adplus-dvertising
Connect with us

Science

Don’t Read Too Much into River Otters’ Return

Published

 on

Standing at the foot of a rocky sandstone cliff, biologist Michelle Wainstein inspected her essentials: latex gloves, two long cotton swabs, glass vials, and tubes filled with buffer solution. She placed them in a blue dry bag, rolled it up, and clipped it to a rope wrapped around her waist. It was late afternoon, and she was slick with dirt and sweat from navigating the dense terrain. Her destination lay across the frigid river: two small logs of otter fecal matter resting on a mossy boulder. In she plunged.

The river, the Green-Duwamish in Washington State, trickles out of the Cascade Range and empties 150 kilometers downstream into Puget Sound. The last eight kilometers of the run—known as the lower Duwamish—is so polluted the US Environmental Protection Agency designated it a Superfund site in 2001. For a century, Seattle’s aviation and manufacturing industries routinely dumped waste chemicals like polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) into the water.

“A lot of the river is still really polluted,” says Jamie Hearn, the Superfund program manager at Duwamish River Community Coalition. “The mud is thick and black, and you can smell it.”

Despite the pollution, river otters are everywhere along the waterway, even in the most contaminated areas near the river’s mouth. “I would be walking the docks looking for scat,” remembers Wainstein, “and a couple of times we were lucky enough to see moms with their pups.”

300x250x1

For several weeks in the summer of 2016 and 2017, Wainstein surveyed otter poop she collected from a dozen sites along the river. Comparing contaminant concentrations in the otters’ poop between the river’s industrial and rural zones, Wainstein uncovered the lingering legacy of the region’s toxic past. The poop from otters in the lower Duwamish contained nearly 26 times more PCBs and 10 times more PAHs than poop from their cousins in cleaner water upstream. PCBs disrupt hormonal and neurological processes and affect reproduction in mammals. Both PCBs and PAHs are human carcinogens.

The discovery that otters along the lower Duwamish are living with such high levels of contamination upends a common narrative: that river otters’ return to a once-degraded landscape is a sign that nature is healing.

In Singapore, where smooth-coated otters have reappeared in canals and reservoirs, they have been embraced as new national mascots. “It plays into that rhetoric that government agencies want to project,” says environmental historian Ruizhi Choo, “that we’ve done such a good job that nature is coming back. That image of a city in nature is the new marketing branding.”

In Europe, the once-common Eurasian otter similarly began reappearing in the late 20th century following successful river cleanup campaigns. Conservationist Joe Gaydos at the SeaDoc Society thinks that this phenomenon has helped form the mental link between otters and ecosystem health.

“The number of animals is our first indicator,” Gaydos says. But few seem to ask the next question: are those animals healthy?

As Wainstein’s study suggests, perhaps not. The otters she analyzed in the lower Duwamish have some of the highest concentrations of PCBs and PAHs ever recorded in wild river otters. Previous research has found a correlation between PCB exposure and health risks in wild river otters, including increased bone pathologies, reproductive and immunological disorders, organ abnormalities, and hormonal changes.

Even so, the contamination is not manifesting in physically obvious ways. “They’re not washing up on shore with tumors all over their bodies,” Wainstein says, and neither is their population dwindling. “They’re not setting off this direct alarm with a big change in their ability to survive.”

The otters’ ability to bear such a heavy contaminant burden suggests that a population resurgence alone may not reflect the quality of an environment. They just become as toxic as the environments they inhabit.

However, their localized bathroom habits, mixed diet of fish, crustaceans, and mammals, and persistence in the face of pollution make them useful indicators of environmental contamination.

River otters have played this role before. Following the 1989 Exxon Valdez oil spill, river otters lingered in oil-drenched waterways, allowing scientists like Larry Duffy at the University of Alaska Fairbanks to track the effectiveness of the oil cleanup. In 2014, scientists in Illinois discovered dieldrin in otter organ tissue even though the insecticide had already largely been banned for 30 years. In these cases, the collection of long-term pollution data was made possible by the creatures’ resilience in contaminated waterways. Wainstein wants to similarly use the Green-Duwamish River otters as biomonitors of the Superfund cleanup over the next decade.

