Trawl trial

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It was a perfect day to try the trawl we received from 5 Gyres : blue skies, around 10 knots of wind, smooth seas and good company. We wanted to try it out here in the waters around Las Palmas, Gran Canaria, before we leave for a larger trip and see how the concept worked and what the effect would be on the speed and the steering of the boat. Edwin had already figured out a way how to put the trawl in the water in the most practical way.

Deploying the trawl

So we set sail in the early morning, together with Richi, Brenda and Joel. Weather turned out to be as predicted so as soon as we were outside the traffic zones we put out the trawl on portside. We made sure that the trawl kept well out of the wake zone of the boat.

Overview

For that we used our spinnaker boom so the trawl would be about 5 meters next to the boat. The line we used gave the trawl another 6 meters of space towards the back. It turned out to work really well right away: 75% of the scoop was beneath the water surface all the time, floating smoothly.

Trawl in action

We also spent time spotting larger debris in the ocean during the deployment of the trawl. The good thing is that we did not see any debris, and we were lucky to spot a loggerhead turtle!

In the afternoon the wind started gusting up so we had to get the trawl on board a little earlier as planned. This too went according to plan. We used an extra safety recovery line, adjusted to the side of the trawl, to get it back on board.

The effect on the boat handling was minor, that on the speed around 1 knot in these conditions: wind 8 to 10 knots N, half wind, current 1,5 knots on the head.

Checking the contents of the sieve

Then began another exciting part of the experiment: to analyze the content of the net! We were really curious to see what was inside. It turned out to be a challenge to determine the material of some of the particles. Joel and Brenda (both graduated marine scientists) managed very well though. It turned that the net contained 11 tiny particles of plastic, all smaller than 5 mm.

Determination

Considering that a relatively small device ‘catches’ that many particles in a vast ocean in just a couple of hours, we think the result is really something to think about.

All in all, we had fun with the experiment and are looking forward to the next time. As for the results: it strengthens our conviction that plastic is a serious major and urgent worldwide problem.

 

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