Category Archives: Reef Restoration

Coral growth after one month on new Cozumel Biorock reefs

Posted on by — No Comments ↓

These photos, taken by Torcuato Pulido Mantas in early July 2018, show typical examples of very healthy coral growth after just one month on new Biorock reefs in Cozumel, Mexico. The corals shown were naturally damaged and were rescued from dying when transplanted onto the Biorock reefs a month before. Around half the coral species now being grown are shown in these photos.

The growth and settlement of corals on the Biorock projects and control sites is now being studied by Torcuato Pulido Mantas, with the advice of Dr. German Mendez of the Cozumel Coral Reef Restoration Program and Dr. Tom Goreau of the Global Coral Reef Alliance.

The coral species shown below are: 1) Eusmillia fastigiata, 2) Porites astreoides, 3) Orbicella (Montastrea) annularis, 4) Agaricia agaricites, 5) Porites porites (front) with Agaricia tenuifolia (top), 6) Diploria labyrinthiformis, and 7) Meandrina meandrites.

More photos and video from these projects will be posted later as the project progresses.


Spectacular Biorock coral growth videos

Posted on by — No Comments ↓

 

Spectacular coral growth on Biorock is seen in the three videos linked below.

Pemuteran, Bali

This video shows Biorock reef growth in Pemuteran, Bali at a site that had been almost barren of corals and fishes when the Biorock projects began 15 years earlier.

Gili Trawangan, Indonesia

This video shows the installation of a new Biorock reef in Gili Trawangan, Indonesia, and the growth of corals on it one year later:

Curaçao

This video shows phenomenal growth of staghorn corals in Curaçao shown by time lapse photos:

To see Biorock results for longer time scales (11 years) please look at: https://www.youtube.com/watch?v=Rx8TV9Kd0ns


Dredging threatens exceptional coral reefs in front of Panama Canal

Posted on by — No Comments ↓

An exceptionally healthy coral reef directly in front of the Panama Canal breakwater is threatened by dredging for the new Isla Margarita Port Terminal. Unless strict measures are taken to prevent mud from getting out of the Eastern Channel onto the adjacent coral reef, Panamanians stand to lose this habitat that is part of their national heritage.

Environmental impact assessments made for the port development only considered dead previously dredged areas inside the breakwater, and completely ignored the healthy coral reefs less than a hundred meters away, connected by an open channel to the dredging and landfill sites.

A survey by the Global Coral Reef Alliance (GCRA) and the Galeta Marine Laboratory of the Smithsonian Tropical Research Institution (STRI), at the request of Centro de Incidencia Ambiental (CIAM), found a healthy coral reef with high living coral cover right in front of Isla Margarita and the eastern end of the Panama Canal breakwater. These reefs are not mentioned anywhere in the port’s Environmental Impact Assessment (EIA): the EIA mentions only dead habitat in the area, which would not be affected from dredging nearby. The living coral reefs are only about 100 meters away from the Port dredge and filling operations.

This reef is close to the Isla Galeta Protected Area, and strong measures are needed to protect the highly vulnerable corals from suspended sediments.

This report, and the photos and video attached to it, describes the health status of this extraordinary reef (figures below) and the measures needed to monitor and protect it.

Proposed dredging plans at Isla Margarita, Panama Canal
Port plans. (Image courtesy of the EIA.) Diagonal striped area will become part of the port facility. Seafloor habitat to be filled in and turned into land is shown in stipple.
Proposed port lies right next to healthy coral reef in front of Isla Margarita, just outside the Panama Canal entrance.
The port lies right next to healthy coral reef in front of Isla Margarita. The photos and video in this report were all taken inside the coral reef area shown in blue, just across the breakwater from the area that will filled in for the expanded port.

The full report, with photographic and video documentation can be seen below.

Isla Margarita, Panama image compilation

Isla Margarita, Panama GCRA survey video

After the survey of Isla Margarita reef was done, the project proponents announced without warning that they had made a mistake: they needed 16 times more dredging material to complete the project than they had projected, and most of the required sand for the filling operations would be dredged in Nombre de Dios. Unfortunately, Nombre de Dios represents the center of the best shallow fringing coral reef flats in the entire Caribbean and is a site of global biodiversity importance.

Nombre de Dios Bay. The shallow reef flat of this bay is the best developed in the entire Caribbean.
Port plans. (Image courtesy of the EIA.) Diagonal striped area will become part of the port facility. Seafloor habitat to be filled in and turned into land is shown in stipple.

 


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

Posted on by — No Comments ↓

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.


Global warming is why I have to shovel so much snow today!

Posted on by — No Comments ↓

Wind speeds and climate extremes are driven by atmosphere temperature and pressure differences, which are increasing due to global warming, because temperature differences between land and sea get greater with global warming.

Here is the latest global sea surface temperature and air temperature anomaly maps. The Arctic is exceptionally warm, and most of the North Atlantic is 2 degrees C or more above average, causing much more evaporation over the ocean that turns into snow in a northeaster, and dumps it on my sidewalk.

Also notice the hot water around Australia. The Great Barrier Reef will bleach for the third year in a row if this hot water does not go away very soon. The biggest patch of cool water, in the eastern equatorial Pacific, is the remains of a La Niña that failed to develop and is fast dissipating.

1. OCEAN TEMPERATURE ANOMALY:

2. AIR TEMPERATURE ANOMALY:


Panamanian bleaching refuge reefs discovered with huge ancient corals

Posted on by — 4 Comments ↓

Panamanian Caribbean coral reef temperatures have been very hot in 2017 and have hovered near the bleaching temperature threshold almost all year.

Bleaching began around March, unusually early, but by June waters had cooled down below the threshold, and corals went into a bleaching recovery phase at that time.

Water temperatures rose again above bleaching thresholds later in the year, leading to predictions of a second bleaching event in a single year.

Fortunately a second bleaching event did not happen despite high temperatures, for a very good reason! It has been a very wet rainy season, with heavy rains almost every day, and the sky is grey with dense clouds, or black with thunderheads, with little or no blue sky, so there has been much less sunshine and light stress late in the rainy season compared to in earlier in the season.

In the 1980s my bleaching experiments with Jamaican corals at combinations of different temperature and light levels showed clearly that:

1) Bleaching took place only above a temperature threshold, showing temperature to be the prime trigger for bleaching.

2) Above that temperature, the rate of bleaching was proportional to the light level, indicating that high light level was a secondary factor for bleaching.

Peter Glynn independently did similar experiments in Okinawa, and found the same.

These experiments explained the clear effects of shading of corals on bleaching responses that we studied in the field in the first Caribbean-wide high temperature bleaching event in 1987, why a second bleaching event did not happen in Panama this year, and why the wettest tropics will be a major refuge for corals against global climate change, but only in areas free of direct human impacts such as deforestation, sewage, and agricultural chemicals.