Watching workers dismantle a portion of the river’s levied banks to make channels for salmon, Wainstein thinks about the seabirds, shorebirds, and small mammals, like beaver and mink, that were driven out by industrial contamination. She wonders if one day the rumbling machinery dredging up clawfuls of sediment from the riverbed will be taken over by the piercing cries of marbled murrelets, the croaks of tufted puffins, and the bubbling twittering of western snowy plovers.

“How long will it take? And will it actually work?” she says of the cleanup effort. The otters might hold the answer.

728x90x4

Source link

Continue Reading

Science

Marine plankton could act as alert in mass extinction event: UVic researcher – Langley Advance Times

Published

 on


A University of Victoria micropaleontologist found that marine plankton may act as an early alert system before a mass extinction occurs.

With help from collaborators at the University of Bristol and Harvard, Andy Fraass’ newest paper in the Nature journal shows that after an analysis of fossil records showed that plankton community structures change before a mass extinction event.

“One of the major findings of the paper was how communities respond to climate events in the past depends on the previous climate,” Fraass said in a news release. “That means that we need to spend a lot more effort understanding recent communities, prior to industrialization. We need to work out what community structure looked like before human-caused climate change, and what has happened since, to do a better job at predicting what will happen in the future.”

300x250x1

According to the release, the fossil record is the most complete and extensive archive of biological changes available to science and by applying advanced computational analyses to the archive, researchers were able to detail the global community structure of the oceans dating back millions of years.

A key finding of the study was that during the “early eocene climatic optimum,” a geological era with sustained high global temperatures equivalent to today’s worst case global warming scenarios, marine plankton communities moved to higher latitudes and only the most specialized plankton remained near the equator, suggesting that the tropical temperatures prevented higher amounts of biodiversity.

“Considering that three billion people live in the tropics, the lack of biodiversity at higher temperatures is not great news,” paper co-leader Adam Woodhouse said in the release.

Next, the team plans to apply similar research methods to other marine plankton groups.

Read More: Global study, UVic researcher analyze how mammals responded during pandemic

Adblock test (Why?)

728x90x4

Source link

Continue Reading

Science

Scientists Say They Have Found New Evidence Of An Unknown Planet… – 2oceansvibe News

Published

 on


In the new work, scientists looked at a set of trans-Neptunian objects, or TNOs, which is the technical term for those objects that sit out at the edge of the solar system, beyond Neptune

The new work looked at those objects that have their movement made unstable because they interact with the orbit of Neptune. That instability meant they were harder to understand, so typically astronomers looking at a possible Planet Nine have avoided using them in their analysis.

Researchers instead looked towards those objects and tried to understand their movements. And, Dr Bogytin claimed, the best explanation is that they result from another, undiscovered planet.

300x250x1

The team carried out a host of simulations to understand how those objects’ orbits were affected by a variety of things, including the giant planets around them such as Neptune, the “Galactic tide” that comes from the Milky Way, and passing stars.

The best explanation was from the model that included Planet 9, however, Dr Bogytin said. They noted that there were other explanations for the behaviour of those objects – including the suggestion that other planets once influenced their orbit, but have since been removed – but claim that the theory of Planet 9 remains the best explanation.

A better understanding of the existence or not of Planet 9 will come when the Vera C Rubin Observatory is turned on, the authors note. The observatory is currently being built in Chile, and when it is turned on it will be able to scan the sky to understand the behaviour of those distant objects.

Planet Nine is theorised to have a mass about 10 times that of Earth and orbit about 20 times farther from the Sun on average than Neptune. It may take between 10,000 and 20,000 Earth years to make one full orbit around the Sun.

You may be tempted to ask how an entire planet could ‘hide’ in our solar system when we have zooming capabilities such as the new iPhone 15 has, but consider this: If Earth was the size of a marble, the edge of our solar system would be 11 kilometres away. That’s a lot of space to hide a planet.

[source:independent]

Adblock test (Why?)

728x90x4

Source link

Continue Reading

Science

Dragonfly: NASA Just Confirmed The Most Exciting Space Mission Of Your Lifetime – Forbes

Published

 on


NASA has confirmed that its exciting Dragonfly mission, which will fly a drone-like craft around Saturn’s largest moon, Titan, will cost $3.35 billion and launch in July 2028.

Titan is the only other world in the solar system other than Earth that has weather and liquid on the surface. It has an atmosphere, rain, lakes, oceans, shorelines, valleys, mountain ridges, mesas and dunes—and possibly the building blocks of life itself. It’s been described as both a utopia and as deranged because of its weird chemistry.

