Ocean Microplastics Are Drastically Underestimated, New Research Suggests
Microplastics, which breakdown into miniscule pieces of plastic are notoriously tricky to catch. Their small size allows them to get buried in ocean sediment and to escape through nets.
Now, a team of researchers, led by scientists at the Plymouth Marine Laboratory in England, used a finer net to get a more accurate picture of the amount of plastic in the ocean. Their research suggests the seas may be holding as many as 125 trillion microplastic particles, according to the study published in the journal Environmental Pollution, as Newsweek reported.
Microplastics are usually defined as tiny pieces of plastic that measure less than five millimeters across. However, despite the abundance of microplastics in the ocean, scientists have actually had a difficult time quantifying and classifying them. Usually, researchers gather samples with nets with a mesh size of 333 micrometers, or 0.333 millimeters, but these do not account for smaller pieces of plastic debris, as Newsweek reported.
The Plymouth Marine Laboratory scientists, along with researchers from the University of Exeter, used nets with a mesh size of 100 micrometers, or 0.1 millimeters, to get a more accurate picture of the microplastics swirling around coastal waters, according to a University of Exeter press release.
"It is quite well known what impact larger pieces of plastic have on marine animals, like turtles eating plastic bags mistaking them for jellyfish, but we wanted to know if microplastics are a problem to smaller marine animals like mussels or zooplankton," said Pennie Lindeque, lead author of the study from Plymouth Marine Laboratory, to Newsweek.
"However, first we needed an accurate picture of how many small microplastics there are in the sea, and what sort of plastic they are. We are interested in really quite small microplastics—around 100 micrometers in size, similar to the width of a human hair—and suspected that the standard sampling methods using a net with pores about 333 micrometers in size, wouldn't give an accurate picture."
The researchers compared the efficacy of a 100 micrometer net to what's collected by a 333 micrometer net and a 500 micrometer net. They found that their net collected 2.5 times as much microplastics as the 333 micrometer mesh net. It collected 10 times more microplastic than a 500 micrometer net, according to the study.
The scientists then extrapolated that data to determine that there are roughly 3,700 pieces of microplastic in one cubic meter. That means that previous global estimates of 5 to 50 trillion particles of microplastics are severely low. The true number, according to the data in the study, is somewhere between 12.5 and 125 trillion particles.
"There is often a mismatch between the number and type of microplastics used in experimental studies and those found in the natural environment," said Rachel Coppock, Marine Ecologist at Plymouth Marine Laboratory and a co-author on the study, in a statement. "This study confirms that microplastic concentration increases with decreasing size and also provides a framework for determining microplastic concentrations in exposure studies, particularly with animals such as zooplankton that eat micron-sized food."
The researchers focused on coastal water since that is where microplastics are likely to have the greatest impact on marine life. They sampled the water on both sides of the Atlantic, choosing a spot off the coast of Maine and another in the English Channel, according to Newsweek.
"I was surprised at the extent that we had been underestimating the microplastic abundance in the marine environment; I was also surprised how consistent the results were on both sides of the North Atlantic, the eastern seaboard of the U.S. and the southwest coast of the UK," Lindeque told Newsweek.
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EcoWatch Daily Newsletter
By Joni Sweet
If you get a call from a number you don't recognize, don't hit decline — it might be a contact tracer calling to let you know that someone you've been near has tested positive for the coronavirus.
Interviews With Contact Tracers<p>Contact tracing is a public health strategy that involves identifying everyone who may have been in contact with a person who has the coronavirus. Contact tracers collect information and provide guidance to help contain the transmission of disease.</p><p>It's been used during outbreaks of sexually transmitted infections (STIs), Ebola, measles, and now the coronavirus that causes COVID-19.</p><p>It starts when the local department of health gets a report of a confirmed case of the coronavirus in its community and gives that person a call. The contact tracer usually provides information on how to isolate and when to get treatment, then tries to figure out who else the person may have exposed.</p><p>"We ask who they've been in contact with in the 48 hours prior to symptom onset, or 2 days before the date of their positive test if they don't have symptoms," said <a href="https://case.edu/medicine/healthintegration/people/heidi-gullett" target="_blank">Dr. Heidi Gullett</a>, associate director of the Center for Community Health Integration at the Case Western Reserve University School of Medicine and medical director of the Cuyahoga County Board of Health in Ohio.</p>
“You’ve Been Exposed”<p>After the case interview, contact tracers will get to work calling the folks who may have been exposed to the coronavirus by the person who tested positive.</p><p>"We give them recommendations about quarantining or isolating, getting tested, and what to do if they become sick. If they're not already sick, we still want them to self-quarantine so that they don't spread the disease to anyone else if they were to become sick," said Labus.</p><p>Generally, the contact tracer won't ask for additional contacts unless they happen to call someone who is sick or has a confirmed case of the virus. They will help ensure the contact has the resources they need to isolate themselves, if necessary. The contact tracer may continue to stay in touch with that person over the next 14 days.</p><p>"We follow the percentage of people that were contacts, then converted into being actual cases of the virus. It's an important marker to help us understand what kind of transmission happens in our community and how to control the virus," said Gullett.</p>
Why You Should Participate (and What Happens If You Don’t)<p>A <a href="https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(20)30457-6/fulltext" target="_blank">Lancet study</a> from June 16, which looked at data from more than 40,000 people, found that COVID-19 transmission could be reduced by 64 percent through isolating those who have the coronavirus, quarantining their household, and contacting the people they may have exposed.</p><p>The combination strategy was significantly more effective than mass random testing or just isolating the sick person and members of their household.</p><p>However, contact tracing is only as effective as people's willingness to participate, and a small number of people who've contracted the coronavirus or were potentially exposed are reluctant to talk.</p><p>"Contact tracers have all been hung up on, cussed at, yelled at," said Gullet.</p><p>The hesitation to talk to contact tracers often stems from concerns over privacy — a serious issue in healthcare.</p>
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NASA scientists say that warmer than average surface sea temperatures in the North Atlantic raise the concern for a more active hurricane season, as well as for wildfires in the Amazon thousands of miles away, according to Newsweek.
