1. HIGHEST CONCENTRATION OF DEEP-SEA MICROPLASTICS DISCOVERED
Deep-sea currents that supply oxygen and nutrients to areas of rich biodiversity also carry microplastics to the same areas, creating microplastic “hotspots” of up to 1.9 million pieces per square metre – “the highest value for any seafloor, globally”.
The news was released in a study published in the journal Science Thursday which looked at converging currents and how these oceanic processes control the spread of plastic. Much like the surface currents that have created plastic accumulation like the pacific garbage patch, forces in the depths of the ocean are creating once unseen build ups of microplastics.
“Almost everybody has heard of the infamous ocean ‘garbage patches’ of floating plastic, but we were shocked at the high concentrations of microplastics we found in the deep seafloor,” said lead author of the study, Dr. Ian Kane of the University of Manchester in the press release.
“We discovered that microplastics are not uniformly distributed across the study area; instead they are distributed by powerful seafloor currents which concentrate them in certain areas.”
Alarmingly, the currents that are transporting microplastics are also carrying oxygenated water and nutrients. This suggests that microplastics are being carried to important ecosystems that can consume or absorb the plastics.
“It’s unfortunate, but plastic has become a new type of sediment particle, which is distributed across the seafloor together with sand, mud and nutrients. Thus, sediment-transport processes such as seafloor currents will concentrate plastic particles in certain locations on the seafloor, as demonstrated by our research,” said Dr Florian Pohl from Durham University in a press release.
2. SATELLITE IMAGERY HELPS TO DETECT OCEAN PLASTIC
A new study shows how satellite imagery can be used to track and locate ocean plastic, with hopes for more targeted clean-up action across the globe.
Published in the journal Nature, the study shows how optical data acquired by satellite Sentinel-2 from the European Space Agency can be used to detect floating plastic and distinguish the plastic from organic materials such as seaweed and driftwood.
Researchers established a “floating debris index” that would pin-point and record the locations of ocean plastics. The research has been tested across 4 countries and has an 86% accuracy rate. Due to the mobile nature of ocean plastic and potential obstruction of satellite imagery due to cloud cover and rough seas, identifying plastics specific whereabouts is difficult and at times, inefficient.
“Things change really quickly, so a Sentinel-2 image that I look at today would have been taken two days ago, and by then anything that I see is gone,” said Lauren Biermann from the study to Mongabay.
The hope is that with the help of satellite imagery and a building index of locations where plastic has been identified, researchers will be able to pinpoint aggregates of plastic waste.
“There will be clean-up operations like the Ocean Voyages Institute, which we’d like to work with. They would then go to where we spotted things, and they would be able to remove tons of plastic at a time,” Biermann said. “This really is the first technical exercise, but we would then like to apply the method, far more broadly … to rivers and open waters,” said Ms Biermann to Mongabay.
3. SEABIRD NESTS MADE FROM PLASTIC POLLUTION
Scientists have revealed that 4 in 10 of seabird nests surveyed on an island off the west coast of Scotland have been constructed using plastic debris.
A survey conducted in 2018 on Lady Isle, said to be Britain’s first seabird reserve according to The Herald Scotland, showed that seabirds such as gulls and shags are using plastic debris to build their nests. Almost half of all nests contained plastic waste, with the nests of European Shags containing as much as 80% plastic.
Researchers believe that the plastic has not been gathered by the birds rather it has washed to the Island due to mismanagement of consumer waste.
“They end up in seabird nests, not because seabirds actively pick them up in built-up areas and carry them to their nest, but because they are brought there passively by the marine currents,” said seabird ecologist Dr Ruedi Nager from the University of Glasgow, according to a press release.