Researchers say the recently discovered species of seaweed is killing large patches of coral on once-pristine reefs and is rapidly spreading across one of the most remote and protected ocean environments on earth. A study from the University of Hawaii and others says the seaweed is spreading more rapidly than anything they've seen in the Northwestern Hawaiian Islands, a nature reserve that stretches more than 1,300 miles north of the main Hawaiian Islands. A study from the University of Hawaii and others says the seaweed is spreading more rapidly than anything they've seen in the Northwestern Hawaiian Islands, a nature reserve that stretches more than 1,300 miles north of the main Hawaiian Islands. Scientists say seaweed blooms happen worldwide and can be seasonal, but this does not appear to be the case. "If something like this got back to Waikiki or anywhere in the main Hawaiian Islands it would be an ecological disaster, but also an economic disaster," Kosaki said.