In Jamaica, where high temperature stress was much less than Panama this year, about half the corals were bleached two weeks ago, much more than in Panama. Jamaica has much higher light than Panama, where the skies are grey through most of the rainy season. Belize, which suffered temperature stress between that of Panama and Jamaica this year, but whose climate is more similar to Jamaica, is predicted to have had more severe bleaching in 2017 than either Jamaica or Panama, due to its combination of thermal and light stress. There have been no reports of bleaching from Belize yet. It will be interesting to see if there was mortality there.

The protective effect of high cloudiness in the warmest time of year is uniquely related to the extreme vertical circulation of the equatorial atmosphere right up to the tropopause. When one flies over Panama or Indonesia in the rainy season there is no blue sky to be seen, even at 10 Kilometers height (30,0000 feet). These refuges are limited to equatorial reefs, and Panama, Colombia, and Indonesia are likely to be the most important. As global warming continues, these corals may have a unique chance of survival due to protection by local weather patterns.

It must be emphasized that these are NOT refuges because the corals are more “resilient”, they are refuges because they are lucky to suffer much less stress from high light, on top of high temperature. Many Australian and American coral “scientists” claim any location where corals survive have “resilient” corals, but they have simply been lucky to escape additional stresses for purely local reasons!

In Panama we have recently found two reef refuges with exceptionally high live coral cover, diversity, and health.

1) We have surveyed a reef with 30-40% live coral cover in shallow water right in front of the eastern end of the Panama Canal breakwater. This reef is not only at the high end for coral cover in the Caribbean today, despite a century and a half of severe disturbance from dredging and pollution, it now has higher live coral cover than when it was last studied in the 1980s, an exceptional circumstance! However it is imminently threatened by dredging for a huge new port that will be constructed only a few hundred meters from the reef! GCRA and our Panamanian colleagues will soon issue a report with photos and video of this reef, and recommendations for protecting it.

2) We have found a truly exceptional reef of global significance in the Guna Yala Indigenous Territories with even higher live coral cover. This reef is remote from human habitation, is free of weedy algae caused by high nutrients (and has no Diadema). The shallow reef is covered with huge intact colonies of elkhorn and staghorn corals of sizes and abundance that I have not seen in the Caribbean since the 1970s. They are growing on top of a layer of even larger intact dead corals of the same species and are clearly regenerating because the reef is free of algae and sediment. Also astonishing is the size, age, and ecomorphotype (phenotype) diversity of coral species, including vast numbers of huge ancient coral heads from 1 to 6 meters tall, and up to 8 meters across. Nevertheless the reef is being affected by black band, yellow band, white band, dark spot, and white plague diseases. These diseases have been declining across the Caribbean over the last two decades, as the most susceptible corals die, or as the disease becomes less virulent. The virulence of diseases at this site suggests that the pathogens have only recently reached the area, since most of the corals are healthy intact with only relatively small areas affected so far.

In the 1950s, Thomas F. Goreau, in a paper on gigantism in reef corals, emphasized the importance of exceptional and rare reef habitats where all the corals were huge and healthy. Jamaica used to have about half a dozen such locations, only one now survives in degraded form. This newly discovered remote reef in the Guna Indigenous territories may be one of very few places left in the Caribbean like this, and urgently needs to be protected. GCRA is preparing a photographic report on this extraordinary reef, and will train Guna marine resource managers to monitor and assess such remarkable sites.

Although Guna Yala has long been regarded as having some of the finest coral reefs in the Caribbean, there has been essentially no work on the best reefs. Peter Glynn’s magnificent work has focused on the completely different Panamanian Pacific reefs. The Smithsonian Tropical Research Institution had a marine lab for many years in westernmost Guna Yala. This was located in the most densely populated area of the Indigenous Territory, where reefs have been in poor condition since the 1980s due to severe algae overgrowth of the corals caused by raw sewage. The Gunas threw the Smithsonian out because American coral researchers removed big corals without permission and then arrogantly treated the Gunas as ignorant natives who should mind their own business. As a result, the good reefs in Guna Yala have never been studied, and diving with tanks is strictly banned by the Gunas. There is therefore a crucial need to establish Guna coral reef monitoring, restoration, and protection efforts for these refuge reefs of global importance. There have also been Biorock coral reef restoration projects in Guna Yala for 21 years, which are doing well, and will soon be expanded.

As the current La Niña sets in, Indonesia and Australia are expected, from the well known El Niño Southern Oscillation teleconnections, to leave the “cold” phase they have been in during the long extended El Niño that is just over, and to enter the “warm” phase this southern summer. Already these areas are unusually warm, and there is therefore a strong likelihood of even more severe bleaching in 2018 than in the last three years. It will be very important to identify the major coral refuges in Indonesia that are protected, like Panama, by high clouds in the warm season.


Biorock™ Electric Reefs Grow Back Severely Eroded Beaches in Months

Posted on by — 2 Comments ↓

marine science and engineering

Biorock™ Electric Reefs Grow Back Severely Eroded Beaches in Months

Thomas J. F. Goreau 1,2  and  Paulus Prong 2,3

1 Global Coral Reef Alliance, 37 Pleasant Street, Cambridge, MA 02139, USA
2 Biorock™ Indonesia, Bali 80361, Indonesia
3 Pulau Gangga Dive Resort, Sulawesi 95253, Indonesia
 
Abstract
Severely eroded beaches on low lying islands in Indonesia were grown back in a few months—believed to be a record—using an innovative method of shore protection, Biorock™ electric reef technology. Biorock™ shore protection reefs are growing limestone structures that get stronger with age and repair themselves, are cheaper than concrete or rock sea walls and breakwaters, and are much more effective at shore protection and beach growth. Biorock™ reefs are permeable, porous, growing, self-repairing structures of any size or shape, which dissipate wave energy by internal refraction, diffraction, and frictional dissipation. They do not cause reflection of waves like hard sea walls and breakwaters, which erodes the sand in front of, and then underneath, such structures, until they collapse. Biorock reefs stimulate settlement, growth, survival, and resistance to the environmental stress of all forms of marine life, restoring coral reefs, sea grasses, biological sand production, and fisheries habitat. Biorock™ reefs can grow back eroded beaches and islands faster than the rate of sea level rise, and are the most cost-effective method of shore protection and adaptation to global sea level rise for low lying islands and coasts.
 
