Some good news on the health of fish in Tryon Creek….read here.
Researchers are testing a way to double the use of cropland to generate renewable energy. Read more here.
A new study shows that better global land stewardship—conserving and restoring wild habitats and practicing more sustainable farming—could get us more than one-third of the way to the Paris climate mitigation targets. Read more…Nature is the tool for carbon reduction
Now, researchers have undertaken the first comprehensive study of how the infrastructure of U.S. cities alters rivers and their biodiversity. The effects are extensive, they reported yesterday in the Proceedings of the National Academy of Sciences, extending both upstream and downstream for tens or even thousands of kilometers like the branches of a nerve cell.
The researchers used data on river hydrology from the U.S. Geological Survey in a computer model to determine the effects of urban land transformation, electric power, and municipal water supplies on rivers nationwide. They also pulled information from a fine-grained database of species occurrence to assess the biodiversity of freshwater fish, mussels, and crayfish in urban-affected stream reaches.
The largest impacts are from urban land cover and electricity production, the researchers found. These aspects of infrastructure have altered at least 7% of the entire length of streams and rivers in the contiguous United States. “Although these estimates may not seem extensive, they result in very large biodiversity impacts,” the researchers write.
Urban infrastructure impacts 60% of all freshwater fish, mussel, and crayfish species in North America, over 1,200 species altogether. It has contributed to local extinctions of 260 species, sometimes in stream reaches distant from city boundaries themselves. It also influences 970 existing native species, 27% of which are threatened or endangered.
“Cities can impact far reaching areas due to the sheer intensity of resource demands,” the researchers write. For example, the energy and water infrastructure of Atlanta, Georgia stretches across four major river basins.
Moreover, the stresses from urban infrastructure are often compounded because multiple cities may be located on the course of the same river. Twenty-one cities lie along rivers downstream of Atlanta.
Surprisingly, however, the researchers found little connection between a city’s size and the severity of its effects on rivers. Atlanta’s infrastructure impacts 12,500 stream kilometers, and has contributed to 100 local extinctions of freshwater species. Las Vegas, Nevada has a similar population size, but impacts less than 1,000 stream kilometers and has contributed to only seven local extinctions.
Some of these differences have to do with differences in the layout of stream networks and the number of species found in the eastern compared to the western United States. But the findings also suggest that as a city grows, its area of hydrologic impact doesn’t necessarily have to expand along with it. For example, cities could check their impact on rivers by managing storm flows better, or choosing sources of electric power that minimize water use.
There are surely tradeoffs involved in such strategies (choices that take less of a toll on rivers may come with greater impacts on some other habitat). Still, the idea that city governments can not only cause ecological harm but also contribute to ecological integrity far beyond the city limits sounds like good news in an urbanizing world.
by Aug 22, 2017|
Source: McManamay R. et al. “US cities can manage national hydrology and biodiversity using local infrastructure policy.” Proceedings of the National Academy of Sciences. 2017.
Scientists Make the Case for Spraying Saltwater Into Clouds to Help Cool the Planet
by Prachi Patel | Jul 27, 2017 Anthropocene Weekly Science Dispatch
Geoengineering is one of the most controversial proposals to combat climate change. The idea is to tinker with the Earth’s atmosphere on a large scale to counter rising temperatures.
In a new study, researchers at the University of Washington make the case for a geoengineering method known as marine cloud brightening. The technique calls for spraying saltwater into low-lying marine clouds, where they help create more clouds that reflect heat back into space.
The UW scientists say in the journal Earth’s Future that conducting small, controlled marine cloud brightening experiments would provide unprecedented data to understand the effects of aerosols on cloud formation and the resulting reflection of sunlight.
The effect of clouds on climate is one of the biggest uncertainties in today’s climate models. Climate scientists believe that increased pollution since the Industrial Revolution has created brighter, reflective clouds. But they don’t understand the scope of the effect.
