[DAY 97] Micoplastics

One of our scientific protocols is for microplastic. A microplastic is a piece of plastic 5 millimeters or less in size. It usually comes from bigger pieces that have been degraded mainly by the effect of the sunlight. All the plastic we see on the surface of the ocean or those I see while swimming will eventually end up as microplastic pieces.

We use a Neuston net, a special net with very small webbing to capture small particles. We tow the net at the surface for half an hour at a constant speed of around 3 knots. The water enters the net through a rigid rectangular opening that maintains the same shape, so we know the volume of water that goes through. At the end of the tow, we count the number of microplastics collected and then we can determine the amount of microplastic, and store it for analysis. Microplastic cannot be seen by the naked eye when in the water, this is the method used to determine its density. Today we collected more than 400 pieces (so far), the most we ever collected. Maria is in charge of this protocol and it has been a long and laborious process for her and she still have to finish it to have the exact count.

We have found microplastic each time we towed the net, starting near the Japanese coasts. Currents and winds create areas in the ocean that gather microplastic where its density is the highest. But microplastic is found everywhere and it is referred to as plastic smog; it is a foreign element to the ocean and a danger to sea life.

Today during the swim I also saw fa ew pieces of plastics, and Ty and Brian on the dinghy, collected some pieces but it was by far not the most plastic we had seen.

Weather conditions:
Sunny (could coverage 0/8)
Wind speed: 5 kts
Wind direction: NE
Waves height: 0.5m
Waves direction: NE
Water temperature: 29.4°C

Miles swam: 14.35 NM