The oil slick from the BP oil spill in the Gulf of Mexico has begun to reach the shores of several islands off the Louisiana coast. Dead jellyfish are washing up on the Chandeleur Islands, while birds have been seen diving in the contaminated waters. Advocates say fish and wildlife could be threatened by chemicals released in BP’s cleanup effort. Larry Schweiger of the National Wildlife Federation said dispersion poured into the waters could produce unknown effects.

Larry Schweiger: “We just want to make clear that just because we cannot see the oil spill does not mean it’s not having an enormous impact on wildlife. It’s having a different kind of impact, and it’s still yet not understood, because this dispersant has been put in at a level, a mile down in some cases, that’s never been done before. So we don’t know what the long-term impact or fate of those chemicals may be over time with the currents in this system.”

BP, meanwhile, continues to put in place a massive containment box to try to stop the over 200,000 gallons of oil leaking from an underwater oil well every day. BP says it won’t know until Sunday whether the effort will succeed.