There is a need for more controlled experiments to fill the gaps in our basic understanding of the physical processes that control clouds, and how sensitive clouds are to manmade emissions, the researchers argue. By running a series of small-scale experiments in which known quantities of particles are injected into the marine boundary layer, they should be able to observe the impact of the particles on cloud properties and compare them with the properties of naturally formed clouds.
The researchers are now developing a nozzle that can turn saltwater into tiny droplets and can spray trillions of these aerosol particles high into the atmosphere per second. This is the first step in their three-year plan.
Once the sprayer has been developed, they propose to test it in the lab; do preliminary coastal tests in Monterey Bay; and finally move to offshore tests. If these small-scale tests of the technology work, they hope that larger-scale versions could eventually be deployed over larger swaths of ocean.
This isn’t the only geoengineering test underway. Harvard physicist David Keith’s team has recently raised money to conduct a small geoengineering test to dim sunlight. They plan to release about 1 kilogram of calcium carbonate or other material from a high-altitude balloon to see how it affects the physics of the atmosphere. Keith has argued in a recent book that we need to understand geoengineering deeply before we dive into it.
Deliberately messing with the planet’s atmosphere brings up many technical and ethical questions. Reflecting sunlight could affect farming yields and solar panel outputs, for instance. It could trigger much more dramatic unforeseen side effects. Experts also worry that it would detract from efforts to reduce carbon emissions.
“There’s a science question about can we do it, but there’s also an ethical question about should we do it, and a policy question about how would we do it,” said Thomas Ackerman, a UW professor of atmospheric sciences and author of the new study in a press release. “I’m an agnostic on this. I want to test geoengineering and see if it works. But the whole time we’re working on this, I think we need to still be asking ourselves: ‘Should we do it?’”
Source: Robert Wood et al. Could geoengineering research help answer one of the biggest questions in climate science? Earth’s Future. 2017.
Photo: John MacNeill
Human noise pollution is disrupting wild places. Read more.
There is literally a ton of plastic garbage for every person in the world. Read more.
It started so innocently. A kid ordered a soda in a restaurant.
“It came with a plastic straw in it,” Milo Cress recalled. He glared at the straw for a while. “It seemed like such a waste.”
Not only did Cress yank the plastic from his drink, but he also launched a campaign, “Be Straw Free,” targeting all straws as needless pollution. He knocked on the doors of restaurants in Burlington, Vt., where he lived at the time, and asked managers not to offer straws unless patrons asked. He was 9 years old.
Today Cress, 15, is one of the faces of a growing movement to eliminate plastic straws. They have been found wedged in the nose of a sea turtle, littering the stomachs of countless dead marine animals and scattered across beaches with tons of other plastics.
Why single out pollution as small and slim as a drinking straw?
A group of marine biologists in Guanacaste, Costa Rica, helped remove a plastic straw from a sea turtle’s nose. (COASTS/YouTube)
Straws are among the most common plastic items volunteers clean from beaches, along with bottles, bags and cups, conservationists say. Americans use half a billion straws every day, at least according to an estimate by Be Straw Free, based on information from straw manufacturers. That many straws could wrap around the Earth 2½ times.
The slightest wind lifts plastic straws from dinner tables, picnic blankets and trash dumps, depositing them far and wide, including in rivers and oceans, where animals often mistake them for food.
And they are ubiquitous. Nearly every chain restaurant and coffee shop offers straws. They’re in just about every movie theater and sit-down restaurant. Theme parks and corner stores and ice cream shops and school cafeterias freely hand them out.
But they are starting to disappear because of the awareness campaign Cress and dozens of conservation groups are waging. Walt Disney World’s Animal Kingdom bans them, as do the food concession areas of Smithsonian Institution museums.
Keith Christman, a managing director for plastics markets at the American Chemistry Council, which promotes plastics manufacturers and fights attempts to ban plastic, said in a National Geographic article two months ago that the group would do the same for attempts to eliminate plastic straws.
But a spokeswoman for the council said “we won’t be able to offer comment” or say whether the group backs Christman’s claim.
