Good-Bye, Everglades? How Tiny Beetles Are Destroying Florida’s Precious Wetlands

Florida’s flora and fauna can’t seem to get a break. They’re getting hit with another piece of bad news just weeks after a tract of endangered forestland was sold to a property developer. This time, instead of Walmart and 88 acres of rockland, a fungus transmitted by the invasive redbay ambrosia beetle is overrunning the Everglades. So far, experts haven’t come up with a way to contain it.

The insect from southeast Asia carries a fungus that causes laurel wilt, a disease deadly to trees. It has decimated swamp bay trees across 330,000 acres in the Everglades since the condition was first identified in 2011, and it shows no signs of stopping. According to The Associated Press, the redbay ambrosia beetle likely entered the United States through a shipment of wood packaging.

The blight threatens to lay waste to the billion-dollar projects aimed at restoring the region. From a bird’s eye view and even from the highway that cuts through the fragile wetlands, one can easily make out the dried-up gray and brown trees, reports the news agency.

The future looks even grimmer. Exotic plants that may overrun the Everglades as a result of the devastation of swamp bays can fuel fires. Also, they’re not a source of food for native wildlife. The plants’ roots can damage the homes of endangered species in the area. According to the National Research Council, about 16 percent of the Everglades’ greenery isn’t native.

“We already have these problems with invasives that are almost too daunting. When you add laurel wilt to the mix, it’s only going to get worse,” Everglades National Park chief of biology Tylan Dean told the AP.

The South Florida Water Management District, the agency managing the restoration of the Everglades, has promised to ramp up efforts to monitor and maintain the swamp bay trees.

“It’s amazing how much of an impact this one little tiny beetle that’s no bigger than Lincoln’s nose on a penny has done,” Jason Smith, a forest pathology expert at the University of Florida, told the AP. “And it continues to spread.”

This summer he plans to gather samples of the surviving trees, hoping to propagate fungus-resistant seedlings to keep their population alive.

Earth Is On The Cusp Of A Sixth Mass Extinction

w photo

.

Approximately 65 million years ago, when the dinosaurs went extinct,  75% of the planet's many species went with them. It was the world's fifth, and most recent, mass extinction event. 

Now, according to a July 25 review in the journal Science, the Earth seems to be at the cusp of a sixth mass extinction. Only this time, an asteroid is not to blame. We are.

"Human impacts on animal biodiversity are an under-recognized form of global environmental change," the team of ecologists and biologists warn in Science. "Among terrestrial vertebrates, 322 species have become extinct since 1500, and populations of the remaining species show 25% average decline in abundance." 

A third of all vertebrates, the scientists write, "are threatened or endangered."

There are several long-time drivers of what researchers call "defaunation" — the decline of various animal species. The study points to " overexploitation,  habitat destruction, and impacts from invasive  species" as continuing threats, but notes that soon, human-caused climate change will be the number one driver of defaunation. Diseases that come from pathogens introduced by humans are another growing threat.

The good news? We're not yet totally doomed. 

As David Biello writes in Scientific American:

To avoid the sixth mass extinction we will probably have to employ more aggressive conservation, such as  moving species to help them cope with a changing climate . Think re-wilding: reintroducing species like wolves or beavers that were once present in a given ecosystem but have since disappeared. Aggressive conservation might also mean killing off newcomer species to preserve or make room for local flora and fauna.

As another study in Science notes, we've already made headway in saving some animals from what seemed like certain ruin.

But if humans as a species don't want to take our chances with a sixth mass extinction, we need to start taking drastic measures now. The momentum is already moving against us.

Giant Ancient Sea Scorpions Had Bad Eyesight

By By Tanya Lewis, Staff WriterJuly 8, 2014 10:44 PM

Sam Ciurca, who collected the sea scorpion specimens,
with a life size model of one called Acutiramus.

Gigantic sea scorpions that lurked in the ocean more than 400 million years ago weren't as scary as they sound, a new study suggests.

The massive creatures, known as pterygotids, were the largest arthropods that ever lived, growing to be up to 6.5 feet (2 meters) long, with claws measuring up to about 2 feet (0.6 m). But contrary to what scientists thought, these animals may not have been true top predators.

"These things were almost certainly still predators of some kind, but the imagined notion that they were swimming around terrorizing anything that looked edible is probably an exaggeration," said Derek Briggs, a paleontologist at Yale University in New Haven, Connecticut, and co-author of the new study, published today (July 8) in the journal Biology Letters.

