More than just a pretty reef: why corals are so important and how they might be saved

Written by Alicia Shephard

In 2020 it was announced that the Great Barrier Reef had lost more than half of its corals since 1995, due mainly to warmer seas driven by climate change. But it was also the year that plans for a huge coral biobank were announced in Australia. The purpose? To provide a safe home for 800 coral species to thrive, and ultimately repopulate the world’s coral reefs. But why do we need to save the reefs in the first place? And is a terrestrial biobank the solution to an oceanic problem?

Coral reefs have long been regarded as treasure troves of wonder. Naturalists and natives alike have spent centuries exploring these vast eutrophic zones of the ocean, harvesting their precious commodities in the name of science, and survival. But these vital ecosystems are in danger. Anthropogenic activity threatens the huge array of species that call the reef home. Without political, environmental and social interventions we risk losing these ecosystems entirely.

It’s no surprise that coral reefs are considered the rainforests of the sea. Covering less than one per cent of the ocean floor, but supporting an estimated quarter of all known marine species, makes them a true haven for biodiversity. As well as their role in global biodiversity, coral reefs can simply be appreciated for the awe they inspire. They’re a pandora’s box of evolutionary developments not seen anywhere else in the world. From all the colours of a carnival to the wildly diverse phenotypic adaptations necessary for survival, these ecosystems are home to an unimaginable collection of organisms. But they’re more than just a pretty reef. They also provide a number of critical ecosystem services.

Most widely known is the role coral reefs play in providing a food source locally, nationally and, in our current food system, internationally. They provide around 10 per cent of the fish caught worldwide, rising to as much as 25 per cent in developing countries, therefore serving as a globally important source of protein.

However, their large formation between the surface and the first few dozen meters of depth also acts as an element-absorbing barrier. This protects our land from coastal erosion, reduces damage from natural events such hurricanes and tsunamis, and in doing so protects the ecosystems between land and the vast open ocean. The implications of this service are widely unappreciated. Without the protective role of coral reefs entire communities and even countries would cease to exist. During the 2004 tsunami in the Indian Ocean, the reefs around the Maldives were credited with sparing the islands from the massive number of deaths experienced elsewhere.

In terms of natural value, coral reefs are priceless. They’re an invaluable oasis of species diversity, ecosystem stability and environmental wonder. But, as if that wasn’t enough, coral reefs can be monetised. Consisting of tourism, coastal protection, fisheries and biodiversity, the total annual net benefit of the world’s coral reefs is $29.8 billion.

Despite all this, our reefs are in danger. Anthropogenic activity threatens to bring an end to these vital ecosystems. In the last 25 years the Great Barrier Reef has lost half of its corals due to warmer seas driven by climate change. Population sizes dropped in all coral sizes and species, but especially in table-shaped corals which provide habitats for fish and other marine life, contributing to a cascading loss of species across the ecosystem.

But the Great Barrier Reef is just one example. Around the world coral reefs are showcasing the telltale sign of degradation due to climate change – bleaching. When corals are stressed by changes in conditions, such as temperature, light or nutrients, they expel the vibrantly coloured symbiotic algae living in their tissues leaving them completely white and barren. As oceans continue to absorb increasing rates of CO2 and human activity contributes exponentially to global warming, our ocean temperatures will continue to rise to dangerous levels.

The loss of coral reefs is, itself, devastating. But the unprecedented global heatwave of 2014-2017 highlights another problem – the vulnerability of hundreds of millions of people dependent on reefs for their livelihoods, wellbeing and food security. Approximately 250 million people are in this position – many of them small island states in developing countries.

Many of the approaches to protecting coral reefs are synonymous with those aimed at reducing the rate of climate change. There are simple things everyone can do in daily life, like saving energy, reducing waste and more sustainable approaches to transport. And there are practices that entire sectors can adopt, for example the agricultural sector could reduce the use of fertilisers. It’s no secret that by reducing rates of climate change we can prevent rising temperatures and CO2 levels, but both of these aspects will also reduce reef degradation.

However, there are also solutions which go beyond the cause of the problem, solutions like The Living Coral Biobank. Dubbed the ‘coral ark’ by its supporters, the biobank is inspired by Norway’s global seed vault, a store of ‘back up’ seed samples from the world’s crop collections. In much the same way as the seed vault, the coral biobank will serve as a technologically advanced facility where 800 different types of hard corals will be kept and bred for use in the future. The facility, based in Queensland Australia adjacent to the Great Barrier Reef, is also going to be connected with aquariums worldwide. All of these are united under a common aim – to coordinate the preservation of diverse coral samples.

“With every coral bleaching event, we are losing the most vulnerable corals and coral reefs – with three mass bleaching events in just five years on the Great Barrier Reef, and over 50% of corals gone in the last few decades, we don’t have a moment to lose”, says Dr Dean Miller, Managing Director of Great Barrier Reef Legacy, talking to the Guardian.

Preserving the genetic biodiversity of coral species through the biobank is a forward-thinking approach to the problem. However, it’s also one I hope we never have to use. By changing behaviours at the individual and population level and by adopting new approaches to ocean governance practices we have the potential to curb climate change and prevent reef loss. Whilst the biobank is a reassuring contingency plan, it should remain exactly that. At the very least, it should be developed in conjunction with other preventative technologies in the hope that we might be able to avoid this currently inevitable loss.

Coral reefs are important. The survival of biodiversity in the ocean and millions of people on land is reliant on them. But their future is uncertain. Conserving their natural beauty and vital roles will take an effort that, on the face of it, may seem gargantuan. But in reality it’s simple. Small changes at every level, by everyone, will defend these oceanic worlds of utopian treasures, and if all else fails researchers have a backup plan. But for the sake of the reef, the ocean and humanity it’s time we all gave a more climate friendly life a try.

A

Alicia is a BSC (Hons) Zoology graduate from the University of Sheffield. She is currently working as a Research Content Producer at the University of Sheffield producing content on an array of subjects from nuclear waste to sustainable food practices. You can follow her on Twitter @AliciaShephard3 or connect with her on Linkedin here.


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