By Andrea Germanos
Oxfam International warned Thursday that up to 12,000 people could die each day by the end of the year as a result of hunger linked to the coronavirus pandemic—a daily death toll surpassing the daily mortality rate from Covid-19 itself.
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By Jun N. Aguirre
An oil spill on July 3 threatens a mangrove forest on the Philippine island of Guimaras, an area only just recovering from the country's largest spill in 2006.
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By James Shulmeister
Climate Explained is a collaboration between The Conversation, Stuff and the New Zealand Science Media Centre to answer your questions about climate change.
If you have a question you'd like an expert to answer, please send it to firstname.lastname@example.org
What was the climate and sea level like at times in Earth’s history when carbon dioxide in the atmosphere was at 400ppm?<p>The last time global carbon dioxide levels were consistently at or above 400 parts per million (ppm) was around <a href="https://www.nature.com/articles/nature14145" target="_blank">four million years ago</a> during a geological period known as the <a href="http://www.geologypage.com/2014/05/pliocene-epoch.html" target="_blank">Pliocene Era</a> (between 5.3 million and 2.6 million years ago). The world was about 3℃ warmer and sea levels were higher than today.</p><p>We know how much carbon dioxide the atmosphere contained in the past by studying ice cores from Greenland and Antarctica. As compacted snow gradually changes to ice, it traps air in bubbles that contain <a href="https://www.cambridge.org/core/journals/annals-of-glaciology/article/enclosure-of-air-during-metamorphosis-of-dry-firn-to-ice/09D9C60A8DA412D16645E6E6ABC1892F" target="_blank">samples of the atmosphere at the time</a>. We can sample ice cores to reconstruct past concentrations of carbon dioxide, but this record only takes us back about a million years.</p><p>Beyond a million years, we don't have any direct measurements of the composition of ancient atmospheres, but we can use several methods to estimate past levels of carbon dioxide. One method uses the relationship between plant pores, known as stomata, that regulate gas exchange in and out of the plant. The density of these stomata is <a href="https://journals.sagepub.com/doi/abs/10.1177/095968369200200109" target="_blank">related to atmospheric carbon dioxide</a>, and fossil plants are a good indicator of concentrations in the past.</p><p>Another technique is to examine sediment cores from the ocean floor. The sediments build up year after year as the bodies and shells of dead plankton and other organisms rain down on the seafloor. We can use isotopes (chemically identical atoms that differ only in atomic weight) of boron taken from the shells of the dead plankton to reconstruct changes in the acidity of seawater. From this we can work out the level of carbon dioxide in the ocean.</p><p>The data from four-million-year-old sediments suggest that <a href="https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2010PA002055" target="_blank">carbon dioxide was at 400ppm back then</a>.</p>
Sea Levels and Changes in Antarctica<p>During colder periods in Earth's history, ice caps and glaciers grow and sea levels drop. In the recent geological past, during the most recent ice age about 20,000 years ago, sea levels were at least <a href="https://science.sciencemag.org/content/292/5517/679.abstract" target="_blank">120 meters lower</a> than they are today.</p><p><span></span>Sea-level changes are calculated from changes in isotopes of oxygen in the shells of marine organisms. For the Pliocene Era, <a href="https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2004PA001071" target="_blank">research</a> shows the sea-level change between cooler and warmer periods was around 30-40 meters and sea level was higher than today. Also during the Pliocene, we know the West Antarctic Ice Sheet was <a href="https://www.nature.com/articles/nature07867" target="_blank">significantly smaller</a> and global average temperatures were about 3℃ warmer than today. Summer temperatures in high northern latitudes were up to 14℃ warmer.</p><p>This may seem like a lot but modern observations show strong <a href="https://journals.ametsoc.org/jcli/article/23/14/3888/32547" target="_blank">polar amplification</a> of warming: a 1℃ increase at the equator may raise temperatures at the poles by 6-7℃. It is one of the reasons why Arctic sea ice is disappearing.</p>
