More Mercury, More Danger

The strict new federal standards limiting pollution from power plants are meant to safeguard human health. But they should have an important side benefit according to a study released on Tuesday: protection a broad array of wildlife that has been harmed by mercury emissions. Songbird and bats suffer from some of the same types of neurological disorders from mercury as humans especially children. Methyl mercury, the most toxic form of heavy metal was found to be at minimal risk. There have been studies to learn the amount of pollution and heavy metals in the atmosphere and the new studies have found dangerously high levels of mercury in several Northeastern bird species, including rusty blackbirds, saltmarsh sparrow and wood thrushes. In some older studies, zebra finches lost the ability to hit high notes in mating songs when mercury levels raised affecting reproduction.“We’re seeing many other species in a much larger landscape of harm from mercury,” said the principal author, David C. Evers, who is the institute’s executive director. He called the Environmental Protection Agency’s new mercury standards, adopted last month and scheduled to take effect over the next four years, “an excellent step forward in reducing and minimizing the impact on ecosystems and improving ecological health, and therefore our own health.”  

Mercury, which occurs naturally in the earth, is released into the air when coal is burned in power plants. The gaseous mercury can drift hundreds of miles before settling back to earth, sometimes along with rain. The mercury can also be absorbed by tree leaves; when they fall to the ground, they are swarmed by bacteria and other organisms that convert the mercury to its organic form. The organic form, methylmercury, is a neurotoxin that can enter the food chain. Small insects, worms and snails that feed on forest litter absorb the mercury. In turn, they are eaten by birds and other small animals, and so on through the food chain. Songbirds with blood mercury levels of just 0.7 parts per million generally showed a 10 percent reduction in the rate at which eggs successfully hatched. As mercury increases, reproduction decreases. At mercury levels of greater than 1.7 parts per million, the ability of eggs to hatch is reduced by more than 30 percent, according to the study.

Speed Limit for Birds

The northern goshawk is one of nature's diehard thrill-seekers. The formidable raptor preys on birds and small mammals, speeding through tree canopies and underbrush to catch its quarry. With reflexes that rival a fighter pilot's, the goshawk zips through a forest at high speeds, constantly adjusting its flight path to keep from colliding with trees and other obstacles. Researchers found that, given a certain density of obstacles, there exists a speed below which a bird and any other flying object has a fair chance of flying collision-free. Any faster, a bird or aircraft is sure to crash into something, no matter how much information it has about its environment. Most UAVs (unmanned aerial vehicles) today fly at relatively slow speeds, particularly if navigating around obstacles. That's mainly by design: Engineers program a drone to fly just fast enough to be able to stop within the field of view of its sensors.
If the goshawk flew as far as it can see, it would not fly as first as it does. It would be like us we can only see up to five meters, we can only go up to a speed that allows us to stop within five meters, which is not very fast. Instead, the goshawk likely gauges the density of trees, and speeds past obstacles, knowing that, given a certain forest density, it can always find an opening through the trees. The team's work establishes a theoretical speed limit for any given obstacle-filled environment. For UAVs, this means that no matter how good robots get at sensing and reacting to their environments, there will always be a maximum speed they will need to observe to ensure survival. Emilio Frazzoli, an associate professor of aeronautics and astronautics at MIT wants to research this same speed limit for humans.

More Planets than Stars in Galaxy

The more astronomers look for other worlds, the more they find. They think planets easily outnumber stars in our galaxy and they're even finding them in the strangest of places. "We're awash in planets where 17 years ago we weren't even sure there were planets" outside our solar system, said Kaltenegger. Astronomers are finding more planets using many different techiniques and telescopes in space and the ground. NASA's new kepler planet-hunting telescope in space is discovering exoplanets that are in a zone friendly to life and detecting planets as small as Earth or even smaller. A study in Nature this week states that the Milky Way averages at least 1.6 large planets per star. In order to find the planets, astronomers look for increases in brightness of distant stars that indicate planets between Earth and the pulsating star; a technique used by South American, African and Australian telescopes. That technique usually finds only bigger planets and is good at finding those further away from their stars, which means that there are probably more planets than those already discovered. Kepler together with another ground-based telescope technique are finding planets closer to their stars. Together, the number of worlds in our galaxy is probably much closer to two or more planets per star. It is also known that Kepler also found three rocky planets tinier than Earth and they are circling a dwarf star, which is only a bit bigger than Jupiter. They are so close to their small star that they are too hot for life. Scientists think that because it is too hard to see their sizes, there are plenty of them up there. “It's not just the number or size of planets, but where they are found. Scientists once thought systems with two stars were just too chaotic to have planets nearby. But so far, astronomers have found three different systems where planets have two suns.”

Plastic Bags

Most grocery store baggers don't bother to ask anymore. They drop the bananas in one plastic bag as they reach for another to hold the six-pack of soda. The pasta sauce and noodles will get one too, as will the dish soap. Plastic bags are cheap to produce, sturdy, plentiful, easy to carry and store that they have captured at least 80 percent of the grocery and convenience store market since they were introduced. They are a huge menace to our ecosystems and our waste diversion goals. Barely recyclable, almost all of the 400 plastic bags used per second in the state are discarded. At least 267 species have been scientifically documented to be adversely affected by plastic marine debris. Plastic bags are considered especially dangerous to sea turtles, who may mistake them for jellyfish, a main food source.  Plastic bags that enter our marine environment eventually break down into small fragments the worst environmental effects of plastic bags is that they are non-biodegradable The ingested plastic bag remains intact even after the death and decomposition of the animal. Thus, it lies around in the landscape where another victim may ingest it. The decomposition of plastic bags takes about 400 years. No one will live so long to witness decomposition of plastic. Each of us should shoulder some of the responsibility for this problem, which ultimately harms us. We should be concerned about those problems because they affect us as well as others. There are many ways to decrease our use of plastic bags and if we put our minds up to that goal, we can succeed. Small steps, one at a time will enable us to live in a waste free and safe environment. It is our duty to protect the environment for the future generations and animals.