Category Archives: Articles & Dossiers

Robert Young: Seaward of Common Sense? SC Needs to Put an End to Building on the Beach

Sand bags and beach erosion at Isle of Palms, Charleston County, South Carolina. Photo source: ©© Kevin Oliver


South Carolina’s beautiful beaches are a vital component of this state’s economy. Managing them wisely is critical to the health of the economy and to ensuring that state and local tax dollars are not wasted on futile efforts to protect homes needlessly placed in areas of obvious high hazard…

Read Full Article, The State

“The Rising Sea”A Book by Orrin H. Pilkey and Robert Young

Finding Floating Forests

Miramar beach, California. Photograph: © SAF — Coastal Care

By Laura Rocchio, Paul Przyborski & Mike Carlowicz / NASA Earth Observatory;

If you have ever walked along the California coast, you’ve likely had to navigate around clumps of seaweed. Before it was thrown up by the surf and left to dry on the beach, that seeming jetsam was part of a majestic underwater forest just offshore.

Giant kelp forests are among Earth’s most productive habitats, and their great diversity of plant and animal species supports many fisheries around the world. The kelp, or Macrocystis, that make up these underwater forests truly are giant. They are the world’s largest marine plants and regularly grow up to 35 meters (115 feet) tall; the largest giant kelp on record stood 65 meters (215 feet) tall. Divers have compared swimming through mature kelp forests to walking through redwood forests.

Unlike redwoods, giant kelp are ephemeral. They live for seven years at most, and often they disappear before that because of winter storms or over-grazing by other species. As fishermen know, giant kelp forests can appear and disappear from season to season, from year to year. But is there a long-term trend or cycle at work?

A few years ago, Jarrett Byrnes was in a bit of a quandary over these disappearing forests. As part of his postdoctoral research at the University of California–Santa Barbara (UCSB), he was studying giant kelp at four National Science Foundation-funded sites off the coast. Since 2000, biologists had been using this Long-Term Ecological Research (LTER) site to make monthly in situ measurements of giant kelp. But Byrnes and his colleagues found that they often could not make measurements in winter because rough seas made the diving unsafe.

Storms remove quite a bit of the canopy in the winter. Sometimes they even remove whole forests if the storms are large enough,” Byrnes explained. “But getting to those sites with regularity in the winter gets very challenging.” Most of the diving had to wait until summer, and by then the kelp had largely recovered or changed, making it difficult to measure how much damage the storms had done.

Strong waves, often fueled by winter storms, can remove large patches of offshore kelp and deposit them on the beaches of California. (Photo courtesy of Chad King / NOAA MBNMS)

To complicate matters, kelp forests have different seasonality depending on where they are. For instance, the forests along the Central California coast are at their maximum size in the fall; in Southern California, they often reach their peak in the winter and spring. How could these dynamic habitats be monitored more frequently without putting divers at risk?

Kyle Cavanaugh, then a UCSB graduate student, had an idea. “These forests change so rapidly and on a variety of different time scales—months to years to decades—so we needed a long record with consistent, repeated observations,” Cavanaugh said. He devised a method to use Landsat satellite data to monitor kelp forests.

Landsat 8 can detect near-infrared wavelengths of light that make it easier to spot offshore kelp forests. (NASA Earth Observatory image by Mike Taylor, using Landsat data from the U.S. Geological Survey)

A few things made Landsat an obvious resource. Since the 1970s, the satellites have had a regular collection schedule (twice monthly). Their data and images are managed by the U.S. Geological Survey and are reliably stored in an archive that dates back more than forty years. And Landsat’s images are calibrated, or standardized, across different generations of satellites, making it possible to compare data collected across several decades.

Landsat measures the energy reflected and emitted from Earth at many different wavelengths. By knowing how features on Earth reflect or absorb energy at certain wavelengths, scientists can map and measure changes to the surface. The most important feature for the kelp researchers is Landsat’s near-infrared band, which measures wavelengths of light that are just outside our visual range. Healthy vegetation strongly reflects near-infrared energy, so this band is often used in plant studies. Also, water absorbs a lot of near-infrared energy and reflects little, making the band particularly good for mapping boundaries between land and water.

“The near-infrared is key for identifying kelp from surrounding water,” Cavanaugh explained. “Like other types of photosynthesizing vegetation, giant kelp have high reflectance in the near infrared. This makes the kelp canopy really stand out from the surrounding water.”

