substantial increase in total horsepower of the operating trawling fleets between 1960s and 1970s. These impacts affected the upper canyon reaches next to fishing grounds, where sediment resuspended by trawling can be transported towards the canyon axes. This study highlights that bottom trawling has the capacity to alter natural sedimentary environments by promoting sediment-starved canyon flanks, and by enhancing sedimentation rates along the contiguous axes, independently of canyons´ morphology. Considering the global mechanisation and offshore expansion of bottom trawling fisheries since the mid-20th century, these sedimentary alterations may occur in many trawled canyons worldwide, with further ecological impacts on the trophic status of these non-resilient benthic communities.