6.5.25

Episode Transcript

Speaker 1 (00:01):
Welcome to Radioized Diary of Science and Nature. Your reader's
Kelly Taylor. I have some articles related to the topics
of science and nature, but first a reminder. The RADIOI
is a reading service intended for people who are blind
or have other disabilities that make it difficult to read
printed material. Our first article is going to come from

(00:23):
BBC Wildlife. What's the most biodiverse country in the world?
From Canada to Brazil. Here are the contenders. Written by
Stuart Blackman, date June fourth. It's always good to remind
ourselves how little we know, or, perhaps more optimistically, how
much we still have to find out. The neuroscientist David

(00:48):
Egelman likens knowledge to a peer jutting out into a
vast ocean of mystery and possibilities. No matter how long
the peer, the horizon never gets any nearer. It's remarkable
how much we still don't know about the animals, plants, fungi,
and the rest that share our tiny corner of what

(01:11):
might as well be an infinite universe. Assuming just the
one universe. We don't even know how many species of
them there are, it might be two million or twenty million.
We do know that we've formally described fewer than two
million of them. We don't know how many fewer because

(01:32):
we don't know how many species have been mistakenly described
more than once. Meanwhile, much more is known about some
countries than others. Rich northern countries have been more thoroughly
surveyed than poor tropical ones, for instance. The upshot is
that any attempt to answer this one is always going

(01:52):
to be a bit back of the envelope. Since twenty sixteen,
the environmental news organization Monga Bay has been giving it
a good try by pulling together the data available for amphibians, birds, fish, mammals, reptiles,
and vascular plants. Though it excludes invertebrates, which comprise the

(02:15):
majority of animal species, it might not be much of
a surprise, Blessed as it is with more than its
fair share of Amazon rainforests, that Brazil comes out on top.
About eighteen percent of all described bird species are found
within its borders, as are fourteen percent of amphibians, seven

(02:38):
percent of mammals, fourteen percent of reptiles, twelve percent of fish,
and thirteen percent of plants. Part of the reason is
its size. All else being equal, big countries will tend
to rank higher just because they have more space. And
Brazil is huge, covering eight and a half million square

(02:59):
kilometers of the world's surface, it is the fifth biggest
of all countries. Indeed, rank countries in terms of species
number per unit area, and Brazil doesn't make the top ten.
But size isn't everything. The two biggest countries, Russia and Canada,
don't even make it into the top fifty for overall
species numbers. Seven of the top ten countries nine out

(03:24):
of ten when country size is taken into account, are
located in the tropics. It's known that biodiversity increases towards
the equator. The reasons for that aren't entirely clear, but
it might have something to do with the tropics having
been spared the ice ages that have intermittently scoured the

(03:44):
life from higher latitudes, and the year round high temperatures
speeding up biological processes, including the creation of new species.
Whatever the explanation, the sheer diversity of life in the
tropics is like the view from the end of a pier,
as humbling as it is inspiring. Now staying with BBC.

(04:10):
From BBC Wildlife, here's an article that is all you
ever needed to Know about Walruses, written by Joe Price
and June three. Walruses live in the Arctic and Subarctic.
They are one of the largest pinnipeds, meaning thin footed,

(04:32):
and are related to seals and sea lions. Their Latin
name Odobenus ross marris translates as tooth walking sea horse
and refers to their most distinguishable feature, large tusks. These
marine mammals feed and slow, are shallow coastal areas and

(04:53):
usually only embark on short dives. Foraging trips can last
from a few hours to several days. They mostly prey
on bivalve molluscs, which they search for in soft sediment
using their super sensitive whiskers. Walruses also eat worms, snails, crabs, amphipods, shrips,

(05:15):
sea cucumbers, truncates, and slow moving fish. These pinnipeds are
extant in Canada, Greenland, Russia, Stalbard and Let's see Stalbard
and Genman and Alaska. In the USA, the species is

(05:36):
documented as presence, uncertain and vagrant in Belgium, Denmark, Finland, France, Germany, Iceland, Ireland, Japan, Netherlands, Norway, Spain, Sweden,
and the UK and Maine. In Massachusetts in the USA,
There have been several sightings of the species appearing outside