For Byrnes, the approach was a breakthrough: “This meant we could see the forests I was analyzing right after storms hit them.”

Growing Fast and Holding Fast

Giant kelp are fast growers, and they thrive in cold, nutrient-dense waters, particularly where there is a rocky and shallow seafloor (5 to 30 meters or 15 to 100 feet). They attach to the seafloor with small root-like structures (haptera) also called, appropriately enough, a holdfast. The holdfast supports a stipe, or stalk, and leaf-like blades that float thanks to air-filled pockets (pneumatocysts). The fronds create dense floating canopies on the water surface, yet these massive plants rely on holdfasts barely 60 centimeters (24 inches) wide to keep them rooted and alive.

Given the right balance of conditions, giant kelp can grow as much as 50 centimeters (1.6 feet) per day, and this robust growth makes it possible for kelp fronds to be commercially harvested. Giant kelp have been plucked from California waters since the early 1900s, and they have long appeared in products like ice cream and toothpaste. At the industry’s peak, large ships using lawnmower-like machinery could harvest more than 200,000 wet tons annually.

Kelp fronds create dense floating canopies near the water surface. Kelp have been harvested for a century for commercial products; they also pose trouble for boat propellers. (Photo courtesy of Chad King / NOAA MBNMS)

“The satellite could definitely see the effects of harvesting, but the kelp recovery was very fast,” said Tom Bell, a UCSB researcher and collaborator with Byrnes and Cavanaugh.

Today, only a few thousand tons of giant kelp are harvested each year, some by hand and some by mechanical harvesters. The kelp can be trimmed no lower than 4 feet below the water surface, and this sustainable harvesting is the equivalent of humans getting a haircut. Studies have shown that negative affects are negligible, although some fish populations are temporarily displaced.

Giant kelp thrive in cold, nutrient-dense waters, particularly where there is a rocky, shallow seafloor. The California coast provides ideal habitat. (NASA Earth Observatory image by Mike Taylor, using Landsat data from the U.S. Geological Survey)

For years, scientists debated whether it was nutrient availability or grazers (not human harvesters, but sea urchins) that had the most influence over kelp forest health, size, and longevity. After using Landsat to look at long-term trends, and comparing those trends to known differences between Central and Southern California waters, Cavanaugh and LTER lead Daniel Reed found that a third force—wave disturbance—was the kingmaker of kelp dynamics. Strong waves generated by storms uproot the kelp from their holdfasts and can devastate the forests far more than any grazer.

Kelp Research Branches Out

When giant kelp first brought Byrnes and Cavanaugh together at UCSB, their work was largely California-focused. The data they collected from the LTER study sites off Santa Barbara became a tremendous resource for kelp researchers. But that work covered four discrete locations for a species found all over the world.
Giant kelp can grow anywhere there are cold, shallow, nutrient-rich waters and a rocky seafloor. Conditions for kelp growth have historically been ideal along the west coast of North America, as well as Chile, Peru, the Falkland Islands, South Africa, and around Australia, New Zealand, and the sub-Antarctic islands.

More and more often these days, though, the conditions are less ideal. Climate change has brought a trifecta of kelp scourges: warmer waters with fewer nutrients; new invasive species; and severe storms.

After a recent meeting on kelp forests and climate change, Byrnes, Cavanaugh, and other colleagues set out to consolidate all of the available kelp forest data from around the world. They wanted to take a step toward understanding how climate change is affecting kelp globally, but they quickly discovered they had a sparse patchwork of information.

Byrnes was struck with a thought. They had used Landsat to expand their studies across time, so why not use Landsat to expand their studies around the world? Could Landsat be used to establish global trends in kelp forest extent? The answer was yes, but the problem was eyeballs.


Natural color (top) and near-infrared (bottom) images from Landsat 8 show the kelp-rich waters around California’s Channel Islands. Clouds, sunglint, and sea foam make it difficult for computer programs to detect the location of forests. So far, human eyes work better. (NASA Earth Observatory image by Mike Taylor and Jesse Allen, using Landsat data from the U.S. Geological Survey)

Unlike research on terrestrial vegetation—which uses Landsat data and powerful computer processing arrays to make worldwide calculations—distinguishing kelp forests requires manual interpretation. While kelp forests pop out to the human eye in near-infrared imagery, computers looking at the data numerically can confuse kelp patches with land vegetation. Programs and coded logic that separate aquatic vegetation from land vegetation can be confounded by things like clouds, sunglint, and sea foam.

