Multi-isotopic composition of brown crab (Cancer pagurus) and seafloor sediment from a mine tailing sea disposal impacted fjord ecosystem.

Sea disposal of mine tailings in fjord ecosystems is an important coastal management issue in Norway and occurs at the land-sea interface. Here we studied accumulation of heavy metals in brown crab (Cancer pagurus) and seafloor sediment from Jøssingfjord, Norway during 2018 to evaluate long-term, legacy pollution effects of coastal mine tailing sea disposal activities. Nickel and copper sediment pollution in the mine tailing sea disposal area was classified as moderate and severe, respectively, under Norwegian environmental quality standards, and highlights the persistent hazard and legacy impacts of heavy metals in these impacted fjord ecosystems. Mercury, zinc, and arsenic had stronger affinities to brown crab muscle likely due to the presence of thiols, and availability of metal binding sites. Our multi-isotopic composition data showed that lead isotopes were the most useful source apportionment tool for this fjord. Overall, our study highlights the importance and value of measuring several different heavy metals and multiple isotopic signatures in different crab organs and seafloor sediment to comprehensively evaluate fjord pollution and kinetic uptake dynamics. Brown crabs were suitable eco-indicators of benthic ecosystem heavy metal pollution in a fjord ecosystem still experiencing short- and long-term physical and chemical impacts from coastal mining sea disposal activities.