Evolution of mimicry in octopuses

From BBC News & Wired

This fascinating creature was discovered in 1998 off the coast of Sulawesi in Indonesia, the mimic octopus is the first known species to take on the characteristics of multiple species.

This octopus is able to copy the physical likeness and movement of more than fifteen different species, including sea snakes, lionfish, flatfish, brittle stars, giant crabs, sea shells, stingrays, jellyfish, sea anemones, and mantis shrimp.

This animal is so intelligent that it is able to discern which dangerous sea creature to impersonate that will present the greatest threat to its current possible predator.

The Indonesian mimic octopus has the boldest defense strategy of any of its cephalopod cousins, and now scientists know how that strategy evolved.
Rather than blending into the scenery, the octopus mimics the swimming behavior and shape of a variety of toxic sea creatures — like flatfish and sea snakes — and displays bold color patterns that shock predators.

For the study, scientists focused on mimic’s ability to swim on the sea floor like a flatfish, of which there are several toxic varieties in the region where the octopus lives.

The analysis revealed that the behavior evolved in three key steps :

• first, mimic octopus ancestors started switching on bold colors to shock predators when camouflage failed.
• next, they learned to swim like sea-floor–dwelling fish and developed longer arms that facilitate the motion.
• third, they combined the bold color patterns and flatfish swimming technique, and started doing it while out on daily forays and resting.

The Indonesian mimic octopus has the extraordinary ability to pass itself off as many of the toxic fishes or sea snakes that share its habitat.
Instead of blending into the background, the animal impersonator often uses a daredevil strategy of making itself more conspicuous to predators.
Scientists believe the behaviour evolved to scare other animals.
By flattening its head and arms, using a bold brown and white colour display and adopting an undulating swimming technique T. mimicus can fool predators that it is, in fact, a poisonous flatfish rather than a tasty meal.

Because this high risk defence strategy is quite rare, scientists from the California Academy of Sciences and Conservation International Indonesia were keen to understand how its abilities evolved and why they are used.

Dr Christine Huffard from Conservation International Indonesia is one of the authors of the study published in the Biological Journal of the Linnean Society.

"The close relatives of T. mimicus use drab colours and camouflage to successfully hide from predators." she said. "Why does T. mimicus instead draw attention to itself, and repeatedly abandon the camouflage abitilies it inherited from its ancestors in favour of a bold new pattern?"

By analysing its DNA the researchers established when different traits appeared in its ancestors' lineage from its brown-and-white colour displays to its ability to swim like a flatfish using its long arms.

The researchers believe its impersonation skills were advantageous because the mimic could fool predators into thinking it was a poisonous flatfish like the peacock or zebra sole which lives nearby.

Dr Healy Hamilton is Director of the Center of applied Biodiversity Informatics at the California Academy of Sciences.

"While the mimic octopus's imitation of flatfish is far from perfect, it may be 'good enough' to fool predators where it lives... In the time it takes a predator to do a double take, the octopus may be able to get away," she said.

Links :

• ScienceDaily : Octopus mimics flatfish and flaunts It
  

Extreme heat bleaches coral, and threat is seen

From NewYork Times

This year’s extreme heat is putting the world’s coral reefs under such severe stress that scientists fear widespread die-offs, endangering not only the richest ecosystems in the ocean but also fisheries that feed millions of people.

From Thailand to Texas, corals are reacting to the heat stress by bleaching, or shedding their color and going into survival mode. Many have already died, and more are expected to do so in coming months. Computer forecasts of water temperature suggest that corals in the Caribbean may undergo drastic bleaching in the next few weeks.

What is unfolding this year is only the second known global bleaching of coral reefs. Scientists are holding out hope that this year will not be as bad, over all, as 1998, the hottest year in the historical record, when an estimated 16 percent of the world’s shallow-water reefs died. But in some places, including Thailand, the situation is looking worse than in 1998.

Scientists say the trouble with the reefs is linked to climate change. For years they have warned that corals, highly sensitive to excess heat, would serve as an early indicator of the ecological distress on the planet caused by the buildup of greenhouse gases.

“I am significantly depressed by the whole situation,” said Clive Wilkinson, director of the Global Coral Reef Monitoring Network, an organization in Australia that is tracking this year’s disaster.

According to the National Oceanic and Atmospheric Administration, the first eight months of 2010 matched 1998 as the hottest January to August period on record. High ocean temperatures are taxing the organisms most sensitive to them, the shallow-water corals that create some of the world’s most vibrant and colorful seascapes.

Coral reefs occupy a tiny fraction of the ocean, but they harbor perhaps a quarter of all marine species, including a profusion of fish. Often called the rainforests of the sea, they are the foundation not only of important fishing industries but also of tourist economies worth billions.

Drastic die-offs of coral were seen for the first time in 1983 in the eastern Pacific and the Caribbean, during a large-scale weather event known as El Niño. During an El Niño, warm waters normally confined to the western Pacific flow to the east; 2010 is also an El Niño year.