Impacts in New Zealand and Australia<p>In the Australian region, there was no Great Barrier Reef, but there may have been <a href="https://link.springer.com/content/pdf/10.1007/BF02537376.pdf" target="_blank">smaller reefs along the northeast coast of Australia</a>. For New Zealand, the partial melting of the West Antarctic Ice Sheet is probably the most critical point.</p><p>One of the key features of New Zealand's current climate is that Antarctica is cut off from global circulation during the winter because of the big <a href="https://www.tandfonline.com/doi/abs/10.3402/tellusa.v54i5.12161" target="_blank">temperature contrast</a> between Antarctica and the Southern Ocean. When it comes back into circulation in springtime, New Zealand gets strong storms. Stormier winters and significantly warmer summers were likely in the mid-Pliocene because of a weaker polar vortex and a warmer Antarctica.</p><p>It will take more than a few years or decades of carbon dioxide concentrations at 400ppm to trigger a significant shrinking of the West Antarctic Ice Sheet. But recent studies show that <a href="http://nora.nerc.ac.uk/id/eprint/521027/" target="_blank">West Antarctica is already melting</a>.</p><p>Sea-level rise from a partial melting of West Antarctica could easily exceed a meter or more by 2100. In fact, if the whole of the West Antarctic melted it could <a href="http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.695.7239&rep=rep1&type=pdf" target="_blank">raise sea levels by about 3.5 meters</a>. Even smaller increases raise the risk of <a href="https://www.pce.parliament.nz/publications/preparing-new-zealand-for-rising-seas-certainty-and-uncertainty" target="_blank">flooding in low-lying cities</a> including Auckland, Christchurch and Wellington.</p>
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By Jo Harper
Investment in U.S. offshore wind projects are set to hit $78 billion (€69 billion) this decade, in contrast with an estimated $82 billion for U.S. offshore oil and gasoline projects, Wood Mackenzie data shows. This would be a remarkable feat only four years after the first offshore wind plant — the 30 megawatt (MW) Block Island Wind Farm off the coast of Rhode Island — started operating in U.S. waters.
Corporates Shift<p>Helping to drive offshore growth, U.S. corporate buyers <a href="https://www.dw.com/en/cities-leading-the-transition-to-renewables/a-42850621" target="_blank">are increasingly relying on wind energy to power their businesses</a>. Walmart and AT&T are the two top corporate wind buyers, while 14 newcomers entered the wind market in 2019, including Estée Lauder and McDonald's.</p><p>"Oil and gas companies have jumped into the U.S. offshore wind market, where they can transfer expertise in offshore fossil fuel development to clean energy investments," says Max Cohen, principal analyst, Americas Power & Renewable research at Wood Mackenzie. Many international oil and gas companies have already recognized this huge potential and entered the US offshore wind market, including Orsted, Equinor and Shell.</p><p>"Given the recent tumult in oil prices, fossil fuel companies may more and more be looking to diversify their portfolios, particularly with assets that are contracted or offer returns uncorrelated with oil and gas," Cohen says. "Offshore wind is an area where they may have a comparative advantage, and they can then leverage the experience with that technology to make the leap to onshore wind, solar, and other renewable technologies," he says.</p>
East Coast leads the way<p>"There is enormous opportunity, especially off the East Coast, for wind. I am very bullish," said former Interior Secretary Ryan Zinke. "Market excitement is moving towards offshore wind. I haven't seen this kind of enthusiasm from industry since the Bakken shale boom," he said.</p><p>Offshore wind initiatives require excessive upfront spending: a 250 MW venture costs about $1 billion, based on International Energy Agency data, but as costs fall the tipping point after which costs fall faster gets nearer</p><p>"The opportunity has been created by Northeastern states seeing the large price declines for offshore wind in Europe," says Cohen. Onshore wind is historically the lowest cost renewable resource, but is at its most expensive in the Northeast, he adds. "But costs are falling slower than for other technologies," he says.</p>
Jobs and Coastal Revitalization<p>U.S. wind energy now supports 120,000 US jobs and 530 domestic factories. A study by the University of Delaware predicted that the supply chain needed to build offshore turbines to feed power to seven East Coast states by 2030 would generate nearly $70 billion in economic activity and at least 40,000 full-time jobs. An American Wind Energy Association's (AWEA's) March 2020 report estimated that developing 30,000 MW of offshore wind along the East Coast could support up to 83,000 jobs and $25 billion in annual economic output by 2030.</p><p>Having said that, not all of the jobs are American jobs. The offshore wind developers with commercial leases in the US are all foreign companies. There is growing interest from the shipbuilding sector in the Gulf of Mexico in partnering with offshore wind companies to provide services. As a result, some of the US oil trade associations have submitted comments supporting certain aspects of offshore wind. "However, it is unclear to what extent offshore wind developers plan to use US vessels and crew, and the existing projects did not incorporate US vessels or labor at all," Hawkins says.</p>
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