All but one of the five points I wrote about the Dalco Passage oil spill also applies to the Unalaska spill now unfolding in the Aleutians. (Granted, the site of the spill is not in Cascadia, but the ship was carrying a cargo—and presumably fuel oil—from the Port of Tacoma. So it’s our spill, too.)
I’ll add a sixth point.
6. Catastrophic spills—ship on the rocks, black ooze in the water, dying birds on the beach—capture the TV cameras and headlines. But most of the oil we spill runs off the land, from roads, parking lots, and industrial sites.
In 2003, the National Research Council did an assessment of oil spills over recent years. Human-released oil reaching marine waters around North America has been 56 percent run off from land, the drips from our vehicles and machinery. Spills from big ships, whether tankers or freighters, has been around 10 percent. (A nice summary of the NRC report, which Google cannot find online, is Michael P. Vandenbergh, "From Smokestack to SUV: The Individual as Regulated Entity in the New Era of Environmental Law," Vanderbilt Law Review, 57:2, March 2004.)
The ecological impacts of chronic low-level exposure to petroleum are little understood, unlike the well-studied effects of bathing small patches of ocean and shore with oil. But lacing marine food chains with substances that are known poisons at high concentrations, such as polycyclic aromatic hydrocarbons (PAHs), sure seems like a bad idea to me. It’s another example of ignoring the precautionary principle.