“I’ve spent many, many years staring at satellite imagery trying to come up with new ways to extract the kelp signal from that imagery, and it is very time and work intensive,” said Cavanaugh, now based at the University of California–Los Angeles. “But automated classification methods just don’t produce acceptable levels of accuracy yet.”

Byrnes, now based at the University of Massachusetts–Boston, realized that the best way to study global kelp changes was to turn to citizen scientists. Byrnes and Cavanaugh put together a science team and joined with Zooniverse, a group that connects professional scientists with citizen scientists in order to help analyze large amounts of data. The result was the Floating Forests project.

Getting Help from a Few Thousand Friends

The Floating Forest concept is all about getting more eyeballs on Landsat imagery. Citizen scientists—recruited via the Internet—are instructed in how to hunt for giant kelp in satellite imagery. They are then given Landsat images and asked to outline any giant kelp patches that they find. Their findings are crosschecked with those from other citizen scientists and then passed to the science team for verification. The size and location of these forests are catalogued and used to study global kelp trends.

In addition to examining the California coast, which Byrnes and Cavanaugh know well, the Floating Forests project has also focused on the waters around Tasmania. Tom Bell and collaborators in Australia and New Zealand have noticed dramatic declines in giant kelp forests there over the past few decades. The decline has been so rapid and extensive that giant kelp are only found now in isolated patches.


Off the east coast of Tasmania, 95 percent of the kelp has disappeared since the 1940s. False-color Landsat images from September 1999 (top) and September 2014 (bottom) provide evidence of recent kelp forest disturbance. (NASA Earth Observatory image by Mike Taylor, using Landsat data from the U.S. Geological Survey)

Off Tasmania’s east coast, 95 percent of the kelp has disappeared since the 1940s. The loss has been so stark that the Australian government listed Tasmania’s giant kelp forests as an “endangered ecological community“— the first time the country has given protection to an entire ecological community. The loss is so stunning because this was a place where kelp forests were once so dense that they merited mention on nautical charts.

Cool, subarctic waters once bathed Tasmania’s east coast, but warmer waters (as much as 2.5ºC (4.3ºF) warmer) have brought many invasive species that feast on giant kelp. Compounding the matter, the overfishing of rock lobsters has removed a key predator of the long-spined sea urchins (which eat kelp). The ecosystem’s new protected status could help curb overfishing and restore the lobsters, which would help diminish the threat from sea urchins.

Using Landsat to monitor the kelp forests and establish trends may shed more light on what is happening off of Tasmania. “We believe the data from Floating Forests will allow us to better understand the causes of these declines,” said Cavanaugh.

As of November 2014, more than 2,700 citizen scientists had joined Byrnes and Cavanaugh to look for kelp in 260,000 Landsat images. All combined, the citizen scientists have now made more than one million kelp classifications. The response has exceeded expectations, and the project has been expanded faster than originally planned.

Already a discovery has been made. A citizen scientist found a large patch of giant kelp on the Cortez Bank, an underwater seamount about 160 kilometers (100 miles) off the coast of San Diego. While giant kelp on this submerged island—which comes within feet of the surface at some points—had been documented by divers and fishermen in the past, the full extent of the kelp beds was unknown.

A citizen scientist found satellite evidence of an outlying kelp forest that was previously known only to divers and local fishermen. (NASA Earth Observatory image by Mike Taylor, using Landsat data from the U.S. Geological Survey)

“The first few months of Floating Forests have been a huge success, and we are hopeful that we will soon be able to expand the project to other regions,” Cavanaugh said. “Our ultimate goal is to cover all the coastlines of the world that support giant kelp forests.”

To learn how to participate in the Floating Forests project,visit their web page.

Original Article and Learn More, NASA / Earth Observatory

Why Sand Is Disappearing ; By John R. Gillis

Illegal beach sand mining, near Tangier, Morocco. Photograph: © SAF — Coastal Care.

By © John R. Gillis, Professor Emeritus of History, Rutgers University

Originally published in The New York Times, November 4th, 2014. All rights reserved.

