Scientists believe higher-than-normal ocean temperatures in the waters around Hawaii could lead to the worst case of coral bleaching the islands have ever seen.

Many corals in the Hawaii region are still recovering from bleaching events that occurred last year, and their prospects do not look good for the coming season, the University of Hawaii at Manoa reported. Coral bleaching causes coral to expel the algae that acts as their primary food source, leading to a distinct white coloring. Bleaching leaves coral vulnerable to disease and greatly increases their risk of death, which is bad news for fish and other marine species that rely on coral for homes and spawning grounds. Extensive bleaching could also have a negative effect on the Hawaii tourism industry and local economy.

"You go from a vibrant, three-dimensional structure teeming with life, teeming with color, to a flat pavement that's covered with brown or green algae," said Ruth Gates, the director of the Hawaii Institute of Marine Biology (HIMB). "That is a really doom-and-gloom outcome but that is the reality that we face with extremely severe bleaching events."

HIMB researcher Courtney Couch spent a month in the Northwest Hawaiian Islands collecting data on coral, and was surprised by what she found. The numbers revealed many of the reefs were between 85 percent and 100 percent dead. The researchers believe the dramatic bleaching phenomenon is linked to significantly warmer ocean temperatures and a powerful El Niño pattern.

"Just mass mortality! I've never seen something that fast happen at that level. It really is a wake-up call," Couch said.

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