The Great Barrier Reef experienced it’s worst coral bleaching event (since modern record-keeping began) in 2016, as we reported a few months ago with an “obituary.” It seems that 2017 may be a repeat (or may not be) of 2016, as coral bleaching has already begun again on the Great Barrier Reef.
As a result, researchers and reef managers from 10 different research institutes in Australia (the National Coral Bleaching Taskforce) have again mobilized to monitor the situation.
“We’re hoping that the next 2–3 weeks will cool off quickly, and this year’s bleaching won’t be anything like last year. The severity of the 2016 bleaching was off the chart,” commented Taskforce convener, Professor Terry Hughes (ARC Centre of Excellence for Coral Reef Studies).
“It was the third major bleaching to affect the Great Barrier Reef, following earlier heatwaves in 1998 and 2002. Now we’re gearing up to study a potential number four. We have now assessed whether past exposure to bleaching in 1998 and 2002 made reefs any more tolerant in 2016. Sadly, we found no evidence that past bleaching makes the corals any tougher.” (More on that can be found in this study, just published in the journal Nature.)
Dr Janice Lough, Senior Principal Research Scientist at the Australian Institute of Marine Science, noted that “average sea-surface temperatures for the Australian summer 2016 were the highest ever recorded on the Great Barrier Reef. In each of the three events since 1998, the pattern of bleaching matches exactly where the warmest water was each year. That allows us to predict when and where bleaching is likely to occur this year.”
Professor Hughes continued: “It broke my heart to see so many corals dying on northern reefs on the Great Barrier Reef in 2016. With rising temperatures due to global warming, it’s only a matter of time before we see more of these events. A fourth event after only one year is a major blow to the Reef.”
Such situations are only going to become more and more common as the oceans continue warming, though. At this point, I think the best long-term possibility (that’s viable) is simply to aggressively protect some of the portions of the reef that have access to cold-water upwellings. The Great Barrier Reef as a whole is very likely doomed at this point.