Ocean Drainage: Plastic's Pathway To Pollution

Plastic waste in the ocean is a pressing issue that threatens marine life and ecosystems. While it is challenging to determine the exact amount of plastic in the ocean, it is estimated that millions of tons of plastic waste enter the ocean each year, with a significant portion originating from land-based sources. Careless waste disposal, littering, and inadequate waste management contribute to plastic pollution in our oceans. Plastic debris, including microplastics and macroplastics, can be carried by wind and stormwater into drains and rivers, ultimately making their way to the sea. The impact of plastic pollution on marine life is devastating, with ingestion and entanglement causing harm and death to various species. Addressing plastic waste requires collective efforts to reduce, reuse, recycle, and improve waste management practices to protect our oceans and the environment.

Plastic waste from land

One major pathway for plastic waste from land to reach the ocean is through rivers and streams. Mismanaged waste disposal, such as littering or inadequate waste management systems, allows plastic to enter waterways that flow into the sea. This includes plastic litter blown by wind or washed away by stormwater into drains and rivers, as well as plastic waste directly dumped into natural environments or overflowing landfills. Once in the water, plastic tends to sink quickly due to its large surface area, contributing to the accumulation of plastic waste in aquatic environments.

Another significant source of plastic waste from land is the fishing industry. Abandoned, lost, or discarded fishing gear, also known as "ghost gear," accounts for about 10% of ocean waste. This includes items such as fishing nets, traps, and lines that can drift for kilometers, trapping and killing marine animals, including endangered species. The impact of ghost gear is not limited to marine life; it also causes financial losses to fisheries and damage to boats.

In addition to these direct pathways, plastic waste from land can enter the ocean through indirect routes. Landfill sites, for instance, may contribute to plastic pollution in the ocean. Plastic waste disposed of in landfills can be carried away by wind or washed out through storm drains, eventually reaching nearby rivers and the sea. Agricultural runoff, especially in areas where municipal sewage sludge is used as fertilizer, also contributes to plastic pollution in oceans by carrying microplastics into river systems.

The impact of plastic waste from land on marine ecosystems is profound. Plastic does not readily decompose, and once it enters the ocean, it can persist indefinitely. Over time, larger pieces of plastic break down into microplastics, which can absorb harmful pollutants. These microplastics are then ingested by marine animals, leading to internal blockages and starvation. It is estimated that more than half of all marine life has ingested plastic, with particularly devastating effects on sea turtles, who mistake plastic bags for jellyfish, a common food source.

Poor waste management

Richer countries produce the most plastic waste per person, but effective waste management systems keep much of it out of the natural environment. In contrast, lower-income countries often have poorer waste management infrastructure, resulting in higher rates of mismanaged waste. Middle-income countries, particularly in Asia, are the largest contributors to ocean plastic emissions. This is due to a combination of increasing plastic consumption and inadequate waste management systems.

The impact of poor waste management is evident in the approximately 1-2 million metric tons of plastic entering our oceans annually. This plastic does not biodegrade and can remain in the ocean indefinitely, causing long-term harm. It is estimated that by 2050, there will be more plastic in the ocean (by weight) than fish unless drastic action is taken.

To address this issue, domestic policies and foreign investments in waste management infrastructure are crucial. Additionally, improving waste management strategies, such as reducing plastic production and usage, are essential to ending plastic pollution. By tackling the problem at its source, we can prevent plastic from reaching our oceans and protect marine life and ecosystems.

Furthermore, the impact of poor waste management extends beyond the environmental realm. Proper waste management can increase economic and job growth, improve human health, and reduce greenhouse gas emissions. Therefore, it is essential to prioritize waste management improvements to address the plastic pollution crisis and promote overall well-being.

Plastic in rivers

The plastic waste in rivers comes from various sources, including mismanaged plastic waste, littering, and leakage from industries. Transport processes such as wind, surface runoff, river flow dynamics, and floods carry the plastic waste into the rivers. Rivers act as long-term sinks for plastic pollution, retaining plastic waste for years, decades, or even centuries. However, under extreme hydrological conditions, such as storms and floods, the plastic waste accumulated in rivers can be emptied into the oceans.

The impact of plastic pollution in rivers extends beyond the marine environment. It also affects human livelihood, with marine plastic costing the global economy billions of dollars annually. Intercepting plastic in rivers is crucial for mitigating the impact of plastic pollution on the marine ecosystem and reducing the economic burden of cleanup efforts. Organizations like The Ocean Cleanup are developing Interceptor solutions to tackle plastic pollution in the most polluting rivers.

The Interceptor technology from The Ocean Cleanup consists of two booms, one upstream and one downstream, to effectively capture plastic waste in rivers. The upstream boom takes the majority of the pressure and waste, while the downstream boom captures any plastic missed due to pressure build-up and rapid trash accumulation. The Interceptors work in conjunction with local partners, governments, and waste handlers to extract, sort, and recycle the plastic waste.

By addressing plastic pollution in rivers through interception technologies and collaborative efforts, we can make significant progress toward reducing the amount of plastic entering the oceans and mitigating its harmful effects on marine life, ecosystems, and the global economy.

Microplastics

The issue of plastic pollution in the world's oceans is a significant environmental concern, and one that is multifaceted. Microplastics, tiny plastic particles measuring less than 5mm in diameter, are a key component of this crisis. These particles can enter the ocean through various pathways, including drainage systems, and once in the marine environment, they can have far-reaching and detrimental effects.

Plastic from the fishing industry

While most plastic waste in the ocean comes from land-based sources, the fishing industry is a significant contributor to the problem. Abandoned fishing gear, such as nets, ropes, and traps, makes up a large proportion of plastic waste in the ocean. This type of pollution is particularly harmful as it can continue to trap and kill marine animals, including fish, crustaceans, mammals, sea turtles, and seabirds.

A study by The Ocean Cleanup, a non-profit organization working to rid the world's oceans of plastic, found that 75% to 86% of the plastic waste in the Great Pacific Garbage Patch (GPGP) comes from offshore fishing activity. The GPGP is an accumulation zone in the North Pacific Subtropical Gyre, also known as the North Pacific Garbage Patch (NPGP), and is one of the five giant ocean garbage patches. It is estimated to be around three times the size of France and contains tens of thousands of tonnes of floating plastic debris. The majority of the fishing gear in the GPGP originates from the U.S., China, Japan, and the Korean Peninsula.

Fishing gear makes up 50-100% of plastic debris found in other parts of the ocean as well. A 2019 oceanographic mission in the North Pacific Subtropical Gyre retrieved over 6,000 hard plastic debris items larger than 5 cm. The debris was analyzed for origin and age, and results revealed that a large fraction was composed of fishing nets and ropes, with the rest being mostly hard plastic objects and fragments. This study provides evidence that fishing activities, particularly from industrialized fishing nations, are responsible for the accumulation of floating plastics in this region.

To address the issue of plastic pollution from the fishing industry, various measures can be taken. Governments can implement regulations and take action to prevent fishing gear from polluting the oceans, including stopping illegal fishing operations and removing abandoned gear. Consumers can also play a role by reducing their demand for fish, thereby decreasing the impact of the commercial fishing industry. Additionally, the fishing industry itself can transition to recycled materials, update packaging, and eliminate single-use plastics.

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