Sep 28thAn invisible threat

I have enjoyed all of my projects here in Samos, but the one I am most concerned and, paradoxically, excited about, is my research into microplastics. I am leading a small team, currently looking into the uptake of plastics by pelagic fishes. Essentially, we have to open the stomach and investigate the contents. Not a pleasant task, I might add. The microplastics we are searching for, are defined as less than 5mm in size, so they have to be kept and examined under the microscope. I just have to point out that we don’t have face masks, we can’t wear gloves or lab coats due to potential contamination, and have to work with very limited ventilation – dedication is what you need! Although unpleasant work, it is necessary.

We all know about the plastic debris problem affecting our defenseless Oceans. The Great Pacific Garbage Patch is one of the most documented problems, along with Turtles, Seabirds and Cetaceans becoming fatally entangled in the mess we have selfishly abandoned. Recently a 19 year old student, Boyan Slat,has proposed a solution to the man-made macro litter problem, by inventing a self sufficient collection cabin with extended beams to collect the litter. On the surface (excuse the pun) it seem like a great idea. In theory it will significantly reduce the amount of marine plastic litter whilst raising awareness and saving the lifes of thousands of marine animals. And will not harm any in the process. But what about the little things? I refuse to believe that it will not somehow suck up a disastrous amount of plankton, depleting the ocean of it’s main source of primary production. But what do I know? It will be interesting to see how it unfolds, especially as he believes that the procedure will bring in several million dollars a year from recycling alone.

It is tremendous that this catastrophic problem has so much attention. But, more effort needs to be directed towards the incidence of microplastics. These tiny fragments of plastic come from 2 main sources. Beach litter is one of the worst culprits. When plastic packaging i.e. bottles, containers, packets are either left by beach bathers or are washed up in the surf, they begin to photo-degrade. And in contrast to what we previously believed, it doesn’t take centuries, the time it takes is actually a lot less.

Next time you are on a beach, have a look at the rubbish and you will probably find half a bottle, or even just the neck and lid – this bottle did not start off like that. Sunlight degrades the plastic into tiny pieces, but it does not degrade fully. It can be broken down only into individual polymers and no more (as far as we know anyway) and could potentially remain in the ocean for ever. The fragments under 5mm are known as microplastics. A large proportion of microplastic particles also come from the break down of discarded fishing gear and other litter from shipping fleets.

Another important source of microplastics is from waste water. This includes, run off from industrial practices, washing machine effluent and even daily use cosmetics such as hand soaps and facial cleansers. Yes we are all guilty!

One of the biggest concerns, and one that we are yet to completely understand, is what harm this does to us, the humans. We know that marine organisms easily mistake small plastic particles for food, which is potentially very disruptive to the animal. First of all, plastic contains substances that have the potential to disrupt the endocrine system as they interfere with hormones. This has been known to cause birth defects in some species. But not only that. Plastic is very good at absorbing organic pollutants such as DDT and PCBs, both of which have been known to cause cancer in humans and animals. So when the fish eat the tiny plastic fragments, there is potential that they would be passed onto us. But like I say, we still don’t know the affects with regards to humans. As the study of microplastics has only been going on for about 10 years, there are many questions unanswered. I am really hoping that my research in Samos and in the future will help determine the future of our plastic oceans.