Evidence of large increases in sedimentation rates due to fish trawling in submarine canyons of the Gulf of Palermo (SW Mediterranean)

Sarah Paradis; Claudio Lo Iacono; Pere Masqué; Pere Puig; Albert Palanques; Tommaso Russo; ISLAND Cruise team

doi:10.1016/j.marpolbul.2021.112861

Evidence of large increases in sedimentation rates due to fish trawling in submarine canyons of the Gulf of Palermo (SW Mediterranean)

Mar Pollut Bull. 2021 Nov:172:112861. doi: 10.1016/j.marpolbul.2021.112861. Epub 2021 Sep 4.

Authors

Sarah Paradis¹, Claudio Lo Iacono², Pere Masqué³, Pere Puig², Albert Palanques², Tommaso Russo⁴; ISLAND Cruise team

Affiliations

¹ Institute of Environmental Science and Technology (ICTA) and Physics Department, Universitat Autònoma de Barcelona, Bellaterra 08193, Spain; Geological Institute, Department of Earth Sciences, ETH Zürich, 8092 Zürich, Switzerland. Electronic address: sparadis@ethz.ch.
² Marine Sciences Institute, Consejo Superior de Investigaciones Científicas, Barcelona 08003, Spain.
³ Institute of Environmental Science and Technology (ICTA) and Physics Department, Universitat Autònoma de Barcelona, Bellaterra 08193, Spain; School of Natural Sciences, Centre for Marine Ecosystems Research, Edith Cowan University, Joondalup, WA 6027, Australia; International Atomic Energy Agency, 4a Quai Antoine 1er, 98000 Principality of Monaco, Monaco.
⁴ Laboratory of Experimental Ecology and Aquaculture, Department of Biology, University of Rome Tor Vergata, Rome 00133, Italy.

PMID: 34523427
DOI: 10.1016/j.marpolbul.2021.112861

Abstract

Bottom trawling in submarine canyons can affect their natural sedimentation rates, but studies addressing this issue are still scarce. In the Gulf of Palermo (SW Mediterranean), bottom trawling occurs on the slope around Oreto, Arenella and Eleuterio canyons. Analyses of excess ²¹⁰Pb concentrations and grain size fractions in sediment cores from their canyon axes revealed that sedimentation rates and silt contents increased in all canyons in the 1980s, due to the expansion of more powerful trawlers (>500 HP) to deeper fishing grounds. In Eleuterio and Arenella canyons, sedimentation rates increased by an order of magnitude (0.1-1.4 cm·yr^-1), whereas they increased less (0.1-0.7 cm·yr^-1) in Oreto Canyon, since the enhanced trawling-derived sediment fluxes into this canyon are affected by sediment resuspension from trawling along its axis. Considering the global expansion of bottom trawling, we anticipate similar alterations in other trawled canyons, with ecological consequences that should be addressed by management strategies.

Keywords: Bottom trawling; Mediterranean; NW Sicily; Pb-210; Sedimentation rates; Submarine canyons.

MeSH terms

Animals
Ecosystem*
Ships*