(05:57):
of its usual range in recent years, particularly in Europe.
In addition to shallow waters, walruses need access to open
water to forage and rely on haul out spots close
to feeding areas. Their preferred haulout platform is sea ice,
but walruses do use sites on land in the summer

(06:18):
and autumn. On land, walruses rest between foraging trips, breed,
give birth, nurse their young, and shelter from rough seas
and predatory polar bears and killer whales. Walruses are gregarious
and tend to gather in large groups when out of
the water. At sea, they usually travel together too. They're

(06:40):
sensitive to disturbance and noise, and at mass gatherings stampedes
can occur if they're frightened. This can be caused by
human disturbance, low flying aircraft, and near shore vessels. Outside
of the breeding season, males are often found in areas
away from females and their cab There are two subspecies

(07:03):
of walrus, the Atlantic walrus and the Pacific walrus. According
to the IUCN, the Atlantic walrus occurs from the eastern
Canadian Arctic to the western Kara Sea. The Pacific walrus
normally ranges from the Bearing and Chuchki Seas, which constitute

(07:26):
the center of its range, to the Laptev Sea in
the west and the Beaufort Sea in the east. Pacific
walruses can reach three point six meters in length and
weigh eight hundred eighty to one thousand, five hundred kilograms.
Adult females are about three meters and weigh five eighty

(07:47):
to one thousan thirty nine kilograms. Atlantic walrus adults are
shorter and lighter. Thick layers of fat under the skin
insulate them so they can cope with temperatures as low
as no negative thirty five degrees celsius. Walruses are brown,
but can turn white after diving in icy water for

(08:07):
long periods, or even pink when they are warm. An
inherent ability to vary the blood supply to the surface
of their bodies. Specialized air sacks in the throat are
known as pharyngeal pouches and can be inflated with air,
allowing walruses to float upright in the water and amplify vocalizations.

(08:31):
Courtship and mating occurs in the winter calves are usually
born in the following May, with one calf produced every
three years. During this season, mature males exhibit aggressive behavior
such as vocalizations, tusk wielding, and confrontation as they fight
for dominance to access the females. Tusks on males and

(08:56):
females grow up to a meter long and weigh five
kilograms in large bulls, and are used to haul out
of the water, to keep icy breathing holes open, and
to fight and defend themselves against predators. Global warming and
sea ice declines threatened populations because suitable areas for breeding

(09:16):
and puffing are reduced and access to offshore feeding areas
becomes limited. Swimming further to find food requires more energy,
leading to exhaustion and lower survival rates. A heavier reliance
on land based haulout sites can result in deaths caused
by overcrowding and an increased risk of stampedes. The reduction

(09:40):
in sea ice has also led to expanded shipping and
development of oil and gas fields in the creature's range,
increasing the thread of spills, pollution, discharge, and disturbance. Walless
populations were severely depleted by commercial hunting from the eighteenth
to the mid twentieth century, but the species he now
receives legal protection through international agreements and national laws. Today's

(10:05):
subsistence harvests by Native people continuing Canada, Greenland, Alaska, and Russia.
Will turn now to the Washington Post and the headline reads,
A salt crisis is looming for US rivers. This is
written by Kasha Patel and dated June fourth. Perhaps on

(10:32):
another day, the calm waters and green trees on the
Anacostia River would have been an escape from downtown d C,
about seven miles away, but recent heavy rains had pushed
discarded bottles and wrappers to the shores, and on this
unusually warm May afternoon, hydrologist su Jay Koshal kayakd through

(10:54):
brownish green waters to investigate if the water quality showed
signs of urban life too. Performing a routine check up
on its salt content, he dropped a black probe into
the water and watched as his hand held monitor showed
a troubling result. The reading showed salt levels were above
the federal recommendations for this region. Quote even after a rain,

(11:17):
it doesn't wash away all the salt, said Koshal, a
researcher at the University of Maryland. It's a pattern Koshal
has found again and again. Freshwater ecosystems like the anacostia
are growing salty yer year round. That increased salinity has
not only been linked to mass depths of aquatic life
and damaged infrastructure, but some people can even taste it

