High ocean temperatures led to two mass coral die-offs in 2016 and 2017.
Studies documented historically high ocean temperatures in the western Pacific, disappearing ice in Antarctica, and accelerating glaciers on Greenland.
High ocean temperatures can kill off both the fish themselves and the sources of food they depend on.
El Niño events occur naturally every few years and stem from abnormally high ocean temperatures in the eastern Pacific.
High ocean temperatures are taxing the organisms most sensitive to them, the shallow-water corals that create some of the world's most vibrant and colorful seascapes.
In 2016 and 2017, persistent high ocean temperatures off eastern Australia killed off as much as half of the shallow water corals of the Great Barrier Reef.
Corals get stressed and can die in high ocean temperatures, with localized pollution and clumsy tourists also degrading reefs that are vital to a host of marine creatures.
Take tropical coral reefs, which already regularly come under stress because of high ocean temperatures, suffering "bleaching" especially during El Niño events – as happened on the Great Barrier Reef in Australia this year.
Working in a large landscape where it was very thick, it was stripped from the Caribbean Islands to some of the highest elevations suggesting suggesting a lot of scouring from glacial water flowage in rather high ocean levels.
In 2015/16, unusually high ocean temperatures associated with one of the strongest El Niño events on record triggered an unprecedented global coral reef crisis, initiating what would become the third documented global mass bleaching event17.
