Should an oil spill take place in the Arctic, polar bears and marine birds would suffer the most

Climate change alone is subjecting Arctic nature to great pressure, which could make an oil spill occurring in this unique and sensitive region result in an environmental disaster. According to a study carried out at the University of Helsinki, polar bears and marine birds are at the greatest risk in a potential oil spill, but the risk varies significantly depending on the timing of any spills and the characteristics of the oil spilled.

Arctic oil spills are a global concern. As climate change is extending the duration of the ice-free period in the north, marine traffic is unavoidably increasing. For now, no large oil spills have occurred in the region, but as their probability grows due to increasing marine traffic, preparations for the consequences should be made. 

“Understanding the consequences of an oil spill can benefit the conservation of Arctic nature when the temporally and spatially varying risk of oil spills can be taken into account when planning shipping routes,” says Maisa Nevalainen, a doctoral candidate from the Faculty of Biological and Environmental Sciences, University of Helsinki. 

What this requires, however, is comprehensive knowledge about the effects an oil spill would have on the Arctic ecosystem. For the time being, such knowledge is fragmented and insufficient for carrying out comprehensive risk analyses. 

Nevalainen’s doctoral dissertation demonstrates that polar bears and marine birds are at the greatest risk should an oil spill occur, but the risk varies significantly depending on the timing of a spill and the characteristics of the oil spilled. In addition, the amount of ice in the spill site impacts the risk posed to the Arctic biota, as it has an effect on both oil spillage and species distribution. In relation to shipping routes, the latter has a particular bearing on how large parts of populations would potentially be exposed to oil. 

On an acute scale, the worst type of disaster appears to be a spill of medium density oil at a time when ice coverage is relatively low. However, it may be difficult to determine the safest shipping routes, as different routes and accident scenarios present varying risks to different species. Nevalainen’s findings allow the comparison of temporally and spatially varying risks for marine mammals in the Kara Sea, chosen as the case study area.

Uncertanties should be researched to improve risk management and help decision-making

Nevalainen’s research provides new information on the risks caused by oil spills to the Arctic biota, serving as a step towards a comprehensive understanding of the environmental effects of oil spills. Many uncertainties remain associated with the topic, and Nevalainen both identifies sources of such uncertainty and proposes a range of measures aimed at enhancing the acquisition of data and improving risk management. Furthermore, she acknowledges the need for a valuing method to help decision-makers compare and make value judgments on the risk posed to various species, as well as make justified decisions under uncertain conditions.

“In the future, further information will be needed particularly on the long-term environmental effects of oil and its persistence in cold environments,” Nevalainen states. 

Doctoral dissertation:

Maisa Nevalainen, MSc, will defend her doctoral dissertation entitled Preparing for the unprecedented Moving towards quantitative understanding of oil spill impacts on Arctic marine biotain the Faculty of Biological and Environmental Sciences on 24 May 2019 at 12.00. The public defence will take place at Biocenter 2, room 1041, Viikinkaari 5. Associate Professor Ullrika Sahlin from Lund University will serve as the opponent and Professor Sakari Kuikka as the custos.The dissertation will be published in the series Dissertationes Schola Doctoralis Scientiae Circumiectalis, Alimentariae, Biologicae. The dissertation is also available in electronic form through the E-thesis service.