(This article belongs to the Special Issue Coastal Sea Levels, Impacts and Adaptation)
 
 
1. Introduction
 
Accelerating global sea level rise is now causing almost all beaches worldwide to erode [1]. The current rate of sea level rise, now 3 mm/year [2], will accelerate greatly in the future as the melting of ice caps increases, masked by shorter term regional fluctuations driven by local weather [3]. IPCC projections of sea level rise are often thought by the public to represent the end point of sea level rise response to fossil fuel CO2, but in fact they are merely points along the first 5, 10, 20— or at most 100—years, of the initial rise of a curve that will continue to increase for thousands of years. The time horizons for IPCCC climate change projections were chosen for political purposes, not for scientific ones, and therefore miss the vast bulk of the real world long-term sea level and temperature responses to increased greenhouse gases [4].
 
Since the ocean holds nearly 93% of the heat in the Earth ocean-atmosphere-soil-vegetation-rock-ice system [5] and it takes around 1500 years for the ocean to mix and turn over [6], Earth’s surface will not fully warm up until after the deep ocean waters, now about 4 degrees above freezing, heat up. Global temperatures and sea levels lag thousands of years behind CO2 increases because of ocean mixing, so we have not yet really begun to feel the inevitable temperature and sea level responses. Because of these politically chosen time horizons, IPCC projections do NOT include more than 90% of the long-term climate response to changing CO2 [4,7-9]. By greatly underestimating the all too real long-term responses of temperature and sea level, they have lulled political decision makers into a false sense of complacency about the magnitude and duration of human-caused climate change or the urgency of reversing them before the really serious impacts hit future generations [4].
 
Improved estimates of long-term global climate impacts are made from actual paleoclimate records of changes in global CO2, temperature, and sea levels from the Antarctic ice cores, deep sea sediments, and fossil coral reefs over the last few million years [7,9]. The last time that global temperatures were 1-2 °C above today’s level, sea levels were about 8 m higher, crocodiles and hippopotamuses lived in swamps where London, England, now stands (Rhodes Fairbridge, 1987, personal communication) [10,11], and CO2 levels were around 270 ppm, around 40% lower than today [7,9]. Comparison of long-term global climate change records suggests that the steady state climate for the present (2017) CO2 concentration of 400 ppm, once the climate system has fully responded, are about 17 °C and 23 m above today’s levels [9]. We are committed to such changes even if there is no further CO2 increase starting right now because of the excess already in the atmosphere, unless that is reduced. No amount of emissions reduction can reduce excess atmospheric CO2, only increased natural carbon sinks with storage in soil and biomass carbon can draw down the dangerous excess in time to avert extreme long term changes [4,8,12], which would last for hundreds of thousands to millions of years. Perhaps the largest cost of adaptation to climate change will be the cost of protecting low lying islands and coasts from being flooded by global sea level rise.
 
Beach erosion is largely controlled by refraction of offshore waves by bottom topography [13]. The reflection of waves by steep cliffs prevents any accumulation of sand at their bases. In contrast, shallow sandy beach fore-shores are almost always protected from waves by reefs, Waves are refracted as water passes through porous and permeable reef structures, without being reflected.
 
Conventional methods of shore protection rely on “hard” solid structures like sea walls and breakwaters that are designed to reflect waves, like rock cliffs. This concentrates all the energy of the wave at the hard, reflecting surface, and the force on the structure itself is twice the momentum of the wave due to the reversal of the wave direction vector [14,15]. The inevitable result of this energy focusing is that first all the sand is washed away in front of the structure, and then is scoured away underneath it until the structure settles, cracks, falls apart, and needs to be rebuilt. These structures protect what is behind them until they fall down, but they cause erosion in front of them and guarantee loss of sediment. All such structures are consequently ephemeral and will fall down sooner or later, depending on how large and strong they are.
 
This is well known to coastal engineers but most feel there is no alternative to impermeable solid walls, even though so called “porous” or “permeable” breakwaters, made of small distributed modules shaped like coral reefs, with holes within structures and passages between them, seem to protect shores with much less material and with greatly reduced reflection. But we could find no experimental or theoretical modeling literature on porous permeable structures like natural coral reef structures found by searching on Google Scholar. Most search results for porous breakwaters were for solid rock walls with crevices between stones rather than reef-like structures with a much greater range of pore and spacing sizes, capable of interacting with waves over larger wavelength ranges.
 
Coral reefs provide the most perfect natural shore protection, dissipating around 97% of incident wave energy by frictional dissipation [16]. Healthy reefs produce sand as well as protect it, and rapidly build beaches behind them. They are sand factories, generating vast amounts of new sand, largely remains of calcareous green and red algae. Every grain of white limestone sand on a tropical beach is the skeletal remains of a living coral reef organism. Once corals die from high temperatures, pollution, or disease, the previously growing and self-repairing reef framework starts to deteriorate and crumble from boring organisms that excavate the rock [17]. Because of the mass mortality of corals around the world caused by global warming [18-23], tropical beaches that were growing until recently have begun rapid erosion, and islands are washing away because of global sea level rise. 
 
Here we describe the results of a novel method of beach restoration—Biorock electric reef shore protection—which avoids the intrinsic physical flaws of hard reflective structures, and which grows beaches back at record rates at a lower cost, with less materials, and with much greater environmental benefits than seawalls. Biorock electric reefs are grown by low voltage electrolysis of sea water, which causes growth of limestone rock minerals dissolved in sea water over steel surfaces, which are completely protected from corrosion [24,25]. Biorock reef structures can be any size or shape, and are the only marine construction material that gets stronger with age and is self-repairing [26]. When grown slowly, less than 1-2 cm/year, this material is several times harder than Portland Cement concrete [25].
 
Biorock shore protection reefs are open mesh frameworks designed to permit water to flow through them, like coral reefs. The size and shape of the structures, and of the holes in them, determine their performance dissipating wave energy. The electricity needed for electrolysis is safe extremely low voltage (ELV) direct current provided by transformers, chargers, batteries, solar panels, wind mills, ocean current generators, or wave energy generators, depending on which source is most cost effective at the site [27].
 
Biorock reefs in Grand Turk survived the two worst hurricanes in the history of the Turks and Caicos Islands, which occurred three days apart and damaged or destroyed 80% of the buildings on the island [28]. Sand was observed to build up around the bases of Biorock reef structures. In contrast, concrete reef balls nearby caused such severe sand scour around and under them that they buried themselves into the sand, digging their own graves. Solid objects, by forcing bottom currents to accelerate as they diverge around them, cause erosion to a depth of about half the height of the structure, and about as wide as the structure height [29]. Biorock reefs, being permeable and porous to waves, had the opposite effect than reef balls, baffling waves, lowering their velocity, and causing sand deposition instead of erosion [30].
 
