RP395 Troubled Waters

 RP395 Troubled Waters

There is an environmental crisis that is brewing deep within the rivers, lakes, and oceans of our planet. It's called eutrophication, and it's what happens when excessive amounts of nitrates or phosphates are added to a body of water.
Eutrophication can ravage entire food chains in underwater ecosystems because it alters the delicate balance of life at its most basic level. Simple plant life like algae thrives in water that has undergone eutrophication. In fact, algae and phytoplankton grow so rapidly that nothing else can survive. As the algae grows and expands, it suck s all of the oxygen out of the water, suffocating more complicated forms of plant life. Consequently, fish and other aquatic life forms lose their primary source of food and starve to death.
As if that wasn't scary enough, scientists have also discovered that eutrophication is increasing acidity in the world's oceans. A recent study by the University of Georgia found that eutrophication increases the amount of carbon dioxide that oceans are able to absorb from the atmosphere. It concluded that the continued eutrophication of coastal waters could lead to the collapse of several species of crabs, snails, clams, and coral.
Eutrophication can occur in freshwater systems just as easily as it can in the open ocean. Surveys have shown that 54 percent of the lakes in Asia are eutrophic, as well as 53 percent in Europe and 48 percent in North America. Some of the world's largest and most well-known lakes are also considered to be eutrophic, such as Lake Erie in the United States and Tai Lake in China. Eutrophic water can be dangerous to drink. Thus, the more eutrophication there is in freshwater lakes, the less drinking water there will be for a global population that is already starting to get thirsty.
Though eutrophication can occur naturally, this crisis is the direct result of human activity. Farming in particular is thought to be a main reason why eutrophication is increasing. Most fertilizers contain either phosphates or nitrates, the two chemicals that cause eutrophication. According to some estimates, over 600,000,000 tonnes of phosphates were added to the earth's surface between 1950 and 1995. With numbers like these, it's not hard to see why eutrophication is becoming so widespread.

RP381 Synthetic Signal Blockers

 RP381 Synthetic Signal Blockers

The human endocrine system is a complex series of glands and pathways that help hormones travel from one point in our body to another. Think of these hormones like workers in a tiny biological postal service. Their function is to deliver messages. For example, when you' re young, they deliver the message that it's time for your body to grow. After you grow old, they start delivering the less uplifting message that it's time for your body to shrink. The endocrine system is responsible for your growth, metabolism, and tissue function. It even affects whether you' re feeling happy or sad.
What happens when something starts interfering with the endocrine system? That's what scientists around the world are currently trying to figure out. They are studying the chemicals that block our body's biological postal service. These endocrine disruptors are synthetic chemicals that humans have created. They have seeped into natural environments all around the world. Endocrine disruptors are known to harm living organisms, and they have been linked to cancer and other reproductive disabilities in humans.
Dichlorodiphenyltrichloroethane, or DDT, is a classic example of a synthetic chemical that is an endocrine disruptor. It was banned in the United States in 1972 after it was discovered that DDT caused birds to lay eggs with soft shells. DDT also harms human reproductive health. It is still being used in some parts of Africa.
The World Health Organization (WHO) has released several reports outlining the threat that endocrine disruptors pose to wildlife. These reports show that mammals, reptiles, birds, and fish species are suffering from altered gender ratios, reproductive deficiencies, and growth disorders. However, the results aren't totally conclusive. Currently, there are so many pollutants in natural environments that it's difficult for these studies to determine what is and isn't being caused by endocrine disruptors.
Only studies that have been conducted in laboratories have proven that endocrine disruptors can harm humans. So far, there have been no conclusive studies linking human disease to endocrine disruptors that already exist in our environment. However, several studies have proven that endocrine disruptors are negatively impacting mammal species in their natural habitats. Since humans are mammals, doesn't that mean that we' re in trouble, too?

