[ad_1]
A wealth of data showing when the Atlantic began to smother with plastic was unearthed in the handwritten logbooks of a little known but stubbornly persistent plankton study dating back to the middle of the last century.
From the fishing string found in the ocean in the 50s, then from a first carrying bag in 1965, she shows how the problem of marine litter has developed from small incidents largely to ignored to a global concern.
This unique dataset, published in Nature Communications, is based on recordings from the continuous plankton recorder, a torpedo-shaped marine sampling device that has been towed over 6.5 m of ocean in the last 60 years.
Founded first in Hull, then Edinburgh and Plymouth, this long-term program initially aimed at collecting pelagic plankton, an indicator of water quality and also a source of food for whales and other animals. sailors.
But the operators also kept a dashboard of entanglements that disrupted their work: what held the equipment, where and when. According to contemporary researchers, this is a valuable source of data on plastic waste.
plastic graphics 1
"This consistent time series provides the earliest data of plastic entanglement and is the first to confirm a significant increase in the number of plastics on the high seas in recent decades," the paper says.
Microplastics, defined as pieces of plastic smaller than 5 mm, are covered with washed synthetic garments, vehicle tires and plastic pellet spills used by manufacturers. The physical decomposition of plastic waste also creates them. Rain carries them into the rivers and the sea, but they can also be washed away by flying insects and end up in the fields when treated wastewater is used as fertilizer.
Studies have revealed the presence of microplastics in marine creatures and marine sediments living on the bottom of the North Sea. When ingested by small creatures, microplastics move through the food chain. One study found the presence of microplastics in each of the 50 marine mammals stranded on the coasts of the UK, and the pollution also affects humans.
In 2018, the World Health Organization announced a study of the potential risks of plastic in drinking water after the analysis revealed that over 90% of the world's most popular bottled water brands contained tiny pieces of plastic. The United Kingdom banned plastic microbeads in cosmetics and personal care products in January 2019, and the EU proposed new measures to limit their use.
The beginning of the problem was so slow that it was barely noticed. The newspaper shows strands of fishing twine discovered off the east coast of Iceland in 1957, then a carry bag in northwest Ireland's waters eight years later. The document indicates that it was a few years before the first information that turtles and seabirds would be trapped in plastic.
In the following decades, the problem grew steadily. In the 50s, 60s and 70s, less than 1% of the traits were disturbed by entanglements with synthetic materials. In the 90s, it reached almost 2% and, in the first decade of this century, the increase "was an order of magnitude," according to the newspaper. The figure now oscillates between 3% and 4%.
Nearly half of the interruptions are caused by nets, lines and other discarded fishing gear. Other plastic objects represent the rest. The newspaper reported that this highlighted the dangers to marine life because the sampling device was towed by ferries and container ships at a depth of about 7 meters, harboring many fish and Marine mammals. The number of entanglements was particularly high in the southern North Sea, but the authors indicated that the problem was evident in a very wide range of oceans.
plastic graphic 2
Clare Ostle of the Plymouth-based Marine Biological Association said, "The message is that marine plastic has increased dramatically and we are seeing it all over the world, even in places you would not like, like the North Passage. -West and others. parts of the Arctic. "
She was encouraged by the fact that the number of transport bags hung by the equipment appeared to have stabilized in recent years and suggested that this could result from a increased consumer awareness. But she warned that the data was not precisely correlated with the amount of plastic in the ocean and that it was best viewed as a guide to general trends.
This is the second time that the continuous plankton recorder provides essential data on marine plastics. Since 2004, microplastic samples have been retrospectively analyzed, revealing a significant increase between 1960-1970 and 1980-1990.
Mr. Ostle stated that the plankton recorder – in service since 1931 – continued to produce important new data because it offered a longer schedule than other more sophisticated studies.
"I was inspired by the history, the legacy of all involved," she said. "It's impressive to see how much they've dealt with many challenges."
Sampling operations nearly collapsed as a result of cuts made by the government in the 1980s, when surveillance of this type was exceeded. According to a project history, "this has been considered a weak science, similar to philately."
The scientists behind the project nevertheless continued to modernize the procedures and the value of the project is now recognized.
[ad_2]
Source link