The first Biorock shore protection reef was built in front of a beach that had washed away at Ihuru Island, North Male Atoll, the Maldives, in 1997. Sand bags were being piled in front of trees and buildings that were falling into the sea, which the hotel thought they had no chance of saving. The Biorock reef was a linear structure parallel to the shore, 50 m long, about 5 m wide, and about 1.5 m high, built on eroded reef bedrock. The structure cemented itself solidly to the limestone bedrock with mineral growth. Waves were observed to slow down as they were refracted through the structure, dissipating energy by surface friction. Sand immediately began to accumulate on the shore line and under and around the reef, and the beach grew back naturally and rapidly in a few years, and stabilized with no further erosion, even though the 2004 Tsunami passed right over it [30]. Corals growing on the Biorock reef had 50 times (5000%) higher coral survival than the adjacent natural coral reef after the 1998 coral bleaching event [25]. For a decade after the bleaching event this resort had the only healthy reef full of corals and fishes in front of their beach in the Maldives. The hotel whose reef and beach were saved by the Biorock project turned the power off, with the result that the corals, no longer protected from bleaching by the Biorock process [31,32], suffered severe mortality in the 2016 bleaching event.
 
The second group of Biorock shore protection reefs were built at three eroding beach locations at Gili Trawangan, Lombok, Indonesia around 2010. These consisted of 4 to 6 separate reef modules designed to break waves up by slowing down separate portions of the wave front and driving the incoming wave front out of coherence, using less structural materials. The Biorock structures are shaped like an upside-down wave, which is optimal for dissipating wave energy, with no vertical surfaces to cause reflections, and so are called Biorock Anti-Wave™ structures (BAW™). Although these structures were small, new beach growth was clearly visible at all sites within 8 months on Google Earth images [30]. One set of structures was of, and creation of a gap underneath it, so that it was on the way to falling down. One year later the gap underneath had completely filled in, and the sand had risen by about a meter to cover half the vertical wall height. The seawall on the neighboring property, built at the same time, but not protected by Bioorck, completely collapsed within a year [30]. The hotels whose beaches had been restored by the projects then turned the power off. Because the structures, no longer maintained, growing, or protected from rusting, are now collapsing, beach erosion has now resumed, with new sea walls being constantly built and falling down.
 
2. Materials and Methods
 
Pulau Gangga, North Sulawesi, Indonesia, has suffered progressive beach erosion. The index maps show its location on various scales (Figure 1a-d), and Google Earth images show the rapid erosion of the beach between 2013 and 2014 (Figure 2a,b). The site is outside the typhoon belt because it is close to the Equator, but it is affected by both the Australian and Indo-China Monsoons. From around December through May the winds and waves are usually from the southeast. A strong southward tidally-modulated current normally sweeps sand from north to south at the site.
 
The formerly wide sand beach had largely washed away by late 2015, leaving an erosion cliff about 1.36 m high along the shore, with trees falling into the sea, and beach pavilion buildings have had to be repeatedly torn down and moved inland. In front of the 200 m of severely eroded beach we built 48 Biorock Anti Wave™ reefs in a staggered design to dissipate wave energy before it hits the beach. The time of installation, January 2016, was just before the monsoon season when erosion takes place on this beach, and was done as fast as possible before waves made installation difficult.
 
48 Biorock Anti Wave™ reefs were deployed in the sea grass beds in front of the eroding beach in January 2016. They were arrayed in twelve groups of four, each group powered by a single power supply located 100 m away on land, connected by electrical cables dug into the sand (Figures 3 and 4a-d). They grow thickest at the bottom, and thinnest on top. The bottom 10-20 cm of the structures were always submerged at low tide, but above this they were exposed to the air for various periods, depending on the tidal cycle. Since structures grow only when and where submerged in salt water, the bottoms are always growing, while the top grows only when submerged, about half of the time. The gabion baskets were deployed in a grid pattern (visible from aerial images below) at low tide in shallow sand, seagrass, and coral rubble.
 
The resort had previously purchased gabion wire baskets for stones to make a breakwater, not knowing that these would quickly rust and fall apart. Because these were already available, they were incorporated into the core of the Biorock Anti Wave™ structures, because the Biorock electrolysis process prevents any rusting of the steel. The rocks are bound in place by growth of minerals over the mesh and by prolific growth of barnacles, oysters, and mussels, preventing rock shifting in heavy surge from breaking the gabion. There are both advantages and disadvantages to the use of rock gabions in Biorock shore protection structures, as they can cause scour by acting as a near solid wall, but they cause more rapid initial results slowing wave erosion than a more open structure that does not incorporate them. Gabions are not an essential part of the design, in fact not using them makes BAW units much faster and cheaper to construct and deploy. In this study gabions were used only for convenience as they had been previously bought and were already on site. Not to include rocks at all relies purely on the growth of a biological reef to provide long-term growing shore protection, instead of that provided by the rocks.
 
The core of each structure was a double gabion basket, 1 m × 1 m × 2 m with the long dimension parallel to the shore. These were placed on the shallow sea floor at predetermined sites, with the long axis parallel to the shore, and filled in with rounded river stones (largely in the 20-50 cm size range). At the start, the rocks had clean surfaces with nothing growing on them. The gabion baskets were overlain with standard welded steel mesh bars used in local construction, spacing 15 cm, dimensions about 2.1 m by 5.4 m. These sheets were curved into an arc to fit over the top of the gabion basket, with the long dimensions at right angles, so that the long axis of the arc was perpendicular to the shore, oriented into the waves coming over the shelf edge coral reef. They were welded across at the base with support rebars and vertical bars to strengthen them. Each unit was carried by four people at low tide, placed over a gabion basket and wired to it with hose clamps and binding wire. The growth of minerals over the steel cement it firmly to any hard rock bottom, and cement sediment around the bases on sand or mud, firmly attaching the structure to the bottom. The structures sit on the bottom under their own weight and that of the rocks they contain.
 
Beach profiles were measured using the U-tube water level measuring method [32]. They are estimated to be accurate vertically to about a millimeter, and horizontally to about a centimeter, by repeated measurements. The beach profile before the start of the experiment was estimated from photographs taken before and after from the same positions with common objects of known size in the images for scale. The accuracy of the pre-project beach profile estimate is thought to be about 10 cm vertically and one meter horizontally. Unfortunately, the apparatus for making rapid and accurate beach profiles was not built until September 2016, eight months after the start of the project. A second set of measurements was made in January 2017, a year after the start of the project, after a severe storm and at several more intervals since then. Initial beach profiles were estimated by measuring the height of the erosion cliff at the start of the project using the measured height of concrete foundations as a scale.

