Tapinoma sessile - odorous house ant, feeding from a droplet of sugar water. Photo: Alex Wild

Salt, while necessary to sustain animal life, can also act as a poison in large doses. Winter road-salting is known to have negative effects on wildlife, especially for adjacent plants, roadside animals and aquatic ecosystems. For less visible organisms such as ants, however, the possible side effects may be less clear.

To understand the effects of road salting on ants (Formicidae), Michael Kaspari of the Smithsonian Tropical Research Institute and the University of Oklahoma led a team that looked at how ant colonies are affected by these conditions; their research is published in a recent issue of the journal Ecological Entomology.

“Sodium is a strange beast in the history of life because plants don’t really need it, but the things that eat plants do. Many animals are thus faced with the challenge of meeting their daily sodium requirement in an environment that is frequently not very salty.” Kaspari said.

Tapinoma sessile, the odorous house ant, with larvae. Photo: Alex Wild

When on sabbatical in 2008 near Massachusetts’ Harvard Forest, Kaspari noticed trucks spreading salt on roadways during snowstorms. He pondered the repercussions of road salt on surrounding wildlife and in particular, his favorite animals, ants.

“Although most research has focused on the negative effects of road salt on plants and adjacent streams, we were curious if these artificial sodium pulses actually had positive effects on ant communities.” said Kaspari. He recruited colleagues to perform a simple experiment.

The team set up a series of vials at different distances from the salty roadside, each filled with cotton balls laced with varied concentrations of salt (NaCl) or sugar (sucrose). They were able to determine what nutrients the ants sought out most at various distances from the roadside. As suspected, ants increasingly craved salt compared to sugar the farther the ants lived from the roadway.

Two nestmates of the odorous house ant (Tapinoma sessile) share a granule of sugar. Photo: Alex Wild

The authors conclude that road salt has a more complicated effect on ecosystems than previously thought. “Ants are an important bellwether, standing in for all the crop pests and decomposers found in any ecosystem. We suspect that road salt likely promotes their health and well-being, even as it hurts roadside plants and aquatic life.” Kaspari said.

Kaspari’s research sheds new light on the effects of road salt to scientists and policy makers. This may be particularly true for citizens of colder states where the application of hundreds of pounds of salt per lane mile is mandatory. He adds, “I also think it’s just fascinating knowing there is this nearly invisible substance spread unevenly over the landscape that can reveal something new about the health and vigor of the critters that live there.” –Brian Ireley

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Image right: This artist’s concept illustrates an imminent planetary collision around a pair of double stars. The stars are similar to the sun in age and mass, but they orbit tightly around each other. With time, they are thought to get closer and closer, until their gravitational influences change, throwing the orbits of planetary bodies circling around them out of whack and leading to collisions.

“This is real-life science fiction,” says Jeremy Drake of the Smithsonian Astrophysical Observatory. “Our data tell us that planets in these systems might not be so lucky — collisions could be common. It’s theoretically possible that habitable planets could exist around these types of stars, so if there happened to be any life there, it could be doomed.”

The particular class of binary, or double, stars in the study are about as snug as stars get. They are separated by only about two million miles (3.2 million kilometers), or one-fiftieth the distance between Earth and our Sun. The stellar pairs orbit around each other every few days, with one face on each star perpetually locked and pointed toward the other.

The close-knit stars are similar to the Sun in size and are probably about a billion to a few billion years old. But these stars spin much faster and, as a result, have powerful magnetic fields and giant, dark spots. The magnetic activity drives strong stellar winds — gale-force versions of the solar wind — that slow the stars down, pulling the twirling duos closer over time. And this is where the planetary chaos begins.

Image left: This artist’s concept illustrates a tight pair of stars and a surrounding disk of dust–most likely the shattered remains of planetary smashups. Using NASA’s Spitzer Space Telescope, scientists found dusty evidence for such collisions around three sets of stellar twins. The stars are similar to our sun in mass and age and orbit very closely around each other. (NASA/JPL-Caltech images)As the stars cozy up to each other, their gravitational influences change, and this could disturb planetary bodies orbiting around both stars. Comets and any planets that might exist in the systems would start jostling about and sometimes banging into each other. This includes planets that could theoretically be circling in the double stars’ habitable zone — a region where temperatures would allow liquid water to exist.

