The cause for the spill is still unclear. What's known is the type of oil that was piped: tar sands oil, also called diluted bitumen. It's a lot harder to clean up than conventional oil.
This year, Chima Williams of Nigeria was a winner of the Goldman Environmental Prize for his activism, targeting Shell for an oil spill in his homeland. Here's how the case went.
Because of waves from Saturday's eruption, an estimated 6,000 barrels of oil were spilled near Peru's main refinery on the coast in an area rich in marine biodiversity.
