Magda Nawrocka-Weekes
By Magda Nawrocka-Weekes on 26/06/2020 in Tech

Reefs 101

An in-depth look at coral reefs and CCell's specially designed reefs which takes inspiration from them.

At CCell, we base our coastal erosion solution on the best designer of all; nature. We have adapted the protective properties and wave breaking characteristics of coral reefs and, using some pretty smart science, are producing artificial reefs that act in the same way, providing rapid and tangible protection to coastal communities.

A healthy coral reef with the words

A healthy coral reef can provide for both humans and marine life.

How coral reefs break waves

Coral reefs take energy out of waves by increasing the turbulence in the water. As the wave moves up the slope of the reef, the water particles from below channel energy upwards, destabilising the water above them and steepening the wave.

A diagram illustrating the ability of coral reefs to cause waves to break.

Reefs disturb the natural paths of water particles, forcing waves to become steeper and eventually breaking. This creates turbulence at the surface while having little effect on the reef itself.

The less-stable wave breaks after the reef, causing the kinetic energy of the wave to be dissipated, reducing its impact before it hits the shore. This process can be seen all over the world when you look at the satellite images of coral reefs and the shoreline behind them.

A satellite image of coral reefs breaking waves before they hit the shore and the calm water after the reef.

Satellite image from a Mexican coastline in the Caribbean showing how natural reefs can cause waves to break. Source: Google Maps

Other Benefits of Coral Reefs

Along with protecting the coastlines of over 100 countries, coral reefs have many benefits to humans and aquatic creatures alike. It is estimated that nearly 25% of all marine life either is born or lives on coral reefs, this means that without this vital ecosystem, small fish, crustaceans and even larger fish such as sharks have nowhere safe to rest or breed. Egg settlement on coral reefs provides fish stock for both local fishers and seabirds. Not only do reefs support a vast variety of life but the reefs themselves, which have often been described as the rainforests of the sea, have been used as sources for new discoveries and are of great importance in the production of new medicines. The bright fish and other creatures that inhabit a coral reef not only attract animals but tourists too, by allowing more people to witness and understand nature its protection can be promoted.

An image from Nature Conservancy illustrating the benefits of coral reefs including supporting marine life, medicines and coastal protection.

Not only do coral reefs protect coastlines from erosion, but they support the biodiversity of the ocean and local food supplies along with being a vital source of new medicines. Source: The Nature Conservancy.

How CCell Builds Reefs

CCell reefs aim to replicate the effectiveness of naturally occurring reefs, along with introducing additional turbulence through their porous design. In nature, wave breaking tends to occur above more developed reefs, those with a more complex structure. This is why hurricanes have such a devastating effect on coastlines for years after they land, by flattening reefs that would have provided future protection. Our design builds on the natural turbulence of reef shapes and its horizontal bars, around which we grow rock, mimic the gaps between pieces of coral and rock.

A diagram illustrating the creation of turbulence between the bars of a CCell artificial reef.

Water particles flowing through the pores of a reef, adding turbulence and instability to a wave.

The CCell reef will grow rock over time, powered by a small electrical current that recruits natural seawater minerals and produces a layer of calcium carbonate (limestone) around the steel frame. Slowly the gaps between the bars of the reef will grow smaller as more rock grows. This will reduce the porosity of the reef, improving its ability to remove energy from the wave while increasing its strength and weight, further securing the frame and adding structural support.

After a layer of rock is built up, the reef is an ideal place to plant coral polyps from nearby hatcheries along with fragments of coral that have been collected after storms and grown on “trees” in the water. This technique for coral restoration has been used all over the world, in places such as Indonesia and Jamacia, for over 25 years. By placing coral polyps onto the reef, they are more easily secured as the rock grows around them, acting as cement. The electrical field which attracts the minerals used to grow the reef rock is also thought to boost the growth of planted corals as they use the same, more easily available, minerals. The current also prevents algae from colonising the reef faster than the coral can. Now for the first time, CCell is using the reef shapes on a larger scale, to protect coastlines as well as provide a habitat for coral.

An image from Science photo library showing a healthy coral reef grown using electrolysis.

Artificial reefs can be as complex as naturally occurring ones, providing a home beneath the waves- Source: Science Photo library

Not only are we putting in extensive reefs where there were none before, but we are also building on the idea of complexity within reefs. Alcoves between corals and rocks are vital places for fish eggs to land, providing protection from the ocean and predators. To introduce more randomness and complexity to the reef itself, we are installing shapes and words onto the reef. These first shapes will be designed by the investors from our super-successful crowdfunding campaign, with shapes including love hearts, clams, octopi, fish and turtles. Each shape is made out of the same steel as the reef and will grow rock, eventually becoming a home for coral and other marine life. The complexity of the reef also contributes to the overall survival of corals as they battle against the changing climate.

Find out more about how you can support our cause by heading to our Sponsor page.

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