There has been a constant stream of death and waste sinking into the depths of the sea as long as there has been marine life.
The snow begins as motes, which aggregate into dense, flocculent flakes that gradually sink and drift past the mouths of scavengers farther down. A squid's guts are just a rest stop on this long passage to the deep, so even marine snow that is devoured will most likely be snowfall again.
Marine snow is mostly dead and brownish, although the term may suggest wintry whites. The ocean's carbon has been transported from the debris to the seafloor by the same things that have been found in plant and animal carcasses. Microplastics areinfiltrating the marine snow with fibers and fragments. Our planet's cooling process appears to have been altered by this fauxfall.
Millions of tons of plastic enter the oceans every year. The material was thought to be destined for garbage patches and gyres, but surface surveys have found only a small amount of plastic in the ocean. A recent model found that almost all of the plastic that entered the ocean since 1950 had sunk. The scientists have found more microplastics on the seafloor than on the surface waters.
One of the main pathways connecting the surface and the deep appears to be helping the plastics sink. Scientists have only begun to untangle how these materials interfere with deep-sea food webs and the ocean's natural carbon cycles.
The researcher at Florida Atlantic University said that they can help each.
The sunlit surface of the sea blooms with a variety of organisms, all feeding on sunbeams or one another. Small shreds of larger carcasses, shells from foraminifera and pteropods, sand and microplastics, which stick together to form larger flakes, are attracted to the lifeless bodies of tiny organisms, as the microbes metabolize.
Marine snowflakes fall at different rates. Anela Choy is a biological oceanographer at the University of California, San Diego. A researcher at Florida Atlantic University said that larger particles can sink quicker.
Plastic in the ocean is constantly being degraded, even something as big as a milk jug will eventually shed and splinter into microplastics. Linda Amaral-Zettler, a scientist at the Royal Netherlands Institute for Sea Research, came up with the term "plastisphere".
Microplastics can cause their raft to sink because they host so many bugs. If the plastic degrades on the way down, it could lead to a yo-yoing purgatory of microplastics in the water column. Marine snow is not stable, as it is constantly falling apart, rent by waves or predator.
Adam Porter is a marine ecologist at the University of Exeter in England.
Dr. Mincer is using a dishwasher-size pump and filters from a research boat to explore the distribution of marine snow and plastic in the water column. The filters are arranged in a way that makes them easy to see. There are nylon fibers and other microplastics in the water column below the South Atlantic subtropical gyre.
Even with a research boat and its expensive and unwieldy equipment, a piece of marine snow can't be easily retrieved from the ocean. The snow is often disturbed by the pumps. The only way to understand how long some snows linger in the water column is to know how fast they sink.
"Is it decades?" Dr. Mincer asked. We can understand what we are in here for and what the problem is.
Some scientists have made and manipulated their own snow in the lab to answer some questions.
Dr. Porter loaded the water into rolling bottles from the nearby estuary. He put in microplastics, including polyethylene beads and polypropylene fibers. The particles were encouraged to stick together because of the constant churned and squirt of sticky hyaluronic acid.
We don't have 300 meters of a tube to make it sink.
He analyzed the number of microplastics in the snow after the bottles rolled. His team found that every type of microplastic they tested aggregated into marine snow, and that microplastics such as polypropylene and polyethylene were very easy to sink into. The marine snow was contaminated with microplastics and sank much faster than the natural marine snow.
Dr. Porter suggested that the change of the snow's speed could have a huge impact on how the ocean captures and stores carbon: Faster snowfalls could store more microplastics in the deep ocean, whereas slower snowfalls could make the plastic-laden particles more available to predators.
The European Union funded Dr. Galgani's experiments in Crete that tried to mimic marine snow on a larger scale. She dropped six large bags of water and seawater in a large pool. The marine snow formed under these conditions. You are manipulating a natural system.
She said that she tried to create a sea and a future ocean with a high concentration of plastic. Microplastics produced more marine snow and also more organic carbon, as they offered more surfaces for microbes to colonize. The ocean's biological pump helps regulate the climate and could be altered by all this.
It is a very big picture and we have some signals that it can have an effect. It depends on how much plastic there is.
Some scientists have turned to creatures for clues about how microplastics might travel through deep-sea food webs.
Every day and night, many species of marine organisms migrate up and down in the water column. Guilherme V.B. Ferreira, a researcher at the Rural Federal University of Pernambuco in Brazil, wondered if it was possible they were transporting the plastic up and down.
The vampire squids and midwater squids were collected from a patch of the tropical Atlantic. They found a lot of plastic in both species.
It made sense for midwater squids to migrate toward the surface at night to feed on fish and copepods that eat microplastics. Vampire squids, which live in deeper waters with fewer microplastics, had higher levels of plastic and foam in their stomachs. The vampire squids' primary diet may be marine snow and meatier fecal pellets.
It is very concerning, Ms. Justino said. They are one of the most vulnerable species for this influence.
Ms. Justino has found beads and fibers from the stomachs of fish that migrate up and down in the mesopelagic. The communities that settle on microplastics draw in fish like a lure.
In the Monterey Bay Canyon, Dr. Choy wanted to know if certain species of filter feeders were transporting microplastics into food webs in deeper water.
Dr. Choy looked at the giant Bathochordaeus stygius. It's worse than the grossest booger you've ever seen, because the larvacean lives inside a palatial bubble of mucus that can reach up to a meter long. The heavy bubbles sink when the snot-houses become blocked from feeding. Dr. Choy found that the palaces of mucus are filled with microplastics, which are funneled to the deep along with all their carbon.
Dr. Choy emphasized that her work was focused on the Monterey Bay Canyon, which is not representative of other, more polluted seas.
The small pieces of marine snow add up. A model created by Dr. Kvale estimated that in 2010 the world's oceans produced as many as 340 quadrillion aggregates of marine snow, which could transport as many as 463,000 tons of microplastics to the seafloor each year.
Dr. Porter said that everything eventually sinks in the ocean and that vampire squids will live and die as a result. After humans are gone, the microplastics that pass through them will settle on the seafloor in a layer that will mark our time on the planet.
All Rights Reserved © 2024
