Menu Close

A Cruel Twist to Plastics and the Oceans

A Cruel Twist to Plastics and the Oceans

by Iain Watt, President EcoNetwork Port Stephens.

The EcoNetwork policy on plastics is to Refuse, Reuse, Repurpose, and Recycle all plastics. To that end EcoNetwork is working with businesses that recycle plastics such as Resourceful Living, Salamander Bay Recycling Centre and Deeps Engineering. They create products from 100% post-consumer waste using recycled plastics, manufacturing furniture, homewares and building supplies. We know that a circular economy means products will be manufactured, used, recycled and reused more than once. We can reduce the consumption of raw materials and ultimately recover all waste by using recycled products in the future. Ways individuals can be more circular include repairing products rather than replacing; sorting your waste; buying local materials; exchanging items rather than upgrading; and reducing waste by reusing.

How plastics came to be

The first synthetic polymers were invented in 1869, but it was not until 1907 a fully synthetic plastic was developed. Plastic production was increased by 300% during WW2, but they really came into their own in the 1960s and 1970s when consumers wanted to replace traditional materials with this modern, versatile cheap and easy to manufacture commodity. Plastic production has increased from 2 million tonnes in 1950 to around 350 million tonnes in 2015. More than half the plastics ever produced has been in the last 15 years and production continues to grow annually.

Two thirds of the plastic produced ends up in the environment and will remain there in one form or another. A plastic water bottle for example can last for 450 years and fishing line for 600 years in the marine environment, slowly breaking down into micro and nano plastics.

90% of plastic is made with fossil fuels and generally produces 2.5 tonnes of carbon dioxide to produce 1 tonne of plastic. It is estimated that 12.5 million tonnes of plastic enter the oceans every year, 9.5 million tonnes from the land and the rest from directly from the fishing and shipping industry.

The Great Pacific Garbage Patch

Alarm about plastic waste in the oceans was first raised in the 1960s and by the 1970s and 1980s considerable angst was growing about plastic waste in general but particularly in the oceans. The Great Pacific Garbage Patch was discovered in 1997 estimated to be 3 times larger than France, it is predicted to double in size in the next 10 years. An estimated 46% of this garbage is made up of abandoned fishing nets and lines, an estimated 705,000 tonnes of discarded fishing nets continue to entangle whales and other animals and accounts for 20% of all marine plastic. The visible plastic debris, that floats, is estimated to be only 1% of the plastic debris and the rest has already sunk to the sea floor. There are 5 major ocean gyres where plastics accumulate. These gyres also form important feeding grounds for marine life, but are being compromised by the conglomeration of plastics blocking light from the crucial phytoplankton underpinning the food web.

The UN states that plastic waste has now reached epidemic proportions and is considered one of the major environmental threats with an estimated 75 – 199 million tonnes of plastic waste currently in the ocean. It can now be found from the top of Everest to the bottom of the Marianas Trench at 10,900 m down. Ingestion of plastic debris is now a globally recognised threat to seabirds and other marine animals.

Of course, the oceans have been used as a rubbish dump since time immemorial – out of sight out of mind, but eventually it will come round, and it looks like we are fast approaching that time. We are facing a sea soup full of plastic and increasing acidification due to climate change.

Impacts on marine life

Plastics have massive impacts on the oceans and coastal seas, as a visual pollutant and an estimated 100,000 marine mammals and turtles and 1 million seabirds are killed by plastic pollution annually. (UK Government Report) In 1960, 5% of seabirds studied were found with plastics in their stomach, by the 1980s, 80% of seabirds studied had plastic in their stomachs. Adult albatross have been known to regurgitate plastic to feed their chicks, severely reducing the ability of the chicks to reach adulthood.

Plastics degenerate in the environment due to weathering, breaking down to micro plastics (less than 5 mm at their longest dimension) and nano plastics – even smaller. These are a threat to both wildlife and human public health. They are probably the most insidious face of plastics, they are unseen, poorly understood and are now found in practically everything including our drinking water, and salt. They are present in 1 in 3 fish caught for human consumption and is a pathway for plastics to enter the human blood stream.

