Damaged Seamounts in Hawaii Are Recovering After Years of Protection

A major underwater mountain chain in and around the Hawaiian Islands is slowly making a comeback from the damaging effects of trawling, thanks to decades of federal protection, according to a new study.

The Hawaiian-Emperor Seamount Chain, a mostly undersea mountain range that stretches 3,600 miles across the Pacific Ocean, was subjected to trawl fisheries from the 1960s to the 1980s that caused extensive damage to deep-sea corals and other marine life. The trawling was substantially reduced in 1977 when the U.S. claimed the seamount as part of its Exclusive Economic Zone. In 2006, President George W. Bush further protected the seamount when he included it as part of the Papahanaumokuakea Marine National Monument.

In an effort to assess whether the protection of the seamount had helped revive damaged deep-sea corals, researchers from Florida State University and Texas A & M University used manned and unmanned underwater vehicles to photograph the seamount roughly 1,000 feet to 2,300 feet below the surface. Analyzing 536,000 images, they discovered that baby corals were springing up in damaged areas and that coral was even regrowing on fragments of trawling nets left on the seafloor. They also found areas of deep-sea corals that had not been damaged by trawling, creating remnant refuges that will help repopulate other areas in the seamount.

“This is a good story of how long-term protection allows for recovery of vulnerable species,” said one of the researchers, Florida State oceanographer Amy Baco-Taylor.

Co-author Brendan Roark of Texas A & M said the findings, published in the journal Science Advances, should be considered by Trump administration officials as they contemplate opening up some marine monuments to fishing.