Posted on 11/08/2019 8:00:33 AM PST by LesbianThespianGymnasticMidget
Study explores removal mechanisms, microbial impacts and lifetimes of select microplastics on the ocean surface
Florida Atlantic University
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A schematic figure of plastic photo-dissolution and plastic dissolved organic carbon (DOC) biodegradation. Credit: Lee Ann DeLeo
Trillions of plastic fragments are afloat at sea, which cause large “garbage patches” to form in rotating ocean currents called subtropical gyres. As a result, impacts on ocean life are increasing and affecting organisms from large mammals to bacteria at the base of the ocean food web. Despite this immense accumulation of plastics at sea, it only accounts for 1 to 2 percent of plastic debris inputs to the ocean. The fate of this missing plastic and its impact on marine life remains largely unknown.
It appears that sunlight-driven photoreactions could be an important sink of buoyant plastics at sea. Sunlight also may have a role in reducing plastics to sizes below those captured by oceanic studies. This theory could partly explain how more than 98 percent of the plastics entering the oceans go missing every year. However, direct, experimental evidence for the photochemical degradation of marine plastics remains rare.
A team of scientists from Florida Atlantic University’s Harbor Branch Oceanographic Institute, East China Normal University and Northeastern University conducted a unique study to help elucidate the mystery of missing plastic fragments at sea. Their work provides novel insight regarding the removal mechanisms and potential lifetimes of a select few microplastics.
For the study, published in the Journal of Hazardous Materials, researchers selected plastic polymers prevalently found on the ocean surface and irradiated them using a solar simulator system. The samples were irradiated under simulated sunlight for approximately two months to capture the kinetics of plastic dissolution. Twenty-four hours was the equivalent of about one solar day of photochemical exposure in the subtropical ocean gyre surface waters. To assess the physical and chemical photodegradation of these plastics, researchers used optical microscopy, electron microscopy, and Fourier transform infrared (FT-IR) spectroscopy.
Results showed that simulated sunlight increased the amount of dissolved carbon in the water and made those tiny plastic particles tinier. It also fragmented, oxidized and altered the color of the irradiated polymers. Rates of removal depended upon polymer chemistry. Engineered polymer solutions (recycled plastics) degraded more rapidly than polypropylene (e.g. consumer packaging) and polyethylene (e.g. plastic bags, plastic films, and containers including bottles), which were the most photo-resistant polymers studied.
Based on the linear extrapolation of plastic mass loss, engineered polymer solutions (2.7 years) and the North Pacific Gyre (2.8 years) samples had the shortest lifetimes, followed by polypropylene (4.3 years), polyethylene (33 years), and standard polyethylene (49 years), used for crates, trays, bottles for milk and fruit juices, and caps for food packaging.
“For the most photoreactive microplastics such as expanded polystyrene and polypropylene, sunlight may rapidly remove these polymers from ocean waters. Other, less photodegradable microplastics such as polyethylene, may take decades to centuries to degrade even if they remain at the sea surface,” said Shiye Zhao, Ph.D., senior author and a post-doc researcher working in the laboratory of Tracy Mincer, Ph.D., an assistant professor of biology/biogeochemistry at FAU’s Harbor Branch and Harriet L. Wilkes Honors College. “In addition, as these plastics dissolve at sea, they release biologically active organic compounds, which are measured as total dissolved organic carbon, a major byproduct of sunlight-driven plastic photodegradation.”
Zhao and collaborators also checked the biolability of plastic-derived dissolved organic carbon upon marine microbes. These dissolved organics seem to be broadly biodegradable and a drop in the ocean compared to natural biolabile marine dissolved organic carbon. However, some of these organics or their co-leachates may inhibit microbial activity. The dissolved organic carbon released as most plastics photodegraded was readily utilized by marine bacteria.
“The potential that plastics are releasing bio-inhibitory compounds during photodegradation in the ocean could impact microbial community productivity and structure, with unknown consequences for the biogeochemistry and ecology of the ocean,” said Zhao. “One of four polymers in our study had a negative effect on bacteria. More work is needed to determine whether the release of bioinhibitory compounds from photodegrading plastics is a common or rare phenomenon.”
Samples in the study included post-consumer microplastics from recycled plastics like a shampoo bottle and a disposable lunch box (polyethylene, polypropylene, and expanded polystyrene), as well as standard polyethylene, and plastic-fragments collected from the surface waters of the North Pacific Gyre. A total of 480 cleaned pieces of each polymer type were randomly selected, weighed and divided into two groups.
The wording of the title is unfortunate. The plastics don’t “go missing”, they are broken down by sunlight, and are consumed by natural biological organisms.
“Now throw all trash and garbage over the side. Sweepers.”
We used the fantail for disposal, not the side.
“Sweepers, man your brooms. Clean sweep down, fore and aft. Sweep down all decks, ladders and passageways. Take all trash and garbage to the fantail.”
Shows you how long ago I last heard that one.
I am a 'Golden' ShellBack so don't mess.
George Carlin on The Environment
https://www.youtube.com/watch?v=EjmtSkl53h4
Earth needed us to make plastic.