RP376 The Cold-Blooded Collapse

 RP376 The Cold-Blooded Collapse

Frogs, toads, and salamanders were the earliest vertebrate life-forms to walk on land. This accomplishment happened about 350 million years ago. Since then, amphibians have gone extinct at a rate of one species every 250 years. That is until humanity arrived and altered Earth's natural balance.
Recently, the extinction rate of amphibians has increased dramatically. Since 1980, over 200 species of amphibians have disappeared from the planet forever, and it's about to get a lot worse. Another 1,856 species are currently facing the threat of extinction. These shocking numbers are causing a worldwide scramble as scientists desperately seek to understand what is behind this amphibian collapse.
It seems that mass amphibian extinction is being caused by several factors. First and foremost is the destruction of natural habitats. As humans continue to tear down forests and build houses in their place, we disrupt ecology all over the planet. Global warming is also adding to the damage. Frogs, toads, and salamanders have evolved in a highly specialized way in order to live in specific habitats. Subtle changes in global temperatures can disrupt their ability to survive.
It's not just humans who are the problem. A deadly disease called chytridiomycosis has ravaged amphibian populations in the Americas and Australia. Amphibians that are infected with this fungus die within weeks. Scientists don't even know where it came from, let alone how to stop it.
Scientists often classify amphibians as bio-indicators. This means that they' re more sensitive to changes in their environment than other organisms are. Frogs, toads, and salamanders are like an early-warning system that can show us what will happen to other species that suffer similar environmental destruction. Therefore, since amphibians are going extinct at an astonishing rate, it's quite possible that birds and mammals won't be far behind.
We may also be losing a wealth of medical science from amphibian collapse. Around 10 percent of all of the Nobel Prizes in Physiology or Medicine have involved research on amphibians. That means that every species that disappears is one that might have cured a terrible disease.

RP346 A Beautiful Menace Under the Ice

 RP346 A Beautiful Menace Under the Ice

While exploring the Canadian north, photographer Paul Zizka came across a wonderful sight. It wasn't the snow-capped mountains, the pine trees, or the tranquil lakes. Rather it was some bubbles that caught Paul's eye. These bubbles were visible just under the icy surface of a lake. There were hundreds of them, all frozen in place. They looked like strange sea creatures, maybe even alien life.
What the photographer had discovered is actually a gas called methane. Methane is a greenhouse gas that's far more powerful than carbon dioxide. By some estimates, it's 25 times more powerful. It's also highly flammable and can explode when released. Methane bubbles are formed by bacteria at the bottom of lakes. These bacteria consume plant matter and releases methane as part of their digestion process. You might say it's a bacterium's way of farting. In warmer weather, these methane bubbles float to the surface and are released into the atmosphere. But when the water is frozen, the bubbles get trapped in the ice.
But methane bubbles are far more than just a pretty picture. In actual fact, they' re a serious threat to all of us. Methane is a gas that contributes to global warming. Some parts of the planet are frozen all year round. It's called "permafrost." As the planet heats up, this permafrost melts, releasing methane bubbles from lakes and rivers. The release of this methane causes more global warming, which melts more frozen lakes and rivers. The process is called a "feedback cycle," because the effect contributes to the cause. According to one scientist, frozen methane is a climate time bomb waiting to go off.
The methane feedback cycle is yet another reason why the fight against global warming is so important. We all must do our part to solve the problem. This could mean planting a tree or even just walking to school or work every day. Doing so will help preserve the natural beauty of these frozen bubbles. It will also help save the entire planet. Let's keep these dangerous bacteria farts where they belong: safely under the ice!

RP293 The Bay of Fundy

 RP293 The Bay of Fundy

The Bay of Fundy on the Atlantic coast of North America doesn't look special on a map. It's not very big, only 270 kilometers long, but it does one amazing thing: it floods with over 100 billion tons of water twice a day. The Bay of Fundy is said to have the world's highest tides.

The bay juts from the tip of Maine in the USA to New Brunswick and Nova Scotia, Canada. At low tide, beaches spread out from under tall cliffs made from flood basalt (ancient lava). As the tide flows, water slowly covers the sand, reaches the basalt walls, and then slides up the stone walls to its maximum. Above the top of the highest tides, trees begin to grow. In many places, you can see exactly how high the tide reaches by the green line of trees.

These tides move 17 meters up and down twice in the course of each day. They make the Bay of Fundy rich with fossils and semi-precious stones. The force of the water erodes cliff sides and reveals these embedded fossils and gems.

The water has also created amazing geological formations, like the flowerpot rocks. The flowerpot rocks are stacks of mostly sandstone rock that stand on their own in the bay, with trees growing out of their tops. The powerful tides have whittled them into top-heavy shapes with narrow bases and tilting, round tops. Some of them form archways that can only be seen at low tide. You can kayak around the trees at high tide and walk along the beaches far below them at low tide!

