SciTech Briefs

Deteriorating plastics hinder seabird scavenging

Plastics are contained in every disposable product imaginable, and when we throw such products away, some inevitably end up in the ocean, where they are broken up into “microplastics” by ultraviolet radiation, waves, and other factors. Seabirds are skilled at managing to find food — krill and other related crustaceans — in vast areas of open ocean, but they have been found to consume microplastics as well.

A new study by two scientists at the University of California, Davis, found that seabirds have a strong sense of smell and use the smell of dimethyl sulfide to find their prey. This is a chemical released when phytoplankton gets broken down or eaten, a signal to the birds that the predators of the phytoplankton — krill, for instance — are likely to be nearby. In the study, after small plastic beads had been in the ocean for several weeks, dimethyl sulfide was found at high enough concentrations that seabirds could mistake it for food. This has implications for the health of the marine ecosystem in general, not just the seabirds, since other animals may use similar methods to find food in the ocean.

Source: The New York Times

Dr. John Roberts, organic chemist, passes away

John D. Roberts, an organic chemist and professor at California Institute of Technology, passed away of a stroke at age 98 on Oct. 29. Roberts was responsible for using nuclear magnetic resonance spectroscopy and other techniques to study the way atoms rearranged themselves in chemical reactions, which played an important role in the field of physical organic chemistry. His studies have paved the way for the commercial development of many organic compounds, ranging from drugs to synthetic clothing fibers.

Besides opening up our understanding of organic chemical reactions, Roberts also popularized the use of isotope tracers in studying reactions and wrote about molecular orbital theory.

Roberts won several awards for his work, including the National Medal of Science in 1990. Yet, despite all of these accomplishments, he claimed the best thing he did in his decades at Caltech was to spearhead the effort to make Caltech coed in order to bring one of his female graduate students with him from Harvard.

Source: The New York Times

Trump election may mean exacerbated climate change

The election of Donald Trump likely means the unraveling of environmental regulations that intend to stave off dangerous anthropogenic climate change. The President-elect has called global climate change “a hoax created by and for the Chinese in order to make U.S. manufacturing non-competitive.” He has also tapped Myron Ebell, a leading climate-change skeptic, to lead his Environmental Protection Agency transition team.

Trump has also promised a return of the U.S. fossil fuel industry at the expense of current environmental regulations, and has proposed that the U.S. decrease its payments to United Nations climate change programs. The President-elect has also vowed to scrap the Paris Climate Agreement. Even if every other country did its part, the agreement would not be able to prevent the planet from warming more than 3.6 degrees Fahrenheit in the next few decades without the U.S., the second largest carbon emitter. Beyond this point, scientists warn we could irreversibly damage the planet and disrupt weather patterns, leading to more droughts, stronger storms, and agricultural disruptions.

Source: The New York Times

Narwhals use echolocation to navigate in dark

For years, many scientists have been puzzled about how narwhals, whales with long tusks native to the frigid, ice-strewn waters of the Arctic Ocean, are able to locate fish and other prey in the dark waters of the ocean and ice cracks in the surface in order to breathe. Scientists understood that whales often use echolocation rather than vision to navigate, so they planted special underwater microphones to listen to narwhals.

The study found that narwhals use clicks of sound inaudible to our ears at rates of up to 1,000 clicks per second to scan their environment. The waves will bounce back when they hit an object, signaling to the narwhal that there is an obstacle. Narwhals may also be able to narrow and widen their beams at different stages of tracking their prey.

Narwhals seem to be able to produce an acoustic image of a resolution higher than any other animal, except possibly beluga whales. As for the single tusk that defines male narwhals, it seems to be for mating displays only and not any sort of “antenna.”

Source: The New York Times

Tsunami caused by volcano near Santorini revisited

Santorini is a volcanic island near Greece, and in the 17th century B.C. during the Late Bronze Age, it was the home of the Akrotiri civilization. The region was later destroyed when a nearby volcano erupted in what was estimated to be one of the most powerful eruptions of the last 10,000 years with a volcanic explosivity index of 6–7. It caused a tsunami, a factor that enabled outside invaders to come and conquer the region.

Before, it was thought that the tsunami was the result of a caldera collapse, which is when the region above a magma chamber collapses downward during an eruption, displacing enough water to cause a tsunami.

But new data shows that the caldera was not underwater at all, so the tsunami could not have been triggered by such a collapse. Pyroclastic material up to 200 feet thick was found located just off the island, however, giving rise to the new theory that pyroclastic flows were responsible for the tsunami. Since pyroclastic flows are extremely hot and can move extremely fast, they are able to transfer that energy to the ocean and create a tsunami.

Source: The New York Times

New Delhi closes schools due to air pollution

Recently, the government of New Delhi, India took the drastic step of closing 1,800 public primary schools due to dangerous levels of air pollution.
Many people blamethe increased air pollution on firecrackers and fireworks set off during the Diwali celebration. Levels of the most dangerous particles, known as PM 2.5, reached about 600 micrograms per cubic meter in parts of the city, exposure to which is equivalent to smoking 40 cigarettes in one day.

The particles can penetrate the lungs and bloodstream, increasing the risk for asthma, pneumonia, stroke, and a variety of other conditions. Children have experienced eye irritation, coughing and congestion due to the pollution, and the pollution has been particularly bad this past week due to the stagnant air over the city.

Parents were advised to keep children indoors, but, unfortunately, the air quality indoors is generally no better unless the windows and doors are shut and sealed.

Source: The New York Times