Ocean lab near Bermuda Triangle

We're in Zodiacs — small, motorised, inflated boats that bob and bounce us across the Atlantic Ocean, close to the Bermuda Triangle. The idea for the 10 of us is to trawl for micro-plastics.

We're part of the Ocean Plastic Leadership Summit — an expedition on a ship where ideas to remove plastics from rivers and oceans are being intensely discussed.

As we trawl, we'll put a T-shaped device into the ocean with a long, mesh tail to suck in water from the oceans and retain the solids. Later, we will analyse what came in, focussed on micro-plastics in the Atlantic Gyre.

The ocean is lapis lazuli blue. I've never seen anything like it before. The waters are choppy, but pristine-looking. We touch it, and it's not as icy as many of us expected. Every now and then, we see a Portuguese man o' war — a jellyfish which is dreaded as much for its toxic sting as for its medusa-like sinister looks.

It looks like a medium, white-translucent bubble, floating along. "I hate its name," says a woman from our boat, shuddering. Everyone feels creeped out when our guide and driver, Allie, explains that they grow up to a foot or so more.

Patches of yellow-orange sargassum bob up and down. These are sea plants that trap plastics, but also, are the backbone of an entire eco-system. Fishes duck in and out of their branches, and nodules.

"Avoid the sargassum patches," says Win — the scientist from the non-profit, 5 Gyres — to the woman who is driving the boat. He doesn't want too much sargassum in the sample. He is more interested in what we find in the open waters. In any case, sargassum clusters are like the trees of the ocean. Trapping them is like cutting down a tree. The trawler is set out into the ocean. It's a T-shaped alumium device, to which a long nylon sock is attached. It is tailing behind the boat, pulled along by a nylon rope. Win notes the coordinates. Half an hour later, we pull it out.

"Look closely," Win says. "You can even see some plastic." I am one of the many on our boat who don't look. Despite a sea sickness tablet, we are too tossed to want to move. We feel sick.

Out of the sea and into the lab.

An hour later, scientists, assisted by science students, begin work at the One Lab set up by 5 Gyres for this expedition. They use tweezers to pull out the microplastic from the fine sieve through which the water has been strained. They also pluck put plastics from the sargassum.

All plastics are placed on the grid, one square per piece of plastic. Micro-plastics are defined as plastic fragments less than 5 millimetre (mm). The grid is designed as squares of this size, making it easier to measure. If it fits in, it's small enough to be called micro-plastic.

Most of the plastic is transparent or white, making it hard to pick out. It takes a long time, and the lab is already crowded. It's like a small kitchen in a tiny apartment. It even has a sink and a fridge. On one side is a small motor oil jerrycan that has travelled 4,500 miles from Western Sahara to the West Coast, before it was found.

I wait inside for about 45 minutes, but our samples are not yet completely counted. Nothing to be surprised — it's a painstaking job, picking one particle at a time. When I come back, I have hard evidence that the lapis lazuli waters are not as pristine as they look.

The Atlantic Gyre has thrown up 29 pieces of plastic, of which 23 are microplastic. The rest include a filament and slightly larger pieces. I look at them, barely discerning anything without a hand-held magnifying lens.

These are the invisible pollutants that get inside animals and slowly change their metabolism — they are the ultimate form of slow poisoning.

(This is a dispatch from the RCSM Resolute where Soulbuffalo, an ecotourism company, has organised a plastic expedition. The views expressed are strictly personal)