OCS Study BOEM 2017-087. U.S. Department of the Interior, Bureau of Ocean Energy Management (BOEM), Alaska Outer Continental Shelf Region, and the University of Alaska Fairbanks. 72 pp.
OCS Study BOEM 2017-087. U.S. Department of the Interior, Bureau of Ocean Energy Management (BOEM), Alaska Outer Continental Shelf Region, and the University of Alaska Fairbanks. 72 pp.
The Arctic marine environment is facing increasing risks of oil spills due to growing maritime activities such as tourism and resource exploration. Entrainment and migration of oil through the sea ice brine channel system may pose a considerable risk to the biota that rely on the ice for food and shelter. These ice-associated biological communities are the base of an Arctic food chain that supports a hugely productive community of polar bears, birds, walruses, whales, and ultimately humans. To investigate the possible impacts of oil, we designed mesocosms allowing for the careful growth of artificial sea ice that would be reflective of natural sea ice. These mesocosms were inoculated with biological cultures collected from landfast sea ice near Utqiagvik (formerly Barrow), AK. Once environmentally-similar ice conditions were established in the tanks, we evaluated the impact of Alaska North Slope crude oil on transplanted sea ice biota using two different oiling scenarios: discrete oil lenses and dispersed emulsions. We found that North Slope crude oil penetrated farther into overlying sea ice than observed in previous experiments (NORCOR, 1975, Glaeser and Vance, 1972, Dickens 2011). We also found that the presence of oil resulted in notable negative impacts on the biological community, with complete inhibition of ice algal growth. These findings suggest that an oil spill in ice-covered waters could have substantial and lasting negative impacts on the microorganisms at the base of this critical Arctic food chain.