screen-shot-2016-10-08-at-9-32-46-amLADI (Low-tech Aquatic Debris Instrument, pronounced “lady”), is a build-it-yourself research trawl that collects microplastics at the surface of the ocean when towed behind a boat (“trawling”). LADI is a smaller, less expensive ($500), and easy to build open source alternative to the current scientific standard, the Manta Trawl, which is expensive ($3500), heavy, and requires specialized equipment and skills to create.

Microplastics (<5mm) account for over 92% of the plastics in the ocean. However, we still do not have a thorough understanding of their origins, how and where they are distributed in the ocean, and the scale and consequences of their presence. Trawls such as LADI and the Manta Trawl are one way to gather data about the number, types, sizes, density, and origins of plastics at the ocean’s surface.

Currently, the cost and size of the Manta Trawl limits its use to scientists with grants or financial resources. A smaller, cheaper, DIY, open source trawl which produces the same type of data will greatly expand the number of possible users, not only to professional scientists, but to citizen scientists as well. Understanding the problems of microplastics is the first step in developing a solution.

CAD drawing
Schematic for building LADI. By Coco Coyle. 2016.


  • Skim the surface of ocean water in choppy water, without dipping below the surface
  • or jumping above it
  • Collect microplastics in the cod end


  • Easy to construct, maintain, and troubleshoot
  • Reusable
  • Robust
  • Easy to carry and transport
  • Cheaper than current industry standard, the Manta Trawl

Design Parameters:

  • Uses a 333 m (micron) mesh net
  • Has a rectangular opening
  • Weighs 20lbs
  • Is able to be counstructed with<$500
  • Is able to withstand being trawled at up to 5 knots
  • Must be leashed on two axes to the side of a boat
  • Is made from materials found in non-specialty stores or online
Screen Shot 2016-08-15 at 6.39.56 PM
Materials, prices, and source list for the LADI trawl.

LADI was invented by Coco Coyle, with Melissa Novaceski, Emily Wells, and Max Liboiron. Click here for the full technical report that outlines the design, instructions on how to build your own, how to validate your trawl, and how to use it to gather samples.

CERN Open Hardware License files:

Full report & CAD drawing:
ladi_and_the_trawl report- high resolution
ladi_and_the_trawl report- low resolution


Have you built or used the LADI trawl? Please take our survey to help us keep improving!