(11:41):
in drinking water, and removing it is no small task.
Leaving salt to add up in waterways. The biggest source
around d C and other major northern inland cities is
an over application of road salt to fall winter ice,
which enters into rivers or or the ground. According to

(12:01):
Koshaw's research, in other places closer to the coasts, such
as Miami or New Orleans, the higher salinity as a
result of ocean water intruding into rivers. Some areas, such
as around the Delaware River, experience trouble from both sources.
Many cities and water managers say salt contamination is a

(12:22):
major worry, especially as drought and rising sea levels allow
more salt to settle into freshwater bodies. We have good
management plans in place, but the information we have is
telling us that the same management plans will probably not
be effective at some point in the future, says Christen Tavanaugh,

(12:45):
executive director of the Delaware River Basin Commission. Around the
d C metro area, the biggest salt contamination comes in
the winter. People apply an abundance of salt on roads.
If you can hear it crunch under your feet, it's
too much and the excess runs off into the rivers.

(13:07):
Spring and summer helped dilute the rivers, but some salt remains,
raising the baseline's salinity year after year. In the Potomac,
December salt concentrations have risen but forty one percent in
the past three decades. The Potuxent River has seen a
one hundred two percent increase over the same time period.

(13:29):
These are the main waterways that provide the DC metroea's
drinking water, and the salt is sometimes seeping through to
our faucets. About sixteen miles from downtown d C, the
Potomac Water Filtration Plant captures water from the Potomac before
it joins the Anacostia River. On a recent day in May,
the river was an opaque brown. As rains muddied the water,

(13:53):
The brown liquid gushed into the plant's intake area, where
sticks trash and aquatic animals are filtered from the water.
What affects us, interestingly is not the rain here, but
it's the rain in Alleghany County, Garrett County in Washington County,
said dnsh Bahad dru Singh, the superintendent of the Potomac Plant.

(14:16):
He was referring to counties in Maryland as well as
other states, as a Potomac and its tributary snake through
Pennsylvania and West Virginia before passing here. That means road
salt from hundreds of miles away contaminates the local water source.
While mud viruses in bacteria can be removed from the water,

(14:36):
salt is not. Once the Potomac water is captured, chemicals
are added to make smaller particles stick together so they
can be more easily filtered out, but salt is a
very small ion and dissolves in water rather than sticking
to other particles. Or the past eight winters, about two

(14:59):
or three people call each season to report salty tasting
drinking water to the Washington Suburban Sanitary Commissioned Water, which
provides water and wastewater services to nearly two million people.
In February twenty twenty one, the Commission received an anomalous
seventy four customer calls, coinciding with the historic coal snap

(15:23):
that knocked out power to Texas and brought record coal
to d C. Those spikes are short lived and don't
occur for the majority of the year, said Priscilla Tow,
director of Operational Reliability and Resilience at the water company,
But the steady increase of salt is more concerning than
the long term, she said, particularly if unabated. Theoretically, she

(15:49):
said they could install a reverse osmosis osmosis system that
pushes water through the smallest hole possible to filter out
the salt, but she said the process uses an extreme
amount of energy, removes other minerals suitable for people, and
is very costly to build. For now, she said, the

(16:10):
baseline salt levels are not high enough to taste in
our tap water to need removal, but over time the
salt can corrode our infrastructure, including the same water pipes
that deliver treated water. Chloride ions necessitate billions of dollars
worth of repairs to bridges, parking structures, and buildings around

(16:31):
the United States each year. The road salt issue has
a relatively simple solution. Use less it can be an
all around wind for communities. The Commission in Washington partners
with Montgomery County on annual winter campaigns to educate communities
on applying less salt. As In many cities, water managers

(16:54):
educate crews on the appropriate amount to use one mug
of salt enough to cover ten sidewalk squares. In Edena, Minnesota,
they also install heated sidewalks or position a building's entrance
towards the sun, leveraging better city planning to melt snow.