 

(a)
(b)
(c)
Figure 1. The site shown on Google Earth Images of the location of the project (red star) on decreasing scales: (a) Indonesia, (b) North Sulawesi, (c) Pulau Gangga
 
(a) 23 May 2013
(b) 4 January 2014
(c) 15 December 2014
(d) 4 August 2017
Figure 2. Erosion of the beach prior to the project. Google Earth images from 2013 (a) and 2014 (b) showing short term changes in the beach before the project, the last available image taken near low tide a year before the project began in early 2016 (c), and the first image after the project, taken near high tide 1.5 years after (d). Notice the cores of the Biorock Anti Wave™ modules as white spots in the seagrass off the regenerated beach. Beach erosion beyond the project near the pier at the south was caused by storm waves from the southeast and longshore drift sand blockage by the solid rock pier. Waves from the northwest shown in (c) are typical during erosion of this westward facing beach. Note the row of pavilions (dark spots) on the edge of the beach erosion scarp and brown dying trees with roots exposed in (c) and how in (d) the roofs are now hidden by new leaf canopies due to prolific tree leaf regrowth after sand buildup around their roots.
 
 
Figure 3. Soon after start of the project, at low tide (wide angle image). The tops of the reef restoration structures are clearly visible. The eroded curve is the area where the beach grew back.
 
 
(a)
(b)
(c)
(d)
Figure 4. Aerial views, oblique at low tide (a) and vertical at high tide (b) on 12 March 2017, fourteen months after the installation, showing the Biorock Anti Wave™ structures (dark spots in sea grass beds). The northern edge of the project, on the same day at high (c) and low (d) tides. The Red spot in the last image two images is the northern limit of the project.
 
 
3. Results
 
The speed of beach regrowth astonished local residents. The formerly concave beach, ending in an eroding cliff, is now convex in its profile and growing. Large trees that had been dying after sand washed away, exposing their roots to sea water, have leafed out new canopies since the sand built up around their roots.
 
By the time of the first beach profile measurements the eroded beach had almost completely grown back and the erosion scarp, 1.36 m tall, was reduced to about 10 cm. About 80% of the beach grew back in less than 3 months and has continued to grow ever since, even during strong storm conditions that in the past caused severe erosion. Over the course of a year the beach has increased in height by more than a meter, and in width by more than 15 m, over a two hundred meter length, a conservative estimate of an increase of beach sand volume of 3000 cubic meters. Most of the gains occurred in the first two months, but have continued since (Figure 5a-g).
 
The beach growth in the first year was wider at the south than at the north. But there were interesting differences after a severe storm in early January, which caused some erosion of the southern end of the beach, while there was substantial growth of the central and northern sections. Since then the center and north have continued to grow, while the south has continued to erode slowly (Figure 6a-c).
 
(a) November 2015
(b) December 2015
(c) December 2015
(d) May 2016
(e) August 016
(f) November 2016
(g) January 2017
Figure 5. Before & after photos of beach taken at various times: (a) November 2015, beach looking north two months before start of project, tree falling into the sea and roots exposed at beach erosion scarp, (b) December 2015, one month before project, 1.36 m high erosion scarp and foundations of beach pavilions about to collapse near center of beach, (c) December 2015, one month before project, large old tree collapsing into the sea, leaves dying, roots exposed, (d) May 2016, 4 months after project installation, lower branches of fallen tree buried in new beach sand growth, roots buried, new growth, (e) August 2016, seven months after, (f) November 2016, ten months after, (g) January 2017, Twelve months after, soon after a severe storm, looking south. Most of the beach grew after the storm, even though this was the sort of event that had caused heavy erosion in the past. The south end, shown here, was worst affected.
 
 
(a)
(b)
(c)
Figure 6. Beach profiles, measured at different times for the north (a), center (b), and south (c). The Zero reference datum for the central profile is the top of the concrete pillar foundation at the left of the December 2015 photograph. A 1.36 m vertical cliff stood at what is now the zero distance, based on measurements from photographs. Dates of measurements: X and dashed line estimate from January 2016; KEY to symbols: B upward triangle, 21 September 2016; C square, 11 January 2017; D downward triangle, 11 March 2017, E circle, 10 July 2017.
 
There has been prolific growth of hard and soft corals all over the bases of the structures and in intervening areas (Figure 7a-e), prolific growth of sea grasses all around them, dense settlement and growth of barnacles, mussels, and clams on the rocks in the core of the BAW structures, and a rapid increase in juvenile fish and echinoderm populations. In addition, there has been prolific growth of sand-producing calcareous green and red algae around and between the structures.
 
(a)
(b)
(c)
(d)
(e)
Figure 7. Underwater images: One end of a Biorock Anti Wave™ structures at high tide soon after installation (a), growth of barnacles over smooth river stones inside the gabions (b), examples of rapid growth of corals, sea grasses, and other organisms under, over, and around their bases (c–e).
 
Wave fronts are dissipated as they pass through the structures, breaking up the coherence of incoming wave fronts (Figure 8a-c). This dissipation behaves as refraction through permeable structures. But the wave interaction can include a reflective component once structures have grown to be solid with all pores filled in, or if the rock fill is too impermeable to transmit wave pressure through intervening spaces. In that case, sand-eroding scour will be caused, while purely refractive dissipation increases sand accumulation underneath and behind the structure. There is also a diffractive component caused by wave interaction with the metal structure spacing and lattice spacing, which appeared to damp waves at spatial scales that range from the spacing of the metal grid used (0.1 m), the size of the modules (1-5 m), and the spacing of the modules (roughly 10 m).
(a)
(b)
(c)
Figure 8. Diffraction of energy. Incoming wave energy dissipated by interaction with structure these photographs were taken in rapid succession, the middle picture appears brighter because of break in the clouds, and the photographer moved between the first two images. (a) approaching wave, (b) wave starting to interact with mesh, (c) wave energy dissipated by friction.
 
4. Discussion
 
We are not aware of any other case in which a badly eroded beach has been grown back so uickly and naturally. In addition, the Biorock reefs have caused prolific growth of corals, barnacles, oysters, mussels, and seagrass, and created a juvenile fish habitat [30]. 
 
Biorock reefs can be any size or shape. Mineral growth extends up to the high tide mark. They can be built entirely subtidal, as at Ihuru, entirely exposed at low tide as at Gili Trawangan, or have only the tops exposed at low tide, as at Pulau Gangga. Since the structures grow only when submerged, those in the intertidal grow most on the bottom, and least on the top. The structures attach themselves solidly to bedrock, and cement loose sand around their bases. Whether the structures are entirely submerged or partially exposed affects their wave mitigating performance. Those that are fully submerged are never visible from shore and generate real coral reef communities or oyster and mussel reefs in muddier or colder waters. Those reefs located in the intertidal zone are visible at low tide, which may be aesthetically objectionable to those who want a clear ocean view from the beach, but they are more effective in protecting the shore if there is a storm during high tide, which would pass over deeper reef structures.
 
