The Seattle Post Intelligencer, which is devoting more resources to the oil spill than the region’s other news outlets, has two especially backgrounders today.

The first is on the ecological impacts of oil in the marine environment. The crux ‘graph:

The most detrimental consequences, according to Randy Shuman, a scientist with the King County Department of Natural Resources and Parks, may be less obvious.

“The oil’s already sinking into the beach, and it’s going to be here for years, causing long-term, slow effects to the ecosystem,” he said. “It’s like the difference between getting hit by a bus and dying from secondhand smoke.”

The second describes the impacts of tribal shellfish operations.