Published: 25.04.2018 Updated: 03.05.2018
Researcher Terje van der Meeren filters large quantities of sea water in search of fish eggs. He lowers a net down to 50 metres, and hauls it straight up to the surface. Each time, he filters around twelve cubic metres of water, and the cup in the bottom of the net collects fish eggs, filaments of algae, zooplankton and other organic matter. Recently van der Meeren has noticed that he isn’t just getting organic matter in his samples – he is also finding strange, colourful threads amongst the fish eggs.
“These are fibres, or thin threads, that appear to be made of plastic. I estimate that they are present in a quarter of all the samples I collect. I see them when I put the samples under a microscope”, he says.
Van der Meeren is actually doing research on fish eggs and juvenile fish, and he is studying the possible impacts of mining on the Atlantic cod in the Repparfjord in Finnmark in northern Norway. He stresses that microplastics are not his field of research, and that he hasn’t carried out an exact quantification, but that it is possible to distinguish plastic fibres from other fibres when he inspects the samples under a microscope.
“I usually zoom in to check whether there is a cellular structure, because I could be looking at filaments of algae. If there is no cell structure, it’s likely to be plastic. There are few natural objects out there with such bright colours”, he says.
Under the microscope, van der Meeren can see fibres of assorted colours. They are only a few millimetres long, and they can be green, blue, grey, red or bright yellow. Some fibres are stiff, while others are curled up, and he also sees some fibres that may come from wood or paper.
Van der Meeren finds microplastics when collecting fish eggs in other parts of Norway as well. For example, there are also microplastics in the samples he takes at Smøla, further to the south. It is possible that some of the plastic fibres may come from the work clothes and ropes onboard the boat we are using, but there are also threads that don’t match the colour of either the ropes or clothes used when collecting eggs.
Bjørn Einar Grøsvik, another researcher at the Institute of Marine Research, does have microplastics as one of his areas of expertise. He finds the observations of his colleague van der Meeren interesting.
“If 25 percent of samples contain plastic fibres, that’s a lot. Off the top of my head, that’s more than I would have expected, and obviously we would like to know more about the situation. What kind of plastic it is, where does it come from, is this local pollution or is it a more general phenomenon, and how does it affect marine life? There are lots of questions”, he says.
The Institute of Marine Research is busy building up its capacity in relation to microplastics, and by the end of May it will have a new microplastics lab. The lab will have a microscope capable of analysing the contents of microplastic particles down to a size of five micrometres. That will improve our understanding of what exactly samples of the type taken in the Repparfjord contain.
“We will be able to scan the fibres to find out their chemical composition and see exactly what plastic polymers they contain. The new lab may also help us to identify what type of plastic we have found, and give us a better idea of where it originated. It will be an excellent tool for finding out what is floating in the oceans”, he says.
Both researchers are concerned about the quantity of microplastics found.
“I am worried that we know too little about the extent of the problem. If we continue adding as much plastic and microplastic to the oceans as we currently do, it may become too late to do anything about it. We cannot remove them from the oceans”, says Grøsvik.