Building and possibly improving a microplastics sampling instrument

The general objective is to stimulate thought and sound decision-making on technological issues that affect our lives.
Students of the technical education sector will build and possibly improve an instrument used for microplastics  sampling on the sea surface: The manta trawl.
The manta net: It is the most accepted sampling instrument for determining the presence of microplastics in open seas (pelagic microplastics). The manta net is an improvement of neuston net (with two wings for better floatability). The filtered volume must be recorder so the manta net  is usually equipped with a flowmeter. 

The flowmeter :  allows recording the volume of water filtered​ by the net and determining the concentration of microplastics (amount of microplastics per volume unit of water). The concentration can also be related to the sampling area by by multiplying the sampled distance by the horizontal width of the net opening​ (the lack of standardisation lead to difficulties when comparing the results of different sampling campaigns).

The sailboat speed ​ during the sampling should not be too high (5 knots or less)

​The net  from 3 to 6 m long and a mesh size of around 300 μm is most commonly used. 

Source: Brown, D.M., Cheng, L., 1981. New net for sampling the ocean surface. Mar. Ecol. Prog. Ser. 5, 225–227.

Sampling of microplastics with a manta net - Photo : Julia Realdon