Aggressive seaweed smothers one of world's most remote reefs

In this Aug. 4, 2019 photo provided by Taylor Williams, a new species of seaweed covers dead a coral reef at Pearl and Hermes Atoll in the remote Northwestern Hawaiian Islands. 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. The algae easily breaks off and rolls across the ocean floor like tumbleweed, scientists say, covering nearby reefs in thick vegetation that out-competes coral for space, sunlight and nutrients. (Taylor Williams/College of Charleston via AP)