Ocean Pollution: Solved Or Still A Problem?

Ocean pollution is a significant environmental issue that poses a threat to the health of our planet and all its inhabitants. Marine pollution is a combination of chemicals and trash, most of which comes from human activities along coastlines and far inland. The majority of the garbage that enters the ocean each year is plastic—and it's here to stay. Plastic pollution has a devastating impact on marine life and ecosystems, with hundreds of marine species negatively impacted by plastic debris. While some promising solutions are inadequate, such as biodegradable plastics, and challenging, such as changing society's approach to plastic use, many countries are taking action, and individuals can also play their part in reducing plastic pollution. So, has ocean pollution been solved? The short answer is no.

Plastic pollution

Plastic waste makes up 80% of all marine pollution, with an estimated 8 to 10 million metric tons of plastic ending up in the ocean each year. Rivers are the primary source of this pollution, with more than 1000 rivers accounting for 80% of global riverine plastic emissions into the ocean. However, another significant source of plastic pollution in the ocean is fishing gear, with 80% of the plastic in the Great Pacific Garbage Patch originating from fishing activities. This includes items such as buoys, eel traps, crates, nets, and oyster spacers.

The presence of plastic in the ocean has devastating impacts on marine life and ecosystems. Animals can become entangled in plastic debris, leading to injury and mortality, as seen in the endangered Steller sea lion. Additionally, marine animals may ingest plastic, causing internal injuries and even death. Research indicates that half of the world's sea turtles have ingested plastic, and plastic ingestion has also been observed in hundreds of thousands of seabirds annually. Microplastics have been found in more than 100 aquatic species, including fish, shrimp, and mussels, which are then consumed by humans. These microplastics have been detected in human blood, placentas, tap water, beer, and salt, with potential acute and chronic toxicity, carcinogenicity, and developmental toxicity.

While the problem of plastic pollution in the ocean is far from solved, there is growing momentum for international cooperation to address this crisis. On March 2, 2022, 175 countries participating in UNEA-5.2 adopted a resolution to launch negotiations for a new legally binding international instrument on plastic pollution. This resolution aims to address plastic pollution throughout the entire lifecycle of plastic, from source to sea. Local and global organizations, companies, and initiatives are actively working towards cleanup efforts and improved waste management to tackle this pressing issue.

Oil spills

Offshore drilling is inherently risky, and despite safety regulations, oil spills remain an unavoidable consequence. In November 2023, a large oil spill hit the Gulf of Mexico, releasing over a million gallons of crude oil, according to the Coast Guard. This spill highlighted the dangers of offshore drilling, as oil contaminated the water and threatened the already vulnerable Rice's whale, a species of baleen whale.

The Deepwater Horizon disaster in 2010 is another example of the catastrophic consequences of oil spills. This incident pumped 134 million gallons of oil into the ocean, killing 11 workers and causing long-lasting harm to communities, animals, and habitats. Eight years after the Deepwater Horizon spill, coastal oil concentrations were still ten times higher than before, demonstrating the persistence of oil pollution.

While regulations and safety measures can help prevent some oil spills, they cannot be entirely eliminated. The constant risk of oil spills highlights the importance of reducing our dependence on offshore drilling and transitioning to more sustainable energy sources. In the meantime, continued efforts are needed to mitigate the environmental impact of oil spills and protect marine ecosystems and communities at risk.

Marine debris

Plastic waste makes up around 80% of all marine debris. It is one of the most enduring materials ever created by humans, taking anywhere from 500 to 1000 years to degrade. Even then, it may not fully degrade but instead break down into microplastics, which are tiny particles that can be ingested by marine animals. These microplastics have now been found in drinking water, salt, beer, and even in the soil where we grow our vegetables. As plastic does not biodegrade quickly, it tends to accumulate in the ocean, forming massive marine garbage patches.

