Coral Bleaching Is Over – For Now
The unprecedented back-to-coral bleaching events that have devastated coral reefs around the world for the past three years are subsiding, according to the United States National Oceanic and Atmospheric Administration.
The agency analyzed data collected by satellites to conclude that the high ocean temperatures that triggered the bleaching events have cooled. That could give coral reefs a chance to recover – provided temperatures don’t spike again soon.
When water temperatures rise, the colorful microscopic algae that live on corals and feed on them turn toxic. The corals jettison the algae, and deprived of nutrition, reefs turn white. If high ocean temperatures persist, coral reefs can die. The bleaching events of 2015-2017 affected an estimated 70 percent of the world’s coral reefs, according to NOAA.
Coral reefs provide a home to a quarter of all fish species, protect coasts from storms, and generate $30 billion a year in economic activity from fishing, trade and tourism.
“This global coral bleaching event has been the most widespread, longest and perhaps the most damaging on record,” C. Mark Eakin, NOAA’s Coral Reef Watch coordinator, said in a statement. “NOAA is working with scientists, resource managers and communities around the world to determine what the true impacts of this event will be on coral reefs.”
Gulf of Mexico “Dead Zone” Doubles
U.S. government scientists predict a low-oxygen area of the Gulf of Mexico will double in size this summer to 8,185 square miles (22,000 square km).
That’s roughly the size of New Jersey and threatens fish and other marine life, including commercially valuable species like shrimp. If estimates from NOAA are accurate, this summer’s dead zone would be the third-largest since monitoring began in 1985.
Hypoxic zones appear after nutrients in agricultural and wastewater runoff stimulate the growth of algae blooms that deprive the ocean of oxygen when they sink and decompose.
“The Gulf’s summer hypoxic zone continues to put important habitats and valuable fisheries under intense stress,” Rob Magnien, director of NOAA’s Center for Sponsored Coastal Ocean Research, said in a statement. “Although there is some progress in reducing nutrients, the effects of the dead zone may further threaten the region’s coastal economies if current levels remain.”
Ocean Elders Fight Mine Threatening Great Barrier Reef
Sylvia Earle, Richard Branson, Jean-Michel Cousteau and other “Ocean Elders” sent a letter to Australian Prime Minister Malcolm Turnbull urging him to withdraw government support for a $12 billion coal mine that environmentalists say threatens the Great Barrier Reef.
The Indian-owned Adani Carmichael coal mine in Queensland would require the dredging of the seafloor near the Great Barrier Reef to build a shipping terminal and other infrastructure. Coal from the mine would add an estimated 4.7 billion tons of carbon dioxide to the atmosphere over the lifetime of the project. Environmentalists and scientists fear the increased ship traffic generated by the mine also threatens the Great Barrier Reef, which has been decimated by back-to-back coral bleaching events.
The federal government in Australia has approved the coal mine and is set to grant Adani a $680 million loan to build a railroad from the mine to a coastal port.
“I am not alone being upset about what is happening to the Great Barrier Reef,” said legendary oceanographer Sylvia Earle, according to the Guardian. “I know people in Australia who are upset, but this is a world heritage area, a place that is unique, and the people who live in Australia have a particular opportunity to take action that can influence something globally, not just now, but far into the future.”
Earle is a member of the OceanElders, a group founded by technology investor Gigi Brisson to bring together global leaders on ocean issues.