Pterygotids were a type of eurypterid, an extinct type of sea scorpion related to arachnids. These ocean-dwelling creatures lived between about 436 million to 402 million years ago, in the Silurian and Devonian periods, Briggs said. Their closest living relatives are horseshoe crabs or modern sea scorpions, he said.

Previously, these spooky sea monsters were thought to be fearsome predators, devouring armored fishes and giant cephalopods (related to modern squids and nautiluses). Their compound eyes and large claws seemed to suggest as much.

But more recently, a study revealed that pterygotid claws wouldn't have been strong enough to break into armored fish or cephalopod shells.

A pterygotid fossil

In the recent study, Briggs and his team set out to examine the eyes of these ancient sea scorpions, to determine whether they had good enough vision to be great hunters.

Some of the lenses in the creatures' eyes were big enough for researchers to see them without any help from technology, but others had to be viewed under an electron microscope. The team estimated the angle between the lenses and the size of the lenses, comparing them with the eyes of a smaller eurypterid relative and of modern arthropods.

Briggs and his team concluded that the giant arthropods actually had poor eyesight. They probably lived near the bottom of the sea and likely hunted soft-bodied animals in dark waters or at night, Briggs said. But the fossil evidence limits these interpretations, so it's hard to know for sure how the animals behaved, he added.

After about 35 million years, pterygotids died out, and "it's a good thing they did," Brigg said. "They wouldn't be good company."

Lost 'Nightsnake' Rediscovered on Volcanic Island off Mexico

The Clarion nightsnake, or Hypsiglena ochrorhyncha unaocularus, lives on an island off the coast of Mexico.

A mysterious species of snake has been rediscovered lurking in volcanic rocks on an island off Mexico

The elusive, nocturnal Clarion nightsnake was first discovered more than 80 years ago on Clarion Island, but was then lost to science.

"The rediscovery of the Clarion nightsnake is an incredible story of how scientists rely on historical data and museum collections to solve modern-day mysteries about biodiversity in the world we live in," lead author Daniel Mulcahy, a researcher at the National Museum of Natural History, in Washington, D.C., said in a statement. "Proper identification is the first step toward conserving this snake, and we plan to continue monitoring this species to learn more about the role it plays in the delicate Clarion Island ecosystem."

In 1936, naturalist William Beebe first unearthed a lone nightsnake, dubbed Hypsiglena ochrorhyncha unaocularus, on Clarion Island, which is one of the four Revillagigedo Islands in the Pacific Ocean. The reptile's speckled, brownish-black camouflage blended in with the black lava rock on the island, making it difficult to spot.

That single snake specimen was tagged and kept in the collections of the American Museum of Natural History in New York, but because no other researchers had seen the snake since, its existence as a separate species was questioned. In part, the snake, which grows to about 18 inches (45 centimeters) long, has remained hidden for decades because of its coloration — dark spots on its head and neck act as camouflage — and secretive behavior; the island itself is so remote that biologists can only access it with a military escort, limiting how many scientists actually searched for these reptiles.

But in 2013, Mulcahy and colleagues at the Instituto de Ecología in Mexico set out on a quest to the Revillagigedo Islands to find the missing species.

The team uncovered 11 of the elusive snakes, all on the volcanic island of Clarion. DNA testing confirmed the snakes were a distinct species from mainland nightsnakes.

Their closest relatives inhabit a region on the border of Sonora and Sinaloa in Mexico, as well as an island off Mexico called Isla Santa Catalina in the Gulf of California. The new species may have first made it to the island by swimming across the sea from a river basin in Sonora, the researchers speculate.

Right now, the population seems to be stable, but bands of feral cats, an invasive species, on nearby islands could spell trouble for the snakes. The cats prey upon the nightsnake's main food source, an island lizard.

Newfound Purple-Pink Mineral Is Like No Other

A new purple-pink mineral that has a chemical composition and crystalline structure unlike any of the known 4,000 minerals has been discovered at a mining site in Western Australia, researchers report.

Now called putnisite, the mineral was discovered in a surface outcrop of Polar Bear Peninsula, Southern Lake Cowan, north of Norseman. While workers with a mining company were prospecting for nickel and gold, one of them noticed the bright-pink grains and sent the mineral to the Commonwealth Scientific and Industrial Research Organization (CSIRO), and then it was sent to Peter Elliott, a research associate with the South Australian Museum, for examination.

