The Ocean's Plight: Pollution's Impact

Covering more than 70% of the Earth's surface, oceans are among the planet's most valuable natural resources. They govern the weather, clean the air, help feed the world, and provide a living for millions. However, human activities have led to the pollution of these vital ecosystems. Marine pollution is a combination of chemicals and trash, with 80% of the waste in our oceans originating on land. From carbon emissions and plastic waste to oil spills and noise, the types of ocean pollution that humans generate are vast. This pollution has far-reaching consequences, impacting the health of marine life, human health, and economic structures worldwide.

Plastic pollution

The ocean is a valuable natural resource, governing the weather, cleaning the air, helping feed the world, and providing a living for millions. However, human activities have led to the ocean being polluted with plastic debris, threatening marine life, the food chain, human health, and the delicate balance of aquatic environments.

Microplastics, or plastic particles smaller than 5mm, are a significant component of marine plastic pollution. They can be ingested by marine organisms, mimicking fish eggs and other tiny organisms, and are nearly impossible to filter out once they reach the ocean. Larger plastic items, such as bottles and bags, also contribute to marine litter and can entangle marine life. Plastic pollution in the ocean has impacted at least 267 species worldwide, including sea turtles, seabirds, and marine mammals, with fatalities resulting from ingestion, entanglement, and other factors.

The majority of plastic pollution in the ocean originates from land-based sources, with 80% of marine litter making its way to the ocean from land through storm drains, sewers, and runoff pollution. Human activities such as littering, poor waste management, and industrial processes contribute to the problem. However, ocean-based sources, such as discharges from ships and discarded fishing gear, also play a role. Addressing plastic pollution requires concerted efforts from individuals, communities, and governments, with a focus on reducing plastic consumption, improving waste management, and promoting sustainable practices.

Oil spills

The impact of an oil spill depends on its composition and relative density. Oil spills typically spread on the surface of the water, but they can break up due to wave action, wind force, and currents. Oil spills can also evaporate, becoming denser and more viscous. Oil deposited on exposed rocky and sandy shores is usually cleared swiftly by wave action. However, oil pollution can persist for many years in rocky crevices, on rough gravel, and on mussel beds. Oil spills can change the composition of biological communities in these habitats, causing populations of crustaceans and molluscs to decline.

Chemical contamination

Marine pollution, also known as ocean pollution, is a combination of chemicals and trash. Chemical contamination, also known as nutrient pollution, is concerning for health, environmental, and economic reasons. This type of contamination occurs when human activities, such as the use of fertilisers on farms, lead to the runoff of chemicals into waterways that eventually flow into the ocean. The increased concentration of chemicals, such as nitrogen and phosphorus, in the coastal ocean promotes the growth of algal blooms, which are toxic to wildlife and harmful to humans.

Nonpoint source pollution is a type of chemical contamination that occurs when pollution from small sources, such as individual cars, boats, farms, and construction sites, accumulates and enters the ocean through runoff. This can happen when rain or snow moves pollutants from the ground into the ocean, or when wind transfers debris and deposits it on the ocean's surface. Nonpoint source pollution is a significant issue, with 80% of marine litter originating from land-based sources.

Another form of chemical contamination is point source pollution, which occurs when pollution comes from a single source, such as an oil or chemical spill. While these events are less frequent, they can have a significant impact on the ocean. For example, the 2010 Deepwater Horizon well blowout in the Gulf of Mexico released approximately 134 million gallons of oil into the ocean. In addition to oil spills, chemical discharges from factories, raw sewage overflow from water treatment systems, and stormwater and agricultural runoff contribute to the chemical contamination of the oceans.

The consequences of chemical contamination in the ocean are far-reaching. The presence of heavy metals and other contaminants in seafood can make it harmful for human consumption. Additionally, marine life can be negatively impacted by ingesting microplastics, which absorb chemicals, or by becoming entangled in marine debris. The degradation of excess debris in the ocean consumes oxygen, leading to hypoxic zones, or dead zones, where animal life suffocates and dies.

It is important to address chemical contamination and find solutions to reduce and prevent ocean pollution. This includes improving waste management practices, regulating the use of disposable plastic items, and implementing plans to control nonpoint source pollution. By taking action, we can help protect the health of marine ecosystems and mitigate the negative impacts of chemical contamination on the oceans.

Noise pollution

Ocean noise pollution is a type of pollution caused by human activities that generate excessive and unnatural sound underwater. Sources of this pollution include commercial shipping, oil exploration, seismic surveys, offshore wind turbine installation, and military sonar. This pollution has negative effects on marine life, particularly marine mammals such as whales, dolphins, and porpoises, who rely on sound to communicate, locate mates and prey, navigate, and defend their territories.

In recent decades, ocean noise pollution in many marine areas has doubled every decade since the 1960s, with shipping being a major contributor. In European waters, noise levels doubled within just 5 years between 2014 and 2019. This constant underwater noise generated by vessels can cause "'masking", where the communication of marine mammals is drowned out by noise. Fin whales, for example, stop singing when noise levels are too high. Vessel noise has also been linked to increased stress levels in right whales.

To reduce noise pollution in the marine environment, policies and regulations are needed to mitigate propeller noise from ships, sonar equipment, seismic air guns, pile driving, and construction. Quieter technologies and technical innovations in shipbuilding should also be developed. These actions can help improve the ocean soundscape and enable the recovery of marine life, reducing the negative impacts of noise pollution on marine ecosystems and wildlife.

Nonpoint source pollution

Another significant source of nonpoint source pollution is runoff from livestock ranches, farms, and septic tanks. Faulty septic systems can release bacteria and nutrients into the water, while livestock waste can introduce harmful substances into water bodies. Timber harvest areas can also contribute to nonpoint source pollution through improper logging practices.

The effects of nonpoint source pollution are far-reaching and detrimental. It impacts drinking water supplies, recreation, fisheries, and wildlife. The pollutants can harm aquatic ecosystems and the organisms that depend on them. Additionally, nonpoint source pollution can have economic consequences, affecting industries such as tourism and commercial fishing in coastal communities.

Addressing nonpoint source pollution is challenging due to its diverse sources and lack of a single point of origin. However, governments and organisations are implementing measures to control and mitigate its impact. For example, the US Environmental Protection Agency, in collaboration with other agencies, is working to monitor, assess, and limit nonpoint source pollution through various programs and initiatives. These efforts aim to protect and restore the health of coastal waters and ecosystems affected by this type of pollution.

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