by Aidan Henri
“I am a piece of marine debris, that found a way into the sea,
Over the waves and into the bay, I have travelled a long way.
But on the beach I do not belong, I get eaten by shore birds that scurry along,
So why don’t you show some care, and pick me up for I do not belong there,
You can hand me into NVT, they know how to handle me.” ~ Aidan Henri
Yip, you guessed it, we’re talking about nurdles. So what is all the fuss about anyway? Do you think conservation agencies are going overboard? (Much like that container that put them in our ocean in the first place). Plastics have been washing up on shores for decades now so what’s a couple of little nurdles going to do?
Well, let’s LOOK at it like this. Nurdles are transparent microplastics roughly the size of a lentil. They are barely visible to the human eye when walking along the tidal zone – the zone you are most likely to find them in. However, from a bird’s eye, the situation LOOKS different.
From left to right: Nurdles collected by Greenwood Bay College;
nurdles on Nature’s Valley Beach; a closer look and a collection of nurdles
collected so far.
Birds unlike humans have five sets of cone cells in their eyes whereas humans only have three (red, green and blue). It is the cone cells that allow us to depict colour. The cones cell of birds have special oil droplets on them which help filter the light, making the cones more sensitive to smaller ranges of colour. As they have five different sorts of oil filters the eyes of birds can often see a far more subtle world than we can. Therefore that colourless nurdle to our eyes looks quite different to a bird. Sea birds such as the Procellariformes use red oil filters to cut out the blue light scattered up from the sea. This makes it easier for them to discern small objects floating on or near the surface (www.birdsofeden.co.za).
It’s no wonder these tiny pellets washing up get mistaken for food right? Can’t really blame the bird. Once ingested these pellets get stuck in the gullet making them feel full, ultimately they stop eating real food and can starve to death.
In addition, nurdles and other plastics when at sea act as a sponge attracting other contaminants to their surface, known as Persistent Bioaccumulating Toxins (PBTs). PBTs are industrial chemicals that can accumulate in animal and human tissue causing long-term ecological damage (www.nurdlehunt.org.uk). Does anyone remember the DDT outcry of the late 1950s in the USA? Lets recap.
In most marine communities, the living weight (biomass) of fish-eating birds is less than that of the fish they eat. When a tonne of contaminated fishes is turned into 200 pounds of seabirds, most of the DDT from the numerous fishes ends up in relatively few birds. As a result, the birds have a higher level of contamination per pound than the fishes do. If Peregrine Falcons feed on the seabirds, the concentration becomes higher still. With several concentrating steps in the food chain, very slight environmental contamination can be turned into a heavy pesticide load in birds at the top of the food chain. The worst part of the 1950s DDT disaster was that the DDT altered the birds’ calcium metabolism which resulted in birds laying eggs with thinner and weaker eggshells. These eggs were then crushed under the weight of the parents incubating the eggs which ultimately lead to reproductive failure. Shell-thinning resulted in the decimation of the Brown Pelican populations in much of North America and the extermination of the Peregrine Falcon in the Eastern United States and South-eastern Canada. DDT was banned almost totally in the United States in 1972.
The inadvertent consumption of nurdles by shorebirds could have similar deleterious effects on local populations if we are not careful and do not monitor the situation. Our very own white-fronted plover already faces so many threats when it comes to reproductive success, from humans, dogs, gulls and raptors, and climate change. Does it really need one more? From the likes of a silly little pellet? It’s these lessons from the past that cause ecologists to ring the alarm bell on nurdles washing up on our beaches. Who really knows the long-term impacts? But by the time we do, it may be too late.
White-fronted Plover and African Black Oystercatcher, some of the shore
birds that may be effected by nurdles
Let’s take this time to sit back and reflect on the impact our consumption and expenditure are having on our beloved holiday destinations. As many of us pack up to head home let’s sit back and reflect on some bad practices we may have acquired over the year. Let’s set fresh goals and let 2018 be the year of smart choices, the year to take ownership of your daily role and responsibility in looking after the environment you are blessed to be a part of.