Serious regional bleaching has occurred intermittently since the 1983 disaster. It is clear that natural weather variability plays a role in overheating the reefs, but scientists say it cannot, by itself, explain what has become a recurring phenomenon.

“It is a lot easier for oceans to heat up above the corals’ thresholds for bleaching when climate change is warming the baseline temperatures,” said C. Mark Eakin, who runs a program called Coral Reef Watch for the National Oceanic and Atmospheric Administration. “If you get an event like El Niño or you just get a hot summer, it’s going to be on top of the warmest temperatures we’ve ever seen.”

Coral reefs are made up of millions of tiny animals, called polyps, that form symbiotic relationships with algae. The polyps essentially act as farmers, supplying the algae with nutrients and a place to live. The algae in turn capture sunlight and carbon dioxide to make sugars that feed the coral polyps.

The captive algae give reefs their brilliant colors. Many reef fish sport fantastical colors and patterns themselves, as though dressing to match their surroundings.

Coral bleaching occurs when high heat and bright sunshine cause the metabolism of the algae to speed out of control, and they start creating toxins. The polyps essentially recoil. “The algae are spat out,” Dr. Wilkinson said.

The corals look white afterward, as though they have been bleached. If temperatures drop, the corals’ few remaining algae can reproduce and help the polyps recover. But corals are vulnerable to disease in their denuded condition, and if the heat stress continues, the corals starve to death.

Even on dead reefs, new coral polyps will often take hold, though the overall ecology of the reef may be permanently altered. The worst case is that a reef dies and never recovers.

In dozens of small island nations and on some coasts of Indonesia and the Philippines, people rely heavily on reef fish for food. When corals die, the fish are not immediately doomed, but if the coral polyps do not recover, the reef can eventually collapse, scientists say, leaving the fishery far less productive.

Research shows that is already happening in parts of the Caribbean, though people there are not as dependent on fishing as those living on Pacific islands.

It will be months before this year’s toll is known for sure. But scientists tracking the fate of corals say they have already seen widespread bleaching in Southeast Asia and the western Pacific, with corals in Thailand, parts of Indonesia and some smaller island nations being hit especially hard earlier this year.

Temperatures have since cooled in the western Pacific, and the immediate crisis has passed there, even as it accelerates in places like the Caribbean, where the waters are still warming. Serious bleaching has been seen recently in the Flower Garden Banks, a marine sanctuary off the Texas-Louisiana border.

In Thailand, “there some signs of recovery in places,” said James True, a biologist at Prince of Songkla University. But in other spots, he said, corals were hit so hard that it was not clear young polyps would be available from nearby areas to repopulate dead reefs.

“The concern we have now is that the bleaching is so widespread that potential source reefs upstream have been affected,” Dr. True said.

Even in a hot year, of course, climate varies considerably from place to place. The water temperatures in the Florida Keys are only slightly above normal this year, and the beloved reefs of that region have so far escaped serious harm.

Parts of the northern Caribbean, including the United States Virgin Islands, saw incipient bleaching this summer, but the tropical storms and hurricanes moving through the Atlantic have cooled the water there and may have saved some corals. Farther south, though, temperatures are still remarkably high, putting many Caribbean reefs at risk.

Summer is only just beginning in the Southern Hemisphere, but water temperatures off Australia are also above normal, and some scientists are worried about the single most impressive reef on earth. The best hope now, Dr. Wilkinson said, is for mild tropical storms that would help to cool Australian waters.

“If we get a poor monsoon season,” he said, “I think we’re in for a serious bleaching on the Great Barrier Reef.”

Links :

• GBRclimatechange videos : coral bleaching on the Great Barrier Reef : I / II / III
• YouTube : Researcher studies warming oceans' effects on coral reef life
  

Ocean Conservancy's International Coastal Cleanup day

From ABC News

rash in our oceans and waterways is one of our planet's greatest, and most preventable, pollution problems. Millions of pounds of disintegrating marine debris was first discovered more than 10 years ago, floating in the Pacific Ocean.

Surfer Laird Hamilton and wife Gabrielle Reece discuss the coastal cleanup event
The discovery of what is called the Great Pacific Garbage Patch provided a startling wake-up call to the problem of floating marine debris.

Since then, trash has been found in every ocean on the planet, as well as in rivers and lakes across the nation. And with the BP oil spill disaster looming in our national consciousness, the health of our country's waterways has become even more paramount.

But the good news is, there is something we all can do about it.

25th Anniversary of Cleanup is Saturday
"Each one of us can get out there and help clean up our coastlines," says Gabrielle Reece, a professional beach volleyball player and wife of big wave surfer Laird Hamilton.

This Saturday, Reece will be hitting her local beach with her and Hamilton's two daughters to clean up the coastline. It's all part of the 25th annual International Coastal Cleanup.

Taking place on Sept. 25, the event is the world's largest volunteer effort to help protect the ocean. Last year, 500,000 volunteers joined their communities to clean up local beaches, lakes and rivers with a common mission of improving the health of the ocean and waterways.