To those of us who visit beaches only in summer, they seem as permanent a part of our natural heritage as the Rocky Mountains and the Great Lakes. But shore dwellers know differently. Beaches are the most transitory of landscapes, and sand beaches the most vulnerable of all. During big storms, especially in winter, they can simply vanish, only to magically reappear in time for the summer season.

It could once be said that “a beach is a place where sand stops to rest for a moment before resuming its journey to somewhere else,” as the naturalist D. W. Bennett wrote in the book “Living With the New Jersey Shore.” Sand moved along the shore and from beach to sea bottom and back again, forming shorelines and barrier islands that until recently were able to repair themselves on a regular basis, producing the illusion of permanence.

Today, however, 75 to 90 percent of the world’s natural sand beaches are disappearing, due partly to rising sea levels and increased storm action, but also to massive erosion caused by the human development of shores. Many low-lying barrier islands are already submerged.

“75 to 90 percent of the world’s natural sand beaches are disappearing, due partly to rising sea levels and increased storm action, but also to massive erosion caused by the human development of shore.”
— John R. Gillis

Yet the extent of this global crisis is obscured because so-called beach nourishment projects attempt to hold sand in place and repair the damage by the time summer people return, creating the illusion of an eternal shore.

Before next summer, endless lines of dump trucks will have filled in bare spots and restored dunes. Virginia Beach alone has been restored more than 50 times. In recent decades, East Coast barrier islands have used 23 million loads of sand, much of it mined inland and the rest dredged from coastal waters — a practice that disturbs the sea bottom, creating turbidity that kills coral beds and damages spawning grounds, which hurts inshore fisheries.

The sand and gravel business is now growing faster than the economy as a whole. In the United States, the market for mined sand has become a billion-dollar annual business, growing at 10 percent a year since 2008. Interior mining operations use huge machines working in open pits to dig down under the earth’s surface to get sand left behind by ancient glaciers. But as demand has risen — and the damming of rivers has held back the flow of sand from mountainous interiors — natural sources of sand have been shrinking.

One might think that desert sand would be a ready substitute, but its grains are finer and smoother; they don’t adhere to rougher sand grains, and tend to blow away. As a result, the desert state of Dubai brings sand for its beaches all the way from Australia.

And now there is a global beach-quality sand shortage, caused by the industries that have come to rely on it. Sand is vital to the manufacturing of abrasives, glass, plastics, microchips and even toothpaste, and, most recently, to the process of hydraulic fracturing. The quality of silicate sand found in the northern Midwest has produced what is being called a “sand rush” there, more than doubling regional sand pit mining since 2009.

But the greatest industrial consumer of all is the concrete industry. Sand from Port Washington on Long Island — 140 million cubic yards of it — built the tunnels and sidewalks of Manhattan from the 1880s onward. Concrete still takes 80 percent of all that mining can deliver. Apart from water and air, sand is the natural element most in demand around the world, a situation that puts the preservation of beaches and their flora and fauna in great danger. Today, a branch of Cemex, one of the world’s largest cement suppliers, is still busy on the shores of Monterey Bay in California, where its operations endanger several protected species.

The huge sand mining operations emerging worldwide, many of them illegal, are happening out of sight and out of mind, as far as the developed world is concerned. But in India, where the government has stepped in to limit sand mining along its shores, illegal mining operations by what is now referred to as the “sand mafia” defy these regulations. In Sierra Leone, poor villagers are encouraged to sell off their sand to illegal operations, ruining their own shores for fishing. Some Indonesian sand islands have been devastated by sand mining.

“…environmental considerations are to become top priority. Only this will ensure that the story of the earth will still have subsequent chapters told in grains of sand.”
— John R. Gillis

It is time for us to understand where sand comes from and where it is going. Sand was once locked up in mountains and it took eons of erosion before it was released into rivers and made its way to the sea. As Rachel Carson wrote in 1958, “in every curving beach, in every grain of sand, there is a story of the earth.” Now those grains are sequestered yet again — often in the very concrete sea walls that contribute to beach erosion.

We need to stop taking sand for granted and think of it as an endangered natural resource. Glass and concrete can be recycled back into sand, but there will never be enough to meet the demand of every resort. So we need better conservation plans for shore and coastal areas. Beach replenishment — the mining and trucking and dredging of sand to meet tourist expectations — must be evaluated on a case-by-case basis, with environmental considerations taking top priority. Only this will ensure that the story of the earth will still have subsequent chapters told in grains of sand.