“These kinds of systems paint a picture of the late stages in the lives of planetary systems,” says Marc Kuchner, a scientist at NASA Goddard Space Flight Center in Greenbelt, Md. “And it’s a future that’s messy and violent.”

The Spitzer telescope spotted the infrared glow of hot dusty disks, about the temperature of molten lava, around three such tight binary systems. The team says that dust normally would have dissipated and blown away from the stars by this mature stage in their lives. They conclude that something — most likely planetary collisions — must therefore be kicking up the fresh dust.

If any life forms did exist in these star systems, and they could look up at the sky, they would have quite a view. Marco Matranga, from the Harvard-Smithsonian Center for Astrophysics and now a visiting astronomer at the Palermo Astronomical Observatory in Sicily, says, “The skies there would have two huge suns, like the ones above the planet Tatooine in ‘Star Wars.’”

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Image right: After this adult anemone broadcast spawned, Smithsonian’s National Zoo animal keeper Mike Henley collected the eggs off the surface. Using coral settling techniques learned in the field, Henley is successfully growing anemones. (Photo by Mike Henley)

“We have many questions about how to care for these animals as they grow from larvae to adults,” said Mike Henley, an animal keeper at the Zoo’s Invertebrate Exhibit who applied the technique to the anemones after they had spawned. “The oceans are not an infinite resource and so anything that we can learn about the captive management of coral and anemones will go far in our ability to conserve them.”

The anemones—both of which are commonly called Tealia red anemones under the species of Urticina—spawned in late April and early May, just days apart. Hours after they spawned, Henley collected the eggs and sperm from the more than 2,000-gallon tank and put them together in smaller tanks to increase the chances of fertilization. After fertilization, the larvae settled and metamorphosed into a polyp. Henley put some of the developing larvae in a circular tank—called a kreisel—that automatically stirs the water to prevent the larvae from binding to one another, which would kill the animals. The kreisel is the same tank Henley and others use in the field in Puerto Rico to hold coral larvae. Other free-swimming larvae went into a regular tank with aeration and rocks to settle on. Now the Zoo has hundreds of thriving anemones behind the scenes, all smaller than the tip of a pencil.

Image left:  The result of National Zoo keeper Mike Henley’s work is hundreds of thriving anemones, all smaller than the tip of a pencil. The one shown here is no bigger than 1-2 mm. (Photo Mehgan Murphy)

“Sometimes we take the lessons we learn with animals in captivity and apply that to conserving them in the wild,” said Alan Peters, curator of the Zoo’s Invertebrate Exhibit. “But here we were able to apply what we’ve learned both in the field and from ex situ work and it is yielding some exciting results.”

While anemones and coral are both in the Anthozoa class of animals, they differ in a few notable ways. Anemones metamorphose into a single polyp, while coral will divide into a second polyp and a third and so on, to form a colony. In addition, anemones have a muscular foot they use to attach to rock, while stony corals make their own calcium carbonate rock that they live on. But both can sting and are carnivorous, feeding on crabs, shrimp, fish and zooplankton. More than 1,000 sea anemone species inhabit the world’s oceans at various depths, from the sandy seashore up to the surface. Visitors to the Zoo can see six different species of anemones, including cold and warm water anemones. Although anemones are not endangered, ocean habitats around the world are in decline as the result of pollution, runoff and sedimentation, climate change, acidification and poor fishing practices.

Henley will continue to observe the anemones to learn about their growth rate and the conditions that are necessary to rear these species in captivity, including the food, light and water temperature they require.

“In the past if the anemones spawned in the tank, it’d be a big headache,” said Henley. “You’d have to do frequent water changes because when the gametes—or reproductive cells—get too concentrated and deteriorate, it causes the water quality to crash. That’s the common experience among many of our zoo and aquarium colleagues. But this was different—so far it’s amounted to young anemones that we will continue to learn from for months, even years, to come.”

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You will not notice it when you look at the moon tonight, but it is actually shrinking. Smithsonian scientist Tom Watters made this discovery and he revealed this finding as the lead author in research published in the Aug. 20 issue of the journal Science.

