DIY Bridge Trawl




About: Empowering citizen scientists to track and together prevent marine pollution.

Trawl for dangling from a bridge or other location above the water.

Made from a 5 gallon bucket rim, and a recycled bottle for weight.

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Step 1: Supplies

You will need the following supplies :

1) Rope

2) 2 Worm gear clamps

3) Paint Filters (1 Pack)

4) 5 liter Paint bucket

5) A used plastic water bottle with thin neck

6) Pebbles

Step 2: Cut the Top of the 5 Liter Bucket

Step 3: Adjust and Fit the Worm Gear Clamp on to the Bucket

Combine two worm gear clamps to fit the diameter.

Adjust and tighten the clamp on to one side of the ring

Step 4: Drill Holes on the Top and Bottom of the Ring

Make sure the holes are aligned to each other

Step 5: Attach the Paint Filter and the Bottle

1) Tie the rope from the bottom hole (3-4 inches in length)

2) Fill up half of the bottle with pebbles and the rest with water

3) Tie the other end of the rope to the neck of the bottle

4) Attach the paint filter and tighten the clamps

Step 6: Tie Rope to the Top Hole of the Ring

Finally, tie the rope to the top hole of the ring (length depends on the height of the bridge)

Step 7: You're Ready to Trawl Over a Bridge!

Step 8: Process Samples

Check out how to process the samples collected.

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    4 Discussions


    2 years ago

    How long did you keep your trawl in the water to get it to collect that much gunk?

    1 reply

    Thank you! We are testing the water for plastic. We design DIY trawls for citizen scientists to make and use in their nearby marine environments thereby reducing the accumulation of plastics through active community engagement.