Tag Archives: Coastal Issues

Darwin’s Elevation Changes Theory Confirmed, Cape Verde

Porto Praia
Porto Praia

Excerpt from NASA Earth Observatory

Born on February 12, 1809, Charles Darwin is best known for his theory of natural selection as a driving force in evolution. Yet he was also an accomplished geologist, studying earthquakes and the formation of coral atolls, among other topics.

When he set sail on the Beagle in December 1831, he was determined to understand the geologic history of the places he visited. He did some of his first digging in Cape Verde, specifically on the islands of Santiago (St. Iago or St. Jago) and Ilhéu de Santa Maria (Quail Island in Darwin’s day).

santa-maria-cape-verde
Fig.1: close-up of Porto Praia (also Porto Praya). Image Source: NASA

The Advanced Land Imager (ALI) on NASA’s Earth Observing-1 (EO-1) satellite captured these natural-color images of Santiago and Ilhéu de Santa Maria. The top image (Fig.1) is a close-up of Porto Praia (also Porto Praya), the harbor where the Beagle anchored in January 1832. The bottom image (Fig.2) shows the rugged topography of Santiago. The area of the close-up is outlined in white in the wide-area view.

Only about 1 mile (1.6 kilometers) in circumference, Ilhéu de Santa Maria was small enough for Darwin to study in detail. He mapped rock layers and collected samples from each one, using the island as a key to understanding the much larger Santiago, which held tantalizing geologic clues of its own. On a cliff face near Porto Praia, Darwin noticed a bed of marine shells resting roughly 45 feet (14 meters) above sea level. He concluded that both islands “are volcanic islands that were submerged for some period beneath the sea, where they collected marine beds and then another layer of melted volcanic material.” He concluded that both islands had gained and lost elevation over time.

To support his hypothesis, Darwin pointed to the Temple of Serapis along the coast of Italy, which Charles Lyell had described in his recently published Principles of Geology. The land under the temple had previously sunk below the water line, enabling mollusks to bore into the temple’s stone pillars. After the land rose again, the borehole layers appeared as dark bands.

santiago
Fig.2: shows the rugged topography of Santiago. Image Source: NASA

More recent geologic studies in Cape Verde have confirmed Darwin’s conclusions, not only about the islands’s volcanic origin, but also about elevation changes. A 2006 study published in Geology found that Cape Verde sits over a relatively stationary hotspot where magma pushes up through Earth’s crust. Hotspot melting has thickened the crust in the area, the study found, buoying the ocean floor underneath the islands of Cape Verde. A 2010 study published in Nature Geoscience concluded that multiple geologic processes under the ocean floor have raised Cape Verde at varying rates over the past 6 million years.

Original Article

Global warming could spur toxic algae, bacteria in marine environment

Red Tide

By Karin Zeitvogel, AFP

Global warming could spur the growth of toxic algae and bacteria in the world’s seas and lakes, with an impact that could be felt in 10 years, US scientists said Saturday.

Studies have shown that shifts brought about by climate change make ocean and freshwater environments more susceptible to toxic algae blooms and allow harmful microbes and bacteria to proliferate, according to researchers from the National Oceanic and Atmospheric Administration (NOAA).

In one study, NOAA scientists modeled future ocean and weather patterns to predict the effect on blooms of Alexandrium catenella, or the toxic “red tide,” which can accumulate in shellfish and cause severe symptoms, including paralysis, in humans who eat the contaminated seafood.

“Our projections indicate that by the end of the 21st century, blooms may begin up to two months earlier in the year and persist for one month later compared to the present-day time period of July to October,” said Stephanie Moore, one of the scientists who worked on the study.

But the impact could be felt well before the end of this century, as early as 2040, she said at the annual meeting of the American Association for the Advancement of Science.

“Changes in the harmful algal bloom season appear to be imminent. We expect a significant increase in Puget Sound (off the coast of Washington state where the study was conducted) and similar at-risk environments within 30 years, possibly by the next decade,” said Moore.

In another study, NOAA scientists found that desert dust, which contains iron, deposited into the ocean from the atmosphere could lead to increases of harmful bacteria in the seawater.

Researchers from the University of Georgia found that adding desert dust to seawater significantly stimulated the growth of Vibrios, a group of ocean bacteria that can cause gastroenteritis and infectious diseases in humans.

“Within 24 hours of mixing weathered desert dust from Morocco with seawater samples, we saw a huge growth in Vibrios, including one strain that could cause eye, ear and open wound infections, and another strain that could cause cholera,” said Erin Lipp, who worked on the study.

