Coral Bleaching: there’s some good news

From Bob Sluka at A Rocha International comes a report on work that A Rocha Kenya has been doing to attempt to mitigate coral bleaching. Many of us are aware that bleaching of coral reefs is a major consequence of climate change and the warming of the seas. A Rocha has been looking for ways to help coral reefs survive ‘bleaching events’.

The A Rocha Kenya marine team recorded bleaching in 2013 and 2016, but with low levels (<10%) mortality for most corals. And now in 2020 the reefs are bleaching again and the A Rocha team in partnership with KWS are back out on the reef. We use permanent quadrats, where the same patch of reef is photographed every month during the event, and the fate of each coral is observed from bleaching response to eventual mortality or survival.

              The result of this current bleaching event will not be known until late 2020, but there are some hopeful signs. Overall coral cover has increased from 10% in 2011 to 20% in 2020 (before bleaching), showing that despite 2 bleaching events the reef recovered slowly towards its pre-1998 state with 40-50% coral cover. Also the crucially important branching Acropora or staghorn corals, which are normally very sensitive to thermal stress, are showing signs of resistance to bleaching during this event. There are many examples of colonies retaining their colour, and some that are regaining it (as of late May). So might the reef become resistant? Possibly, but there are still many colonies that are looking very unhappy and some that are starting to die. Scientists think that if we can propagate the resistant colonies that survive bleaching via ‘coral gardening’ we can help repopulate the reef with thermally tolerant corals, and give a much needed boost to this ailing ecosystem. Some think this is what is needed to get these ecosystems through the next hundred years or so until the world can get to grips with our CO2 emissions, the ultimate cause for the coral’s calamity. We will continue to collect data and share stories about this work until September when the event will be over. Let’s pray for a dramatic recovery…”

Read the full report here. If you want to help out in efforts like this, or if you live in a part of the world that has coral, and would like to know how to help your own reefs survive, we’re sure Bob would love to chat with you!