Threatened coral reefs can benefit if protective measures are taken on land and at sea at the same time. Researchers show this with a study in Hawaii over a period of 20 years, in which the corals were also exposed to an unusually strong heat wave in the Pacific in 2015.

Reefs in areas with less overfishing and less pollution, such as from sewage or runoff, showed more stable growth. In stressful situations, such as after rising sea temperatures, coral destruction was lower there. In addition, the reefs recovered more quickly from the coral bleaching. This is what the group led by the oceanographer Jamison Gove from the US climate agency NOAA and the marine biologist Gareth Williams from Bangor University in Great Britain write in the journal “Nature”.

Coral reefs are increasingly at risk worldwide due to ocean warming as a result of climate change. A fading of the colorful hard corals is called bleaching. Corals are cnidarians that live with algae in a mutually beneficial community. At high temperatures, the corals repel the algae and lose their color.

The scientists refer to the goal set by the international community of states to place at least 30 percent of the world’s land and sea areas under protection by 2030. According to the study, in order to strengthen and heal the threatened coral reefs, human influences – in combination on land (e.g. sewage pollution) and in the sea (e.g. overfishing) – must be kept to a minimum.

Article journal Nature