The amount of iron-containing dust deposited in the sea has increased over the last 30 years and is expected to continue to rise, based on precipitation trends in western Africa that are causing desertification.

Rising precipitation in some parts of the world and lack of rain in other parts has been blamed on climate change by some experts.

Global warming has also been blamed for rising ocean temperatures, and “a warming ocean, which we know is happening, increases the likelihood of disease that affects both wildlife and humans,” NOAA administrator Janet Lubchenco told AFP.

Unhealthy oceans impact not only human and animal health but also affect countries’ economies, said Lubchenco, noting that US coastal states are home to eight in 10 Americans and generated 83 percent of US GDP in 2007.

Red Tide
The Florida “red tide” occurs almost annually along portions of the state’s Gulf Coast, causing beach and shellfish closures and negatively impacting Florida’s tourism industry. Just one harmful algal bloom event can impose millions of dollars in losses upon local coastal communities. Image courtesy of P. Schmidt, Charlotte / NOAA

Original Article

Red Tide in New York Harbor, in Coastal Care

Algae Blankets China Beaches, in Coastal Care

Wave of Toxic Green Beaches, France, Coastal Care

Whole coastline of Namibia is designated a national park

skeleton-coast
Skeleton Coast. Photo Source: Alamy

By Mark Rowe, The Telegraph UK

Namibia designates its entire 976-mile coastline a national park, consolidating several existing preserves into the 26.6 million-acre Namib-Skeleton Coast National Park.

With the declaration of the Dorob National Park on December 1, 2010, the last piece of the puzzle has finally been put in place, thus converting the total Namibian coast into the eighth largest protected area in the world and the largest park in Africa, called the Namib-Skeleton Coast National Park.

The Namib-Skeleton Coast National Park covers 26.6 million acres, making it larger than Portugal.

It stretches for 976 miles (1,570km), from the Kunene River, at the northern border with Angola, to the Orange River, on the border with South Africa, and is expected to be promoted as a unified destination. The protected coastline consolidates three national parks: Skeleton Coast, Namib-Naukluft and Sperrgebiet. The last is the site of Namibia’s diamond mines, which have long been closed to the public.

The national park does not stop at the national borders – at the southern end it connects with South Africa’s Richetersveld National Park, while in the north it is linked to Angola’s Iona National Park. Some coastal roads are good, particularly in Dorob National Park, but there is no pan-Namibian highway.

Historically, Namibia has been a trailblazer in using tourism to fund conservation, and has encouraged tribal communities to set up conservation areas, which they manage sustainably in order to keep poaching at bay and to attract tourism. “The aim of the new park is to rein in environmentally damaging activities and encourage tourism,” said Chris McIntyre, MD of the travel company Expert Africa.

Namibia is the driest country in southern Africa and its national parks are desert and savannah. In the desert wilderness of the Skeleton Coast, wildlife includes hyenas and abundant birds. Black rhino and desert elephants follow the area’s water courses, while small prides of lions have recently returned. Other highlights include African penguins and a vast colony of Cape fur seals.

Namibia Coastline
Photo Source: Evelyn Hockstein / The New York Times

Original Article

All Africa Article

The New York Times

Uncontrolled Sand Mining Days Numbered in Namibia, in Coastal Care

Geographer Recreates The Great Louisiana Hurricane of 1812

1812 Hurricane
Image Source: Mock, C.J., M. Chenoweth, I. Altamirano , M.D. Rodgers, and R. García-Herrera. The Great New Orleans Hurricane of 1812. Bulletin of the American Meteorological Society 91: 1653-1663.

Excerpt from the University of South Carolina

Nearly 200 years before Hurricane Katrina, a major storm hit the coast of Louisiana just west of New Orleans. Because the War of 1812 was simultaneously raging, the hurricane’s strength, direction and other historically significant details were quickly forgotten or never recorded.

But a University of South Carolina geographer has reconstructed the storm, using maritime records, and has uncovered new information about its intensity, how it was formed and the track it took.

Dr. Cary Mock’s account of the “Great Louisiana Hurricane of 1812” appears in the current issue of the Journal of the American Meteorological Society, a top journal for meteorological research.

“It was a lost event, dwarfed by history itself,” said Mock, an associate professor in the College of Arts and Sciences. “Louisiana was just in possession by the United States at the time, having been purchased from France only years before, and was isolated from the press.”

Mock says historians have long known that a hurricane hit New Orleans on Aug. 19, 1812, but they didn’t know the meteorological details about the storm.

