Humans dump about 10 million tons of plastic in the world’s oceans every single year – and it is beginning to create some serious problems. Besides being unsightly, the litter is damaging the marine ecosystem.
Although most of it ends up along our coastlines, plastic litter is also found in the open ocean and from the equator to the poles. Plastic pieces have even been found frozen in Polar ice.
From disposable bottles to plastic bags – it all ends up being broken down into micro-fibers by wave action and degradation. Besides endangering marine life and seabirds, the micro-fibers are ending up in the global food chain. And the scary part about this is that we still don’t know all the consequences eating micro-fibers will cause to human or animal health.
The marine plastic litter problem
Scientists at the European Space Agency (ESA) are working on a technology that will allow them to detect and identify from space just how much plastic there is floating around in oceans. We already use satellite mapping to simulate the amount of ocean trash we have, but the new project will use optical measurements to provide an actual scale of the problem.
“Indirect measurements from space are already used to get to grips with the marine plastic litter problem,” explains ESA’s Paolo Corradi, overseeing the project. “For instance, satellite maps of ocean currents let us simulate the accumulation of litter in vast ‘gyres’ within the Pacific, Atlantic and Indian Oceans,” he adds.
Corradi says the project they have embarked on may sound like a “Mission Impossible,” but what they want to do with the new project is “assess the feasibility of direct optical measurement of seaborne plastic waste from satellites.” He thinks it is doable, especially for certain larger concentrations.
“We’re not talking about actually spotting floating litter items but instead, to identify a distinct spectral signature of plastic picked up from orbit, in the same way as the processing software used today to pick out concentrations of phytoplankton, suspended sediments, and water-borne pollution.”
In this case, the ESA’s software would work in the same way software in recycling plants work, picking out plastics by their infrared “fingerprints.”
At the present time, two teams are working on the project, supported by ESA’s Basic Activities. The teams include Argans Limited in France and Plymouth Marine Laboratory in the UK. They started last September, assessing the feasibility of using current technology from the top of the atmosphere, via satellites.
Corradi says they are working from the middle of the atmosphere using aircraft or drones, and the observations are checked against satellite images from missions such as the Sentinel-3 ocean-color tracker. The project will deliver a preliminary set of requirements for a satellite to detect marine plastic litter in the shortwave infrared.
“The ultimate goal might be an actual global map showing litter concentrations,” concludes Paolo: “Simulations are all well and good, but an image based on actual measurements would provide important insights to scientists and would hold greater power for the public and policymakers alike.
The initial results were presented last week at the Sixth International Marine Debris Conference in San Diego, California.
