From commuter town to coral reef

9 min
A close up of five coral polyps. They have short, soft looking green tentacles with fluorescent blue tips and give the impression of underwater movement.

If you’re familiar with London, you’ll have heard of the Northern Line. Part of the famous London Underground, it runs all the way from the Northernmost tip of London, right down to the south – terminating at the town of Morden. It would be reasonable to say that Morden is fairly unexceptional as London suburbs go – quieter, filled with family homes and green spaces. It’s not, however, known for its scuba diving, azure skies and tropical climates. So, how on earth is Morden home to the secrets of coral reefs?

Tucked away on an industrial estate, in a warehouse bursting to the seams with equipment, a small team of exceptional people are creating something truly magnificent. They have discovered how to artificially align the forces of nature and trigger a coral spawning – a mating event that’s equally been a source of wonder for its staggering beauty, and deeply frustrating to scientists due to its seemingly random occurrences. Here, dozens of aquariums and troughs sit in darkened rooms, connected to systems that control their environment – temperature, photoperiod, lunar cycle, nutrition – and Canon cameras, which track their progress over days, weeks and months.

Together they monitor and induce foreseeable spawning events with a greater frequency than nature itself. And when you learn that coral is often referred to as the ‘rainforests of the sea’, it goes some way to understanding why this work is not just magical, but necessary. And through their partnership with Canon, they are now able to use a wealth of professional photography equipment – cameras and an assortment of lenses – to create a visual encyclopaedia of coral spawning like no other.

Against a black background, coral branches upwards, releasing purple spherical cells. The purple coral resembles sprigs of lavender and are covered in small bud-like bumps.

During these annual spawning events thousands of eggs/sperm packages are release into the water in a few short minutes. Here we see an acropora muricata (or ‘staghorn coral’) spawning in the lab.

The brainchild of Marine Biologist Dr Jamie Craggs, Reef-keeper and expert in Aquarium Husbandry, Vincent Thomas and Professor in Aquatic Biology, Dr Michael Sweet, the Coral Spawning Lab is the commercial arm of a research project that has been the whole of Jamie’s adult life in the making. But it wasn’t until after a decade of trying to unravel the mysteries of coral spawning that he stumbled across a ‘eureka!’ moment that became the origin story of the lab – and, again, he was nowhere near the ocean when it happened.

“There was a tweet from a dive company in Fiji saying, ‘in two days’ time, come out and dive, and see the coral spawning!’” he recalls. But how did they know? “That Tweet gave me a moment in time that I could use to start delving into the environmental parameters,” he explains. “Because it gave a date, we could work backwards and figure out when the lunar cycle was. We could start to get data from the reef.” Within a year, Jamie, Mike and a team at London’s Horniman Museum and Gardens had produced the world’s first predictable broadcast coral spawning, in a completely closed system.

You might expect the machinations of this incredible mystery to be a closely guarded secret, but no. The team have let their research be open source, allowing anyone, anywhere in the world, to use it to restore their local reefs or undergo further research using it as the basis. In fact, Mike says, “this is a really important part of the whole process. We want to make an impact; we want to do our bit to ensure reefs survive for generations to come”. They quickly found that, while there was a huge appetite to undertake restoration projects, they also were being asked for support. And this included a number of requests to provide the tools and expertise required to get these projects underway, which quickly became unsustainable.

So, they looked at commercialising the concept. Before long they were producing and shipping huge numbers of ‘boxed laboratories’ which could effectively plug and play on sites around the world – with some expert technical support from Jamie, Vince, and Mike, of course. “'Vince and I, collectively, have 55 years of experience keeping marine aquariums, and Mike has been delivering cutting edge science for the past 20 years,” explains Jamie. “It’s a perfect combination, we have a breadth of knowledge, not just in building an aquarium, but understanding all the nuances around how to make it work. And so that's really, I think, our unique selling point, and why people have come to us. Because they want our support to enable them to succeed.”


As the business scales up, so does the technology and Jamie draws parallels with manufacturing methodologies, where every part of the process can be revisited, improved, adapted and developed as new information and tools become available. For example, they have also designed new v-shaped troughs, which can be connected (“like Meccano,” laughs Jamie) and extended to meet capacity. Additional elements can then be attached, as required, to achieve all sorts of aims. “A company based in San Francisco is looking at building a frame with a robotic arm to automate a lot of the processes, feeding, syphoning and cleaning 24/7,” he explains. “It can of course also integrate photography,” adds Vince. “It could take a picture of every coral and map that over a period of time.”

