LONG TERM ICE EXPOSURE STUDIES FOR ENHANCING ARCTIC NEBA SCIENCE BASE

Abstract

ABSTRACT #2017-097 The Arctic Oil Spill Response Technology - Joint Industry Programme has the goal to advance arctic oil spill response strategies and equipment as well as to increase understanding of potential impacts of oil on the Arctic marine environment. In 2013 a comprehensive review of investigations into environmental consequences of spilled oil and oil spill response technologies in the Arctic marine environment was performed by a multi-disciplinary team of experts. This review indicated that there is a significant science base for oil spill response decision-making in the Arctic already available and also listed recommendations for studies to enhance the science-base for Arctic Net Environmental Benefit Analysis (NEBA). To follow up on the reviews’ recommendations a unique long-term mesocosm experiment was executed to improve the scientific knowledge of the fate and biodegradation of oil and oil spill response residues in ice, as well as the environmental effects to ice associated ecology. Eight mesocosms were installed in the sea ice of the Van Mijenfjorden in Svea, Svalbard, Norway in February 2015 and remained in place until July 2015. The study was designed to monitor the long term fate, behaviour, persistence and biodegradation of the oil in ice together with the impact on the microbial communities, following different response scenarios. Additionally, under-ice phyto- and zooplankton communities were sampled and monitored for effects. The same exposures were replicated in the laboratory to measure the sensitivity and resilience of the polar cod. Over the five month period that the mesocosm experiment lasted, the following parameters were studied within the water column, through the ice layer and within the water-ice interface:Chemical composition of the oilBacterial populations and oil degrading microorganismsMicrobial activity and biodegradation activityZooplankton - survival, feeding and reproduction (under ice)Ice algae primary production Results from the studies and additional modelling activities have improved our understanding of what happens to oil once frozen into ice, how microbiology is reacting to oil in ice and what the exposure potential is of the ecology associated with the ice. This information enhances the NEBA science base and helps the response community in selecting a combination of response strategies that minimises the effects to people and the environment.