'Unprecedented' Ocean Temperatures on Track to Bring Death to Coral Ecosystems

Coral reefs off of the Western Australian coast are in extreme peril due to "unprecedented" ocean temperatures caused by climate change, a report released Tuesday by the Australian Institute of Marine Science (AIMS) warns.

While ocean temperatures fluctuate over the years, both the highs and lows have consistently reached new heights in the Indian Ocean where the scientists did their research. The period since 1980 has been "the warmest period with highest sea levels" in the waters off of the West Australia coast since records began in 1795.

An effect of this warming is an event known as coral bleaching, which often leads to the death of coral ecosystems.

"Indian Ocean warming towards the end of the twenty-first century could potentially increase coral bleaching risk," the report warns, "and affect maintenance of the current diverse high-latitude coral reef ecosystem and associated fisheries."

"We were hoping that West Australia ... still had some time to react or adapt to the changes," AIMS scientist Dr. Jens Zinke told the Guardian. "But we're now seeing all these heatwaves. It's not that change is going to come, it's that change is already happening."

"We've crossed this line where coral bleaching can now occur on a large scale," he warned.

The realization that coral reefs are already facing extreme peril in the the face of global warming comes as the UN's Intergovernmental Panel on Climate Change (IPCC) released its groundbreaking report Monday, warning that climate change is already decimating life on the planet, with the worst effects yet to come.

"Ocean temperatures have warmed so much and sea levels have risen so much over the last 150 years that every natural event is amplified," said Zinke. "So any future heatwave is probably going to be more extreme."

According to the AIMS scientists, warming periods in 1999, 2008 and 2011 were the highest surface temperatures ever recorded in the West Australia region. As a result the worst case extreme coral bleaching occurred in 2011, 2012 and 2013.

As the scientists report, the extreme warming period in 2011 led to "the first ever reports of large-scale coral bleaching and fish kills" in the area.

This spike in water temperatures and subsequent coral destruction must be looked at amidst the "ongoing background" of the "warming of ocean temperatures associated with climate change," said Zinke.

As the report states:

We show that interannual and decadal variations in SST [sea surface temperatures] and LC [Leeuwin current] strength characterized the past 215 years and that the most extreme sea level and SST anomalies occurred post 1980. These recent events were unprecedented in severity and are likely aided by accelerated global ocean warming and sea-level rise.

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