7 October 2020.

Introduction:

The Commonwealth Scientific and Industrial Research Organisation (CSIRO) analysed the deep ocean 380km (236 miles) from the coast of South Australia and found that the amount of very small plastic particles on the seafloor was more than double the amount of plastic pollution on the surface of the sea globally.According to the study ,an estimated 14 million tonnes of harmful microplastics may be present in the bottom of the world’s deep oceans as a result of the pervasive use of plastic.

Highlights of the study:

• The study is the first global estimate of how much microplastic there is on the seafloor.
• Millions of tonnes of plastic enter the world’s oceans every year and the volume of plastics in the marine environment is expected to increase further.
• Plastic pollution that ends up in the ocean deteriorates and breaks down, ending up as microplastics.
• Once in the sea, the plastics gradually disintegrate and can be easily ingested by marine organisms.
• They can also end up in the human food chain.
• Microplastics are  sinking to the ocean floor making deep sea susceptible to plastic pollution problem.
• Microplastics range in size from 5mm,  down to microscopic size, which makes it easy for them to be ingested by sea creatures.
• They include tiny pieces of degraded plastic, and synthetic fibres as well as plastic beads used in cosmetic items and even in toothpaste and laundry powder soap.
• Microplastics are also the result of larger plastic debris that degrades into smaller and smaller pieces.
• The Netherlands was the first to ban plastic microbeads in cosmetics and personal care products in 2014, and the United States followed suit in 2015. But many other countries continue to allow their use.

Steps for mitigation:

• The samples used in the study were collected using a robotic submarine at depths of as much as 3,000 metres (9,842 feet).
• Based on the deep-sea plastic densities, an estimation of   the volume of microplastics on the seafloor worldwide can be made.
•  There was an urgent need to generate effective plastic pollution solutions.
• By identifying where and how much microplastic  a better picture of the extent of the problem can be made.
• This will help to form waste management strategies and create behavioural change and opportunities to stop plastic and other rubbish entering our environment.
• Among the steps that can be taken are the reduction, if not elimination, of single-use plastics and recycling.
• Government, industry and the community need to work together to significantly reduce the amount of litter along the beaches and in the oceans.

How are microplastics harmful?

•  Microplastics that get accumulated on the sea floor bed can be dangerous to Marine organisms.
• This is because the ocean currents are the main source of oxygenated water and nutrients to see floor Hotspots.
• These currents deposit nutrients carried a long way and thereby help developing deep sea floor hotspots and deep sea coral reefs.
• As the microplastics increase in the ocean water the currents tend to carry these harmful  substances along with nutrients and silt.
• Eventually the microorganisms end up ingesting these microplastics and slowly the particular hotspot begins to deteriorate.