And, sure enough, the crystal was novel.

"A mineral is different from currently known minerals if it has either a different chemical composition or it has a different crystal structure, or sometimes both," Elliott told Live Science in an email. "Occasionally, a new mineral will have a chemistry that is very different to other minerals, or it will have a crystal structure that is very different to other minerals." 

Elliott added, "Putnisite, a strontium calcium chromium sulfate carbonate, has both a unique chemical composition and a unique crystal structure." (The color of putnisite crystals ranges from pale to dark purple, with a pink streak, according to the researchers.)

Found on volcanic rock, the new mineral occurs as tiny crystals just 0.02 inches (0.5 millimeters) in diameter, and looks like spots of dark pink on dark-green-and-white rock; under a microscope, the mineral appears as cubelike crystals.

"When the rocks in the Lake Cowan area were deposited millions of years ago, they contained small concentrations of strontium calcium chromium and sulfur," Elliott said. "Over time, weathering released these elements and concentrated them, allowing putnisite to crystallize."

Though it is not uncommon to find a new mineral — 50 to 100 such specimens have been discovered in each of the past several years — they aren't usually discovered by miners, Elliott said.

"Often, they are found in museum mineral collections," he said. "Many new minerals are found by mineral collectors who will forward a specimen they have found to a mineralogist at a museum of [a] university for identification."

The researchers are not sure if the mineral, described in Mineralogy Magazine, has any practical uses. Putnisite gets its name from Australian mineralogists Andrew and Christine Putnis.

Dolphins Put Sponges on Snouts to Snag Elusive Snacks

Dolphins can use sponges as tools to snag food they could not otherwise grab, researchers say.

This is the first direct evidence that dolphins can use toolsto carve out unique places in the food chain, scientists added.

Dolphins are often ranked among the smartest members of the animal kingdom. They engage in complex forms of communication, may recognize themselves in mirrors, can understand sign language, and can learn to poke an underwater keyboard to request toys to play with.

Recently, scientists discovered Indo-Pacific bottlenose dolphins in Shark Bay off the coast of Australia apparently use tools in the wild. Specifically, the most common foraging tactic dolphins practice in deep-water channels involves carrying sponges on their snouts — more than 60 percent of all female dolphins practice sponging, and up to half of all males born to "spongers" in one part of the bay grow up to become spongers themselves. 

The sponges may help protect dolphin beaks from sharp rocks, stingray barbs and other painful experiences as they probe the seafloor for food. However, it was unknown whether tool use helped spongers get food they could not obtain otherwise, as is the case with humans and nut-cracking chimpanzees.

To solve this mystery, evolutionary biologists Michael Krützen and Sina Kreicker at the University of Zurich and their colleagues analyzed chemicals in tissue samples from both 11 spongers and 27 non-spongers. The investigators focused on molecules known as fatty acids, which come from prey and thus shed light on the diets of the dolphins.

The scientists discovered spongers apparently have completely different diets from non-spongers.

"We were blown away as to how strong the differences between tool users and non-tool users were, especially given that these animals live in the same habitat," Krützen told Live Science.

These findings are the first direct evidence that dolphin tool use can help them acquire new spots in the food chains of their ecosystems. "This has been demonstrated in only a few species so far, and has been implicated as a significant driver for human evolution," Krützen said.

The researchers suggest that spongers may feed on fish that live near the seafloor, ones lacking organs known as swim bladders that help fish stay buoyant in the water. These bottom-dwelling fish are difficult to spot using the echolocation, or biological sonar, that dolphins normally use to pinpoint prey — the complex surface of the seafloor can muddy a dolphin's echolocation.

It remains uncertain what fish sponges actually help spongers catch. To identify this prey, researchers would have to sample the fatty acids of all potential food in the bay, including ones living near, on or buried in the seafloor. "This was beyond the scope of the project, but might be done in the future," Krützen said.

In future studies, the scientists would also like to discover what benefits accrue from another tool-use strategy, known as shelling, that dolphins in Shark Bay practice; with shelling, dolphins carry seashells around in their mouths.

Suicidal Wasps, Zombie Cockroaches, and Other Parasite Tales