Environmental Impact of Submarine Rock Blasting and Dredging Operations in an Arctic Harbor Area: Dispersal and Bioavailability of Sediment-Associated Heavy Metals Lis Bach & Morten Holtegaard Nielsen & Sandra M. Bollwerk Received: 20 November 2016 /Accepted: 3 April 2017 # Springer International Publishing Switzerland 2017 Abstract In order to determine the possible impact on the marine environment, we present a study on the dispersal and bioavailability of sediment-associated heavy metals related to underwater blasting and dredg- ing of bedrock operations during a quay construction. The environmental impact was primarily assessed by deploying a buoy setup including sediment traps, blue mussels, and passive samplers (diffusive gradient in thin films, DGTs) in a gradient from the construction site during the operations. Samplings were made during five separate periods covering a total span of about 2.5 months. Analyses included sedimentation rates, or- ganic content, and metal concentrations of the material collected in the sediment traps and metal concentrations of the mussels and passive samplers. The construction work was associated with a considerable dispersion of sediments, organic material, and associated heavy metals. The major fraction of the sediment settled in the vicinity of the construction site. While the mussels were found to accumulate some metals in a distance- related manner to the construction site and no such accumulation in the DGTs occurred, we conclude that most of the dispersed metals were particle associated. It was found that while a large part of the material settled in the vicinity of the construction site, most of the fine- grained and/or organic sediment that was brought into suspension was transported further away from the con- struction site (beyond the 350 m) most likely carrying contaminants including heavy metals. For future studies of risks and monitoring of underwater blasting and dredging, we recommend to include a larger monitoring area and more importantly water samples of the suspended plumes. Keywords Underwater blasting and dredging . Heavy metals remobilization . Bioavailability . Arctic . Environmental monitoring 1 Introduction The environment in remote, sparsely populated areas such as the Arctic is generally considered highly pris- tine, but seafloor sediments in fjords and coastal areas close to populated and/or industrial areas may be highly impacted by contaminants, i.e., heavy metals, PAHs, PCBs, TBTs, etc. (Søndergaard et al., 2011; Bach et al., 2009; AMAP, 2005). The contaminants do not necessarily remain at the seafloor but may become remobilized to the water column by biological, geo- chemical, and/or physical processes. Such mobilization Water Air Soil Pollut (2017) 228:198 DOI 10.1007/s11270-017-3363-z L. Bach and M. H. Nielsen share first authorship. L. Bach (*) Arctic Research Centre, Department of Bioscience, Aarhus University, Frederiksborgvej 399, DK-4000 Roskilde, Denmark e-mail: lb@bios.au.dk M. H. Nielsen Marine Science & Consulting, Peder Lykkes Vej 8, 4 th, DK-2300 Copenhagen, Denmark S. M. Bollwerk GEO-mare, Peder Lykkes Vej 8, 4 th, DK-2300 Copenhagen, Denmark