Animals also love the bay. At least eight whale species come to feast in the bay in the summer. Seabirds flock to the shores to prey on tidal creatures. Humans follow to watch the whales and birds and try to understand the force of nature in this unique place.

RP278 Jeita Grotto

 RP278 Jeita Grotto

In 1836, a man fired a gun into a cave and discovered one of the wonders of the world. Reverend William Johnson followed an underground river— the source of the important water source the Nahr-al-Kalb river— deep into a cave. The echoes of his gunshot proved to him that he'd found a huge cave system, but the caves weren't formally explored until 1873. Engineers from the Beirut Water Company pushed further into the caves for the next few years. They only stopped when they reached the dangerous Hell's Rapids, where sharp rocks turned the river deadly.

Over the next few decades, other explorers penetrated and explored the caves, which extend kilometers deep into the earth. In 1958, the lower cave was opened to the public. Visitors could see the underwater river that runs through it, the waterfall at its entrance, and the lake (Dark Lake) that it forms. All around are vast halls and stalagmite formations that have been formed over millions of years.

The same year, a whole new upper cave was discovered after brave explorers climbed over 600 meters above the underground river entrance. The dry upper cave contains even more stone formations, including flowing stone draperies, sinkholes, stalagmites, and stalactites. A chamber in the upper caves holds the world's longest stalactite—a 27-foot-long V shape. chambers in the upper cave show dramatic color changes, particularly in the Red Chamber and White Chamber, where different chemical combinations create vivid red and white stone formations.

The caves seem to have been inhabited in prehistoric times, but they were lost for unknown years until their recent discovery. Lately, political unrest has kept the caves from the public. They were closed from 1978 to 1995 because of war. Since then, the caves have been reopened to the public and even honored for their sustainable development. With responsible management, these wonders should be impressing visitors for hundreds more years.

RP261 Mud Volcano

 RP261 Mud Volcano

The image that comes to mind when we hear "volcano" is a black peak, with red lava flowing down the sides and smoke bursting from the top. There's another type of volcano, though: one that belches mud.

Mud volcanoes are like lava volcanoes in that they explode with pentup, sometimes burning gases. Mud volcanoes, however, are much cooler than volcanoes that spew molten rock. Some mud volcanoes can even be cool. Many, in fact, are the sites of spas, where people can rub the mud on their bodies for health and cosmetic benefits.

Mud volcanoes form when pressurized gas, water, mud, and sometimes oil make a channel to the earth's surface. Sometimes they build up domes or cones like lava volcanoes; in other places, the mud simply bubbles up and seeps over wide areas. They occur at weak points in the earth's crust, and they often indicate oil and gas reserves below the surface.

Mud volcanoes can also be man-made. In 2006 in the village of Sidoarjo, East Java, the Lusi mud volcano started erupting. It was only about 500 feet from a gas exploration well. East Java has lots of oil and gas, and naturally, mud volcanoes. Most experts agree that it was the removal of the drill and drill string from a deep hole that caused instability below the surface. Mud began to flow out of it, and it hasn't stopped yet. Scientists say it's likely to continue erupting for the next 25 years! And Lusi is no trickle of mud. At its height, it was emitting 180,000m³(cubic meters) of mud per day! It has been a disaster for local residents.

Other mud volcanoes, however, are beneficial. Tourists visit Azerbaijan, which has more mud volcanoes than anywhere else, to see their strange shapes. Visitors flock to Yellowstone, to Colombia, to Java, and other places to witness these natural wonders.

RP246 The Cotton Castle

 RP246 The Cotton Castle

Well, it's not actually a castle, and it's certainly not made of cotton. Turkey's Pamukkale, however, is almost as weird.

In Denizli Province, Turkey, are hot springs that have been used by humans for nearly 2,000 years. The hot springs were the site of an ancient Greco-Roman spa town, Hierapolis, and since it was built— and perhaps before then— people have been coming to the hot springs to be healed or just to relax. The minerals in the water there are said to help with asthma, skin conditions, eye conditions, and muscle aches, among other problems.