Marine plastic pollution affects 100% of turtles, 59% of whales (mainly entanglement in abandoned fishing gear), 30 % of seals and 40 % of seabirds. (Condor Ferries 2023 Statistics). Importantly, plastics and micro plastics have not been around long enough to really assess their long-term impacts on the environment and people, but we can be sure there will be some long-term impacts not yet known.

Dr Lauren Roman from the University of Tasmania found that balloons and balloon fragments posed the highest risk of mortality for seabirds and that they are 32 times more likely to cause fatality than the ingestion of hard plastics. While soft plastics were found to account for just 5% of the items ingested, they accounted for 40% of the mortalities, killing 1 in 5 that ingested them. These results are replicated in studies on turtles, where it was found that hard plastics were more likely to pass through while the soft plastics compact and cause obstructions. However, even a single piece of plastic can be fatal.

It is estimated that seabird populations have dropped by nearly 70% over the past 60 years and one third of seabirds are now threatened with extinction. This is largely a result of overfishing (removing their natural prey), and by-catch (accidental catching of seabirds in fishing gear), and habitat destruction of critical nesting sites, including the introduction of rats and cats. Add to this, the seas they rely on are highly polluted with oil, plastics metals (mercury), other toxins and the acidification of the seas through climate change. Approximately 30% of CO2 is absorbed from the atmosphere by the oceans, creating Carbonic Acid and the acidic seas.

Seashells, coral reefs, and zooplankton form calcareous shells or skeletons. The acidic seawater dissolves the calcium carbonate that forms these structures, with some shells reported to be 16 – 30 % thinner than they were 50 years ago. However, dissolving of the skeletal shell of zooplankton is particularly worrying as zooplankton is a primary food source for many fish species and other marine animals. Meanwhile, the southeastern waters of Australia are one of the four fastest warming oceans in the world, which should give some pause for thought. Most people are blind to the threat to seabirds – they live far offshore and (in reality) very few people ever venture very far offshore and if so, not for long and in the main those that do don’t seem to have noticed.

The seabird cry is a warning of the plight of the oceans. When one in three species of seabird are in trouble it indicates that the marine ecosystem is also in trouble. Seabirds and shore birds are like the canaries in the coal mines, they provide an early warning of impending danger for the marine and coastal ecosystems.

Of the 10,000 species of birds, there are only 300 species of seabirds, i.e. those that depend entirely on the sea for survival. That means only 3% of all bird species are seabirds, yet the oceans cover 70% of the planet, leaving the remaining birds crowded into the 30% of land. But seabirds are important oceanic ecosystem builders much like the humpback whales, contributing to the ecosystem in a variety of ways including the food chain their demise has serious implications.

Shearwaters, fulmars, albatross, and petrels are Procellariiformes, referred to as tube noses because they have enlarged exterior nostrils on the upper side of their bills. These and other ocean wanderers use smell and complex gas patterns to navigate the oceans and not magnetism. The main food source for shearwaters and other oceanic species is krill – like the humpback whale.

Krill feed on phytoplankton and NOAA scientists have found that when phytoplankton is in dense numbers and being predated by krill they release an odour called dimethyl sulphide (DMS). This odour leads the tube noses to the feeding grounds and the krill.

However, small pieces of plastic floating in the oceans also produce dimethyl sulphide which the tube noses now mistake for food. Once the plastic is in their gullet it cannot be dispelled and accumulates in the animal’s gut until it dies of starvation or septicaemia due to perforation of the gut by sharp pieces of plastic. This is disastrous for the tube noses and other marine animals.

It is likely that there are similar links to other animals such as turtles eating plastics, not because they look like prey but because they smell like prey. The vast amounts of plastic in the ocean are being mistaken for food causing an untold problem.

What can you do to help?

  • Respond to the ‘NSW Plastics Next Steps’ paper. This is our opportunity as a community to have input into progress for reducing plastic waste, at least in NSW. EcoNetwork asks you to please submit your feedback by email or via the EPA webpage. If you prefer, you can respond to the online survey which takes only a few minutes. Please do this before 5pm on 4 February 2024. We provide you with some ideas to help you with your feedback here.
  • Avoid buying non-reusable plastic items
  • Be inspired – read Plastic Free by Rebecca Prince-Ruiz and Joanna Atherfold-Finn (a Port Stephens local).

Useful Links

Published: 11 Jan 2024