Scientific American Topic - Coral Reefs

Reefs at risk: Roundup at the not-so-OK coral corral

Coral, the reef-building organisms responsible for some of the oceans' most vital ecosystems, are in trouble around the world because of climate change, ocean acidification and human interference. But lots of people are also trying to save coral reefs before it's too late. Here's a roundup of some of the latest research into this important class of organism.

Some of the worst news comes out of Indonesia, where the Wildlife Conservation Society (WCS) found that rising surface water temperatures have created a large-scale bleaching event in the local coral. Bleaching occurs when environmental factors stress the living organisms residing within coral reefs, causing them to either leave their reef structures or die. As a result, reefs turn white. WCS marine biologists found that at least 60 percent of the area's coral reefs, and 80 percent of some coral species in the region, have bleached and died following a 4-degree Celsius rise in water temperatures. Bleached coral reefs cannot support the variety of marine life that depend on coral for their survival. That, in turn, affects the ability of people to fish for their livelihoods around those reefs.

Categories: Coral Feeds

Living in a Landscape of Fear: How Predators Impact an Ecosystem

Editor's Note: The following is an excerpt from Cristina Eisenberg's  book The Wolf’s Tooth .

A doe burst out of the forest and tore across the meadow, two wolves in close pursuit. This drama unfolded not twenty feet from where my young daughters and I knelt in our garden peacefully pulling weeds, our pant legs wet with morning dew. One black, the other gray, the black wolf in the lead, they closed in on the doe's haunches. In less than two heartbeats they pierced the deep wood on the far side of the meadow, leaving a wake of quaking vegetation.

Categories: Coral Feeds

How Acidification Threatens Oceans from the Inside Out (preview)

"Slow sperm ... now that’s a problem,” said Jonathan Havenhand, his British accent compounding the gravity of the message. “That means fewer fertilized eggs, fewer babies and smaller populations.” We were sharing a hilly cab ride along the glistening northern coast of Spain to attend an international symposium about the effects of climate change and excess atmospheric carbon dioxide on the world’s oceans. As researchers, we were concerned about the underappreciated effects of changing ocean chemistry on the cells, tissues and organs of marine species. In laboratory experiments at the University of Gothenburg in Sweden, Havenhand had demonstrated that such changes could seriously impede the most fundamental strategy of survival: sex.

Ocean acidification--a result of too much carbon dioxide reacting with seawater to form carbonic acid--has been dubbed “the other CO 2 problem.” As the water becomes more acidic, corals and animals such as clams and mussels have trouble building their skeletons and shells. But even more sinister, the acidity can interfere with basic bodily functions for all marine animals, shelled or not. By disrupting processes as fundamental as growth and reproduction, ocean acidification threatens the animals’ health and even the survival of species. Time is running out to limit acidification before it irreparably harms the food chain on which the world’s oceans--and people--depend.

Categories: Coral Feeds

Fact or Fiction: Can a Squid Fly Out of the Water?

Marine biologist Silvia Maciá was boating on the north coast of Jamaica in the summer of 2001 when she noticed something soar out of the sea. At first she thought it was a member of the flying fish family--a group of marine fish that escape predators by breaking the water's surface at great speed and gliding through the air on unusually large pectoral fins. But after tracing the creature's graceful arc for a few seconds, Maciá realized this was no fish. It was a squid--and it was flying. [More]



Squid - Fish - Marine biology - Jamaica - Proxying and Filtering

Categories: Coral Feeds

Extreme Function: Why Our Brains Respond So Intensely to Exaggerated Characteristics

If someone showed you a caricature of Richard Nixon--a man’s face with oversize shaggy eyebrows, a bulbous nose and pronounced jowls--you would probably recognize the former president immediately, even though the drawing is not true to life. A cartoonist creates such a sketch by taking the average of many male faces and subtracting it from Nixon’s face, then amplifying those distinctive differences. To an observer, the result looks more like Nixon than Nixon himself. Why is it that our brains respond so intensely to extremes?

