Spread of oil from theTenyo Maru,off the Southwest coast of Vancouver Island

We provide background oceanography and observations and hindcast simulations of spreading oil leaked from the wreck of theTenyo Maru, a fishing vessel that sank off the western entrance to Juan de Fuca Strait in July 1991. The vessel sank in the region of the Tully Eddy on the continental shelf. Although this eddy is normally present in summer, its location shifts and its trapping time varies considerably. The spread of theTenyo Maru oil is represented reasonably well by assuming the eddy to be a littler further to the east and north of its position as observed during drifter studies in 1986. Observations in 1985 showed that the preferred exit route of surface water from the eddy was toward the southeast, the direction followed by theTenyo Maru oil in 1991; however, other drift paths are possible, and under different weather conditions the oil could have drifted toward the Vancouver Island coast.