By Elizabeth Claire Alberts
There are trillions of microplastics in the ocean — they bob on the surface, float through the water column, and accumulate in clusters on the seafloor. With plastic being so ubiquitous, it's inevitable that marine organisms, such as sharks, will ingest them.
A new study in Scientific Reports investigated microplastic ingestion in four species of demersal sharks found in the North Atlantic Ocean, which were captured as bycatch by a local fishery in Penzance, U.K. A team of six researchers, from the University of Exeter and the University of Leeds, examined the stomachs and digestive tracts of 46 sharks, and found that 67% contained microplastics. A total of 379 microplastics — plastic particles or fibers smaller than 5 millimeters, or a fifth of an inch — were found in the sampled sharks.
Many of the plastic fibers were synthetic cellulose, the material found in polyester clothing and hygiene products such as face masks, which have become increasingly prevalent during the COVID-19 pandemic.
"I think there is definitely some cause for concern," Kristian Parton, lead author of the study and researcher at the University of Exeter's Centre for Ecology and Conservation, told Mongabay in an email. "Although many of the particles ingested by these sharks will be excreted eventually, they potentially remain inside the body long enough for inorganic pollutants and chemicals (attached to the particles), to enter into the bodies of these sharks."
Parton said he found it surprising that sharks living off the coast of Penzance in Cornwall, on the southwestern tip of Britain, would contain so many plastic particles.
Polyproylene fibers found in one of the sampled sharks. Kristian Parton
"I actually didn't expect to find as many as we did in these sharks," he said. "The waters around Cornwall are thought to be some of the most beautiful in the U.K., and so I didn't think there would be much pollution."
Parton's co-author, Tamara Galloway, holds a similar view.
"We were not expecting to find microfibers from textiles in so many of our native shark species," Galloway, a marine biologist and professor of ecotoxicology at the University of Exeter, said in a statement. "Our study highlights how important it is to think before we throw things away."
Demersal sharks can be found at depths of 5 to 900 meters (16 to 3,000 feet), although they tend to live and feed in the demersal zone of the ocean, which is near the seafloor. The four species of demersal sharks used in this study included the small-spotted catshark (Scyliorhinus canicula), starry smooth-hound (Mustelus asterias), spiny dogfish (Squalus acanthias) and bull huss (Scyliorhinus stellaris).
Spiny dogfish. NOAA / Wikimedia Commons
"There appear to be two routes for these particles to end up in the sharks," Parton said. "The first through their food source [such as] crustaceans. Their prey may already contain these fibers, and consequently it's passed to the shark through bioaccumulation up the food chain. The second pathway is direct ingestion from the sediment. As these sharks feed, they'll often suck up sediment into their mouths, some of this is expelled straight away, although some is swallowed, therefore fibers and particles that may have sunk down into the seabed may be directly ingested from the surrounding sediment as these sharks feed."
Some sharks only contained a few plastic particles, but others contained dozens. The larger the shark, the more plastic was in it, the findings suggested. The highest number of microplastics was found in an individual bull huss, which had 154 polypropylene fibers inside its stomach and intestines.
"It's perhaps likely this individual shark had swallowed a larger piece of fishing rope/netting and this has broken down during digestive processes within the shark, and also broken down into smaller pieces during our analysis," Parton said.
Lesser-spotted dogfish caught as bycatch. Kristian Parton
While this study only examined the stomach and digestive tracts of demersal sharks, Parton says it's possible that plastic would be present in other parts of the sharks' bodies, such as the liver and muscle tissue. However, more research would be needed to prove this.
At the moment, there is also limited understanding of how microplastic ingestion would impact a shark's health, although microplastics are known to negatively influence feeding behavior, development, reproduction and life span of zooplankton and crustaceans.
"If we can show that these fibers contain inorganic pollutants attached to them, then that could have real consequences for these shark species at a cellular level, impacting various internal body systems," Parton said.
Parton in the lab. Kristian Parton
This new study demonstrates how pervasive and destructive plastic pollution can be in the marine environment, according to Will McCallum, head of oceans for Greenpeace U.K.