The movement was growing at a slow, steady pace when Cress joined it six years ago, but it exploded after a YouTube video of a sea turtle with a straw stuck in its nose went viral in 2015. The cringe-inducing effort to pull the plastic out of a bloody nostril outraged viewers — 11.8 million so far.
Cress has launched a website on the issue, partnered with several organizations that support the cause and testified against straws in the Vermont legislature. Colorado Gov. John Hickenlooper (D) cited Cress’s activism in a 2013 proclamation that made July 11 a straw-free day in the state.
Manhattan Beach outside Los Angeles banned all disposable plastics, including straws. Berkeley, Calif., is considering a ban. Restaurants in San Diego; Huntington Beach, Calif.; Asbury Park, N.J.; New York; Miami; Bradenton, Fla.; London; and British Columbia have pledged to ban straws or withhold them until patrons ask for them.
The Plastic Pollution Coalition estimates that 1,800 “restaurants, organizations, institutions and schools worldwide have gotten rid of plastic straws or implemented a serve-straws-upon-request policy,” said Jackie Nunez, founder of a group called the Last Plastic Straw.
More than 20 such restaurants near Wrightsville Beach, N.C., signed up last year to be certified by a coalition of groups as establishments that won’t serve straws unless they’re requested.
Ginger Taylor, a volunteer who cleans trash from the five-mile beach, said the campaign is working, at least anecdotally.
“I’ve been picking up straws on Monday morning on that same stretch of beach for five years,” she said. Four years ago, she picked up 248 straws in about two weeks. The next two years, she collected about 500. But the number fell to 158 after the awareness campaign started last year.
Diana Lofflin, founder of a group called Straw Free, said the turtle video inspired her year-old organization. Her volunteers persuaded California’s Joshua Tree Music Festival to go straw-free in May. They also knock on the doors of Orange County, Calif., homeowners who grow bamboo to ask whether they can harvest a little and make reusable straws from the plant. Like several other groups, Straw Free sells reusable bamboo straws online, theirs in packs of 10 for $1.50.
Xanterra Parks & Resorts, a concessions company that partners with the National Park Service to provide food and lodging at Rocky Mountain National Park, the Grand Canyon and other national parks, offers straws at dispensers but posts fliers asking patrons not to use them.
“Humans didn’t really evolve around straws. It’s not like we have to consume fluids with this appendage. What really, what is this?” said Catherine Greener, vice president of sustainability for the company.
The prevailing notion says flexible straws were invented in the late 19th century by Marvin Stone, a D.C. man who didn’t like how the traditional ryegrass straw people used for drinking would disintegrate and leave gritty residue in his mint juleps. Stone wrapped strips of paper around a pencil, glued the strips together and test-marketed the contraption, and in 1888, the disposable straw was born, according to the Smithsonian’s Lemelson Center for the Study of Invention and Innovation.
The new paper straw was limited mostly to use in hospitals, which used the innovation to avoid spreading disease. Usage widened during the polio epidemic that began in 1900 as people avoided putting their mouths on others’ drinking glasses. Finally in the 1960s, restaurants offered a new invention: a disposable plastic straw.
It’s a convenience people seem to use arbitrarily. Millions drink soda with a straw, but hardly any suck beer through one. Hot-coffee drinkers gulp directly from cups but stick straws in iced coffee. Bar hoppers drink highballs from a glass, but mixed cocktails come with a straw.
“There are plenty of times when straws just aren’t necessary,” said Aaron Pastor, a restaurant consultant and one of dozens of vendors who sell stainless steel, bamboo and other reusable straws online.
“I’ve sold thousands of [reusable] straws,” Pastor said, but it’s not a booming business. “This isn’t paying my mortgage.”
Pastor said chastising plastic straw users isn’t his style. “If your goal isn’t to preach and come across as ‘I’m better than you,’ that’s best. I just say they’re wasteful, they end up in oceans and, hey, do you really need one.”
At the Smithsonian’s National Museum of Natural History in Washington, Melissa and Brian Charon said no. The parents, visiting from Boston with small children who grabbed at food spread on a table, shrugged when told the museum doesn’t offer straws.