(17:16):
In New Hampshire, workers or contractors who apply salt are
often protected from lawsuits from people slipping and falling, a
practice the city of Edena has been trying to adopt.
Sometimes folks think more salt means more safety, and that's
not necessarily true, said Jessica Wilson, water resources manager for Edena. Quote,

(17:38):
you can have safe spaces not be over using salt,
and you can do other things other than salt to
achieve that safe space. Along the coastlines, excess salt is
coming from seawater pushing inland, often during droughts. The boundary
where freshwater meets the salt water called the salt front

(17:59):
has gotten anxiously close to drinking water intakes or is
contaminating ground wheels for drinking. In the fall of twenty
twenty four, water managers saw the salt front reach within
twenty miles of drinking water intakes in Philadelphia and South Jersey. Typically,
rains and snow milk pushed the ocean water away, keeping

(18:20):
the salt front near Wilmington, Delaware, but an ongoing drought
allowed it to creep farther upstream near the Philadelphia International Airport.
A Delaware River Basin Commission released water from reservoirs to
help keep the salt front at bay. Rains finally came too.
Sometimes you don't know when that next rain of inn

(18:41):
is going to come, said Kavanaugh. If it hadn't come,
then we could have been in a much different situation.
The Commission is modeling and evaluating how changing conditions, including
sea level rise, will affect water flow and use. Kavanaugh
said these areas are also experiencing notable land subsidence, making

(19:03):
it even easier for ocean waters to flow farther inland.
The Delaware River Basin is also affected by road salt
farther upstream, although it has lesser impact, Kevanaugh said, we
do know that it's going to get more challenging to
manage along the banks of the Anacostia River. Koshal pointed

(19:25):
to long green grasses called fragmites australis. These invasive plants,
which can grow in salty environments, are warning signs of
the changing chemistry of the environment. They are typically seen
on the eastern shores of Maryland, which receive a lot
of salt input from the oceans. It's odd to see
them thriving here, meaning the water is getting as salty

(19:48):
as coasts inundated by seawater. But Koshal's research has shown
that the Anecostia's salinity increased by five hundred percent over
the past four decades. We definitely know that the long
term trends of salt are increasing or building up. We
just have different plants that adapt to that and change

(20:09):
in the organisms. The concentrations around the Anacostia, although poor,
have relatively tame implications compared with other nearby areas. About
ten miles away, a volunteer group at Slago Creek and
Montgomery County takes salt samples to help monitor the health
of the river, but the higher salt concentrations exceeded some

(20:31):
of their testing equipment. This past winter, salinity measurements exceeded
six hundred and forty one milligrams per liter, the capacity
of their regular test strips. They upgraded to higher range
test strips and measured concentrations upward of six thousand, six
hundred milligrams per liter at five sites, were seven times

(20:52):
higher than the criteria for acute toxicity. The creek remained
above this lethal toxicity for weeks, said Christine Dunathan, who
runs the winter's salinity monitoring program, even as federal standards
say they shouldn't meet or exceed those levels for more
than three hours every three years. Quote. Sligo is a long,

(21:15):
skinny thing that has very little buffer, Dunathan said, so
whatever happens in the neighborhood or on those local streets
ends up in the creek. Quote. The impacts on wildlife
aren't known for this past winter, but during that historic
twenty twenty one season, more than two hundred fish and
salamanders are found dead in the creek. Montgomery County Department

(21:37):
of Environmental Protection attributed the die offs to road salt
coming from the Capitol Beltway. The problems extend well beyond
the region. Along the eastern coasts, swaths of dead trees
called ghost forests have also succumbed to the increased salinity,
no longer able to protect coastal communities from large storms.

(22:01):
Back at the Anacostia River, Koschel dips his paddle in
the water and muses on the memories he's had on
this river with his son. He recounts the trips they've
taken by boat, kayak, and foot, making this his favorite river. Now,
it's hard to believe that such a simple compound can
create so many complex problems. Quote. I'd love to see

(22:22):
people protect it. I just hope that future generations can
enjoy it, Koschl said. Now we'll go to Smithsonian. We
have an article that's headlined Passage to the Pleistocene. In Wyoming,
a trove of ice age fossils is rewriting our understanding
of prehistoric animals. This is by Michael Taylor. June third.