John R. Gillis is a professor emeritus of history at Rutgers University and the author of “The Human Shore: Seacoasts in History.”

Stop Confusing Coasts with Shores; By John R. Gillis

Photograph: © SAF – Coastal Care

By © John R. Gillis, Professor Emeritus of History, Rutgers University

We have gotten into the habit of using the terms coast and shore interchangeably. But there is a difference, and it is not just semantic.

Coasts and shores occupy quite different locations in both history and geography. Long before countries thought of themselves as having something called coasts, they had shores. Coasts are a relatively recent concept, reflecting the modern impulse to bring nature under control, to draw lines and impose uniformity where neither previously existed. It was not until the eighteenth century that the notion of the coastline was deployed. First conjured in the minds of cartographers, it has now been so massively engineered into the environment as to appear natural. The British geopolitican Lord Curzon called it “the most uncompromising, least alterable and most effective” of borders.

“Coasts and shores occupy quite different locations in both history and geography. Coasts are the product of human design, while shores belong to nature, are alive and unruly…”
— John R. Gillis

Coasts are the product of human design, while shores belong to nature, are alive and unruly, famously described by Rachel Carson as an “elusive and indefinable boundary.” They are fractal and irregular, assemblages of micro environments, no one quite like another. Nature’s shores are fractal rather than linear. And they vary by time as well as space, changing with every tide, with each storm.

We like to think of shores as a permanent part of our landscape heritage, not unlike the Rocky Mountains or the Great Lakes. Even Rachel Carson sometimes described them as timeless, a term that she also applied to the sea itself. But in her 1958 essay, “Our Ever-Changing Shore,” she acknowledged that they were vulnerable to what she called the “sordid transformation of “development”– cluttered with amusement concessions, refreshment stands, fishing shacks – all the untidy litter of what passes under the name of civilization.”

Back then, Carson held out hope that some element of wilderness might be preserved on America’s shores. The National Park Service had hoped that fifteen percent of the east coast might be protected from development. Today, this seems unimaginable, for the surge of population to the shore has turned it from a potential public resource into a highly privatized asset, out of reach of most ordinary
people. In Maine, Carson’s favorite shore, only 25 of its 5300 miles of coast are designated as working waterfronts. Of California’s 1,100 miles of coast, all of it below the highest tide line is accessible, but only 42 percent is publically owned. Everywhere getting down to the sea has become more complicated and contested. Little of the terrestrial shore can any longer be categorized as wild in the way that Carson understood that term. The anthropogenic coast has now obliterated nature’s shore in many places, including California, where one observer notes that you can no longer see the shore for the stores.

Nature’s shores, as opposed to built coasts, are porous and fluctuant. That is what attracted humans to the southern tip of Africa some 165,000 years ago. Mossel Bay in what is now South Africa offered the fecundity of an ecotone where two ecosystems, one of land, the other of water, met. This was the first home of Homo Sapiens from which our species has evolved. Shores were fluid frontiers which liberated humans to move about the world in an unprecedented manner. Today’s coasts, engineered to separate land and water, have radically reduced biodiversity and cut off the movement of fish and peoples. The sand that once nourished barrier islands and beaches is a necessary constituent of the concrete used to build sea walls and levees which stop the natural flow of sands and are the death of beaches. In Indonesia, sand mining has destroyed whole islands. So-called sand wars are won by the strongest states and highest bidders, often at the expense of the poor, who have seen their homes and livelihoods vanish beneath the waves. In Japan, a massive state-subsidized concrete industry has walled 65 percent of that nation’s coasts with disastrous ecological results.

“What we like to think of as our most natural boundary is revealed to be among the most unnatural.”
— John R. Gillis

As Robert S. Young recently reminded us (“A Beach Project Built on Sand,” NYTimes OP-ED, Friday, August
21, 2014
) sea walling and massive beach nourishment projects are not only environmentally damaging, but lead to a false sense of security based on the mistaken notion that we can engineer ourselves out of danger. In many parts of the globe the dream of taming unruly shores has proved to be a costly illusion. What was meant to stabilize has become itself the source of instability. In Japan, the massive sea walls built to protect against tsunamis enhanced the velocity and force of the destructive storm surges which natural wetlands and gently sloping shores would have dissipated.