Set to reach Titan in 2034, the Dragonfly mission will last for two years once its lander arrives on the surface. During the mission, a rotorcraft will fly to a new location every Titan day (16 Earth days) to take samples of the giant moon’s prebiotic chemistry. Here’s what else it will do:

300x250x1
  • Search for chemical biosignatures, past or present, from water-based life to that which might use liquid hydrocarbons.
  • Investigate the moon’s active methane cycle.
  • Explore the prebiotic chemistry in the atmosphere and on the surface.

Spectacular Mission

“Dragonfly is a spectacular science mission with broad community interest, and we are excited to take the next steps on this mission,” said Nicky Fox, associate administrator of the Science Mission Directorate at NASA Headquarters in Washington. “Exploring Titan will push the boundaries of what we can do with rotorcraft outside of Earth.”

It comes in the wake of the Mars Helicopter, nicknamed Ingenuity, which flew 72 times between April 2021 and its final flight in January 2023 despite only being expected to make up to five experimental test flights over 30 days. It just made its final downlink of data this week.

Dense Atmosphere

However, Titan is a completely different environment to Mars. Titan has a dense atmosphere on Titan, which will make buoyancy simple. Gravity on Titan is just 14% of the Earth’s. It sees just 1% of the sunlight received by Earth.

function loadConnatixScript(document)
if (!window.cnxel)
window.cnxel = ;
window.cnxel.cmd = [];
var iframe = document.createElement(‘iframe’);
iframe.style.display = ‘none’;
iframe.onload = function()
var iframeDoc = iframe.contentWindow.document;
var script = iframeDoc.createElement(‘script’);
script.src = ‘//cd.elements.video/player.js’ + ‘?cid=’ + ’62cec241-7d09-4462-afc2-f72f8d8ef40a’;
script.setAttribute(‘defer’, ‘1’);
script.setAttribute(‘type’, ‘text/javascript’);
iframeDoc.body.appendChild(script);
;
document.head.appendChild(iframe);

loadConnatixScript(document);

(function()
function createUniqueId()
return ‘xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx’.replace(/[xy]/g, function(c) 0x8);
return v.toString(16);
);

const randId = createUniqueId();
document.getElementsByClassName(‘fbs-cnx’)[0].setAttribute(‘id’, randId);
document.getElementById(randId).removeAttribute(‘class’);
(new Image()).src = ‘https://capi.elements.video/tr/si?token=’ + ’44f947fb-a5ce-41f1-a4fc-78dcf31c262a’ + ‘&cid=’ + ’62cec241-7d09-4462-afc2-f72f8d8ef40a’;
cnxel.cmd.push(function ()
cnxel(
playerId: ’44f947fb-a5ce-41f1-a4fc-78dcf31c262a’,
playlistId: ‘aff7f449-8e5d-4c43-8dca-16dfb7dc05b9’,
).render(randId);
);
)();

The atmosphere is 98% nitrogen and 2% methane. Its seas and lakes are not water but liquid ethane and methane. The latter is gas in Titan’s atmosphere, but on its surface, it exists as a liquid in rain, snow, lakes, and ice on its surface.

COVID-Affected

Dragonfly was a victim of the pandemic. Slated to cost $1 billion when it was selected in 2019, it was meant to launch in 2026 and arrive in 2034 after an eight-year cruise phase. However, after delays due to COVID, NASA decided to compensate for the inevitable delayed launch by funding a heavy-lift launch vehicle to massively shorten the mission’s cruise phase.

The end result is that Dragonfly will take off two years later but arrive on schedule.

Previous Visit

Dragonfly won’t be the first time a robotic probe has visited Titan. As part of NASA’s landmark Cassini mission to Saturn between 2004 and 2017, a small probe called Huygens was despatched into Titan’s clouds on January 14, 2005. The resulting timelapse movie of its 2.5 hours descent—which heralded humanity’s first-ever (and only) views of Titan’s surface—is a must-see for space fans. It landed in an area of rounded blocks of ice, but on the way down, it saw ancient dry shorelines reminiscent of Earth as well as rivers of methane.

The announcement by NASA makes July 2028 a month worth circling for space fans, with a long-duration total solar eclipse set for July 22, 2028, in Australia and New Zealand.

Wishing you clear skies and wide eyes.

Adblock test (Why?)

728x90x4

Source link

Continue Reading

Trending