On one day, volunteers removed and tallied 7.4 million pounds of debris, in 108 countries and 45 U.S. states and the District of Columbia.

"The ocean is our life support system, yet marine debris continues to threaten its health. From product design to disposal, we all have a role to play in keeping our ocean clean and eliminating marine debris," said Vikki Spruill, president and CEO of Ocean Conservancy.

"The International Coastal Cleanup is an essential step to finding solutions," she said. "Data collected by dedicated volunteers inform solutions to the threat of trash in our ocean. By understanding sources of marine debris, we can work together to solve this problem. Join me and communities around the world this Sept. 25 to celebrate the International Coastal Cleanup and a 25-year Sea Change."

Event started with cleanup on just one beach : over the last quarter-century, the International Coastal Cleanup has grown from a single cleanup on a Texas beach to a worldwide movement to end the threat of trash in our ocean.

In the span of 25 years, the International Coastal Cleanup expanded to include hundreds of thousands of volunteers from around the world who have removed many millions of pounds of trash from the Earth's ocean, lakes and waterways and documented what they found.

This unwavering dedication over the years has helped to make the environment safer for wildlife and people alike

And now this year, you have a chance to get involved, cleaning up the waterways in your own area.

For additional information about the International Coastal Cleanup and to sign up to be a part of the next wave of volunteers visit: www.oceanconservancy.org.

What better thing do you have to do this Saturday?

Links :

• Kaisei project (World Ocean Day 2010 cleanup -June 8th-)
• Surfrider beach cleanup
  

Ocean comes to Google Earth for iPhone, iPad and iPod touch

From Google Mobile Blog

Peter Birch, Google Earth Product Manager :
"We recently announced the arrival of ocean bathymetry and ocean layer content to Google Earth for Android.
Today, with the latest release of Google Earth 3.1 for iOS, we’re proud to announce that you can now explore underwater landscapes and terrain on your iPhone, iPad, and iPod touch."

Dive below the ocean’s surface to explore underwater canyons, or travel to the ocean’s deepest point, the Mariana Trench.
Once underwater, simply swipe the screen with two fingers to “look around.”
You can always reset your view by clicking on the north arrow on the iPad, or on the compass on the iPhone and iPod.
As with the desktop and other mobile versions of Google Earth, we’ve also added the “Ocean” layer, which features hundreds of photos and videos from more than 100 contributors curated by the Sylvia Earle Alliance.

This version also includes native support for the new Retina display, which means that if you have an iPhone 4 or the new iPod touch, you’ll get to enjoy an even sharper view of the world.

Google Earth 3.1 for iPhone, iPad and iPod touch is available now in the App Store, or navigate to http://m.google.com/earth in your mobile browser.
You can also download Google Earth by scanning this QR code.

Shark-finning puts species on verge of extinction

Sharks in Deep Trouble : by filmmaker and shark conservationist Lesley Rochat, in South Africa

From Wired

It’s estimated that as many as a million sharks a year are killed just for their fins.

Shark-finning is a cruel practice. Sharks are caught on long lines, or in nets, regardless of size or species. The shark is often stabbed or clubbed, to be less of a threat to the fisherman. The shark’s fins are then cut off and the shark is thrown back into the water, alive, to be eaten by other fish as it sinks to the bottom.

Shark-finning has increased over the past decade for a number of reasons, including increasing demand for shark-fin soup and traditional cures, improved fishing technology and improved market economics, according to the conservation group Shark Water.

Shark fins go for big money. A single dried fin can fetch up to $300.

A growing Asian middle class now has access to shark-fin soup, a dish once reserved for royalty. Cities like Shanghai have multistory shopping centers dedicated to fish and animal sales, which include bin after bin of shark fins.

Local Asian markets in the United States and Europe supply shark fins to eager customers. And shark fins are increasingly found in other products such as energy drinks, pet supplies, makeup, vitamins and homeopathic medicines.

Consequently, many species of shark may already be on the way to extinction, which could be bad news for the entire ocean ecosystem. According to the National Shark Research Consortium, “Sharks are involved in several steps of this web including feeding on the sick and dying, and feeding on larger animals such as whales, seals and tuna, which have few predators.”

Laws have been enacted to protect the shark in Hawaii, the Maldives and Palau, which have no–shark-finning zones, The conservation group Sea Shepherd is using new strategies, including sniffer dogs, to fight shark-finning in the Galapogos.

Scientists are backing up these efforts. Marine biologist Mahmood Shivji of the Guy Harvey Research Institute at Nova Southeastern University in Fort Lauderdale, Florida, is using DNA to help law enforcement agencies convict smugglers, and his research has shown that hammerheads from the Atlantic Ocean end up in Hong Kong seafood markets.

In its video, Wired speaks to scientists and conservation groups about the severity of the situation and what is being done to fight back.

Links :

• SharkTrust
• Stop shark finning
  
• PRNewswire : Honduras and Palau challenge the world to save sharks
  
• PR-Canada : Shark attack survivors press U.N. to 'Save the sharks'