Our ancestors knew better. Their name for shore was marge, a word that suggests not a narrow hard edge but a broad soft margin. Premodern maps portray a series of disconnected points rather than a continuous coast. Until surveyed in the early nineteenth century, shores were terra incognita to both mariners and landlubbers. Cautious captains stayed well off shore and houses were rarely built at the edge of the sea. Unlike contemporary developers, premodern coastal peoples left themselves a wide margin for error. Shores were the world’s most extensive commons, open to all up to the high tide line. Today they are more likely to be treated as private property, with access increasing restricted by fences and barriers. The recent massive destruction of up to 90 percent of coastal wetlands has hardened the line between land and sea, eliminating one of nature’s great nurseries but also alienating us from the sea.

Today’s coasts are under assault by rising seas and storm-induced erosion, calling the very idea of coastline into question. What we like to think of as our most natural boundary is revealed to be among the most unnatural. Fortunately, what is left of our unruly shores still offers hope for resolution of at least some of the problems associated with modern coasts. It turns out that shores have a remarkable ability to heal themselves if only left to their own devices. Instead of pinning them down, narrowing them to that thin line which has no counterpart in nature, we should be allowing them to find their own shape and flow.

It is time to focus our attention on flow rather than fixity. The great geoengineering projects of the past, sea walls as well as dams, have all been called into question. But we are not without historical examples of floating cities and aquaculture that can be as secure and productive as any static territorial system of based on impenetrable borders. The Dutch are now in the forefront of the reimagining the place where land and water meet as a fluid frontier. Shore dwellers of NewYork and New Jersey have much to learn from them. We cannot roll back coasts any more than we can hold back seas, but we can, given our present level of environmental awareness, work out a variety of accommodations that meet our commercial interests without sacrificing the global environment. But the first requirement is to recognize that coasts and shores are very different phenomena and then make them work with rather than against one another.

“…shores have a remarkable ability to heal themselves if only left to their own devices.”
— John R. Gillis

Teasing apart shore and coast is not just a semantic exercise, for behind our choice of words lie powerful political and economic forces. To call a shore “coast” is to align it with a certain kind of territoriality. It encourages us to opt for certain measures – sea walling and beach nourishment – which are presented to us as coastal protection, when, in fact, they cause shore erosion. Calling something a shore evokes its natural qualities and leads to a different kind of planning focused on maximizing the life that exists there.

Clarifying the difference between coasts and shores would therefore go a long way toward creating the basis of a public discussion of what is really at stake. Clearly there is a place for both coasts and shores in our conception of our world. But confusing one with the other does a service to neither.

The Human Shore: Seacoasts In History; A book by John R. Gillis
In his new book, The Human Shore: Seacoasts in History, published by University of Chicago Press, November 2012, historian John R. Gillis explores the deep history of seacoasts, the original home of humankind.

Paradise Lost: Filmmakers Document the Maldives’ Trash Island


With its luxurious resorts, white-sand beaches and crystal-clear waters, the Maldives is known as a luxury destination. But there’s a dark side to paradise.

Not far from the Maldives’ capital of Male, only a half-hour boat ride away, mountains of trash and waste pile up on Thilafushi island, marring the seascape of the normally idyllic archipelago.

Thilafushi receives hundreds of tonnes of rubbish from other islands in the Maldives every day. Sixteen years ago it was an unspoilt coral reef…

Read Full Article, Weather News- Travel

Paradise lost on Maldives’ rubbish island, Guardian UK (01-02-2009)
It may be known as a tropical paradise, an archipelago of 1,200 coral islands in the Indian Ocean. But the traditional image of the Maldives hides a dirty secret: the world’s biggest rubbish island…

This Island Is A Toxic Bomb In The Center Of Paradise, Bloomberg News, (03-09-2013)
Hundreds of tons of solid waste and toxic material from Malé and luxury hotels on nearby islands are unloaded on Thilafushi every day.The amount of waste continues to grow as more and more tourists flock to the islands…

In Pictures: Maldives ‘rubbish island’ turns paradise into dump, Guardian UK
Thilafushi receives hundreds of tonnes of rubbish from other islands in the Maldives every day. Sixteen years ago it was an unspoilt coral reef…

Featured image by ©© Hani Amir

“Seawalls Kill Beaches,” Open Letters by Warner Chabot And Rob Young

Photograph: © SAF — Coastal Care

Report And Open Letter from Warner Chabot and Robert S. Young, presented to the Ocean Protection Council (OPC) meeting in Sacramento, August 26th, 2014.

