Transcript

6.5.25 · Science Show KY

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Speaker 1: Welcome to Radioized Diary of Science and Nature. Your reader's
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Kelly Taylor. I have some articles related to the topics
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of science and nature, but first a reminder. The RADIOI
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is a reading service intended for people who are blind
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or have other disabilities that make it difficult to read
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printed material. Our first article is going to come from
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BBC Wildlife. What's the most biodiverse country in the world?
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From Canada to Brazil. Here are the contenders. Written by
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Stuart Blackman, date June fourth. It's always good to remind
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ourselves how little we know, or, perhaps more optimistically, how
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much we still have to find out. The neuroscientist David
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Egelman likens knowledge to a peer jutting out into a
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vast ocean of mystery and possibilities. No matter how long
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the peer, the horizon never gets any nearer. It's remarkable
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how much we still don't know about the animals, plants, fungi,
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and the rest that share our tiny corner of what
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might as well be an infinite universe. Assuming just the
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one universe. We don't even know how many species of
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them there are, it might be two million or twenty million.
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We do know that we've formally described fewer than two
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million of them. We don't know how many fewer because
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we don't know how many species have been mistakenly described
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more than once. Meanwhile, much more is known about some
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countries than others. Rich northern countries have been more thoroughly
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surveyed than poor tropical ones, for instance. The upshot is
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that any attempt to answer this one is always going
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to be a bit back of the envelope. Since twenty sixteen,
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the environmental news organization Monga Bay has been giving it
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a good try by pulling together the data available for amphibians, birds, fish, mammals, reptiles,
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and vascular plants. Though it excludes invertebrates, which comprise the
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majority of animal species, it might not be much of
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a surprise, Blessed as it is with more than its
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fair share of Amazon rainforests, that Brazil comes out on top.
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About eighteen percent of all described bird species are found
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within its borders, as are fourteen percent of amphibians, seven
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percent of mammals, fourteen percent of reptiles, twelve percent of fish,
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and thirteen percent of plants. Part of the reason is
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its size. All else being equal, big countries will tend
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to rank higher just because they have more space. And
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Brazil is huge, covering eight and a half million square
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kilometers of the world's surface, it is the fifth biggest
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of all countries. Indeed, rank countries in terms of species
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number per unit area, and Brazil doesn't make the top ten.
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But size isn't everything. The two biggest countries, Russia and Canada,
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don't even make it into the top fifty for overall
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species numbers. Seven of the top ten countries nine out
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of ten when country size is taken into account, are
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located in the tropics. It's known that biodiversity increases towards
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the equator. The reasons for that aren't entirely clear, but
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it might have something to do with the tropics having
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been spared the ice ages that have intermittently scoured the
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life from higher latitudes, and the year round high temperatures
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speeding up biological processes, including the creation of new species.
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Whatever the explanation, the sheer diversity of life in the
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tropics is like the view from the end of a pier,
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as humbling as it is inspiring. Now staying with BBC.
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From BBC Wildlife, here's an article that is all you
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ever needed to Know about Walruses, written by Joe Price
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and June three. Walruses live in the Arctic and Subarctic.
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They are one of the largest pinnipeds, meaning thin footed,
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and are related to seals and sea lions. Their Latin
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name Odobenus ross marris translates as tooth walking sea horse
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and refers to their most distinguishable feature, large tusks. These
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marine mammals feed and slow, are shallow coastal areas and
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usually only embark on short dives. Foraging trips can last
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from a few hours to several days. They mostly prey
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on bivalve molluscs, which they search for in soft sediment
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using their super sensitive whiskers. Walruses also eat worms, snails, crabs, amphipods, shrips,
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sea cucumbers, truncates, and slow moving fish. These pinnipeds are
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extant in Canada, Greenland, Russia, Stalbard and Let's see Stalbard
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and Genman and Alaska. In the USA, the species is
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documented as presence, uncertain and vagrant in Belgium, Denmark, Finland, France, Germany, Iceland, Ireland, Japan, Netherlands, Norway, Spain, Sweden,
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and the UK and Maine. In Massachusetts in the USA,
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There have been several sightings of the species appearing outside
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of its usual range in recent years, particularly in Europe.