“Hurricane Katrina is not the worst-case scenario for New Orleans, as its strongest winds were over water east of the eye,” said Mock. “The 1812 hurricane was the closest to the city, passing just to the west. It wasn’t as big as Katrina, but it was stronger at landfall, probably a mid-three or four category hurricane in terms of winds.”

Detailed information about past hurricanes is critical to helping climatologists today forecast and track hurricanes. But until recently, little was known of hurricanes that occurred before the late 19th century, when weather instrumentation and record keeping became more sophisticated and standardized. Mock’s research has shed light on much of the nation’s hurricane history that has remained hidden for centuries.

“A hurricane like the one in August 1812 would rank among the worst Louisiana hurricanes in dollar damage if it occurred today,” said Mock. “Hurricane Betsey was 100 miles to the west. Katrina was to the east. A 1915 hurricane came from the South. By knowing the track and intensity, as well as storm surge, of the August 1812 hurricane, we have another worst-case-scenario benchmark for hurricanes. If a hurricane like it happened today, and it could happen, it would mean absolute devastation.”

Mock has spent the last decade conducting research and creating a history of hurricanes and severe weather of the Eastern U.S. that dates back hundreds of years. Using newspapers, plantation records, diaries and ship logs, he has created a database that gives scientists the longitudinal data they’ve lacked. His research has been funded by nearly $700,000 in grants from the National Science Foundation (NSF) and the National Oceanic and Atmospheric Administration (NOAA).

Mock began researching the August 1812 hurricane along with other early Louisiana hurricanes in 2006. It took 18 months for him to reconstruct the 1812 storm’s complete track.

Newspaper accounts, which included five from Louisiana and 17 from other states, described hourly timing of the storm’s impact, wind direction and intensity, rainfall, tide height and damage to trees and buildings.

The Orleans Gazette description of the impact of storm surge on the levees is one example:

“The levee almost entirely destroyed; the beach covered from fragments of vessels, merchandize, trunks, and here and there the eye falling on a mangled corpse. In short, what a few hours before was life and property, presented to the astonished spectator only death and ruin,” reported the newspaper.

The environmental conditions of the Louisiana coast were different in 1812; the sea level was lower, elevation of the city was higher and the expanse of the wetlands far greater. These conditions would have reduced the storm surge by at least several feet, says Mock.

Some of the most valuable sources to Mock’s research were maritime records, which include ship logbooks and ship protests, records submitted by ship captains to notaries detailing damage sustained to goods as a result of weather. Ship logs, kept hour by hour, include data about wind scale, wind direction and barometric pressure.

Because of the war, England bolstered its naval presence, providing Mock, the first academic researcher to conduct historical maritime climate research, with a bounty of records to help him recreate the storm’s path and intensity.

“The British Royal Navy enforced a blockade of American ports during the War of 1812,” said Mock. “The logbooks for ships located in the Gulf of Mexico and the Caribbean Sea had all sorts of valuable information.”

In addition to 12 British Navy logbooks, he was able to use information from logbooks of the USS Enterprise and another from an American merchant vessel. Ship protest records from the New Orleans Notarial Archives provided Mock with some surprising contributions.

“I was initially pretty pessimistic on what I would find in the ship protests,” said Mock. “I thought I’d find a few scraps and be in and out in two days. I was wrong. I found a trove of material and ended up going back eight times.”

Archivists presented Mock with upwards of 100 books for every year, each 800 pages in length and none indexed with the word hurricane. After scouring the records, Mock uncovered nearly 50 useful items related to the 1812 hurricane, including accounts from the schooner, Rebecca, which described the storm in the middle of the Gulf of Mexico in a protest that was filed with notary Marc Lafitte.

It described a 4 p.m. heavy gale that increased to a perfect hurricane wind, with the shifting of winds by noon the next day. The shift of winds from the northeast to the northwest told Mock that the storm track passed to the east of the Rebecca.

Using the logs and protests, Mock was able to correlate the precise location of ships with the hourly weather and create a map of the storm’s path through the Gulf of Mexico.

“Its initial approach was toward Mississippi, but then it turned northwest toward Louisiana as it approached landfall in the afternoon on Aug. 19,” Mock said. “The USS Enterprise had the most detailed wind observations at New Orleans. A change in winds to the southwest around local midnight tells me that the storm center skimmed as little as five kilometers to the west of New Orleans.”

To further understand the hurricane’s formation and dissipation, Mock reviewed records stretching as far north as Ohio and east to South Carolina. Included among them were meteorological records by James Kershaw in Camden, S.C., which are part of the collections of USC’s South Caroliniana Library.