LMAO! That can be one way to view this!!! :-)
And we want to bring more $hitheads into this country from THAT $hithole!?
Plastic is recycled in treatment plants and not dumped anywhere.
The plastics they are referring to is all the debris that ends up in the ocean, 85% of which comes from the Asian continent with China and Indonesia being the top two countries in pollution.
India dumps a butt load and it is not on there.
Did they sponsor the study? ;-)
American are having their plastic waste collected by their garbage services and put on container ships. These ships take the waste to be processed at off shore centers in countries where labor is cheap. Many times these processing centers become overwhelmed by the amount of waste they are receiving. For them, the answer to their problem is easy: Take the excess plastic out to the ocean and dump it.
If we were to process our own plastic, we wouldn't have the ocean dumping. In those countries that do, it is because there is no regulation of what they do.
I remember the “sweepers” words over the ship’s intercom. Whenever I hear about plastic in the oceans, I wonder about all the ships at sea dumping their waste over the back end (fantail). The biggest source would be cruise liners. I know there are laws about such ocean dumping, but how many avoid detection by dumping at night?
I remember a time when our ship received from the Tender an overstock of beef roasts. I remember being in the chain sending 40 20 pound boxes of beef right off the fantail.
Total malarkey. The inert plastic particles provide substrate for bacteria and microfauna to attach themselves and grow, consuming and breaking up the plastic further as they do. Show me ANY hard evidence of ANY negative effect by such “microparticles”. It’s all sheer speculation.
Not anymore.
How Do You Take the Trash Out At Sea?
Story Number: NNS020723-42Release Date: 7777/23/2002 4:05:00 PMA
By Fireman (SW/AW) Vernishia Vaughn, USS Wasp (LHD 1) Public Affairs
ABOARD USS WASP, At Sea (NNS) — How do ships that are deployed or underway dispose of their trash? It’s not as easy as dragging a can to the curb.
For Fireman Segun Iluyomade, who is part of the USS Wasp (LHD 1) auxiliary division, working in environmental for a little over two years has taught him the importance of properly processing and dumping trash that is brought in from different work centers.
Proper dumping of trash is vital and, if it is not done correctly, can become unsanitary, unhealthy and life-threatening for marine mammals and fish.
“My job is very challenging and, believe it or not, it has given me a wide range of knowledge,” Iluyomade said. “It is a job that many people on board don’t like and make light of. Not only do I gain knowledge on how vital it is to do the job properly, I also gain knowledge on how to fix some of the equipment if it happens to break down.
“Generally, most of our trash comes from the mess decks, usually 100 to 150 bags of food waste and other things a day, and that is a lot,” said Iluyomade, a Brooklyn, N.Y., native. “Being allowed to dump some trash, such as paper and metal, over the side has eliminated some of the backup that we have had. That allows us to take trash that has to be taken from food service.”
Wasp’s environmental includes five temporary duty personnel from the ship, including both Sailors and Marines.
“The different work centers that provide our personnel give us high quality people,” said Senior Chief Engineman (SW/AW) Raymond Brown of Providence, R.I. “They don’t give us people they want to get rid of.”
When temporary assigned duty Sailors and Marines report to environmental, they attend a training course before working with the machines and the trash. They learn to use the machines and how to properly discard the trash that comes in.
“The job may not be the best job on board,” said Fire Controlman 3rd Class Eric Moore of Macon, Ga., who is TAD to environmental. “But somebody’s got to do it.”
Several machines help environmental to run smoothly and get rid of trash that is on board. The compressed melting unit melts plastics into discs that are placed in a tri-wall until the next underway replenishment transfers the discs to another ship for disposal on shore. The pulper grinds the food and paper waste and discharges it overboard.
“We [even] have a metal shredder that shreds metal and glass,” said Iluyomade.
Every job on board is important and plays a vital role in the ship’s mission. Preventing health hazards and unsanitary spaces is environmental’s part, and they are going to do the job until the end.
“Being the one to work in environmental has made me more responsible,” Iluyomade said. “I am not only responsible to my division, but to the whole ship.”
Iluyomade never thought he would be dealing with trash, but now that he has been exposed to the job, he has learned to enjoy it.
“Others may complain about how dirty or nasty the job may be. I consider it a wonderful job because, to the best of my ability, it is done accurately and in a professional manner,” Iluyomade said. “Though some look down on the job and don’t want to do it, it is good to know that others appreciate what I am doing and the service I provide.”
For more news on the USS Wasp (LHD 1), go to www.news.navy.mil/local/lhd1, or visit them on the Web at www.spear.navy.mil/ships/lhd1.
Trillions of plastic fragments are afloat at sea, which cause large “garbage patches” to form in rotating ocean currents called subtropical gyres. As a result, impacts on ocean life are increasing and affecting organisms from large mammals to bacteria at the base of the ocean food web. Despite this immense accumulation of plastics at sea, it only accounts for 1 to 2 percent of plastic debris inputs to the ocean. The fate of this missing plastic and its impact on marine life remains largely unknown.
Seems like a nice floating template to get some kelp forests, sponges, maybe even coral going. Thanks LTGM.
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