Bottom trawling resuspends sediment and releases bioavailable contaminants in a polluted fjord

Abstract

Sediments are sinks for contaminants in the world's oceans. At the same time, commercial bottom trawling is estimated to affect around 15 million km(2) of the world's seafloor every year. However, few studies have investigated whether this disturbance remobilises sediment-associated contaminants and, if so, whether these are bioavailable to aquatic organisms. This field study in a trawled contaminated Norwegian fjord showed that a single 1.8 km long trawl pass created a 3-5 million m(3) sediment plume containing around 9 t contaminated sediment; ie. 200 g dw m(-2) trawled, equivalent to c. 10% of the annual gross sedimentation rate. Substantial amounts of PCDD/Fs and non-ortho PCBs were released from the sediments, likely causing a semi-permanent contaminated sediment suspension in the bottom waters. PCDD/Fs from the sediments were also taken up by mussels which, during one month, accumulated them to levels above the EU maximum advised concentration for human consumption. (c) 2012 Elsevier Ltd. All rights reserved.

Keywords

Sediment resuspension; Bottom trawling; Contaminant; Bioavailability; Blue mussel; SPMD

Published in

Environmental Pollution
2012, volume: 170, pages: 232-241
Publisher: ELSEVIER SCI LTD

SLU Authors

• Sköld, Mattias

  • Department of Aquatic Resources (SLU Aqua), Swedish University of Agricultural Sciences
    

• Nilsson, Hans

  • Department of Aquatic Resources (SLU Aqua), Swedish University of Agricultural Sciences
    

Global goals (SDG)

SDG3 Good health and well-being
SDG6 Clean water and sanitation
SDG14 Life below water

UKÄ Subject classification

Oceanography, Hydrology, Water Resources

Publication identifier

• DOI: https://doi.org/10.1016/j.envpol.2012.06.019

Permanent link to this page (URI)

https://res.slu.se/id/publ/42571