When the cartoon’s “Nixon-ness” jumps out at you, you are experiencing what scientists call “peak shift.” To understand the concept, imagine, for argument’s sake, that you want to teach a rat to distinguish a rectangle from a square. It’s quite easy to do. Simply give the animal cheese every time it picks the rectangle, and it will soon learn to select the rectangle every time. Once the rat has developed this preference, let’s say you show it a longer, skinnier rectangle. Inevitably, you will find that the rat prefers the exaggerated one to the original. What the rat has learned to recognize is not a particular rectangle but rather rectangularity itself: the more rectangular the better. The savvy rodent looks at the longer, skinnier quadrilateral and goes, “Wow, what a rectangle!” In scientific parlance, the rat’s “peak response”--its strongest reaction--has shifted away from the original--hence the term “peak shift.”

Categories: Coral Feeds

Ancient Ocean Acidification Intimates Long Recovery from Climate Change

Single-cell life-forms thrive throughout the world's oceans--and have for hundreds of millions of years. Tiny varieties known as calcareous nanoplankton build exuberant, microscopic shells --resembling wagon wheels, fishlike scales, even overlapping oval shields decorated with craggy explosions at their centers--known as "coccoliths". The ability to form these shells rests on the amount of calcium carbonate (CaCO3) dissolved in the seawater--and that amount depends on the concentrations of atmospheric carbon dioxide (CO2). [More]



Climate Change - Environment - Ocean acidification - Carbon dioxide - Activism

Categories: Coral Feeds

The New Normal?: Average Global Temperatures Continue to Rise

Hot summers (and balmier winters) may simply be the new normal , thanks to carbon dioxide lingering in the atmosphere for centuries. [More]



Carbon dioxide - Atmosphere - Environment - Carbon Cycle - Products and Services

Categories: Coral Feeds

Unfair trade: A week in the world of illegal wildlife trafficking

Illegal trade in endangered species continues to grow around the world. How big is the problem? Here are 10 major cases that have hit the media in just the past week: [More]



EndangeredSpecies - Wildlife - Illegal drug trade - Environment - Conservation and Endangered Species

Categories: Coral Feeds

Sea Level Rise Swamps Islands

It's a restful sound, waves, unless they happen to be submerging the island or coastal plain you call home. A combination of climate change and bad environmental practices like coral mining is now swamping some low-lying lands.

Take the islands off the coast of Panama. These Caribbean islands regularly find themselves inundated with seawater for days--and some indigenous inhabitants have begun to move to hillsides on the mainland.

Categories: Coral Feeds

Fish Fare Futilely in Future pH

More carbon dioxide emissions lead to more CO2 dissolving in the oceans, which turns the water acidic. Those sour seas slow the growth of corals. And it turns out acidic seawater also makes clownfish and damselfish suicidally bold and reckless, according to a study in the Proceedings of the National Academy of Sciences . [Philip Munday et al., http://bit.ly/blfQHy ] [More]



Fish - Clownfish - PH - carbondioxide - Water

Categories: Coral Feeds

Gulf Coast Dead Zone Set to Grow

Categories: Coral Feeds

Biological Breakdown

Skimmers, scoops and thousands of kilometers of booms cannot compare with bacteria and other microbes when it comes to removing oil. The microorganisms that naturally inhabit the Gulf of Mexico are the only real defense against the Deepwater Horizon spill. As researchers study how the microbes are cleaning up the mess, they remain wary of how these saviors could also choke marine life, too.

That natural microbes are better than human mop-up efforts may come as a surprise, considering that for decades, genetic engineers have touted the creation of an oil-gobbling superbug--the first patent issued for a genetically modified organism was for such a hydrocarbon-chewing microbe. But such microbes “are not effective for the most part,” says marine microbiologist Jay Grimes of the University of Southern Mississippi.

Categories: Coral Feeds

Drastic Measures: 8 Wild Ways to Combat Invasive Species

Some floated here on boats. Others flew. Still others arrived on the sole of a dirty boot. Many were invited, but some arrived unannounced. At this point, however, no one really cares how so-called alien species like the ash borer and the zebra mussel got here. Scientists are more focused on how to get rid of these pests. [More]



Invasive species - Biodiversity - Environment - Species - Terrestrial

Categories: Coral Feeds

Fact or Fiction: The Days (and Nights) Are Getting Longer

The summer solstice that falls this year on June 21 marks the longest day of the year in the Northern Hemisphere, sunlight-wise. Almost imperceptibly, however, Earth's day–night cycle --one rotation on its axis--is growing longer year by year, and has been for most of the planet's history.