Those healing minerals— mostly calcium, magnesium sulfate, sodium hydrogen carbonate— are the reason for the Cotton Castle's name. For thousands of years, the water bubbling up out of the many springs has obeyed the law of gravity and gradually flowed downhill. As it went, it deposited calcium and released carbon dioxide and in the process created travertine. This white rock built up gradually, forming terraces of pools, cascading downward. Many terraces have stalactite formations hanging over their sides. The soft-looking white rock makes the entire site look like it's been molded out of a fluffy cloud or out of cotton. It is, of course, much more solid than any cloud, and people can explore the many shallow pools with their milky-looking water and porous stone sides.

There are many pools to bathe in at Pamukkale. One of the most special is the Sacred Pool. The Sacred Pool was the most important bathing spot of the ancient spa town and is still scattered with collapsed pieces of ancient marble columns. More ruins can be seen where Hierapolis once stood. Some surviving parts of the old city are Roman tombs, ancient archways, a theater, and a cave temple. Just as it did in ancient times, the site calls people to be healed or simply to bask in the beauty of nature.

RP229 Rock Star

 RP229 Rock Star

Uluru rises, huge and red, out of the vast center of Australia. The land spreads flat around it, making the colorful, humped rock look very dramatic. For the aboriginal Anangun u native to that area, Uluru is a sacred spot. It is central to their creation story and their history. To visitors, it is a breathtaking natural wonder.

Uluru (also called Ayers Rock) is an island, which means" island mountain." It is the remains of an ancient sandstone mountain range that gradually eroded around it. We can actually only see the tip of Uluru. The majority of it is underground. However, about 350 meters of it thrusts up out of the soil.

Uluru is remarkably cohesive, with few fractures; it appears solid and uniform. Most photos show Uluru at sunset, when it looks bright red, but the huge formation changes color with the seasons and times of day. It can look silver or even violet in the rain.

Aside from being astounding naturally, Uluru also safeguards the history of the most ancient cultures on Earth. Humans have lived near Uluru for more than 10,000 years. The Anangu people believe the shapes of Uluru and the rocks around it contain the stories of ancestors and gods. Areas of Uluru are decorated with rock paintings that have been updated for thousands of years.

Uluru was first spotted by Western explorers in 1873 and named Ayers Rock after Henry Ayers, Premier of South Australia at the time. By 1920, part of the area had been made into an aboriginal reserve. The land was later taken back, though. It wasn't until 1985 that the Australian government gave ownership of Uluru back to the local aboriginal people. They agreed to manage it jointly with the Australian park service. The natural and cultural wonder remains open for visitors. The aboriginal owners ask merely that tourists show respect for their sacred land and its stories.

RP212 The Great Wall of the Ocean

 RP212 The Great Wall of the Ocean

Skirting the coast of northeast Australia is the only living thing that can be seen from space. The Great Barrier Reef runs alongside Queensland for 2,600 kilometers, providing food and shelter for a huge variety of plants and animals, many of which are endangered. Only tropical rain forests house as many species as the Reef does.

The Great Barrier Reef is the longest coral reef in the world, but it isn't all one mass. It's made up of 2,900 or more separate reef systems, which combine to make one long, interconnected whole. Four hundred species of hard and soft coral make up the body of the Reef. Bright, living coral grows on top of the skeletons of the old. The current Reef is estimated to be about 20,000 years old. When the Reef began growing, sea levels were much lower. As sea levels rose, new coral climbed higher, but coral underneath died. coral needs sunlight to live, and light can only penetrate water to a certain depth.

Among all this coral are plants, snails, whales, sharks, jellyfish, and other sea creatures. Six endangered species of sea turtle live in the Reef, laying their eggs on nearby sandy shores. Humpback whales migrate there every winter, and since whaling ended in 2008, their numbers are increasing. The dugong, or sea cow, lives there, grazing on fields of sea grass. These mammals are in danger of extinction, and are one of the many protected animals who make the Reef their home.

Despite its huge size, the Reef isn't invulnerable. Rising ocean temperatures are dangerous to coral and some fish. Pollution from farms reduces the water quality and promotes the growth of algae, which blocks the light. Shipping accidents have done major damage. Predators cause trouble. The crown-of-thorns starfish eats coral. Its recent population boom put the entire Reef at risk.

Constantly growing, constantly dying, this great wall relies on a complex ecological balance. We should guard it carefully.