“Seawalls Kill Beaches… So California Sea Level Rise Policy Should Ban Them,” By Warner Chabot

They are highly efficient and effective killers. Their unique, ugly skill is their ability to simultaneously kill in all directions.

First, they choke the sediment eroding down the bluffs that would otherwise replenish beaches.

The seawalls reflect the power of retreating waves which rip away the body of the beach and drown it by carrying the valuable beach sand out to sea.

Equally destructive but unseen, is the often undersea beach loss from the seawalls. That’s because the outgoing, reflected waves also rip away the sea floor on each outgoing surge.
This outgoing surge creates a steeper, undersea slope. Those steeper slopes then choke the ability of incoming waves to bring new sand to replenish an already eroded beach.

Just think of the difficulty of pushing a boulder uphill. The new, steeper offshore slopes are the same thing – just at a smaller, granular scale.

And finally, like a serial killer, seawalls often kill the nearby beaches. The new, steep undersea slope breaks the back of the sand supply moving down the coast. Gravity simply pulls the grains of sand into the ocean depths. So neighboring beaches are often starved of the sand that would otherwise be supplied from littoral, shoreline currents.

What’s Wrong With This Picture?
A society that encouraged killers would be judged to be absolutely mad. Californian’s take pride in being green and enlightened. We love our public beaches. They are part of our identity. California’s many public beaches also provide one of the best sources of recreation for inland and working class people.

So if we’re so smart and environmental, why do we continue allow the very thing (seawalls), that kill the invaluable public beaches we claim to love?

Why would we ignore that which our scientists and engineers have warned us for years? Why have other states like Maine, North and South Carolina and Texas long banned all seawalls and jetties?

Why did some of these “conservative” states reach this enlightened conclusion 30 years ago and stick with it? Why has California not been a leader?

Our Beaches Need An Intervention
About 10% of California’s coastal shore has seawalls. In Southern California, it’s over 30% of the shoreline.

Seawalls provide immediate protection for a single coastal property owner. Yet when seawalls go in, public beaches vanish. Sea level rise will magnify the problem. Is our coastal future really destined to be a shoreline of seawalls and dead or vanished beaches?

Seems like we’re shooting ourselves in the foot by ‘serial killing’ our beaches for several past decades. What’s worse is that our state law actually requires it! Maybe we need an intervention. We may be overdue for a very serious talk about just why official state policy is killing our beaches.


Comments submitted by Robert S. Young, PhD, PG

August 26, 2014

“I am the Director of the Program for the Study of Developed Shorelines, a joint Duke University-Western Carolina University venture. The Program is a research and policy outreach center serving the global coastal community. We conduct scientific research into coastal processes and sea level rise.

I fully support the efforts of the California Ocean Protection Council to formally address sea level rise and storms while developing a hazard avoidance policy under the Safeguarding California Plan. OPC leadership should also make it very clear that the construction of seawalls, bulkheads and revetments must not be included in the toolkit for wise climate change adaptation or infrastructure protection.

The reason for this is simple: seawalls ultimately destroy the beaches in front of them and have significant impacts on neighboring beaches and properties. This is why states ranging from North and South Carolina to Oregon currently ban the construction of new seawalls. The science is clear and indisputable. The United States Army Corps of Engineers recognized these problems in a 1981 Technical Note entitled “Seawalls Their Applications and Limitations” (CETNIII-8):

Seawalls protect only the land immediately behind them, offering no protection to fronting
beaches. Also on a receding shoreline, recession will continue on the adjacent shore and
may even be accelerated by the construction of a seawall. If nearby beaches were being
supplied with sand by the erosion of the area protected by a new seawall, the beaches will
be starved and will experience increased erosion. Therefore, if a beach is to be retained
adjacent to a seawall, additional structures may be necessary. Seawalls generally reflect
wave energy which causes increased scour immediately in front of the wall. Wave run-up
and overtopping of the wall may scour the backfill.

Much of the beach loss from seawall construction comes from what scientists call “Passive Erosion.” Building a seawall between a building and a beach does not stop the natural retreat of that shoreline. The beach will continue to erode until it simply disappears in front of the seawall. Sea level rise will make this process happen even more quickly. So, as the calls to provide protection for private property and infrastructure grow louder due to changing climate, the impacts of bad decision, like building seawalls, will become even more severe.

