Biorock electric coral reefs survive the most severe hurricanes with little or no damage

Two new Global Coral Reef Alliance videos answer the question many people have: what happens in a hurricane? Here we show that Biorock reefs hit by the eye of three of the strongest Caribbean hurricanes, Hanna, Ike, and Irma, suffered almost no physical damage and built up sand around them during the event.

In contrast, solid concrete objects nearby caused so much scour and erosion around and under them that they sank into the sand. Solid breakwaters cause reflection of waves at the solid surface, concentrating all the wave energy in one plane, which causes sand to wash away in front of the structure, then underneath, until it is undermined and collapses. This is the inevitable fate of any vertical seawall, so they need constant and costly repair and replacement. After Hurricane Andrew every single shipwreck in South Florida was torn apart or moved great distances due to the strong surface drag. Not one remained intact.

Biorock electric coral reefs can be any size or shape. For growing corals, we make open frameworks, so the corals can benefit from the water flow through the structure, just as they do in coral reef. As a result of their low cross section to waves, they dissipate energy by surface friction as waves pass through them, refracting and diffracting waves rather than reflecting them. Their low drag coefficient means that they survive waves that would move or rip apart a solid object of the same size.

Here we show what happened to Biorock reefs after the most severe hurricanes ever to hit Saint Barthelemy and Grand Turk. Incredibly, there was little or no physical damage to the structures or to the corals, even though these structures were not welded, simply wired together by hand, and they were not physically attached to the bottom, simply sitting on the bottom under their own weight, attaching themselves to hard bottoms and cementing sand around their bases through growth of limestone rock over their surfaces.

Saint Barthelemy:

Grand Turk:

These astonishing results follow our previous video showing the record recovery of severely eroded beaches behind Biorock reefs:

Scientific papers documenting the Grand Turk results are at: Effect of severe hurricanes on Biorock Coral Reef Restoration Projects in Grand Turk, Turks and Caicos Islands

and the rapid restoration of the beach at: Biorock Electric Reefs Grow Back Severely Eroded Beaches in Months

It is important to realize that neither rocks nor structures exposed at low tide shown in this video are an essential part of the method. Almost all of Biorock structures are completely submerged and have no rocks. At Pulau Gangga this design was used to protect the beach from storms at high tide, and effectiveness was more important than aesthetics to the Resort, so they opted not to have what most people want: an invisible watchman that you can’t see at low tide sunset!

In addition, Biorock electric reefs greatly increase the settlement, growth, survival, and resistance to stress of all marine organisms, with only a single known exception: predatory sharks avoid electric fields that confuse them, protecting people and sharks from each other (Uchoa, O’Connell, & Goreau, 2017). In 2016 there was nearly complete survival of Biorock corals during severe high-temperature events that bleached and killed more than 95% of corals on nearby reefs.

Our results show that Biorock electric reefs are the most cost-effective method for saving corals from global warming, restoring reef communities (whether corals, oysters, or mussels), and protecting coastlines from erosion and global sea level rise.

Sustainable Ocean Management for Small Island Developing States (SIDS)

A Vision for the UN SIDS Summit in Mauritius, January 2005

Thomas J. Goreau, Ph.D. President, Global Coral Reef Alliance UN Expert Meeting on Ocean Management in Small Island Developing States, Suva, Fiji, May 2004

1. SIDS depend on healthy oceans All SIDS are intimately dependent on healthy marine habitats for most of their fisheries, protein intake, tourism, sand supply, shore protection, marine biodiversity, and other benefits. Their marine energy resources could provide all the renewable power they need, if it were developed it instead of wasted. SIDS marine resources have been devastated almost everywhere in recent years from combinations of coral heatstroke from global warming, new diseases, land-based sewage and fertilizer nutrients, mud from eroded deforested watersheds, global sea level rise, over-fishing, toxic chemicals on land and in the sea, and direct physical damage from destructive fishing, dredging, boats, anchors, tourists, reef harvesting, and increased storm wave intensity.

2) Our marine resources are quickly vanishing As a result, renewable marine resources are vanishing, endangering food supplies, tourism income, and shorelines. This forces people to harvest species previously regarded inedible, until nothing edible is left, and causes steadily increased fishing pressure on offshore banks and remote reefs, which are the only remaining sources of new baby corals and fish for impoverished coastal ecosystems. These critical nurseries must be protected, not wiped out. The losses are mounting as corals die and we kill the last big wild fish. Future generations will never be able to be sea hunters like their forefathers: they will have to become ocean and reef farmers, or starve. The methods to reverse course and nurture our reefs back to life are already available, but are not being applied on a meaningful scale.

