In March 2016 staff from the Seychelles National Parks Authority (SNPA) and its partner, Global Vision International (GVI) were busy monitoring the bleaching event unfolding within marine protected areas under its management. The authority was also communicating with other reef monitoring organisations and reports of bleaching were received from all over the country, including Aldabra, Alphonse, North, and Aride Island. The situation looked bleak! Even healthy coral nubbins in the new coral nursery on Curieuse were affected. There was a sense of panic in the environment circle.

SNPA staff conducting bleaching surveys

Marine park practitioners were awaiting patiently for the South East trade winds to start blowing to cool down the sea water, which in some cases had reached 31°C. Staff participating in bleaching surveys around Mahe in May that year were shocked to find huge areas of white branching corals, Acropora, spreading for miles and divers were describing the reefs as a ‘cemetery’. Stepping in the shallow water at Baie Ternay was like stepping into a warm bath, the water was just too hot for a dip.

In April 2016, Sea Surface Temperatures (SST) data from satellite record, showed that it was way above the bleaching threshold. The first recorded bleaching report was from Aldabra in January and that was followed by other outer islands. In fact the inner islands were the most affected with an average 60% decline in coral cover compared to 17% in the outer islands. A Scenario similar to what happened in 1998, this thermal stress to the corals can be explained in part, due to the warmer conditions experienced over the shallow banks surrounding the Inner Islands, compared to the deeper waters surrounding the outer islands.

Bleached corals

The 2016 bleaching event had brought a 50% decrease in live hard coral cover. In 2018 average coral cover in Seychelles stands at 17% while fleshy algae stands at 42%. Dominance of fleshy algae on reefs impedes coral recovery, and it can be observed that our reef are shifting to an algae dominated habitat. This latest bleaching though, longer lasting and more extensive, resulted in lower mortality compared to 1997-1998 event. This can be explained by the fact that corals in the country might be becoming more acclimated and resilient to hot conditions.

According to the June 2018 report on ‘The Impact of the 3rd bleaching event on the WIO in 2016’, Seychelles was the worst hit in the region (50 % loss in coral cover), followed by Madacasgar, with a loss of 13 %. Some countries like South Africa was not affected by the bleaching event. As a whole, Coral reefs in the Western Indian Ocean region have suffered a 20% decline, while fleshy algae had increased by 35%.

Since it is predicted, that due to the rapidly changing climate, that bleaching events will become more frequent, SNPA is ensuring proper management of its marine parks to limit stress to coral reefs.  This consist of regular patrols to make sure that park users abide to park regulations. Similarly its long term reef monitoring program in North West Mahe will continue, with the hope of seeing a positive recovery of the reef.