"Our addiction to plastics combined with the lack of mechanisms to protect our oceans is suffocating marine life," McCallum said in a statement. "Sharks sit on top of the marine food web and play a vital role in ocean ecosystems. Yet, they are completely exposed to pollutants and other human impactful activities. We need to stop producing so much plastic and create a network of ocean sanctuaries to give wildlife space to recover. The ocean is not our dump, marine life deserves better than plastic."
Reposted with permission from Mongabay.
- Pregnant Sperm Whale Found Dead With Nearly 50 Pounds of ... ›
- Green Turtles Are Mistaking Plastic for the Sea Grass They Normally ... ›
- Microplastics Pose Major Problems for Ocean Giants - EcoWatch ›
- Seafood Study Finds Plastic in 100% of Samples - EcoWatch ›
- Coast Guard Opens Fire as Shark Interrupts Swim Break - EcoWatch ›
A pygmy rabbit rescued from a breeding site in Beezley Hills, Washington, eats owl clover in its new enclosure. Kourtney Stonehouse, WDFW
- 7 Devastating Photos of Wildfires in California, Oregon and ... ›
- California Wildfires Destroy Condor Sanctuary, at Least 4 Birds Still ... ›
EcoWatch Daily Newsletter
By Mark Hertsgaard
What follows are not candidate endorsements. Rather, this nonpartisan guide aims to inform voters' choices, help journalists decide what races to follow, and explore what the 2020 elections could portend for climate action in the United States in 2021 and beyond.
Will the White House Turn Green?<p>Whether the White House changes hands is the most important climate question of the 2020 elections. President Donald Trump rejects climate science, is withdrawing the United States from the Paris Agreement, and has accelerated fossil fuel development. His climate policy seems to be, as he tweeted in January when rejecting a U.S. Army Corps of Engineers proposal to protect New York City from storm surges, "Get your mops and buckets ready."</p><p>Joe Biden, who started the 2020 campaign with a climate position so weak that activists gave it an "F," called Trump a "climate arsonist" during California's recent wildfires. Biden backs a $2 trillion plan to create millions of jobs while slashing emissions—a Green New Deal in all but name. Equally striking, his running mate, California Senator Kamala Harris, has endorsed phasing out fossil fuel production—a politically explosive scientific imperative.</p><p>The race will be decided in a handful of battleground states, five of which already face grave climate dangers: Florida (hurricanes and sea-level rise), North Carolina (ditto), Texas (storms and drought), Michigan (floods), and Arizona (heat waves and drought). <a href="https://climatecommunication.yale.edu/visualizations-data/ycom-us/" target="_blank">Public concern is rising</a> in these states, but will that concern translate into votes?</p>
Will Democrats Flip the Senate, and by Enough to Pass a Green New Deal?<p>With Democrats all but certain to maintain their majority in the U.S. House of Representatives, the Senate will determine whether a potential Biden administration can actually deliver climate progress. Democrats need to pick up three seats to flip the Senate if Biden wins, four if he doesn't. But since aggressive climate policy is shunned by some Democrats, notably Joe Manchin of coal-dependent West Virginia, Democrats probably need to gain five or six Senate seats to pass a Green New Deal.</p><p>Environmentalists, including the League of Conservation Voters, are targeting six Republicans who polls suggest are vulnerable.</p><ul><li>Steve Daines of Montana, who denies climate science</li><li>Martha McSally of Arizona</li><li>Thom Tillis of North Carolina</li><li>Susan Collins of Maine</li><li>Joni Ernst of Iowa (bankrolled by Charles Koch)</li><li>John James of Michigan (also a Koch beneficiary)</li></ul><p>Republican Senators are even at risk in conservative Kansas and Alaska. In both states, the Democratic candidates are physicians—not a bad credential amid a pandemic—who support climate action. In Kansas, Barbara Bollier faces an incumbent funded by Charles Koch. In Alaska, Al Gross urges a transition away from oil, though his openness to limited drilling in the Arctic National Wildlife Preserve dims his appeal to green groups. He faces incumbent Republican Dan Sullivan, who receives an 8 percent lifetime voting record from the League of Conservation Voters.</p>