More than 10% of California’s iconic shorelines are already walled off. These existing walls are already causing significant problems to neighboring beaches because they close off the eroding bluffs, cliffs, and dunes that were naturally adding sand to shorelines nearby. Sand is to the coast what water is to the West. You cannot allow it to go unmanaged, and you cannot allow individuals or localities to seal off sand that was destined for the benefit of all. This is what seawalls do.

I urge you to pursue policies that reduce risk along the oceanfront by truly avoiding the hazards, not blocking them with brute force engineering. This will preserve public recreation, public access, the California aesthetic, and the economic value of the coast shared by all Californians.” —Robert S. Young, Director, Program for the Study of Developed Shorelines, Professor, Coastal Geology, Western Carolina University

Further Reading: Griggs, G.B., 2010, The effects of armoring shorelines—The California experience.

Do the Right Thing: Institutions Can Responsibly Divest from Fossil Fuels

Photo source: ©© Alabos Life


“The world is on track to dump 2.5 trillion tons of global warming pollution into the atmosphere by mid-century. Does that sound like an innocuous number? It’s not. It’s terrifying. It’s nearly 3 times what our planet can absorb without disastrous impacts. That level of pollution, scientists agree, will push average global temperatures up by almost 11 degrees Fahrenheit—the tipping point beyond which the most calamitous impacts of climate change start to become unavoidable for most people on Earth. The track we’re on, the track of little to no concerted global action on climate, is literally a dead end.

That’s why 400,000 people, myself included, took to the streets of New York City at the People’s Climate March yesterday to demand that world leaders take bold action on climate change—to limit carbon pollution, to shift to clean energy, and to create a more secure future for the planet…”

Read Full Article, NRDC

Effect Of The Spanish Conquest On Coastal Change In Northwestern Peru

Reed watercrafts used by Peruvian fishermen for the past 3,000 years; Northern Peru. Photo source: ©© Pirindao


Culture contact can lead to unexpected consequences. The population of Peru dropped precipitously after the Spanish Conquest, changing the patterns and intensity of economic activities. In northern Peru, such changes affected the evolution of beach ridges (narrow sand dunes many kilometers long, parallel to the shoreline) north of the Chira River. A similar hiatus in beach ridge formation about 2,800 y ago correlates with increased El Niño frequency, and possibly a local decline in population at that time. This study illustrates the value of comparing historic, archaeological, climatic, and geological data to understand change in coupled natural and human systems.

When Francisco Pizarro and his small band of Spanish conquistadores landed in northern Peru in A.D. 1532 to begin their conquest of the vast Inca Empire, they initiated profound changes in the culture, language, technology, economics, and demography of western South America. They also altered anthropogenically modulated processes of shoreline change that had functioned for millennia. Beginning with the extirpation of local cultures as a result of the Spanish Conquest, and continuing through today, the intersection of demography, economy, and El Niño-driven beach-ridge formation on the Chira beach-ridge plain of Northwestern Peru has changed the nature of coastal evolution in this region. A similar event may have occurred at about 2800 calibrated y B.P. in association with increased El Niño frequency…

Read Full Study, PNAS

How The Spanish Invasion Altered The Peruvian Coast, Earth Magazine

Reuters’ Water’s Edge Report – Part I

Photograph: © SAF — Coastal Care


A Reuters analysis finds that flooding is increasing along much of the nation’s coastline, forcing many communities into costly, controversial struggles with a relentless foe…

Read Full Article: “As the seas rise, a slow-motion disaster gnaws at America’s shores- PART I,” From the: “Water’s Edge: the Crisis Of Rising Sea Levels – PART I,” A Report By Reuters

“Why Americans Are Flocking To Their Sinking Shores Even As The Risks Mount” – Reuters’ Water’s Edge Report – Part II, Published 09-17-2014, Reuters

We Need to Retreat From the Beach; By Orrin H. Pilkey
As ocean waters warm, the Northeast is likely to face more Sandy-like storms. And as sea levels continue to rise, the surges of these future storms will be higher and even more deadly. We can’t stop these powerful storms. But we can reduce the deaths and damage they cause…

“The Rising Sea;”A Book by Orrin H. Pilkey and Rob Young