The size, shape, and spacing of the modules affect their performance, and cost. What is astonishing is that record beach growth was achieved with far less material and far lower cost than sea wall or a breakwater. Conventional reinforced concrete structures are made by first building a reinforcing bar frame, and the steel is a very small part of the total cost compared to cement, stone, wooden forms, and labor. Since steel in reinforced concrete structures invariably rusts, expands, and cracks the concrete, such structures have finite lifetimes, especially in salty coastal air. 
 
Biorock structural steel is completely protected from rusting, and the continuous growth of hard minerals makes it constantly stronger, and able to grow back first in areas that are physically damaged. The cost is far less than a reinforced concrete structure of the same size and shape, because instead of cement, rocks, labor, and wooden forms we simply provide an electrical supply instead. Estimates of Biorock reef costs range from $20-1290/m of shoreline depending on the size of the reef grown, while other methods range from $60-155,000/m, or 3-120 times more expensive [16]. The amount of electricity used is small, the entire Pulau Gangga beach restoration project uses about one air conditioner worth of electricity.
 
Shore protection provided by Biorock includes both production of new sand by prolific growth of calcareous algae around them, and physical protection from sand erosion by wave energy dissipation. The results of beach growth after the project was installed indicate that beach sand accumulation is a very dynamic function of wave and current interactions with reef structures. Biorock reef structures physically dissipate wave energy and reduce erosion at the shoreline, while also generating new sand. They should slow down transport of sand by north to south tidal currents at the site. That, and the interplay of the structures with waves coming from different directions, may explain why the unusual January 2017 storm seems to have transported sand in the reverse of the usual direction. Further measurements will reveal if this trend continues, or is reversed by sand production from increased calcareous algae growth around the structures.
 
Wave energy dissipation due to friction at the surface of the growing limestone minerals produced by the Biorock process is very quickly exceeded by the much larger, and rougher, surfaces provided by the prolific growth of corals, barnacles, sea grass, and all other living marine organisms as the structure becomes rapidly overgrown. The size, shape, and spacing of the structures, as well as the reef organisms growing on them, affect their performance as wave absorbers, and their designs can be readily changed by adding, or removing, sections as needed. Such structures can be designed to be oyster, mussel, clam, lobster, or fish habitat for highly productive and sustainable mariculture.
 
Biorock structures interact with waves over a very broad range of wavelengths, and are expected to produce wave diffraction on wavelength scales similar to the spacing of the structures—about 10 m—and over the spacing of the mesh—about 10 cm. Since the growing, self-repairing Biorock structures cannot be modelled by conventional hydrodynamic modeling schemes, it will be important to make physical measurements of wave energy around such structures to evaluate actual performance, and to optimize them for beach growth purposes.
 
The initial results of this project resulted in extraordinary beach growth, which could be improved with further experimentation under a wider range of conditions, and should be much more widely applied as a cost-effective beach restoration solution that uniquely restores marine ecosystem  services.
 
5. Conclusions
 
We have grown back severely eroded beaches naturally in months by growing Biorock electric reefs in front of them. These structures cost far less than sea walls or breakwaters and work on entirely different physical principles. They restore marine ecosystems as well as beaches. The exceptionally rapid growth of corals on them [31,33] provides additional shore protection, and the rapid growth of sand-producing calcareous algae on and around them produces new biological sand supplies. These structures can easily keep pace with global sea level rise because solid hard electrochemical minerals can be grown upwards at rates up to 2 cm/year—around 5 times faster than sea level rise—and grow still much faster when corals, oysters, mussels, and other calcareous organisms cover them. As a result, Biorock shore protection reefs quickly turn eroding beaches into growing ones, can protect entire islands and even grow new ones. Biorock is the most cost-effective technology for protecting eroding coasts, for restoring fisheries habitat, and is critically needed to save the low-lying islands and coasts now threatened by global sea level rise, and the billions of coastal people who will become climate refugees if global warming is not rapidly reversed [4,12].
 
6. Dedication
 
This paper is dedicated to the memory of the late Wolf Hilbertz, who first invented the Biorockprocess of growing minerals in the ocean in 1976, and who foresaw all its applications, including shore protection.
 
Acknowledgments: We thank the entire management and staff of Pulau Gangga Dive Resort and its parent company, Lotus Resorts, for their willingness to try new, better, more natural and effective approaches to shore protection. Lotus Resorts paid for all materials, equipment, domestic travel, and time. The authors thank them deeply for their willingness to pioneer innovative methods of shore protection. We also thank Lori Grace for providing funds for a round trip ticket to Indonesia for Thomas J. F. Goreau to construct the device to measure beach profiles. We thank the anonymous reviewers for their constructive suggestions that have improved the original draft.
 
Author Contributions: T.J.F.G. and P.P. conceived, designed, built, and installed the first four Biorock Anti Wave modules and connected them to power; P.P. then built and installed the rest. T.J.F.G. analyzed the data; contributed reagents/materials/analysis tools; and wrote the paper. Although they are not listed as authors, because they did not work on the projects in the water, the entire management and staff of Lotus Resorts, operators of Pulau Gangga Dive Resort, played absolutely crucial roles in the design, logistics, funding, advice, information, and support for the work described. T.J.F.G. is a co-inventor of the Biorock electric technology of marine ecosystem restoration.
 
Conflicts of Interest: The authors declare no conflict of interest.
 
