Africa: When Coral Reefs Die, Coastal Communities Pay the Price

Mombasa, Kenya — For decades, the outlook for the coral reefs has been increasingly bleak.

Corals are some of the world’s most biodiverse ecosystems, which have faced an existential threat due to rising temperatures that cause increased incidences of bleaching. This makes it inevitable that reefs will experience rapid decline. However, scientists’ latest findings seem to paint a slightly different picture regarding the survival prospects of reefs.

Dubbed “the rainforests of the sea”, the coral reefs occupy less than 1% of the ocean floor yet are home to up to 25% of marine life. Millions of fish and other species live, feed, and reproduce in and around the reefs. Notably, reefs are essential to people since they protect shorelines from flooding due to storms or tidal waves. They are global ecosystems whose value extends to sustaining the lives of many millions of people.

However, over the past decades, the planet has lost 50% of its reefs. Many corals in the world have been affected by the effects of global warming. Today, more than 80% of the world’s reefs are experiencing bleaching stress due to rising ocean temperatures. According to Earth org, during 2023 and 2025, together with the strongest El Niño effect ever recorded, which caused never-before-seen atmospheric and ocean temperatures, heat stress at bleaching-levels impacted nearly 84% of the Earth’s total coral reef coverage area across over 83 countries and territories. This particular event has been classified as the fourth global mass coral bleaching event and the second within the last ten years.

Moreover, fishing activities, pollution from the land, building developments, and shipping activities have all contributed to the decline.

It is estimated that the widespread distribution of coral reefs able to survive or even recover after the influence of climate change is approximately three times higher than previously assumed. 50 Reefs Plus, a scientific project designed to identify key coral reef sanctuaries that would survive and adapt to climate change. The research drew on more than 45,000 coral surveys and decades of climate and ocean data to produce what its authors described as a global map of coral refugia: the places most likely to persist as the planet warms.

This study, which was released during the Our Ocean Conference in Kenya through the collaboration of the Wildlife Conservation Society (WCS) and Macquarie University with the help of the Bloomberg Ocean Initiative, represents an important step forward for determining which reefs could potentially withstand further increases in temperature across the world. It will become the starting point for a new civil society campaign entitled Our Reefs, Our Future, advocating that governments safeguard these reefs from local dangers.

“Often, coral reefs are portrayed as ecosystems that are already beyond saving,” said Dr Emily Darling, one of the co-authors of the paper and Director of Coral Reefs at WCS. “Our research demonstrates that there are three times as many reefs with the capacity to survive the climate emergency as we previously believed.”

allAfrica’s Melody Chironda had the privilege of talking to Dr Darling.

When scientists talk about reef decline, what does it actually mean?

When scientists talk about reef decline, it is often related to a loss of living coral cover on reefs.

Corals are alive; they are incredibly important animals that build these huge structures that can be seen from space. These are natural structures that protect coastlines; they create habitat for fish and fisheries, and they’re also an important source of local economies like tourism, food security, and, of course, culture for local communities.

So when we talk about coral reef decline, we typically think about the decline of the architect species, the corals themselves, but there are also knock-on effects to other parts of the ecosystem, like the reef fish, and then just the habitat complexity of the reefs themselves. So it’s a full ecosystem decline, and we can look at that in different ways, and that has been the trend over the past few decades, with too much pressure on coral reefs.

Why are coral reefs such decisive climate investments?

Coral reefs are decisive climate investments because they’re on the front lines of climate change right now. Ocean heating, super El Ninos, all cause too much stress for corals and can lead to mass coral mortality and a loss of this critical foundational architecture of an entire ecosystem. At the same time, we know that there are climate-resilient reefs, and in fact, we have found over 150,000 kilometres squared of these areas in 71 countries and 100 territories around the world in this new study released. This means that there are strategic investments for coral reefs, where they can have the most long-term persistence to climate change, and, in fact, for finance, these are then de-risked investments.

These are places that should have less climate risk than other areas and are critical places to think about bonds, reef-positive businesses, support to local communities who are managing them, and the entire portfolio of finance that can be used to improve coral reef and community outcomes.

What policy gap worries you most?

I think the policy gap that worries me most is when coral reefs or any ecosystem are siloed in one ministry. So we often see a ministry of environment, maybe a ministry of climate change, considering ecosystems, particularly climate-impacted ones like coral reefs.

But these ecosystems have national importance; they need to be elevated into national policy, and ministries need to be working to mainstream coral reefs into their policies. So one thing that I think is very optimistic is the role of national coral reef action plans. This means that a country is taking its coral reefs seriously; it knows where its climate-resilient reefs are; it commits to monitoring them into the future and really prioritising them in their biodiversity and climate commitments, but also thinking about them around health and food security and the blue economy for people.

So my biggest concern is when coral reefs are seen as a small part of the environment as opposed to the national priority that they should be. So many people depend on fisheries, reef fisheries.

If coral reefs collapse, what impact does that have on coastal communities and fisheries?

So coral reef fisheries are deeply connected to the coral reef structure itself.

We have seen, following mass bleaching events, for example in the Seychelles, that there can be lag effects where the habitat crumbles when corals die and that there are then less fish on a reef to support fisheries, or the types of fisheries change. Algae can take over a reef so it’s no longer a coral reef; it’s more of an algal reef. And then there are different fisheries and fishermen need to spend a lot of time and money adapting from a coral fishery to other fisheries.

But I think the loss of fish biomass and the impacts of fisheries are the deepest concerns from mass coral bleaching and the loss of the coral structure.

You were talking about coral bleaching, and we know scientists have been warning about it. Why is there still a gap between scientific warnings and policy action?

Well, scientists aren’t just warning about it.

We’ve been measuring it for decades and showing its impacts. This is even more urgent today as we know a super El Niño is building and that will come to affect the coast of East Africa and Kenya next March and May when waters get quite hot. So I think there needs to be a more proactive policy to really make sure that countries are monitoring the impact of this bleaching, looking for resilient places, and then looking at how local economies can be resilient to these changes as well.

Things like being able to reduce pressures from pollution, from overfishing, or from habitat damage like ship groundings. Those are all important to reduce as much stress as possible on the coral habitat so that it has a chance to recover and resist bleaching.

Is it still possible for the coral reef ecosystem in Africa to recover?

Absolutely.

And that’s what this report that we’re releasing shows. There are climate-resilient reefs along the east coast of Africa throughout the western Indian Ocean. They’re not everywhere, but they are there, and that’s where governments need to be prioritizing working with their communities, working with partners to really make sure that we are reducing other local pressures to these reefs, prioritizing them in national policies, and then championing other governments in the region and internationally with the work that countries like Kenya are taking.