Greenpeace hosts Dr. Jose Lopez and Dr. Charles Messing from Nova Southeastern University's Oceanographic Center aboard the Arctic Sunrise as they study the diversity of sponges in the reefs of the Dry Tortugas and their potential as bio-indicators of reef health. "Its possible that the oil from the BP spill may have been so effectively submerged and 'miniaturized' that resident bottom organisms, such as sponges, can best detect the oil or dispersants at the molecular level", said Dr. Jose Lopez.