Big 2014-15 El Nino Could Reduce Global Reef Coverage By 10-20% In Single Episode

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It’s not so much the fact that 10 or 20 percent of global reef coverage could be lost in the next year or so, but the reduced ability of these reefs to recover. This is death by a thousand cuts, an aggregation of impacts, from extreme weather events to invasive species to destructive fishing practices, with global warming reverberating across all of them. A landmark 2007 study by John Bruno and Elizabeth Selig showed that the Coral Triangle had lost nearly 50 percent of its reefs since the 1980s. Beset by constantly rising temperatures, they simply can’t bounce back.

The Coral Triangle is particularly vulnerable because it’s more prone to non-climate related pressures than other reefs. According to the World Resources Institute, more than 85 percent of reefs within the bioregion are threatened by local stressors (overfishing, destructive fishing and pollution), which is substantially higher than the global average of 60 percent. About 120 million people depend directly on these reefs for their livelihood. As the coral dies, more and more of them will be forced to migrate to live. “You’re looking at a situation where a once vibrant ecosystem that offered goods and services for humanity is heading towards extinction,” says Professor Guldberg.

The broad scientific consensus is that corals worldwide could be on the verge of extinction by as early as 2050. In the broader context of global warming, coral reefs are not necessarily the first ecosystems to go, but they are the most graphic. They can be seen as an early warning system – the proverbial canary in the coalmine, except when corals start to expire, it tends to presage species annihilation on a scale witnessed only five times previously in the planet’s history. That’s why the term “sixth extinction” is becoming part of the media lexicon.

The only meaningful solution in the long term is to drastically reduce carbon emissions worldwide. Not much can be done to mitigate the impact of an impending El Niño, but some of the other non-climate related stresses can be removed. This means establishing areas of undisturbed marine habitat – lots of them – and reducing pressure on fisheries. Guldberg offers the metaphor of a chronically ill patient that needs radical treatment – “but they also need remedial care – blankets, water, food. That’s something immediate we can achieve.” As for the radical treatment, it needs to happen very soon. If not, corals could soon become mere aquarium artifacts.

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http://www.climatecentral.org/news/el-nino-could-spell-disaster-for-coral-reefs-17520