Forces from afar conspire to put the brakes on our spinning world--ocean tides generated by both the moon and sun's gravity add 1.7 milliseconds to the length of a day each century, although that figure changes on geologic timescales. The moon is slowly spiraling away from Earth as it drives day-stretching tides, a phenomenon recorded in rocks and fossils that provides clues to the satellite's origin and ultimate fate. "You're putting energy into the moon's orbit and taking it out of the Earth's spin," says James Williams , a senior research scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif.

Categories: Coral Feeds

How Will the Oil Spill Impact the Gulf's Dead Zone?

Each spring and summer fertilizer from the fields of the U.S. Midwest runs off into the Mississippi River. Old Muddy carries the nutrients down the length of the continent before dumping them into the Gulf of Mexico. Once introduced, the nitrogen and phosphorus prompts a bloom in algae, phytoplankton and other microscopic plants. After the plants die they drift to the bottom and their decomposition sucks the oxygen out of the seawater. The result is a vast dead zone , lethal to sea life that cannot swim out of the way, in inhabitable waters near the Gulf Coast that is sometimes as large as New Jersey--and the as much as 3.8 million liters of oil now spilling into the Gulf per day may make it worse. [More]



Gulf of Mexico - Mississippi River - Dead Zone - New Jersey - Mississippi

Categories: Coral Feeds

Student squid cruise comes to a close

Editor's Note: William Gilly , a professor of cell and developmental biology and marine and organismal biology at Stanford University, is traveling with a group of students on board the Don José in the Sea of Cortez. The team is monitoring and tracking Humboldt squid and sperm whales in their watery habitats. This is the group's 10th and final blog post. [More]



Stanford University - Biology - Humboldt Squid - William Gilly - Developmental biology

Categories: Coral Feeds

Lasting Menace

More than 20 years after the Exxon Valdez foundered off the coast of Alaska, sea otters still dig up oil in their hunt for clams in Prince William Sound. Nearly 25 years after an oil storage tank ruptured near mangrove swamps and coral reefs of Bahia Las Minas in Panama, oil slicks still form in the water. And some 40 years after the fuel-oil barge Florida ran aground off Cape Cod, the muck beneath the marsh grasses makes the area smell like a gas station.

Similar damage may be in store for the U.S. Gulf coast, given that millions of gallons of light sweet crude spewed from BP’s broken well 1,500 meters down and approximately 65 kilometers off the Louisiana coast. Its oil-drilling rig Deepwater Horizon exploded on April 20, and efforts to cap the flow--estimated to be 200,000 to a few million gallons a day during the weeks right after the accident--suffered setbacks and delays. All the oil released, which could ultimately exceed the Valdez spill several times over, could compromise wildlife and local livelihoods for years.

Categories: Coral Feeds

Slick Solution: How Microbes Will Clean Up the Deepwater Horizon Oil Spill

The last (and only) defense against the ongoing Deepwater Horizon oil spill in the Gulf of Mexico is tiny--billions of hydrocarbon-chewing microbes, such as Alcanivorax borkumensis . In fact, the primary motive for using the more than 830,000 gallons of chemical dispersants on the oil slick both above and below the surface of the sea is to break the oil into smaller droplets that bacteria can more easily consume. [More]



Oil spill - Gulf of Mexico - Deepwater Horizon - Environment - Alcanivorax

Categories: Coral Feeds

The evolution of emotion: Charles Darwin's little-known psychology experiment

Charles Darwin is famous for his prolific writing about biology. In addition to publishing his theory of evolution , Darwin wrote books about coral reefs, earthworms and carnivorous plants. But the eminent naturalist made important contributions to more than just the life sciences. It turns out Darwin was also an early experimental psychologist. [More]



Charles Darwin - Evolution - Biology - Psychology - Carnivorous plant

Categories: Coral Feeds

Local Governments Lead Efforts to Combat Climate Change

Call them the Silicon Valley garages of climate policy.

Categories: Coral Feeds