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In addition to shallow waters, walruses need access to open
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water to forage and rely on haul out spots close
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to feeding areas. Their preferred haulout platform is sea ice,
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but walruses do use sites on land in the summer
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and autumn. On land, walruses rest between foraging trips, breed,
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give birth, nurse their young, and shelter from rough seas
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and predatory polar bears and killer whales. Walruses are gregarious
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and tend to gather in large groups when out of
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the water. At sea, they usually travel together too. They're
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sensitive to disturbance and noise, and at mass gatherings stampedes
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can occur if they're frightened. This can be caused by
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human disturbance, low flying aircraft, and near shore vessels. Outside
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of the breeding season, males are often found in areas
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away from females and their cab There are two subspecies
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of walrus, the Atlantic walrus and the Pacific walrus. According
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to the IUCN, the Atlantic walrus occurs from the eastern
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Canadian Arctic to the western Kara Sea. The Pacific walrus
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normally ranges from the Bearing and Chuchki Seas, which constitute
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the center of its range, to the Laptev Sea in
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the west and the Beaufort Sea in the east. Pacific
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walruses can reach three point six meters in length and
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weigh eight hundred eighty to one thousand, five hundred kilograms.
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Adult females are about three meters and weigh five eighty
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to one thousan thirty nine kilograms. Atlantic walrus adults are
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shorter and lighter. Thick layers of fat under the skin
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insulate them so they can cope with temperatures as low
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as no negative thirty five degrees celsius. Walruses are brown,
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but can turn white after diving in icy water for
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long periods, or even pink when they are warm. An
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inherent ability to vary the blood supply to the surface
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of their bodies. Specialized air sacks in the throat are
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known as pharyngeal pouches and can be inflated with air,
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allowing walruses to float upright in the water and amplify vocalizations.
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Courtship and mating occurs in the winter calves are usually
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born in the following May, with one calf produced every
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three years. During this season, mature males exhibit aggressive behavior
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such as vocalizations, tusk wielding, and confrontation as they fight
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for dominance to access the females. Tusks on males and
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females grow up to a meter long and weigh five
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kilograms in large bulls, and are used to haul out
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of the water, to keep icy breathing holes open, and
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to fight and defend themselves against predators. Global warming and
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sea ice declines threatened populations because suitable areas for breeding
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and puffing are reduced and access to offshore feeding areas
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becomes limited. Swimming further to find food requires more energy,
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leading to exhaustion and lower survival rates. A heavier reliance
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on land based haulout sites can result in deaths caused
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by overcrowding and an increased risk of stampedes. The reduction
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in sea ice has also led to expanded shipping and
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development of oil and gas fields in the creature's range,
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increasing the thread of spills, pollution, discharge, and disturbance. Walless
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populations were severely depleted by commercial hunting from the eighteenth
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to the mid twentieth century, but the species he now
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receives legal protection through international agreements and national laws. Today's
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subsistence harvests by Native people continuing Canada, Greenland, Alaska, and Russia.
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Will turn now to the Washington Post and the headline reads,
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A salt crisis is looming for US rivers. This is
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written by Kasha Patel and dated June fourth. Perhaps on
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another day, the calm waters and green trees on the
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Anacostia River would have been an escape from downtown d C,
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about seven miles away, but recent heavy rains had pushed
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discarded bottles and wrappers to the shores, and on this
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unusually warm May afternoon, hydrologist su Jay Koshal kayakd through
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brownish green waters to investigate if the water quality showed
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signs of urban life too. Performing a routine check up
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on its salt content, he dropped a black probe into
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the water and watched as his hand held monitor showed
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a troubling result. The reading showed salt levels were above
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the federal recommendations for this region. Quote even after a rain,
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it doesn't wash away all the salt, said Koshal, a
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researcher at the University of Maryland. It's a pattern Koshal
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has found again and again. Freshwater ecosystems like the anacostia
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are growing salty yer year round. That increased salinity has
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not only been linked to mass depths of aquatic life
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and damaged infrastructure, but some people can even taste it
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in drinking water, and removing it is no small task.
