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New freshwater database tells water quality story for 12K lakes globally – Phys.org

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A sunset caught over Boundary Lake in Ontario’s Killarney Provincial Park. Credit: Amanda Liczner

Although less than one per cent of all water in the world is freshwater, it is what we drink and use for agriculture. In other words, it’s vital to human survival. York University researchers have just created a publicly available water quality database for close to 12,000 freshwater lakes globally—almost half of the world’s freshwater supply—that will help scientists monitor and manage the health of these lakes.

The study, led by Faculty of Science Postdoctoral Fellow Alessandro Filazzola and Master’s student Octavia Mahdiyan, collected data for lakes in 72 countries, from Antarctica to the United States and Canada. Hundreds of the lakes are in Ontario.

“The database can be used by scientists to answer questions about what lakes or regions may be faring worse than others, how has changed over the years and which environmental stressors are most important in driving changes in water quality,” says Filazzola.

The team included a host of graduate and undergraduate students working in the laboratory of Associate Professor Sapna Sharma in addition to a collaboration with Assistant Professor Derek Gray of Wilfrid Laurier University, Associate Professor Catherine O’Reilly of Illinois State University and York University Associate Professor Roberto Quinlan.

The researchers reviewed 3,322 studies from as far back as the 1950s along with online data repositories to collect data on chlorophyll levels, a commonly used marker to determine and ecosystem health. Chlorophyll is a predictor of the amount of vegetation and algae in lakes, known as primary production, including invasive species such as milfoil.

York University researchers have created a publicly available water quality database for close to 12,000 freshwater lakes globally – almost half of the world’s freshwater supply – that will help scientists monitor and manage the health of these lakes. Credit: York University

“Human activity, , agricultural, urban runoff and phosphorus from can all increase the level of chlorophyll in lakes. The primary production is most represented by the amount of chlorophyll in the lake, which has a cascading impact on the phytoplankton that eat the algae and the fish that eat the phytoplankton and the fish that eat those fish,” says Filazzola. “If the chlorophyll is too low, it can have cascading negative effects on the entire ecosystem, while too much can cause an abundance of algae growth, which is not always good.”

Warming summer temperatures and increased solar radiation from decreased cloud cover in the northern hemisphere also contributes to an increase in chlorophyll, while more storm events caused by contribute to degraded water quality, says Sharma. “Agricultural areas and urban watersheds are more associated with degraded water quality conditions because of the amount of nutrients input into these lakes.”

The researchers also gathered data on phosphorous and nitrogen levels—often a predictor of chlorophyll—as well as lake characteristics, land use variables, and climate data for each lake. Freshwater lakes are particularly vulnerable to changes in nutrient levels, climate, land use and pollution.

New freshwater database tells water quality story for 12K lakes globally
Postdoctoral Fellow Alessandro Filazzola standing at the edge of David Lake in Ontario’s Killarney Provincial Park. Credit: Amanda Liczner

“In addition to drinking water, freshwater is important for transportation, agriculture, and recreation, and provides habitats for more than 100,000 species of invertebrates, insects, animals and plants,” says Sharma. “The database can be used to improve our understanding of how levels respond to global environmental change and it provides baseline comparisons for environmental managers responsible for maintaining quality in lakes.”

The researchers started looking only at Ontario lakes, but quickly expanded it globally as although there are thousands of lakes in Ontario a lot of the data is not as readily available as it is in other regions of the world.

“The creation of this database is a feat typically only accomplished by very large teams with millions of dollars, not by a single lab with a few small grants, which is why I am especially proud of this research,” says Sharma.

The research is published in Nature’s Scientific Data journal.


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More information:
Scientific Data, DOI: 10.1038/s41597-020-00648-2

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New freshwater database tells water quality story for 12K lakes globally (2020, September 22)
retrieved 22 September 2020
from https://phys.org/news/2020-09-freshwater-database-quality-story-12k.html

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Space telescopes capture asteroid strike – CTV News

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CAPE CANAVERAL, Fla. –

The world now has stunning new photos of this week’s asteroid strike, the first planetary defence test of its kind.

NASA on Thursday released pictures of the dramatic event taken by the Hubble and Webb space telescopes.

Telescopes on all seven continents also watched as NASA’s Dart spacecraft slammed Monday into the harmless space rock, 7 million miles (11 million kilometres) from Earth, in hopes of altering its orbit.

Scientists won’t know the precise change until November; the demo results are expected to instill confidence in using the technique against a killer asteroid headed our way one day.

“This is an unprecedented view of an unprecedented event,” Johns Hopkins University planetary astronomer and mission leader Andy Rivkin said in a statement.

All these pictures will help scientists learn more about the little asteroid Dimorphos, which took the punch and ended up with a sizable crater. The impact sent streams of rock and dirt hurling into space, appearing as bright emanating rays in the latest photos.

The brightness of this double asteroid system — the 525-foot (160-metre) Dimorphos is actually the moonlet around a bigger asteroid — tripled after the impact as seen in the Hubble images, according to NASA.

Hubble and Webb will keep observing Dimorphos and its large companion Didymos over the next several weeks.

The US$325 million Dart mission was launched last year. The spacecraft was built and managed by Johns Hopkins’ Applied Physics Laboratory in Laurel, Maryland.

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The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Department of Science Education. The AP is solely responsible for all content.

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3 Russian cosmonauts return safely from Intl Space Station – Lethbridge News Now

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By Canadian Press

Sep 29, 2022 | 1:32 PM

MOSCOW (AP) — Three Russian cosmonauts returned safely Thursday from a mission to the International Space Station.

The Soyuz MS-21 spacecraft carrying Oleg Artemyev, Denis Matveyev and Sergey Korsakov touched down softly at 4:57 p.m. at a designated site in the steppes of Kazakhstan, 150 kilometers (90 miles) southeast of the city of Zhezkazgan.

The trio had arrived at the space station in March. For Artemyev, the mission marked a third space flight, bringing his total time spent in orbit to 561 days. Matveyev and Korsakov each logged 195 days on their first missions.

As the Soyuz capsule was descending, using a big striped red-and-white parachute under clear skies, Artemyev reported to Mission Control that all members of the crew were feeling fine.

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Mary Vaux Walcott – The Canadian Encyclopedia

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Mary Vaux Walcott | The Canadian Encyclopedia

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