With one two metre tray holding 1260 corals, the scale of this photography opportunity, and the data it has the potential to collect, is vast. And this is important because it essentially creates a huge and comprehensive database of coral activity that can be used to optimise the growing process. As you might imagine, a macro lens is invaluable to them when tracking the progress of the corals and by photographing every new ‘plug’ of coral at set times, mortality rates can be tracked, and you can also start to extrapolate the surface area of every piece of coral because they all start at a standardised size. “So, we can start evaluating flow rates, feeding regime, strength of lighting, the different herbivores required – what's working, what's not working,” explains Vince. “We’re trying to replicate nature, but we’ve got so much more control.”

Coral Spawning Lab_EN Version

“If we attach a camera to a fluorescent microscope, we can apply different fluorescent markers at different stages,” adds Jamie. “Basically, we've documented different embryological stages and these all contribute to the figures that are in the research papers we publish.” In this respect, his camera equipment also finds itself attached to microscopes and sterile equipment, capturing time lapse imagery and more. It’s become part and parcel of the team’s lab equipment and, just as importantly, enables them to share the story of their work on a global stage.

Their work and the meticulous documentation of each stage of the process is crucial to the understanding and restoration of coral reefs around the world, which are currently suffering in a huge number of human-made ways. Climate change, ocean acidification, pollution, overfishing and even physical damage are all contributing to the depletion of valuable reefs, which are widely understood to be among the most diverse ecosystems on earth. But this is only half of the picture. The United Nations states that “coral reefs provide up to $2.7 trillion per year in services, including providing critical natural infrastructure that protects increasingly vulnerable coastlines from storms and flooding, food security for vulnerable populations, tourism revenue and even raw materials for life-saving medicines.” The imperative to restore them is clear.

“And the reality is, if climate change wasn't happening, we wouldn't have to do any of this. And we are certainly not going to rebuild the world's reefs with restoration,” states Mike. “We know that's a fact, because the scale is just enormous. But what we can do is try and buy enough time.” He cites the example of the island of Palau, where reefs can and do slowly recover from bleaching (where an increase in temperature turns the coral white, removing their energy and food source), as it is naturally isolated and not subject to overfishing or exposure to human-created pathogens. “Restoration is about giving the corals a helping hand and kickstarting that recovery process.”

Against a black background, the branches of corals are tightly packed together and pointing upwards. Each branch is covered in a spiky, bud-like texture, with bright green-white cells emerging from the tips.

Described by Dr Craggs as “like a living lava lamp”, it’s easy to see how these beautiful spawning acropora millepora coral can fascinate and capture the imagination

To fully understand the work of the Coral Spawning Lab, we need to go back to reproductive basics. A spawning event is where colonies of coral release an explosion of eggs and sperm into the water. It’s mesmerising to watch, and Jamie describes it as “like a living lava lamp”. These eggs and sperm drift to meet each other, naturally inseminating and producing larvae, which then float in ocean currents until they eventually settle onto rock or another coral structure. The larvae then undergo a metamorphosis into the kind of coral we are familiar with. In the process undertaken by Jamie and his team, however, these eggs and sperm are gathered in special containers and taken to the lab. Here, a kind of coral IVF procedure takes place and new ‘test tube baby’ coral larvae develop after a few days. These are then returned to the aquarium to grow.

Part of the reason for this process is to allow the teams to study the reproductive activity and ensure genetic diversity in coral, which will in turn make it more resilient in the future. Jamie explains: “In bleaching events, you will always have individual corals that don't necessarily bleach. So, within their genetic code, they're already robust. However, if surviving colonies are on opposite sides of an island, they will never reproduce without intervention. So, we can bring those two together in the lab to create the next generation. We can also selectively breed from those individuals. So, the offspring that you're producing are hardier in the face of climate change.” But the same environmental factors also mean that the Coral Spawning Lab is in a race against time. “We probably have a window of no more than eight years left,” explains Mike. “If we don't make a big impact by then, it is possibly too late.”

Through their partnership with Canon, the team at the Coral Spawning Lab are using state-of-the-art cameras and lenses to document this extraordinary work. These are tools that will help them to inspire amateur aquarists, conservation activists and the marine biology community, yes, but they also help them to create a story that can travel beyond specialist communities. Because when something fascinates and educates in equal measure, it makes the world sit up and take notice – and, often, action. And though the audiences may be different, the visual story is the same: a powerful tale of wonder, urgency and hope that hits home, regardless of whether home is the South Pacific… or South London.