Bottom-trawling along submarine canyons impacts deep sedimentary regimes

Sarah Paradis, Pere Puig, Pere Masque Barri, Xenia Juan-Diaz, Jacobo Martin, Albert Palanques

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

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. preindustrialization) values after a substantial increase in total horsepower of the operating trawling fleets between 1960 s and 1970 s. 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 20(th) 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.

Original languageEnglish
Article number43332
Number of pages11
JournalScientific Reports
Volume7
DOIs
Publication statusPublished - 24 Feb 2017

Cite this

Paradis, S., Puig, P., Masque Barri, P., Juan-Diaz, X., Martin, J., & Palanques, A. (2017). Bottom-trawling along submarine canyons impacts deep sedimentary regimes. Scientific Reports, 7, [43332]. https://doi.org/10.1038/srep43332