“I wanted to collect data from a wide area to understand patterns, pressure systems and the very nature of the 1812 hurricane,” said Mock. “A better understanding of hurricanes of the past for a wide area provides a better understanding of hurricane formation and their tracks in the future.”

Beach Gulf of Mexico, Ms
Waveland beach, located in Hancock County, Mississippi, on the Gulf of Mexico. It is part of the Gulfport–Biloxi area. Photo Source: T. Effendi.

Original Article

Oysters Disappearing Worldwide: Study

Oyster Reef
Oyster Reef

Excerpt from the American Institute of Biological Sciences

A new, wide-ranging survey that compares the past and present condition of oyster reefs around the globe finds that more than 90 percent of former reefs have been lost in most of the “bays” and ecoregions where the prized molluscs were formerly abundant. In many places, such as the Wadden Sea in Europe and Narragansett Bay, oysters are rated “functionally extinct,” with fewer than 1 percent of former reefs persisting.

The declines are in most cases a result of over-harvesting of wild populations and disease, often exacerbated by the introduction of non-native species.

Oysters have fueled coastal economies for centuries, and were once astoundingly abundant in favored areas.

Mangrove Recolte Huitres
Oysters harvesting in mangroves, Dakar. Photo Source: flick’r

The new survey is published in the February issue of BioScience, the journal of the American Institute of Biological Sciences. It was conducted by an international team led by Michael W. Beck of The Nature Conservancy and the University of California, Santa Cruz.

Beck’s team examined oyster reefs across 144 bays and 44 ecoregions. It also studied historical records as well as national catch statistics. The survey suggests that about 85 percent of reefs worldwide have now been lost. The BioScience authors rate the condition of oysters as “poor” overall.

Most of the world’s harvest of native oysters comes from just five ecoregions in North America, but even there, the condition of reefs is “poor” or worse, except in the Gulf of Mexico. Oyster fisheries there are “probably the last opportunity to achieve large-scale oyster reef conservation and sustainable fisheries,” Beck and his coauthors write.

Oysters provide important ecosystem services, such as water filtration, as well as food for people. The survey team argues for improved mapping efforts and the removal of incentives to over-exploitation. It also recommends that harvesting and further reef destruction should not be allowed wherever oysters are at less than 10 percent of their former abundance, unless it can be shown that these activities do not substantially affect reef recovery.

huitres
Photo Source: Maohi 64

Read Full Article, Science Daily

Surf’s Up: New Research Monitor Ocean Wave Behavior and Shore Impacts

wave
Photograph: © SAF — Coastal Care

Excerpts;

Engineers have created a new type of “stereo vision” to use in studying ocean waves as they pound against the shore, providing a better way to understand and monitor this violent, ever-changing environment.

The approach, which uses two video cameras to feed data into an advanced computer system, can observe large areas of ocean waves in real time and help explain what they are doing and why, scientists say…

Read Full Article, Oregon State University

Can the sea solve China’s water crisis?

hong-kong-sand-barge
Photograph: © SAF — Coastal Care

The highest-tech effort yet to ease China’s water crisis sits between a wide, flat grid of salt farms and two giant cooling towers that rise up from a vast expanse of reclaimed land on the western shore of the Bohai Sea.

Odourless, quiet and billowing clear white smoke into a sharp blue sky, the Beijiang desalination and power plant contrast sharply with the tangled pipes, dirty chimneys and foul waterways more usually associated with China’s traditional industrial landscape…

Read Full Article, Guardian UK

Desalination Projects: Option or Distraction for a Thirsty World?

Mapping the Grassroots

sand-foam
Photograph: © SAF — Coastal Care

Excerpts;

Last May, with the Deepwater Horizon oil-spill disaster barely two weeks old, Jeff Warren stood in the park outside the New Orleans Museum of Art, conducting a tutorial in kite-flying. “The rule of thumb is, less than 10 miles an hour is good balloon weather,” he cheerfully told his audience. “More than 10 miles an hour is good kite weather.”..

Read Fulll Article, OnEarth

UN chief: economic model and environmental threat

ocean
Photograph: © SAF — Coastal Care

Excerpts;

The world’s current economic model is an environmental “global suicide pact” that will result in disaster if it isn’t reformed, U.N. chief Ban Ki-moon warned Friday, at the annual meeting of business and political leaders in Davos Switzerland.

Ban said that political and business leaders need to embrace economic innovation in order to save the planet.

“We need a revolution,” the secretary-general of the U.N. told a panel at the World Economic Forum on how best to make the global economy sustainable.

“Climate change is also showing us that the old model is more than obsolete.”

Read Full Article, Guardian UK