Will Local and State Races Advance Climate Progress?<h4>THE CLIMATE HAWKS</h4><p>Under Democratic and Republican leadership alike, Washington has long been a graveyard for strong climate action. But governors can boost or block renewable energy; the Vermont and New Hampshire races are worth watching. Attorneys general can sue fossil fuel companies for lying about climate change; climate hawks are running for the top law enforcement seats in Montana and North Carolina. State legislatures can accelerate or delay climate progress, as the new Democratic majorities in Virginia have shown. Here, races to watch include Pennsylvania, North Carolina, and Colorado.</p><h4>THE CLIMATE POLICY MAKERS</h4><p>Perhaps the most powerful, and most overlooked, climate policy makers are public utility commissions. They control whether pipelines and other energy infrastructure gets built; they regulate whether electric utilities expand solar and energy efficiency or stick with the carbon-heavy status quo. Regulatory capture and outright corruption are not uncommon.</p><p>A prime example is Arizona, where a former two-term commissioner known as the godfather of solar in the state is seeking a comeback. Bill Mundell argues that since Arizona law permits utilities to contribute to commissioners' electoral campaigns, the companies can buy their own regulators. Which may explain why super-sunny Arizona has so little installed solar capacity.</p><p>In South Dakota, Remi Bald Eagle, a Native American U.S. Army veteran, seeks a seat on the South Dakota Public Utilities Commission, which rules on the Standing Rock oil pipeline. And in what <em>HuffPost</em> called "the most important environmental race in the country," Democrat Chrysta Castaneda, who favors phasing out oil production, is running for the Texas Railroad Commission, which despite its name decides what oil, gas, and electric companies in America's leading petro-state can build.</p>
Will the Influencers Usher in a Green New Era?<h4>THE UNCOUNTED</h4><p>The story that goes largely under-reported in every U.S. election is how few Americans vote. In 2016, some 90 million, <a href="https://www.pewresearch.org/politics/2018/08/09/an-examination-of-the-2016-electorate-based-on-validated-voters/" target="_blank" rel="noopener noreferrer">roughly four out of every 10 eligible voters</a>, did not cast a ballot. Attorney Nathaniel Stinnett claims that 10 million of these nonvoters nevertheless identify as environmentalists: They support green policies, even donate to activist groups; they just don't vote. Stinnett's <a href="https://www.environmentalvoter.org/" target="_blank" rel="noopener noreferrer">Environmental Voter Project</a> works to awaken this sleeping giant.</p><h4>THE SUNRISE MOVEMENT</h4><p>Meanwhile, the young climate activists of the <a href="http://www.sunrisemovement.org/" target="_blank" rel="noopener noreferrer">Sunrise Movement</a> are already winning elections with an unabashedly Green New Deal message. More than any other group, Sunrise pushed the Green New Deal into the national political conversation, helping Representative Alexandria Ocasio-Cortez and Senator Ed Markey draft the eponymous congressional resolution. In 2020, Sunrise has helped Green New Deal champions defeat centrists in Democratic primaries, with Markey dealing Representative Joe Kennedy Jr. the first defeat a Kennedy has ever suffered in a Massachusetts election. But can Sunrise also be successful against Republicans in the general elections this fall?</p><h4>THE STARPOWER</h4><p>And an intriguing wild card: celebrity firepower, grassroots activism, and big-bucks marketing have converged behind a campaign to get Latina mothers to vote climate in 2020. Latinos have long been the U.S. demographic most concerned about climate change. Now, <a href="https://votelikeamadre.com/" target="_blank" rel="noopener noreferrer">Vote Like A Madre</a> aims to get 5 million Latina mothers in Florida, Texas, and Arizona to the polls. Jennifer Lopez, Salma Hayak, and Lin-Manuel Miranda are urging mothers to make a "pinky promise" to vote for their kids' climate future in November. Turning out even a quarter of those 5 million voters, though no easy task, could swing the results in three states Trump must win to remain president, which brings us back to the first category, "Will the White House Turn Green?"</p>
- Climate Activists Prepare for November Election - EcoWatch ›
- The Next Election Is About the Next 10,000 Years - EcoWatch ›
- Latino Voters Worried About Climate Change Could Swing 2020 ... ›
- Climate Crisis Could Change Permafrost Soil Microbes, With ... ›
- Zombie Fires Could Be Awakening in the Arctic - EcoWatch ›
- The Arctic Is on Fire and Warming Twice as Fast as the Rest of the ... ›
By Tony Carnie
South Africa is home to around 1,300 of the world's roughly 7,100 remaining cheetahs. It's also the only country in the world with significant cheetah population growth, thanks largely to a nongovernmental conservation project that depends on careful and intensive human management of small, fenced-in cheetah populations. Because most of the reserves are privately funded and properly fenced, the animals benefit from higher levels of security than in the increasingly thinly funded state reserves.
