What to do with derelict offshore oil rigs?

Via the Long Beach Press-Telegram: The disposition of derelict offshore oil rigs is a challenging issue. While one's initial reaction might be to remove them and dispose of the steel on land, scientists at Cal State Long Beach are saying that parts of these rigs have become vital habitat and should be left in place.
Fish Co-opt Oil Rigs despite state rule saying these 'artificial reefs' can't be permanent.