(22:48):
Julie Nietschen, an expert in ice age megafauna, skirts a
dirt ledge called the saddle deep inside a remarkable hollow
in northern Wyoming known as as Natural Trap cave. She
stops to observe Megan Hormel, a graduate student at Des
Moines University and one of several volunteers who have repelled

(23:13):
into the cave on a nylon line dangling from the
entrance eighty feet overhead. Sunlight streams through a jagged skylight
to illuminate a bell shaped chamber one hundred forty feet
in diameter. I sit to one side of the saddle
as remains of ice age mammals slowly emerge into the light,

(23:35):
like the scientists scattered over the subterranean hillside. I wear
warm clothing, boots, and a caving helmet. My cumbersome climbing
gear rests along with everyone else's on a tarp above
ground on the western flank of the Big Horn Mountains,
less than two miles from the Montana border. It's a
scorching July day down here. The temperature hovers at a

(23:58):
near constant forty two tu degrees fahnheight, shifting only a
few degrees with seasonal heat waves or blizzards. Bundled in
thick coveralls and fleece jackets, the researchers wheeled trowels with
gloved hands. It is the next to last day of
a two week expedition. The twenty two members on this
twenty twenty four dig include seasoned scientists and students undergrudge

(24:23):
to undergraduate to postdoctoral, along with expert cave explorers who
ensure the safe and smooth operation of delicate work at
the bottom of a deadly pit. The cave's name natural
trap is literal. Over the past one hundred and fifty
thousand years, countless animals have fallen into it, perhaps because

(24:45):
they were running or because of their relative weights and
body shapes. Certain animals fell more horizontally, landing on the
cave's floor well beyond the seventy five foot perimeter of
the entrance and dying on impact. As the degree pile
grew over millennia, some animals that fell rolled or bounced,
creating the broad field of bones that fills the chamber today.

(25:09):
The bones of at least one extinct cat, commonly known
as the American cheetah, stayed together. Its intact skeleton was
observed on a ledge deep inside the cave in twenty
twenty three, setting aside her pick ormel cleans, an exposed
bone with a sort of small paintbrush normally used on

(25:32):
interior trim. A foot or so to her right, a
bony plate the size of an iPad angles upward from
the dirt. A scapula from an animal closely related to
present day big orange sheep, a male. If it matches
the skull fragment that Tony Hotchner, another grad student, found
just yesterday, possibly twenty three thousand years old, based on

(25:54):
the dating of previous signs within the cobbly gray, this
is another vert Wormel tells Michen, using paleon paleontological shorting
and for vertebrate beach and nods, after you get the
vert out, I would take this little wall down. She
indicates a jumble of packed rocks and dirt. Yeah, the

(26:15):
wall has to go, but there's ribs in the wall.
Hormill says, Okay, do your best to start taking it down,
take that little nubbin out, and then worry about the scalpula.
Beach And says, that's a beautiful scalpula, and I'd love
to get it out. These workers are not hunting future
museum displays. Instead, by documenting subtle changes within animal species

(26:39):
over time, they seek clues to extreme climate changes of
the past and natural Trap Cave provides an astoundingly well
suited resource for the purpose, holding a largely unbroken record
of mammal lineages going back tens of thousands of years.
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
and the time range over which it was open as long,
so it has the potential to show change over time,
as long as the individual skeletons are dated. That's why
Mitcham and her team are focusing on the past thirty
nine thousand years, a time starting in the late Pleistocene

(27:22):
that coincides with the most carefully dated bone bearing layers
inside the cave, deposits that were laid down during a
continuous cycle of glaciers advancing and retreating. Quote. We're going
to see if we can accurately model the dry and
wet cycles at the site during that period. Mechion says.

(27:42):
This sort of climate analysis has never been published in
the scientific literature. Let's offer today's Diary of science and Nature.
Your reader is Kelly Taylor. Now stay tuned for the
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