Presentation Information
[U08-06]Ocean acidification may increase the biological impact of legacy metal pollution, a case study from mine waste deposits in Arctic Norway.
*Sam Rastrick1, Helen Rastrick1, Weiwei Jiang2, James Brown, Terje van der Meeren van der Meeren1, Zengjie Jiang2, Michael Bank Bank1 (1.The Institute of Marine Research, Norway, 2.Yellow sea fisheries research institute)
Keywords:
Ocean acidification,mine waste,metal pollution,arctic
Historically Norway has used fjords for the disposal of waste including mine-tailings, fine grained waste material produced by mining activity which is often contaminated with toxic metals. At present advice to regulators regarding the possible legacy effects of proposed, present, and historic mine-tailing deposits in Norwegian fjords is based on current environmental conditions. However, little is known about how metals associated with these mine tailings will interact with climate change and ocean acidification and subsequent effects on costal fisheries and aquaculture. Recent studies of commercial bivalve species (Arctica islandica, Venerupis corrugate) show that elevated pCO2 leads to adjustments in coelomic acid-base balance, with increased bicarbonate concentrations buffering pH in response to elevated pCO2. However, this bicarbonate compensation is not observed in bivalve’s exposed to mine tailings resulting in significant acidosis, increased metabolic costs, and mortality. To further investigate the mechanisms and breakpoints behind these physiological responses A. islandica, and V. corrugate were exposed for 5 weeks to sediments collected from historic mine-tailing deposits (Repparfjorden, Norway) in combination with 5 different pH/pCO2 treatments (pH 7.4 to 8.2). When exposed to mine-tailings the activity of gill enzymes (Na+/K+-ATPase) involved in ion-regulation and critical for bicarbonate up-take was reduced. Combined with effects on energetics and electron transport chain activity, and the increased bioavailability of metals under more acidic conditions, metal contamination may further exacerbate the negative effects of climate change. The findings from our investigation highlight the regulatory importance of considering future environmental conditions when assessing the possible legacy effects of proposed, present, and historic mining activities.