By looking at images and data taken by the Lunar Reconnaissance Orbiter, a team of scientists, including Watters, a planetary scientist in the Center for Earth and Planetary Studies at the National Air and Space Museum, were able to examine geological features on the moon called lobate scarps—thrust faults that occur primarily in the lunar highlands. These scarps are the result of the interior of the moon slowly cooling, and as it does so, it shrinks causing its surface area to crack and buckle.

“One of the remarkable aspects of the lunar scarps is their apparent young age,” said Watters. “Relatively young, globally distributed thrust faults show recent contraction of the whole moon, likely due to cooling of the lunar interior. The amount of contraction is estimated to be about 100 meters in the recent past.

The moon’s lobate scarps were first recognized in photographs taken near the moon’s equator by the panoramic cameras flown on the Apollo 15, 16 and 17 missions. Fourteen previously unknown lobate scarps have now been revealed in very high resolution images taken by the Lunar Reconnaissance Orbiter Camera. The newly detected scarps indicate that the thrust faults are globally distributed and not clustered near the moon’s equator.

“The ultrahigh resolution images from the Narrow Angle Cameras are changing our view of the moon,” said Mark Robinson of the School of Earth and Space Exploration at Arizona State University, coauthor and principal investigator of the Lunar Reconnaissance Orbiter Camera. “We’ve not only detected many previously unknown lunar scarps, we’re seeing much greater detail on the scarps identified in the Apollo photographs.”

Because the size change is relatively small, however, Watters said that there would be no effect on lunar cycles, tides, etc. It would take millions of years for there to be a perceivable difference in the size of the moon to the naked eye. But this discovery does help change the commonly held belief that the moon is just a dead rock, showing that it is still active and dynamic.

The mare basalts that fill the Taurus-Littrow valley were thrust up by contractional forces to form the Lee-Lincoln fault scarp, just west of the Apollo 17 landing site (arrow). It is the only extraterrestrial fault scarp to be explored by humans (astronauts Eugene Cernan and Harrison Schmitt). The digital terrain model derived from Lunar Reconnaissance Orbiter Camera (LROC) stereo images shows the fault extending upslope into North Massif were highlands material are also thrust up. The fault cuts upslope and abruptly changes orientation and cuts along slope, forming a narrow bench. LROC images show boulders shed from North Massif that have rolled downhill and collected on the bench. Credit: NASA/GSFC/Arizona State University

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Photo right: Fungia, one of the corals deposited into the frozen repository. (Ann Farrell, University of Hawaii)

“Because frozen banked cells are viable, the frozen material can be thawed one, 50 or, in theory, even 1,000 years from now to restore a species or population,” said Hagedorn. “In fact, some of the frozen sperm samples have already been thawed and used to fertilize coral eggs to produce developing coral larvae.”

Coral reefs are living, dynamic ecosystems that provide invaluable services: They act as nursery grounds for marine fish and invertebrates, provide natural storm barriers for coastlines, purify carbon dioxide from the atmosphere and they are potential sources for undiscovered pharmaceuticals.

However, coral reefs are experiencing unprecedented levels of degradation due to human impact. Globally, greenhouse gasses from burning fossil fuels are warming the oceans, making them more acidic and causing corals to stress and bleach. As a result, the corals are more susceptible to emergent diseases. Locally, reefs are affected by pollution and sedimentation from poor land-use practices, nutrient run-off from farms and waste-treatment plants, and destructive practices such as dynamite fishing and trawls.

Photo right: Interns Malia Paresa and Kelly Martonrana place coral into the frozen repository (Hawaii Institute of Marine Biology)

Unless action is taken now, coral reefs and many of the animals that depend on them may cease to exist within the next 40 years, causing the first global extinction of a worldwide ecosystem during current history.

This work highlights the importance of basic science and discovery for developing creative solutions to pressing conservation problems,” said Steve Monfort, director of the Smithsonian Conservation Biology Institute. “We are confident that this effort will one day help to restore these vital marine ecosystems.”

Saving reef habitat alone will not stop corals’ decline because many of the most serious threats are global rather than local. Done properly over time, researchers can store samples of frozen material and place them back into ecosystems to infuse new genes and vigor into natural populations, thereby enhancing the health and viability of wild stocks.

Currently, the Hawaiian bank contains frozen sperm and embryonic cells from mushroom coral (Fungia scutaria) and rice coral (Montipora capitata), but it is only a beginning. The researchers hope to store many of the corals that are important to Hawaiian reefs.

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