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Public Lab Wiki documentation


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BabyLegs is a research trawl (net system) for monitoring plastic pollution, especially microplastics, in surface water.

Design goals

Created with baby’s tights, soda pop bottles, and other inexpensive and easy to find materials that cost ~$15, Babylegs can be used to trawl for floating microplastics from the surface of the water. She can be used with a boat (motorized going as fast as 5 knots in calm water, or human-propelled such as a canoe or paddle board), or by being tied off on a bridge or pier for passive sampling. BabyLegs mimics the type of samples collected by the more expensive Manta Trawl: floating microplastics between 5mm-1mm in size.

Originally designed by Max Liboiron at the activist science laboratory CLEAR for sampling in Newfoundland and Labrador, Canada, BabyLegs is specifically built with items that are easy to come by in northern, rural communities. But the design supports hacks, replacements, and innovations that suit local needs.

Community and NGO groups have had success using BabyLegs to gather samples. The main expertise bottleneck is not in building or using BabyLegs, but in interpreting the samples. Microplastics are very hard to visually identify, since many things like rocks, bones, and organics look like plastics, and tiny plastics can be hard to see at all. The guide below is divided into sections on building and using BabyLegs and analyzing the samples for this reason.


The image above shows some of the microplastics BabyLegs captured in the Hudson River, New York City.


Q: Can I change materials on the trawl, or change the design? A: Of course! The only thing you have to make sure of is that the mouth of the trawl is always half in the water and half out. It cannot dive or skip over the water. Also beware of any materials that might put more plastic into the ocean or into the sample (plastic 3D printing, fleece, and plastic thread are particularly bad for this). Also, the design outlined here has been tested in a variety of waters. New designs might not behave as well in choppy water, at higher speeds, or in wind.

Q: What sort of data does a sample from BabyLegs yield?
A: Things you can know from a sample:

  • The types of plastics (fragments, films, beads, threads, etc) that are in a body of water.
  • The relative frequency of each type of plastic compared to others (perhaps you have a lot of fishing gear, but not many microbeads compared to other places)
  • The relative hotspots for plastics if you do sample strategically in different areas.
  • Whether there are more or fewer plastics after rainfall events if you trawl before and immediately after rainfalls. This can include other temporal events that you think are adding plastics to your water (storms, tourist festivals, seasons).

You will not know:

  • Where the plastics come from. They might be local, or they might have come from far away.
  • How long plastics have been in the water. Some things can get tossed around in strong waves and look beat up after short periods of time, while plastics that sink can look pristine after years.
  • About plastics that are smaller than 1mm. You might be able to see some, but research has shown that 1mm is the smallest cut off size that human eyes can reliably identify a plastic.

Q: Has BabyLegs been validated? Does she collect the same kind of sample as instruments like the manta trawl?
A. BabyLegs has not been validated yet, but we are working on it. Stay tuned-- we should have it done by the end of fall 2019. In the meantime, you can use BabyLegs to understand types of plastics, relative proportions of types of plastics, and hotspots. Validation will additionally let us calculate the density of plastic pollution. Other questions are answered in the guides below.