“It’s fine with me. I don’t really miss it,” Melissa said. Then Brian added: “I look in the drawer in our kitchen every day and say, ‘Why do we have so many straws?’ ”
At Xanterra’s national parks concessions, “We want people to think about this throwaway society, especially in these beautiful places,” Greener said. “They can take to the air. It’s easy for them to get blown around.”
The anti-straw message is also getting blown around. Greener was looking for composting tips a few years ago when she came across a profile of Cress, who had partnered with a recycling center in Colorado called Eco-Cycle.
Greener wanted to talk to the kid, who by then was powering the anti-straw movement in Colorado, where his family had moved. Based on their conversation, Greener decided to promote straw awareness at Xanterra’s concessions.
“He’s obviously a gifted teen. He’s probably running for Congress. He was very inspirational and innovative,” Greener said. “All I wanted to do at his age was get my driver’s license. I look at kids like that, and it makes me very hopeful.”
Cress isn’t running for office — yet. He said he’s enjoying a six-year passion that has taken him to Australia, Portugal, Germany, France, Boston, Washington and many high schools all over to deliver speeches.
“My favorite part about it has been getting to talk to other kids and listening to their ideas,” Cress said. “It’s really cool, and I think it’s really empowering. I certainly feel like I’m listened to and valued in a larger community, and I really appreciate that.”
By Darryl Fears, June 24, The Washington Post
What do fish sound like?
When Gulf Corvina breed, their mating calls could be likened to an immense, underwater roar. Now, a group of researchers have found a way to use the deafening din to save these fish from exploitation. Using underwater microphones, they’ve developed a method for converting sound recordings of the fish’s calls into precise population estimates. Those could inform more accurate catch limits, they say, that would ultimately make corvina fisheries—and others—more sustainable.
Fish stocks worldwide are being depleted by overfishing, which often boils down to inaccurate population surveys that can lead to overly-liberal catch quotas. For the Gulf Corvina especially, overfishing over the last 20 years has taken its toll; the fish now has a vulnerable status.
Part of the problem for this species, the researchers explain in Scientific Reports, is that every year the entire population of two million corvina migrate to one spot in the Northern Gulf of California, Mexico, to spawn. There, males attract mates by producing their spectacular cacophony—so loud that fishers can easily locate them from the surface, and haul up more than a million over the course of three weeks. The researchers realized that if they could instead use the noise to monitor the population, there might be a solution for these fish.
Over the course of eight surveys in 2014, they used underwater hydrophones to record the corvinas’ roar at the Colorado River Delta where they spawn. The louder the din, the more fish there were assumed to be. But because of the way sound travels underwater it can be misleading, meaning the recordings alone couldn’t provide a dependable estimate. So the researchers paired them with sonar. This method pings sound waves into the water that bounce off objects and create a detailed picture of how many objects—i.e. fish—there are beneath the surface.
Sonar would be too costly to use for every population estimate. But in this case, the researchers only used it to sample the population size at different points in the survey, adding a layer of detail to the sound recording. If it worked, this would prove whether there was a link between more noise and more fish. And it did: “When all the fish are packed into the spawning grounds and males are chorusing during the peak spawning activity, we find a tight correlation between sound and abundance,” says co-author Brad Erisman from the University of Texas Marine Science Institute. “Now you can imagine a situation, if it’s predictable, [where] you can just have the underwater microphones out there,” he says. “Because you know this sort of sound intensity and this loudness corresponds to about this many fish. Then you have a very powerful monitoring capability.”
The researchers were thus able to determine that at peak spawning, there were between 1.53 and 1.55 million corvina in the delta. Compared to more traditional surveying tools, the advantage of this method, they showed, is its cost-effectiveness and efficiency. Hydrophones can easily and regularly be deployed to monitor the population, which could inform more accurate catch quotas and move the fishery towards sustainability.
As a tool, it also holds promise for other species. Commercial fish like pollock, cod, haddock, and grouper all produce calls during spawning. Now the researchers say they’re looking into how their method could be used to set sustainable catch limits for those species, too.