References
 
1.      Pilkey, O.H.; Neal, W.J.; Bush, D.M. Coastal erosion; In Coastal Zones and Estuaries. Encyclopedia of Life
Support Systems (EOLSS); UNESCO: Paris, France, 1992.
2.      Dieng, H.B.; Cazenave, A.; Meyssignac, B.; Ablain, M. New estimate of the current rate of sea level rise
from a sea level budget approach. Geophys. Res. Lett. 2017, doi:10.1002/2017GL073308.
3.      Nieves, V.; Marcos, M.; Willis, J.K. Upper-Ocean Contribution to Short-Term Regional Coastal Sea Level Variability along the United States. J. Clim. 2017, 30, 4037-4045.
4.      Goreau, T.J. Global biogeochemical restoration to stabilize CO2 at safe levels in time to avoid severe climate\change impacts to Earth’s life support systems: Implications for the United Nations Framework Convention on Climate Change. In Geotherapy: Innovative Technologies for Soil Fertility Restoration,  Carbon Sequestration, and Reversing Atmospheric CO2 Increase; Goreau, T.J., Larson, R.G., Campe, J.A., Eds.; CRC Press: Boca Raton, FL, USA, 2014.
5.      Levitus, S.J.; Antonov, I.; Boyer, T.P.; Baranova, O.K.; Garcia, H.E.; Locarnini, R.A.; Mishonov, A.V.; Reagan, J.R.; Seidov, D.; Yarosh, E.S.; et al. World ocean heat content and thermosteric sea leve change (0-2000 m), 1955-2010. Geophys. Res. Lett. 2012, 39, L10603, doi:10.1029/2012GL051106.
6.      Gebbie, G.; Huybers, P. The Mean Age of Ocean Waters Inferred from Radiocarbon Observations: Sensitivity to Surface Sources and Accounting for Mixing Histories. J. Phys. Oceanogr. 2012, 42, 291-305.
7.     Goreau, T.J. Balancing atmospheric carbon dioxide. Ambio 1990, 19, 230-236.
8.     Goreau, T.J. Tropical ecophysiology, climate change, and the global carbon cycle. In Impacts of Climate Change on Ecosystems and Species: Environmental Context; Pernetta, J., Leemans, R., Elder, D., Humphrey, S., Eds.; International Union for the Conservation of Nature: Gland, Switzerland, 1995; pp. 65-79.
9.      Rohling, E.J.; Grant, K.; Bolshaw, M.; Roberts, A.P.; Siddall, M.; Hemleben, C.; Kucera, M. Antarctic temperature and global sea level closely coupled over the past five glacial cycles. Nat. Geosci. 2009, doi:10.1038/NGEO557.
10.     Koenigswald, W.V. Mammalian faunas from the interglacial periods in Central Europe and their stratigraphic correlation. In The Climate of Past Interglacials; Sirocko, F., Claussen, M., Sanchez Goñi, M.F., Litt, T., Eds.; Elsevier: Amsterdam, The Netherlands, 2006; pp. 445-454.
11.     Koenigswald, W.V. Discontinuities in the Faunal Assemblages and Early Human Populations of Central and Western Europe During the Middle and Late Pleistocene. In Continuity and Discontinuity in the Peopling of Europe: One Hundred Fifty Years of Neanderthal Study, 101 Vertebrate Paleobiology and Paleoanthropology; Condemi, S., Weniger, G.-C., Eds.; Springer Science + Business Media B.V.: Dordrecht, The Netherlands, 2011.
12.     Goreau, T.J. The other half of the global carbon dioxide problem. Nature 1987, 328, 581-582.
13.     Munk, W.H.; Traylor, M.A. Refraction of Ocean Waves: A Process Linking Underwater Topography to Beach Erosion. J. Geol. 1947, 55, 1-26.
14.     Wiegel, R.L. Oceanographical Engineering; Dover: New York, NY, USA, 1992.
15.     Schiereck, G.J. Introduction to Bed, Bank, and Shore Protection: Engineering the Interface of Soil and Water; VSSD: Delft, The Netherlands, 2006.
16.      Ferrario, F.; Beck, M.W.; Storlazzi, C.D.; Micheli, F.; Shepard, C.C.; Airoldi, L. The effectiveness of coral reefs for coastal hazard risk reduction and adaptation. Nat. Commun. 2014, doi:10.1038/ncomms4794.
17.      Goreau, T.F.; Goreau, N.I.; Goreau, T.J. Corals and Coral Reefs. Sci. Am. 1979, 241, 124-136.
18.      Goreau, T.J. Testimony to the National Ocean Policy Study Subcommittee of the United States Senate Committee on Commerce, Science, and Transportation, S. HRG. 101-1138: 30-37; US Government Printing Office: Washington, DC, USA, 1991
19.     Hayes, R.L.; Goreau, T.J. The tropical coral reef ecosystem as a harbinger of global warming. World Resour. Rev. 1991, 3, 306-322.
20.     Goreau, T.J.; Hayes, R.L.; Clark, J.W.; Basta, D.J.; Robertson, C.N. Elevated sea surface temperatures correlate with Caribbean coral reef bleaching. In A Global Warming Forum: Scientific, Economic, and Legal Overview; Geyer, R.A., Ed.; CRC Press: Boca Raton, FL, USA, 1993; pp. 225-255.
21.      Goreau, T.J.; Hayes, R.L. Coral bleaching and ocean “hot spots”. Ambio 1994, 23, 176-180.
22.      Goreau, T.J.; Hayes, R.L. Global coral reef bleaching and sea surface temperature trends from satellite-derived Hotspot analysis. World Resour. Rev. 2005, 17, 254-293.
23.      Goreau, T.J.; Hayes, R.L.; McAllister, D. Regional patterns of sea surface temperature rise: Implications for global ocean circulation change and the future of coral reefs and fisheries. World Resour. Rev. 2005, 17, 350- 374.
24.      Hilbertz, W.H.; Goreau, T.J. Method of Enhancing the Growth of Aquatic Organisms, and Structures Created Thereby. U.S. Patent No. 5,543,034, 6 August 1996.
25.      Goreau, T.J.; Hilbertz, W. Marine ecosystem restoration: Costs and benefits for coral reefs. World Resour. Rev. 2005, 17, 375-409.
26.      Goreau, T.J. Marine electrolysis for building materials and environmental restoration. In Electrolysis; Kleperis, J., Linkov, V., Eds.; InTech Publishing: Rijeka, Croatia, 2012; pp. 273-290.
27.      Goreau, T.J. Marine ecosystem electrotherapy: Practice and theory. In Innovative Technologies for Marine Ecosystem Restoration; Goreau, T.J., Trench, R.K., Eds.; CRC Press: Boca Raton, FL, USA, 2012.
28.      Wells, L.; Perez, F.; Hibbert, M.; Clervaux, L.; Johnson, J.; Goreau, T. Effect of severe hurricanes on Biorock coral reef restoration projects in Grand Turk, Turks and Caicos Islands. Rev. Biol. Trop. 2010, 58, 141-149.
29.      Shyue, S.-W.; Yang, K.-C. Investigating terrain changes around artificial reefs by using a multi-beam  echosounder. ICES J. Mar. Sci. 2002, 59, S338-S342, doi:10.1006/jmsc.2002.1217.
30.     Goreau, T.J.; Hilbertz, W.; Azeez, A.; Hakeem, A.; Sarkisian, T.; Gutzeit, F.; Spenhoff, A. Restoring reefs to grow back beaches and protect coasts from erosion and global sea level rise. In Innovative Technologies for Marine Ecosystem Restoration; Goreau, T.J., Trench, R.K., Eds.; CRC Press: Boca Raton, FL, USA, 2012.
31.     Goreau, T.J. Electrical stimulation greatly increases settlement, growth, survival, and stress resistance of marine organisms. Nat. Resour. 2014, 5, 527-537, doi:10.4236/nr.2014.510048.
32.      Andrade, F.; Ferreira, M.A. A Simple Method of Measuring Beach Profiles. J. Coast. Res. 2006, 22, 995-999, doi:10.2112/04-0387.1.
33.      Goreau, T.J.; Cervino, J.; Polina, R. Increased zooxanthellae numbers and mitotic index in electrically stimulated corals. Symbiosis 2004, 37, 107-120.
 