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Leaving salt to add up in waterways. The biggest source
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around d C and other major northern inland cities is
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an over application of road salt to fall winter ice,
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which enters into rivers or or the ground. According to
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Koshaw's research, in other places closer to the coasts, such
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as Miami or New Orleans, the higher salinity as a
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result of ocean water intruding into rivers. Some areas, such
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as around the Delaware River, experience trouble from both sources.
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Many cities and water managers say salt contamination is a
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major worry, especially as drought and rising sea levels allow
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more salt to settle into freshwater bodies. We have good
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management plans in place, but the information we have is
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telling us that the same management plans will probably not
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be effective at some point in the future, says Christen Tavanaugh,
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executive director of the Delaware River Basin Commission. Around the
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d C metro area, the biggest salt contamination comes in
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the winter. People apply an abundance of salt on roads.
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If you can hear it crunch under your feet, it's
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too much and the excess runs off into the rivers.
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Spring and summer helped dilute the rivers, but some salt remains,
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raising the baseline's salinity year after year. In the Potomac,
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December salt concentrations have risen but forty one percent in
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the past three decades. The Potuxent River has seen a
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one hundred two percent increase over the same time period.
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These are the main waterways that provide the DC metroea's
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drinking water, and the salt is sometimes seeping through to
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our faucets. About sixteen miles from downtown d C, the
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Potomac Water Filtration Plant captures water from the Potomac before
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it joins the Anacostia River. On a recent day in May,
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the river was an opaque brown. As rains muddied the water,
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The brown liquid gushed into the plant's intake area, where
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sticks trash and aquatic animals are filtered from the water.
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What affects us, interestingly is not the rain here, but
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it's the rain in Alleghany County, Garrett County in Washington County,
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said dnsh Bahad dru Singh, the superintendent of the Potomac Plant.
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He was referring to counties in Maryland as well as
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other states, as a Potomac and its tributary snake through
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Pennsylvania and West Virginia before passing here. That means road
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salt from hundreds of miles away contaminates the local water source.
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While mud viruses in bacteria can be removed from the water,
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salt is not. Once the Potomac water is captured, chemicals
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are added to make smaller particles stick together so they
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can be more easily filtered out, but salt is a
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very small ion and dissolves in water rather than sticking
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to other particles. Or the past eight winters, about two
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or three people call each season to report salty tasting
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drinking water to the Washington Suburban Sanitary Commissioned Water, which
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provides water and wastewater services to nearly two million people.
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In February twenty twenty one, the Commission received an anomalous
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seventy four customer calls, coinciding with the historic coal snap
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that knocked out power to Texas and brought record coal
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to d C. Those spikes are short lived and don't
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occur for the majority of the year, said Priscilla Tow,
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director of Operational Reliability and Resilience at the water company,
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But the steady increase of salt is more concerning than
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the long term, she said, particularly if unabated. Theoretically, she
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said they could install a reverse osmosis osmosis system that
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pushes water through the smallest hole possible to filter out
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the salt, but she said the process uses an extreme
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amount of energy, removes other minerals suitable for people, and
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is very costly to build. For now, she said, the
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baseline salt levels are not high enough to taste in
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our tap water to need removal, but over time the
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salt can corrode our infrastructure, including the same water pipes
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that deliver treated water. Chloride ions necessitate billions of dollars
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worth of repairs to bridges, parking structures, and buildings around
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the United States each year. The road salt issue has
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a relatively simple solution. Use less it can be an
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all around wind for communities. The Commission in Washington partners
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with Montgomery County on annual winter campaigns to educate communities
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on applying less salt. As In many cities, water managers
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educate crews on the appropriate amount to use one mug
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of salt enough to cover ten sidewalk squares. In Edena, Minnesota,
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they also install heated sidewalks or position a building's entrance
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towards the sun, leveraging better city planning to melt snow.
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In New Hampshire, workers or contractors who apply salt are
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often protected from lawsuits from people slipping and falling, a
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practice the city of Edena has been trying to adopt.
