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Technology and data initiatives aim to preserve the world’s declining coral reefs

Cath Everett Profile picture for user catheverett April 26, 2024
Coral reefs have been described as the “rainforests of the ocean”. Which is why these two initiatives to try and preserve them are so important.

An image of multicoloured coral reef
(Image by Marcelo Kato from Pixabay)

Coral is in trouble. The world has lost half of its reefs over the last three decades and could lose more than 90% by 2050 if urgent action is not taken to prevent climate change.

This is important because, despite occupying less than 0.1% of the ocean floor, coral reefs are home to a quarter of all marine life. But global warming means they are currently experiencing their fourth recorded mass bleaching event. This is the second in 10 years and is affecting more than half the world’s reefs in the Pacific, Indian and Atlantic oceans.

To make matters worse, such events not only damage, or even kill, the coral itself. They can also lead to hardship for the communities that depend on its ecosystems for their livelihoods. As Dr Jessica Reichert, Postdoctoral Researcher at the Hawaii Institute of Marine Biology, explains:

[Coral reefs] provide habitat for a third of all fish, act as a coastal protection from storms and are an important source of income through tourism for local communities. But it’s likely we’ll lose coral reefs in the form we know and will transition to less complex, more isolated structures that can only persist in refugia where environmental conditions are milder.

This transition is happening due to oceans experiencing climate-induced heatwaves. These result in the microalgae on which corals feed producing harmful rather than nutritious substances. As a result, the coral expels them and starts to starve. 

Although they can recover over time, the current intervals between heatwaves (around two to three years) are now too short to do so effectively. This means the reefs, which Reichert describes as the “rainforests of the ocean”, are losing their complex three-dimensional structures.

But climate change is not the only challenge, although it is the most significant one. Other factors include destructive fishing practices, coastal development, shipping, and pollution. 

Understanding the impact of microplastics on coral

One of these pollutants is microplastics, whose presence is steadily increasing in oceans across the world. So to better understand the impact of this anthropogenic stressor, Reichert started investigating the scenario in 2015 while undertaking her PhD at the Justus Liebig University in Giessen, Germany.

Such research is “still in its infancy”, especially when compared with investigations into the implications of microplastics elsewhere, Reichert says. But her focus is on understanding how they directly but often subtly affect coral’s physiology, growth, and survival. She also works on identifying how these impacts, in turn, affect the wider coral reef ecosystem. 

Unsurprisingly, she says, technology has “always been a key feature of my research”, enabling her to investigate things that were not possible before: 

It started with using 3D scanning to document the growth and shape of corals. I then continued developing analytical methods for the data collected from 3D scanning, using novel algorithms to analyze the shape and color of the corals. Using 3D documentation methods has since defined my research. I’ve now expanded it to coral reefs, where we use state-of-the art photogrammetry to document the shape and any changes to them. 

Traditional methods of measuring corals, such as using hot wax in a tub of scalding paraffin, were destructive, usually killing them in the process. But 3D scanning using an Artec Spider handheld device means it is now possible to measure them with sub-millimeter precision while still dripping wet from the experiment tank in which they are grown. The corals are then returned as quickly as possible to prevent damage to their fragile polyps. Reichert explains:

For the first time, it allowed us to document coral growth rates in a highly precise but non-invasive way. It allows us to document the 3D shape of the sensitive coral organisms in less than a minute. For this, we take the coral out of its experiment tank, place it on a rotating plate in a well-illuminated space and scan the coral with a handheld 3D scanner in two rotations from different angles. Together, this takes between 40 and 60 seconds.

The next step will be to develop methods for analyzing how the complex changes to coral due to microplastics can best be quantified. As Reichert says:

Moving forward, these methods will allow us to better understand how global change stressors affect the structural complexity of coral reefs that is so crucial for their ecological functions. In future, we might also be able to use this knowledge to reconstruct and restore affected reef sites by reintroducing their previous structural complexity through artificial reef structures. It would give stressed ecosystems more time to recover before measures against climate change, which are still the most important means of protecting coral reefs, kick in.

Regenerating coral ecosystems

Another organization that is keen to play its part by helping to regenerate coral reefs is Tenaka, a social business set up six years ago to restore and protect marine ecosystems. It does this by tailoring its projects to meet enterprises’ corporate social responsibility requirements.

The organization’s focus is on enhancing the resilience of coral reefs in Marine Protected Areas (MPAs) in Malaysia and Indonesia. Jean-Luc Roux, its Chief Executive, explains:

The coral is particularly well preserved and isn’t so much at threat there, so we can restore any damage and grow it more effectively. In other areas, such as the Mediterranean, it could already be too late due to global heating – it’s not global warming anymore.

One place Tenaka is currently doing a lot of work is the Malaysian MPA in the western Pacific Ocean’s Coral Triangle. This work consists of two elements. The first involves working with local communities to replant the most resilient species of coral in areas where damage has occurred. The reef is then regularly tended and monitored.

The second part entails measuring bioindicators to understand the reef’s health. Such bioindicators include fish, invertebrates, and particularly sharks as they visit more regularly if food is plentiful. 

Measurements are undertaken manually by divers once a week, who produce monthly reports based on their findings. This and other data are then entered into the Tenaka Science platform to provide customers with graphs and other insights demonstrating the health of the reef they are sponsoring.

The benefits of digitization

But much of this physical measurement work is now in the process of being automated. A Yucca lab BlueCam marine research station has been introduced into the Malaysian MPA reef. It consists of an underwater live monitoring device with waterproof 360-degree cameras, attached to a solar-powered floating buoy. The cameras take pictures every 30 seconds. 

The research station connects to a local 4G mobile network using a SIM card from Orange Business, which is a sponsor. This means images can be transferred to the (Microsoft Azure) cloud. Here a system with an algorithm developed by Orange Business analyses them and identifies and quantifies in near real-time what marine life exists in the reef. Roux says:

The leap forward in learning is huge. The prototype was finished in March and the results have been very positive so far. The second phase, which is currently in progress, is training the AI algorithm. The third will be immersing the research station in Tioman this October when we should have our first real feedback.

The key benefit of digitizing this process is that it will allow teams to spend less time in monitoring and more in preserving the reef. Roux explains:

The idea will be to see what sensors we should put in place to measure sound, PH, temperature etc. The next step after that will be to replicate our work in other parts of the world. But since day one, we’ve dreamed of having an underwater camera. As a small social business being able to develop such an ambitious project is like climbing Everest in a T-shirt. And it demonstrates how important it is to work in coalition with others.

My take

Given the all-too-often unrecognized importance of our oceans in general and coral ecosystems in particular in both biodiversity and carbon sequestration terms, the value of the work being done to try and save them cannot be underestimated.

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