SENSITIVITY, EXPOSURE, AND VULNERABILITY TO PETROLEUM POLLUTION, GJOA HAVEN COASTLINE, NU Norm Catto (ncatto@mun.ca) and Stephanie Papadimitriou (steph_papa@yahoo.ca)

A Contribution to ArcticNet Project 1.2

Memorial University, St. John’s NL A1B 3X9 Canada

Gjoa Haven lies along the Northwest Passage. With ongoing reductions in ice cover, interest in the use of the Northwest Passage as a transportation route is growing. The visit of a small cruise ship in summer 2006 also indicates that the potential exposure to petroleum contamination from marine vessels is increasing. The cultural and socio-economic significance of coastal activity, coupled with the potential for increased traffic and tourism, indicate that the potential impact of petroleum contamination is significant.

Study of sand and gravel beaches showed differences in morphology, sedimentology, energy regime, and sediment transport. These characteristics change the fate and effect of petroleum contamination on each beach. Beaches have been ranked on their sensitivity to oil pollution based on their physical characteristics.

The Gjoa Haven beaches are sand and gravel dominated. However, most of the sediment represents relict deposition and reworked glaciomarine deposits, rather than reflecting the present coastal dynamics. Present wave activity is generally insufficient to move clasts.

The movement of sediment and marine detritus in the nearshore and beach environments provides analogies for how oil will behave. Lower energy beaches will not self-clean as well as high energy reflective beaches, and are more sensitive to pollution. Although the beaches in the Gjoa Haven area are composed of sand and gravel, they are effectively low energy dissipative systems, and would not effectively self-clean. This increases the sensitivity of the coast to petroleum contamination.

Petroleum contamination potentially can come from both offshore and terrestrial sources. The degree of exposure to potential petroleum contamination from both offshore and terrestrial sources forms a basis for assessment of the risk of contamination on each beach. At Gjoa Haven, only the interior harbour is exposed to potential contamination from terrestrial sources. The entire coastline could be affected by an offshore event.

Consideration of the risk of contamination from all sources, in combination with sensitivity analysis, will allow a vulnerability assessment. Compilation is in progress. The vulnerability assessment can be used as a basis for planning and allocation of resources, to cope with petroleum pollution and to promote an effective response to a potential major event.

Gjoa Haven, looking west across the harbour. The shallow, restricted harbour could be readily isolated from an offshore oil spill, if suitable equipment was available. A spill within the harbour would present significant difficulties in clean-up.

Low energy, dissipative beach system dominated by shore parallel transport, western shoreline. This beach system would be exposed to offshore petroleum contamination resulting from offshore traffic.

Gravel-dominated system, southeast of Gjoa Haven harbour. The clasts were deposited by glaciomarine processes. All clasts larger than coarse pebbles are not mobilized by wave action.

Coarse clasts are immobile under wave action but are moved by seasonal ice shove.

Seasonal ice shove influences substrate configuration and texture, which in turn affects sensitivity to petroleum contamination.

Low energy sandy beaches with organic detritus are particularly vulnerable.