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Sometimes folks think more salt means more safety, and that's
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not necessarily true, said Jessica Wilson, water resources manager for Edena. Quote,
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you can have safe spaces not be over using salt,
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and you can do other things other than salt to
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achieve that safe space. Along the coastlines, excess salt is
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coming from seawater pushing inland, often during droughts. The boundary
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where freshwater meets the salt water called the salt front
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has gotten anxiously close to drinking water intakes or is
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contaminating ground wheels for drinking. In the fall of twenty
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twenty four, water managers saw the salt front reach within
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twenty miles of drinking water intakes in Philadelphia and South Jersey. Typically,
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rains and snow milk pushed the ocean water away, keeping
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the salt front near Wilmington, Delaware, but an ongoing drought
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allowed it to creep farther upstream near the Philadelphia International Airport.
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A Delaware River Basin Commission released water from reservoirs to
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help keep the salt front at bay. Rains finally came too.
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Sometimes you don't know when that next rain of inn
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is going to come, said Kavanaugh. If it hadn't come,
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then we could have been in a much different situation.
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The Commission is modeling and evaluating how changing conditions, including
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sea level rise, will affect water flow and use. Kavanaugh
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said these areas are also experiencing notable land subsidence, making
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it even easier for ocean waters to flow farther inland.
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The Delaware River Basin is also affected by road salt
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farther upstream, although it has lesser impact, Kevanaugh said, we
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do know that it's going to get more challenging to
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manage along the banks of the Anacostia River. Koshal pointed
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to long green grasses called fragmites australis. These invasive plants,
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which can grow in salty environments, are warning signs of
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the changing chemistry of the environment. They are typically seen
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on the eastern shores of Maryland, which receive a lot
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of salt input from the oceans. It's odd to see
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them thriving here, meaning the water is getting as salty
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as coasts inundated by seawater. But Koshal's research has shown
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that the Anecostia's salinity increased by five hundred percent over
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the past four decades. We definitely know that the long
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term trends of salt are increasing or building up. We
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just have different plants that adapt to that and change
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in the organisms. The concentrations around the Anacostia, although poor,
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have relatively tame implications compared with other nearby areas. About
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ten miles away, a volunteer group at Slago Creek and
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Montgomery County takes salt samples to help monitor the health
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of the river, but the higher salt concentrations exceeded some
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of their testing equipment. This past winter, salinity measurements exceeded
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six hundred and forty one milligrams per liter, the capacity
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of their regular test strips. They upgraded to higher range
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test strips and measured concentrations upward of six thousand, six
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hundred milligrams per liter at five sites, were seven times
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higher than the criteria for acute toxicity. The creek remained
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above this lethal toxicity for weeks, said Christine Dunathan, who
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runs the winter's salinity monitoring program, even as federal standards
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say they shouldn't meet or exceed those levels for more
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than three hours every three years. Quote. Sligo is a long,
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skinny thing that has very little buffer, Dunathan said, so
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whatever happens in the neighborhood or on those local streets
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ends up in the creek. Quote. The impacts on wildlife
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aren't known for this past winter, but during that historic
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twenty twenty one season, more than two hundred fish and
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salamanders are found dead in the creek. Montgomery County Department
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of Environmental Protection attributed the die offs to road salt
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coming from the Capitol Beltway. The problems extend well beyond
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the region. Along the eastern coasts, swaths of dead trees
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called ghost forests have also succumbed to the increased salinity,
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no longer able to protect coastal communities from large storms.
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Back at the Anacostia River, Koschel dips his paddle in
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the water and muses on the memories he's had on
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this river with his son. He recounts the trips they've
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taken by boat, kayak, and foot, making this his favorite river. Now,
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it's hard to believe that such a simple compound can
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create so many complex problems. Quote. I'd love to see
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people protect it. I just hope that future generations can
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enjoy it, Koschl said. Now we'll go to Smithsonian. We
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have an article that's headlined Passage to the Pleistocene. In Wyoming,
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a trove of ice age fossils is rewriting our understanding
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of prehistoric animals. This is by Michael Taylor. June third.
