Our research


We are all
in this together

We believe that seeing is believing. That is why we take people on a journey to make them see that small plastic fragments are pretty much everywhere. By taking samples our researchers are able to show our expedition members fragments that are invisible from above the surface. This way we illustrate how much bigger the problem is than just the bigger bottles and bags floating around.

How we do it

Citizen Science

With our Manta Trawl we take samples to look for plastic particles in the surface water. The Manta consists of two metal wings that float on the water surface and has a broad mouth. The net behind the system skims the surface catching everything in the toplayer. The design is based on the Manta ray, a large species of ray that feeds predominantly on plankton by swimming with its mouth wide open.

The Manta trawl does basically the same; it filters the upper 15 cm of the water column with a 300 micrometer (0.3 millimeter) mesh-size of the net and thereby collecting the plastic particles in the end of the net, the cod’s end. he trawl is towed by a vessel for 30 minutes at a speed of maximum 3 knots, according to a standardized protocol designed by the 5Gyres institute. Next, plastic particles caught in the cod’s end are collected, sorted and measured. Finally the concentration of plastic particles in the water is calculated from the items found per trawl and the amount of water filtered during the trawl measured with a flowmeter.


Seeing is believing

Collaborative science

We sample the North-West European waters since 2016 and are planning to do this for many more. Therefore, we are investigating the possibility to use our data for monitoring purposes.

In addition, we share these measurements with scientists, giving them baseline values of plastic densities which they can use to focus their research. Scientific expeditions are very expensive and not having to use resources for such baseline measurements can give plastic research a real head start.

Citizen science

The protocol we use is designed for citizen science. Citizen science is generally seen as low-tech research executed by ‘non’-scientists. The aim is to engage citizens with science to inspire them to enrich their views and beliefs. Therefore this is a very suitable method for us to use on board a sailing vessel with non-scientists. We make the pollution visible, provide the opportunity to conduct research, and give insight in scientific research and methods.

Why it matters

  • Making the invisible visible - By taking samples our researchers together with our expedition members reveal the plastic fragments from the water.
  • Data is knowledge - We share our measurements with other scientists, giving them a better insight of plastic densities.
  • Plastic is everywhere - Our research shows that plastics are everywhere in high numbers, underlining the magnitude of the plastic pollution.
Our findings

During the analysis we select all the particles bigger than 1 mm. We differentiate between bigger and smaller than 5mm, 5 different types (fragment , film, nurdle, line, and foam) and store the samples. The 5Gyres method is limited in the size of plastic particles it analyses (>1mm). Although this ignores the plastics at smaller sizes, it allows analysis of the samples onboard and educational activities with members of the public. If sampling was done to smaller sizes, analysis could not be done out at sea due to the risk of contaminating the sample with airborne plastics making the results useless.

Currently we have 110 samples with 94% of the samples containing plastic. The average number of items found per km² is 13680 with a highest catch of 125760 items per km². The pie-chart shows us that the majority of the items found are fragments followed by line and thin film. Pellet and foam are each accountable for 7% of the items found.

These numbers show us that plastics are everywhere in high numbers. Taking our average of 13680 #/km² and imagine that the North Sea is 575,000 km², this would mean that there are 7.86 million pieces of plastic larger than 1mm floating in the North Sea. Considering we measure pieces bigger than 1mm and only a small fraction of plastic in the seas and oceans is floating, the number of plastic in the North Sea could be much higher. We need to be careful with these extrapolations but it gives an idea of the magnitude of the problem.

2024 The Ocean Movement - Created by Wilde Amsterdam & Webbakery