Coral Reefs
The ROPME Sea Area (RSA) is said to have had 8% of the world’s Coral Reefs, and its Inner Area is home to the warmest reefs in the world. The RSA coral reef ecosystems support the economies of the countries in the Region, particularly in fisheries and to a lesser extent in tourism sectors, and provide livelihood opportunities and income for local communities. However, anthropogenic pressures at all scales, from development, fishing, and climate change, are all increasing with human population growth and local to Regional development, particularly during the first decade of this millennium.
Goniopora djiboutiensis
(Farur Island, February 2003, Photo by O. Sedighi)
The RSA Coral Reefs experienced widespread coral bleaching during the first global coral bleaching event in 1998, in which >80% of corals died. They were also affected by what has been dubbed the “3rd global coral bleaching event” in 2017, in which mortality surpassed 85-95%. It is timely, therefore, to assess the “State of the Coral Reefs” of the RSA.
(Extracted from the report Status and Trends of Coral Reefs in the ROPME Sea Area Past, Present and Future (2020) by Dr. Mohammad Reza Shokri, Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, I.R. Iran as commissioned by ROPME).
Climate Change Risks to Corals in the RSA
A combination of climate change and other pressures have caused a dramatic decline in the extent of live hard corals in the last two decades. In the Inner RSA, the harsh environment and impacts from extracting activities and rapid urban development have contributed to the most significant losses, with reefs being less diverse and more patchy than in the Middle and Outer RSA. It is estimated that more than 70% of reefs in the Inner RSA have been effectively lost.
The majority of coral reefs in the RSA will be at a critical threat level by 2050. The nature of climate change risks differ across the RSA. Coral bleaching events have been most intense in the Inner RSA but are not uncommon elsewhere in the region. Sea surface temperatures in the Inner RSA are currently rising at twice the global average rate, and it is highly likely that severe bleaching will reoccur every year by the second half of this century.
Increased storms and cyclones are the main climate change risk to reefs in the Outer and Middle RSA, as strong wave action and increased turbidity cause substantial and long-lasting damage. Between 2007 and 2021, six tropical cyclones reaching category 3 or higher have made landfall in the RSA: Gonu (2007), Phet (2010), Ashobaa (2015), Mekunu (2018), Kyarr (2019) and Shaheen (2021), with super cyclonic storm Gonu being the strongest storm on record to reach the RSA. In the future, more intense storms and cyclones are expected to occur in the Outer and Middle RSA, and may even reach the Inner RSA.
Stronger monsoons and seasonal upwelling are creating a more hostile environment for corals through increased nutrients and decreased pH. Depletion of dissolved oxygen across the region, and in particular the intensification and expansion of the permanent oxygen minimum zone in the Outer RSA, is threatening not just corals but other marine life as well.
(Extracted from ROPME (2022) Policy Brief: Coral Climate Change Adaptation. ROPME (Cowburn, B., Devlin, M., Lincoln, S., Harrod, O., Buckley, P., Bradley, K., Le Quesne, W.J.F. eds.), Cefas, Lowestoft, 12pp.)