Other common types of marine debris include derelict fishing gear, metals, rubber, paper, textiles, and various wastes from ships, oil rigs, and industrial processes. This debris can damage sensitive habitats, entangle and kill wildlife, and interfere with navigation safety. It can also impact human health, as toxic chemicals released by manufacturing plants can contaminate the ocean and enter the food chain.

The majority of marine debris comes from land-based sources, with littering, poor waste management practices, stormwater discharge, and extreme natural events contributing to the problem. However, ocean-based sources, such as lost or abandoned fishing gear and vessels, also play a significant role.

Addressing marine debris requires a multi-faceted approach. The NOAA Marine Debris Program, for example, supports projects that aim to prevent debris from entering the ocean through outreach and education, as well as funding research and community-based removal projects. International laws and policies, such as the UN's Sustainable Development Goal 14 "Life Below Water", have also been adopted to reduce marine pollution. While there is no one-size-fits-all solution, individual actions, such as reducing plastic use and supporting local cleanup initiatives, can make a significant difference in mitigating this global issue.

Nonpoint source pollution

Agricultural practices are a significant contributor to nonpoint source pollution. Sediment, which is soil that has eroded from farm fields, construction sites, and streambanks, can be carried by water into aquatic ecosystems. This sediment clouds the water, making it difficult for aquatic organisms to see and feed properly. It can also damage fish gills and the breathing of aquatic insects, and reduce sunlight penetration, affecting plant growth. Sediment can further carry other harmful pollutants, such as metals and toxic chemicals.

Fertilizers and animal waste from farms can also be picked up by runoff, leading to an excess of nutrients in the water. This can cause algae blooms, which can deplete oxygen levels in the water, creating "dead zones" where marine life cannot survive.

While the issue of nonpoint source pollution is complex and widespread, there are efforts to address and mitigate its impacts. The US Environmental Protection Agency (EPA) has developed programs and fact sheets to help control and reduce nonpoint source pollution, especially regarding agricultural practices and coastal waters.

Noise pollution

Ocean noise pollution refers to the loud and continuous noises from human activities that distress marine animals physiologically and behaviourally. Sources of noise in the marine environment are not regulated at an international level, although international institutions have begun to recognize the threat it poses to marine wildlife.

The major contributors to ocean noise pollution include cargo vessels, recreational boating, and energy exploration. Cargo vessels produce very low-frequency sounds that may travel hundreds of kilometres underwater. As global shipping runs day and night, this constant drone masks the natural soundtrack of the sea. Even terrestrial traffic, on structures like bridges or at coastal airports, can produce low-level, continuous noise that can penetrate underwater. Dredging technology, which is used to deepen ports and harvest minerals from the seafloors, also generates low-frequency noise that travels far. Seismic surveys, used to map offshore oil and natural gas fields, are known to severely damage the internal organs of giant squid and kill zooplankton within a 1.2-kilometre radius.

Sonar operations have also been directly linked to mass whale strandings. In one example, 17 beaked whales were stranded off the coast of the Bahamas following naval exercises involving mid-frequency sonar, with post-mortem examinations revealing physical trauma and internal bleeding. Even at much lower sound levels, blue whales have been recorded to stop feeding, increase their swimming speed, and move away from the sound source, which can have significant impacts on their individual fitness, foraging ecology, and population health.

There are, however, solutions to this problem. The International Maritime Organization (IMO) has established guidelines encouraging the adoption of quieter ship designs to minimize underwater noise pollution, including modifications to hull designs and the use of quieter propellers. Technologies such as bubble curtains—barriers of bubbles created by compressors—are effectively used during offshore construction to absorb and scatter sound waves, significantly lowering underwater noise transmission. By reducing ship speeds by approximately 10%, we could also protect marine life and reduce propeller noise from ships. During the COVID-19 pandemic, marine life surveys conducted around April 2020, when 60% of the world’s population was under lockdown, showed that ocean noise went down by 20%, leading to marine life returning to once-busy waterways. This demonstrates that even a small reduction in noise pollution can have an almost instantaneous positive impact on marine ecosystems.

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