Research reveals devastating impact of microplastic on marine life


by Randima Attygalle

Does a whale in the deep seas deserve to have its stomach filled up with plastics we humans are responsible for? Are coral reefs to pay the ultimate penalty for the plastic water bottles which end up on the seabed? The island nation that we are, Sri Lanka is sadly one of the largest polluters of the ocean in terms of plastic, Dr. Terney Pradeep Kumara, the General Manager of the Marine Environmental Protection Authority (MEPA) and senior lecturer from the Department of Oceanography and Marine Geology at the University of Ruhuna says.

While plastic may be a necessary evil in certain manufacturing sectors, the ‘unethical use’ of it has today led to an array of environmental and health hazards, says the MEPA’s GM. "Today, plastic has invaded many unwanted spaces threatening many of our traditional industries such as pottery and reed for instance," observes Dr. Kumara, who cites plastic pots, tills and mats.

These, as he further notes, have not spared even religious places, "Gone is the traditional kalaya (clay pot) used in the temple to pay homage to the Bodhi, but plastic pots have become an eyesore. Home gardens are invaded by plastic flower pots. A dumbara pedura is an item of the past as plastic mats have replaced them," he told The Sunday Island.

Most of the plastic waste ends up in the ocean and it breaks into very small particles which are called ‘microplastic’. The US National Oceanic and Atmospheric Administration (NOAA) defines microplastic as ‘small plastic pieces less than five millimeters long which can be harmful to our ocean and aquatic life.’ Aquatic life and birds can mistake plastics for food. Microplastics have been found in the stomachs of many marine organisms from plankton species to whales says NOAA further.

Certain reports on microplastics predict that in a few decades, the ocean will have more micro plastic pieces than fish! A recent study in the UK by the University of Exeter and Plymouth Marine Laboratory (PML), on 50 stranded creatures including porpoises, dolphins, grey seals and pygmy sperm whale had indicated micro plastics in each animal.

As The Guardian reports, this study found that nylon made up more than 60% of the plastics, with possible sources including fishing rope and nets, clothing microfibres and toothbrush bristles. Polyethylene terephthalate (PET) and polyester were also widely present. Through accidental consumption, microplastics are ingested indirectly when predators consume contaminated prey such as fish. On average, 5.5 particles were found in the guts of each animal, suggesting they pass through the digestive system, or are regurgitated.

The Guardian further notes that Dr. Penelope Lindeque, the head of the marine plastics research group at PML, has found microplastics in animals at every level of the food chain, from tiny zooplankton to fish larvae, turtles, and now marine mammals. "It’s disconcerting that plastic is everywhere – all animals are exposed to it and they are ingesting it in their natural environment. The ocean is a soup of microplastics and it’s only going to get worse, so we need to reduce the amount of plastic waste released into our seas now."

Microplastic, as the MEPA’s GM explains, is of two types: primary and secondary. Primary plastics are manufactured in small sizes which are used in particular industries or for domestic purposes. They include plastic particles called ‘micro beads’. These micro beads are used in certain facial cleaners and scrubs, tooth paste, cosmetics, resin pellets and synthetic clothing. In 2015, the U.S. banned the use of primary micro beads. "These primary micro plastic particles are found in the air around us, water we drink and the clothes we wear and they can penetrate into our skin and then to the blood stream at times causing even cancers," warns Dr. Kumara who goes onto note that research has revealed that annually human consumption of primary micro plastics at present is equal to the size of a credit card!

"The situation is only becoming worse," he further warns. Secondary microplastics are the result of larger pieces of plastic breaking down into smaller pieces. This occurs when plastic debris is exposed to environmental changes such as sunlight, heat, rain and rays and the plastic begins to weather and fragment.

The ocean covers two-thirds of the planet and is the largest carbon sink which cools the planet. At the same time, the ocean provides nearly 50 to 85% of the oxygen we breathe explains the oceanographer. "This oxygen is released from the top layer of the ocean which is about 100 meters in depth. When microplastics float on this top layer and mix with the plankton, they don’t receive enough sunlight to photosynthesis and release oxygen into the air. The lack of sunlight to the top layer of the ocean can result in the destruction of marine life not only in the top layers, but also in the bottom layers, causing dead ocean zones. The dead ocean zones release hydrogen sulphate which is toxic and makes the situation worse.

"At the same time, ocean absorbs carbon dioxide which is a greenhouse gas. Microplastics will obstruct this whole process contributing more to the global warming. Moreover, when they enter the food chains, fish diversity will be affected."

Recent investigations by the Faculty of Fisheries and Marine Sciences and Technology (affiliated to the Department of Oceanography and Marine Geology) of the University of Ruhuna have unearthed alarming findings on the effect of microplastics on soil, shore sand, coastal waters and ocean bottoms of several Marine Protected Areas (MPAs) in the country. These, as Dr. Kumara says, include the Hikkaduwa Marine National Park and the Bundala National Park. "In addition, recently concluded survey of NARA onboard Dr. Fridtjof Nansen research vessel revealed the presence of microplastics in most parts of Sri Lankan waters showing the highest in North Western waters."

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