 © 2017 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution 
(CC BY) license (http://creativecommons.org/licenses/by/4.0/).

The death of “resilience”: Hurricane recovery of coral reefs destroyed by global warming, pollution, and pathogens

Posted on by — 2 Comments ↓

The remaining coral reefs of Barbuda, Saint Barthelemy, Saint Martin, Anguilla, Tortola and the British Virgin Islands, Grand Turk, Cuba, Dominica, and Puerto Rico have all been devastated in recent weeks by direct hits from the eye of the strongest hurricanes on record. Having dived extensively around all of these islands except for Anguilla, none of these areas had remaining shallow reefs in good condition before the event. The question now is how quickly they will recover?

The first study of hurricane impacts on coral reefs was after Hurricane Charlie, which devastated Jamaica in 1951, and tore the roof off of our home. After the hurricane, my father dived in the reefs and found large areas of shallow elkhorn and staghorn coral smashed to rubble, and large old coral heads cracked and toppled (Goreau, 1956). By the mid 1950s, about half of the reef had grown back (see photo below), and by the late 1950s there were almost no traces of the damage visible because vigorous coral settlement and growth rapidly colonized the damaged areas.

That is why we always said that healthy coral reefs could recover from near-total hurricane devastation in a decade or so (Goreau, Goreau, & Goreau, 1979). But Jamaican coral reefs never recovered from Hurricane Allen (1979), Gilbert (1989), and Ivan (2004) because by then the coral reef ecosystem’s intrinsic internal biological resilience had already been destroyed by stresses exceeding their capacity to adapt.

Bob Trench, Belize’s most famous scientist and the world’s top expert on coral symbiosis and I have recently looked at the oldest underwater photographs of Belize coral reefs taken in 1968, 7 years after the worst hurricane in Belize history, Hurricane Hattie, had devastated Belizean coral reefs and mangroves (Stoddart, 1963). These include the reefs that Bob grew up on fishing before Hurricane Hattie. The elkhorn and staghorn zones had already largely recovered at that point. So in the 1960s, Belize reefs, like Jamaican reefs in the 1950s, were still able to recover from devastating physical damage in a decade.

Recovery on this scale is now completely impossible because global warming, nutrient pollution, and diseases have degraded or destroyed the capacity of the most critical ecosystem framework-building coral species to survive or recover from. Dead areas destroyed by hurricanes now stay dead, are overgrown by weedy algae indicating sewage pollution, or are colonized by communities of weedy coral species, which most people confuse with real coral reefs because they have never seen one.

The old massive coral reef walls that surrounded most Caribbean islands when I was a boy still remain as a dead reef in only a few lucky spots where they have not yet been torn apart by bio-erosion and wave forces, but they have completely vanished in most places, where there is no trace remaining of the magnificent reefs that once stood there.

Coral reefs were resilient and would spring back in devastated areas on decadal scales in the old days only because there was no human-caused climate change, pollution, and new diseases. That was because devastation by storms or dredging were brief in time and space, and damaged areas grew right back from the healthy reef all around the damaged areas. Now there is no healthy surrounding reef, and no spatial or temporal refuges left from high temperatures, pollutants, and pathogens that are accelerating everywhere.

It is time that the bogus fraud of “coral reef resilience” be buried forever. This vile lie, based on invincible ignorance of fundamental coral biology, has been pimped for the last 30 years by governments and Big International NGOs (BINGOs) in order to prevent efforts to eliminate the real root causes of coral reef destruction, and to prevent serious efforts to restore them, thereby deliberately sentencing coral reefs to death from preventable causes.

goreau, biorock, Jamaica, 1950, coral reef
Image: TF. Goreau 1950’s

Before and After : Biorock Electric Reefs in Curaçao

Posted on by — No Comments ↓

Before and After time-lapse series by Michael Duss showing spectacular coral growth on Biorock electric reefs in Curaçao.

This video shows the coral development at our BioRock project in Curacao with the status September 2017. The video was created by the Curacao Divers for the Curacao BioRock Foundation.

 


Shark bites deterred by Biorock Electric Coral Reef Projects

Posted on by — No Comments ↓

Coral reefs are the most biologically diverse marine ecosystems and provide vital ecosystem services. Global warming, deteriorating water quality, overharvesting, and other threats are accelerating coral reef decline. An innovative coral reef restoration method, invented by Prof. Wolf Hilbertz and Dr. Tom Goreau, Biorock® technology, uses electricity to make corals to grow faster and healthier, and survive lethal bleaching temperatures.

A study entitled “The effects of Biorock-associated electric fields on the Caribbean reef shark (Carcharhinus perezi)and the bull shark (Carcharhinus leucas)” just published in ANIMAL BIOLOGY by Marcella Uchoa, Craig O’Connell and Tom Goreau investigated how electric fields associated with Biorock reefs influence behavior of sharks and bony fishes. It is well known that sharks can feel extremely weak electrical fields through specialized electroreceptors called ampullae of Lorenzini.

They studied behavioral responses of two shark species, the bull shark (Carcharhinus leucas) and the Caribbean reef shark (Carcharhinus perezi) and several bony fish species towards weak electric fields in Bimini, Bahamas. Statistical analyses of 90 trials found both shark species fed the least, and avoided bait food they knew was there, when the electric field was turned on. Sharks approached the bait yet completely missed and exhibited signs of disorientation. Since detection of electric fields by sharks is important in the final phases of prey capture, Biorock generated electric fields clearly confused them. In contrast, bony fish feeding behavior was not affected by the electrical field.

This study demonstrates a need for future studies with more species of shark and fish species around Biorock electrical reef restoration projects, since deterrence of sharks, as top predators, may impact ecosystem balance”, said Marcella Uchoa, a Brazilian student who did the study for her Masters Degree in the RIMER Erasmus Mundi Marine Science Program at the University of the Basque Country, Spain. “Since this initial study demonstrated that Biorock reefs elicit close-range shark deterrent responses, further testing is warranted to assess the ability for these systems to serve as either a personalized shark deterrent or a shoreline bather protection system” said Craig O’Connell, head of the O’Seas Conservation Foundation, which specializes in shark behavior and conservation. Tom Goreau, President of the Global Coral Reef Alliance added that “Biorock electric reefs could benefit humans and sharks as well as corals and fishes. The electrical fields inhibit attacks in the vicinity of restoration projects, but would not affect sharks further away, so it helps preserve coral reefs, fishes, humans, and sharks at the same time, while avoiding the damage and bycatch from nets, baited hooks on lines, and poisons”.

Biorock, shark, bite, Bimini, Goreau, Hilbertz
Marcella Uchoa preparing fish food for sharks in Bimini (photograph by Craig O’Connell)

For more information please contact: info (think) globalcoral.org