3) SIDS are the first and worst victims of global climate change SIDS are the most vulnerable countries of the world to global warming and sea level rise. Dead reefs cannot protect shorelines or provide fish and beach sand. High temperatures have already killed most corals in many islands, and entire islands are disappearing beneath the waves. The last time global temperatures were one degree C above today’s levels, during the Ray Ban outletinter-glacial period 130,000 years ago, sea levels were 7 meters higher than today, crocodiles and hippopotamuses flourished in London, England, and tropical coral reefs were smashed flat by violent storms. At that time our ancestors did not have the technology for deforestation or to pollute the air and water, and CO2 levels were 30% lower than they already are today. Therefore conditions at that time greatly underestimate the changes we will ultimately see even if no more fossil fuels are ever used, much less if CO2 doubles from fossil fuels in the next generation!

4) Adaptation is essential, it is too late to avoid the impacts of global climate change Even if the entire world were to abandon fossil fuel addiction today these changes would still continue for a thousand years, due to excess greenhouse gases already polluting our air. We URGENTLY need large scale funding to adapt to the changes that are inevitably overwhelming all our coastal resources on land and in the sea. Pretending that these changes are not happening and will go away by themselves is inviting certain disaster. Marine Protected Areas, fashionable and worthy as they are, cannot protect corals from the major factors killing them, increasing global warming, new diseases, and land based pollution. Reefs in MPAs are full of dead and dying corals and increasingly barren of fish. Fish populations and diversity will not recover if the habitat is so degraded that it can no longer support the variety and numbers it did in living memory.

5) Restoration is essential to maintain ocean resources Without large scale restoration of degraded habitats to make them capable of supporting larger fish and shellfish populations, there will be few or no fish in the future. Without healthy growing corals, there will be no beaches or tourism income, and in many cases, no islands. Restoration of degraded reef and coastal habitats on a scale that makes a difference must be the number one environmental and ocean management priority of SIDS, not an afterthought. More conventional management will not restore reefs and fisheries without active large scale programs to grow them back: our ecosystems are under such increasing strains that they can no longer recover naturally the way they used to. The damages will rise dramatically unless we apply new methods to grow corals faster and make them more resistant to environmental stress.

6) The technology already exists to restore reefs and fisheries and protect shorelines New Biorock technologies developed in SIDS and applied in around 20 islands increase coral growth rates 3 to 5 times, increase coral survival under lethal high temperatures, pollution, and mud by 16 to 50 times, keep corals alive where they would die, grow reefs where corals cannot recover naturally, create lush ecotourism and fisheries habitats, even denser with fish and shellfish than normal reefs, and turn severely eroding atoll island beaches into growing ones in a few years at a fraction of the cost of concrete or stone breakwaters and with vastly greater ecological benefits. Large scale research and training programs are critically needed to train SIDS students, fisherfolk, and tourism interests to apply the new coral reef and fisheries restoration technologies on the scale needed for sustainable fisheries, tourism, and shore protection.

7) The technology already exists for large-scale ocean energy production in SIDS Ocean currents and temperature gradients contain a vast storehouse of power that is completely untapped. The tidal currents running like clockwork through the reef passes of all Pacific and Indian Ocean islands could provide all their energy needs plus enough to export, if only they would apply already existing turbine and thermal energy technology that languishes undeveloped and unapplied where it is most needed. A tiny fraction of these vast renewable energy resources would be enough to grow coral walls around islands that keep pace with rising sea level and provide mariculture of fish and shellfish without external food inputs, and to grow new islands. A crash program of sustainable marine energy development is needed now in SIDS.

8) SIDS must develop their own capacity to solve their problems SIDS will be hit with a tidal wave of environmental change in coming years and decades that will dwarf anything we have ever seen, and for which we are now wholly unprepared. We will have to evolve or drown. The technology already exists to grow our way out of these crises using local sustainable ocean energy, only if we have the seriousness to develop it. It is time to stop copying incremental and outdated solutions that have failed elsewhere, and develop our own capacity. We have allowed our “development” to be determined by international aid programs that are largely irrelevant, and not based on long-term wide-scale, functional understanding of the changes that have taken place or serious analysis of what is needed to solve them. They do not reflect what we want our islands to be!

9) SIDS Leaders must take the lead funding sustainable development in Mauritius SIDS need to work to create their own solutions and not await the random drift of “expert” overseas consultants peddling “solutions” that have not worked. An immediate effort is needed to develop SIDS research, development, and training institutions to refine these new technologies and apply them on the large scale needed for sustainable ocean and coastal management and a better quality of life for our people. This is our only way out, short of emigration. We call on all SIDS heads of states at the UN Summit in Mauritius to urgently pursue major new international funding for this effort. Our children and grandchildren cannot afford a business as usual approach. Future generations will not forgive our leaders and international funding agencies if they fail to grasp the opportunity to build sustainable SIDS ocean management in Mauritius.