Vincent van der Merwe at a cheetah translocation. Endangered Wildlife Trust
Under Pressure<p>Cheetah populations elsewhere in Southern Africa have not prospered over the past 50 years. In Zimbabwe, cheetah numbers have crashed from 1,500 in 1975, to just 170 today. Botswana's cheetah population has held steady at around 1,500 over the same period, but illegal capture for captive breeding and conflicts with farmers and the growing human population are increasing. In Namibia, there were an estimated 3,000 cheetah in in 1975; roughly 1,400 remain today.</p><p>In contrast, South Africa's cheetah numbers have grown from about 500 in 1975 to nearly 1,300 today. Van der Merwe, who is also a Ph.D. student at the University of Cape Town's Institute for Communities and Wildlife in Africa (iCWild), says he's confident that South Africa will soon overtake Namibia and Botswana, largely because the majority of South African cheetahs are protected and managed behind fences, whereas most of the animals in the neighboring countries remain more vulnerable on mainly unfenced lands.</p><p>Wildlife researchers Florian Weise and colleagues have reported that private stock owners in Namibia still trap cheetahs mainly for translocation, but there are few public or private reserves large enough to contain them. Weise says that conservation efforts need to focus on improving tolerance toward cheetahs in commercial livestock and game farming areas to reduce indiscriminate trapping.</p><p>Van der Merwe says fences can be both a blessing and a curse. While these barriers prevent cheetahs and other wild animals from migrating naturally to breed and feed, they also protect cheetahs from the growing tide of threats from humanity and agriculture.</p><p>To simulate natural dispersion patterns that guard against inbreeding, the trust helps landowners swap their animals with other cheetah reserves elsewhere in the country. The South African metapopulation project has been so successful in boosting numbers that the trust is having to look beyond national boundaries to secure new translocation areas in Malawi, Zambia and Mozambique.</p><p>Cheetah translocations have been going on in South Africa since the mid-1960s, when the first unsuccessful attempts were made to move scores of these animals from Namibia. These relocations were mostly unsuccessful.</p>
Charli de Vos uses a VHF antenna to locate cheetahs in Phinda Game Reserve. Tony Carnie for Mongabay
Swinging for the Fences<p>But other wildlife conservation leaders have a different perspective on cheetah conservation strategy.</p><p>Gus Mills, a senior carnivore researcher retired in 2006 from SANParks, the agency that manages South Africa's national parks, after a career of more than 30 years in Kalahari and Kruger national parks. He says the focus should be on quality of living spaces rather than the quantity of cheetahs.</p><p>Mills, who was the founder of the Endangered Wildlife Trust's Carnivore Conservation Group in 1995, and who also spent six years after retirement studying cheetahs in the Kalahari, says it's more important to properly protect and, where possible, expand the size of existing protected areas.</p><p>He also advocates a triage approach to cheetah conservation, in which scarce funds and resources are focused on protecting cheetahs in formally protected areas, rather than diluting scarce resources in an attempt to try and save every single remaining cheetah population.</p><p>"People have an obsession with numbers. But I believe that it is more important to protect large landscape and habitats properly," Mills said.</p><p>He suggests that cheetahs enclosed within small reserves live in artificial conditions: "It's almost like glorified farming."</p><p>"In the long run we have to focus on consolidating formally protected areas," he added. "Africa's human population will double by 2050, so cheetah populations in unfenced areas will become unsustainable if they are eating people's livestock."</p>
Scientists are on the brink of scaling up an enzyme that devours plastic. In the latest breakthrough, the enzyme degraded plastic bottles six times faster than previous research achieved, as The Guardian reported.
- Mutant Enzyme Recycles Plastic in Hours, Could Revolutionize ... ›
- Scientists Find Bacteria That Eats Plastic - EcoWatch ›
- Plastics: The History of an Ecological Crisis - EcoWatch ›
- Scientists Accidentally Develop 'Mutant' Enzyme That Eats Plastic ... ›