As humans become more aware of the vast amounts of plastic on land and in the ocean, researchers have started measuring the depth and extent of plastic in our oceans.
Although little is known about exactly how plastics get into the deeper parts of the ocean, researchers found substantially higher microplastic counts in the Great Australian Bight than found before. This data estimated around 14 million tonnes of microplastic on the ocean floor.
How Much Plastic Is In The Ocean?
This is so much plastic in the world’s oceans – from large waste to micro plastics. It’s estimated that there is around 269,000 tons of macro and micro pieces of plastic across all the oceans. This is not just the ocean floor as there is limited data the deeper into the oceans you go. So that means there is likely much more than that the deeper you go.
This is around eight million pieces of plastic ending up in the ocean EVERY day! The damage this can do to our marine life and quality of water is astounding. With the time it takes for plastic to completely break down or even degrade into microplastics being decades and or even centuries, our oceans will just continue to become more and more polluted.
Read more about plastic on land and in the ocean here.
What Are Microplastics?
Microplastics is a term used to describe very small pieces of plastic that end up in the environment – waterways, soil or rivers – resulting from incorrect disposal of waste or the breakdown of consumer products and industrial waste.
Microplastics are typically less than five millimeters long and can be harmful to marinelife, soil and other wildlife on land as they can choke or poison animals, or leave toxic residue in soil or water.
As they occur from other plastics breaking down, microplastics can be from cosmetics, synthetic clothing, plastics bags, bottles or containers. There are two types of microplastics: primary and secondary.
Primary microplastics are microbeads found in personal care products, plastic pellets or nuggets used in industrial manufacturing or packaging, and plastic fibres you may find in textiles such as nylon fabric.
Secondary microplastics are formed from the breakdown of larger plastics which happens when plastics are exposed to elements such as waves, wind or UV light.

How Does Plastic Get Into Water?
Plastic and microplastics can get into the oceans or waterways several ways:
- Through wastewater
- Via wind (more microplastics)
- Rain and floods
- Human disposal of plastic directly into the ocean.
In particular, single-use plastics such as carry bags, cotton buds, food or item wrappers, straws, takeaway items are lightweight and easily carried on the wind to the coast or into river networks that lead into the sea.
Find out more about plastic in groundwater in this blog.
Why is 99% of Ocean Plastic Pollution ‘Missing’?
Scientists estimate that there is much more plastic and microplastic in the ocean than they can find, which is called the ‘missing 99%’. This refers to the plastic we can’t find – usually buried deep in the ocean floor or under dirt and sediment.
This also includes plastic particles so small they are almost like chemicals floating in the ocean, which is perhaps most concerning when it comes to animals ingesting or even humans if it makes it into sea salt, seafood that is consumed or groundwater.
What Does This Mean For Marine Life?
Plastic in the waterways and oceans is extremely dangerous for our marine life across the world who can ingest microplastics, be tangled or suffocated by larger plastics or choke on plastic. Larger plastics can even cause fatal injuries by wrapping around necks, legs and other body parts.
Small particles or chemicals can end up slowly poisoning marine life or ending up in seafood that humans eat.
What Does This Mean For Humans?
Plastic products have been found to be toxic to humans. This is due to the chemicals added to plastics and then absorbed by humans, such as from water or other bottles. Microplastics entering the human body through ingestion or inhalation can also be toxic.
When it comes to plastic in the water, this can be seen when plastic particles or chemicals end up in sea salt, seafood or groundwater.
Although research is still limited, there are several implications that microplastic contamination in groundwater could have on human health:
- Microplastics can attract bacteria found in sewage which can infect humans with pathogens
- Microplastics can contain and absorb chemicals which can have adverse impacts on health
- Potential long-term impacts on human health through consuming microplastics which are made up of toxic chemicals.
Read more about how plastic has been toxic to humans here.
What Should We Do?
Although it’s hard to completely eliminate your exposure to microplastics in the ocean and the resulting complications, there are a few things you could do to potentially protect yourself:
- Capture rain water and purify it yourself
- Drink bottled water – this may or may not be microplastic-free
- Purchase a carbon block faucet filter
- Purchase a reverse osmosis filter
- Purchase your seafood from suppliers clear about their water quality and source
- You can minimize your exposure to microplastics in salt by switching to high-quality sea salts or bamboo salt. You can also reduce your use of salt on a daily basis.
You can also reduce your own plastic waste by considering how you can stop using plastic and switch to alternatives in your life. This may be through purchasing fabric shopping bags, switching to compostable plastics and not using disposable containers, bottles, cups or cutlery.
Read more about plastic alternatives in this article.