Related Experiment Video
Updated: May 20, 2026

A Flow-through Exposure System for Evaluating Suspended Sediments Effects on Aquatic Life
Published on: January 9, 2017
Bottom trawling resuspends sediment and releases bioavailable contaminants in a polluted fjord
C Bradshaw1, I Tjensvoll, M Sköld
1Department of Systems Ecology, Stockholm University, S-10691 Stockholm, Sweden. clare@ecology.su.se
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.
Related Concept Videos
Freshwater Microbial Ecology
Marine Microbial Ecology
Microbial Bioremediation of Hydrocarbons
Bioremediation
Primary Production