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Julie Nietschen, an expert in ice age megafauna, skirts a
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dirt ledge called the saddle deep inside a remarkable hollow
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in northern Wyoming known as as Natural Trap cave. She
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stops to observe Megan Hormel, a graduate student at Des
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Moines University and one of several volunteers who have repelled
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into the cave on a nylon line dangling from the
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entrance eighty feet overhead. Sunlight streams through a jagged skylight
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to illuminate a bell shaped chamber one hundred forty feet
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in diameter. I sit to one side of the saddle
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as remains of ice age mammals slowly emerge into the light,
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like the scientists scattered over the subterranean hillside. I wear
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warm clothing, boots, and a caving helmet. My cumbersome climbing
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gear rests along with everyone else's on a tarp above
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ground on the western flank of the Big Horn Mountains,
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less than two miles from the Montana border. It's a
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scorching July day down here. The temperature hovers at a
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near constant forty two tu degrees fahnheight, shifting only a
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few degrees with seasonal heat waves or blizzards. Bundled in
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thick coveralls and fleece jackets, the researchers wheeled trowels with
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gloved hands. It is the next to last day of
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a two week expedition. The twenty two members on this
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twenty twenty four dig include seasoned scientists and students undergrudge
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to undergraduate to postdoctoral, along with expert cave explorers who
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ensure the safe and smooth operation of delicate work at
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the bottom of a deadly pit. The cave's name natural
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trap is literal. Over the past one hundred and fifty
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thousand years, countless animals have fallen into it, perhaps because
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they were running or because of their relative weights and
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body shapes. Certain animals fell more horizontally, landing on the
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cave's floor well beyond the seventy five foot perimeter of
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the entrance and dying on impact. As the degree pile
25:00
grew over millennia, some animals that fell rolled or bounced,
25:04
creating the broad field of bones that fills the chamber today.
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The bones of at least one extinct cat, commonly known
25:13
as the American cheetah, stayed together. Its intact skeleton was
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observed on a ledge deep inside the cave in twenty
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twenty three, setting aside her pick ormel cleans, an exposed
25:28
bone with a sort of small paintbrush normally used on
25:32
interior trim. A foot or so to her right, a
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bony plate the size of an iPad angles upward from
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the dirt. A scapula from an animal closely related to
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present day big orange sheep, a male. If it matches
25:46
the skull fragment that Tony Hotchner, another grad student, found
25:50
just yesterday, possibly twenty three thousand years old, based on
25:54
the dating of previous signs within the cobbly gray, this
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is another vert Wormel tells Michen, using paleon paleontological shorting
26:05
and for vertebrate beach and nods, after you get the
26:08
vert out, I would take this little wall down. She
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indicates a jumble of packed rocks and dirt. Yeah, the
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wall has to go, but there's ribs in the wall.
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Hormill says, Okay, do your best to start taking it down,
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take that little nubbin out, and then worry about the scalpula.
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Beach And says, that's a beautiful scalpula, and I'd love
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to get it out. These workers are not hunting future
26:33
museum displays. Instead, by documenting subtle changes within animal species
26:39
over time, they seek clues to extreme climate changes of
26:42
the past and natural Trap Cave provides an astoundingly well
26:47
suited resource for the purpose, holding a largely unbroken record
26:51
of mammal lineages going back tens of thousands of years.
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It's an amazing place, says Kurt Johnson, paleontologist and direct
27:00
Smithsonian's National Museum of Natural History. It's a single site
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and the time range over which it was open as long,
27:08
so it has the potential to show change over time,
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as long as the individual skeletons are dated. That's why
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Mitcham and her team are focusing on the past thirty
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nine thousand years, a time starting in the late Pleistocene
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that coincides with the most carefully dated bone bearing layers
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inside the cave, deposits that were laid down during a
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continuous cycle of glaciers advancing and retreating. Quote. We're going
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to see if we can accurately model the dry and
27:38
wet cycles at the site during that period. Mechion says.
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This sort of climate analysis has never been published in
27:46
the scientific literature. Let's offer today's Diary of science and Nature.
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Your reader is Kelly Taylor. Now stay tuned for the
27:56
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