Freshwater Pollution's Impact On Our Oceans

Freshwater pollution is a pressing issue that poses a serious threat to the health and well-being of our planet. Oceans, which cover more than 70% of the Earth's surface, are among the most valuable natural resources, playing a pivotal role in governing the weather, cleaning the air, helping feed the world, and providing a living for millions. However, human activities have led to the degradation of ocean health at an alarming rate. One of the significant sources of ocean pollution is nonpoint source pollution, which occurs due to runoff from various small sources like septic tanks, vehicles, farms, and livestock ranches. Another contributing factor is atmospheric pollution, where objects are carried by the wind into the ocean, often caused by littering and including single-use plastics. The consequences of ocean pollution are far-reaching, affecting both marine life and human health. Marine animals, such as sea turtles, seabirds, and fish, suffer from entanglement, ingestion of plastic, and the toxic effects of oil spills. Pollutants in the ocean also make their way back into the human food chain, leading to potential long-term health issues.

Plastic pollution

Another source of plastic pollution in oceans is microplastics. Microplastics are tiny plastic particles that can come from a variety of sources, such as the breakdown of larger plastics or the release of plastic microfibers from synthetic clothing during washing. These microplastics can be ingested by marine organisms and accumulate in their bodies, potentially transferring up the food chain to larger animals, including humans who consume seafood.

The impact of plastic pollution on marine life is devastating. It is estimated that at least 800 species worldwide are affected by marine debris, with plastic accounting for 80% of this litter. Research indicates that half of all sea turtles worldwide have ingested plastic, often mistaking it for food and suffering fatal consequences. Seabirds are also severely affected, with an estimated 60% of all seabird species having eaten plastic, leading to starvation as it fills their stomachs. Marine mammals, such as whales and seals, are also at risk, with cases of ingestion and entanglement in plastic debris leading to fatalities.

In addition to the direct impact on marine life, plastic pollution also has indirect effects on marine ecosystems. Floating plastics in the oceans can accumulate and transport pollutants through ocean currents, releasing them into the surrounding environment. This can promote the growth of pathogens and increase the risk of disease in marine organisms, such as corals, which have an 89% chance of contracting a disease when exposed to plastic debris.

The problem of plastic pollution in oceans is a pressing issue that requires urgent attention. With the amount of plastic in the ocean expected to outweigh all the fish in the sea by 2050, it is essential to address this crisis at its source by reducing plastic consumption, improving waste management practices, and advocating for policies that regulate plastics as pollutants.

Oil spills

The effects of oil spills can be long-lasting. Even after cleanup efforts, oil can remain within the water and organisms, continuing to affect marine life. Additionally, it can be difficult for an ecosystem to return to a balanced state, with species populations changing or disappearing.

It is important to note that while some oil spills are small, all spills, regardless of size, can have detrimental effects.

Noise pollution

Marine animals, particularly marine mammals such as whales, dolphins, and porpoises, rely on sound to communicate, locate mates and prey, avoid predators, navigate, and defend their territories. Noise pollution interferes with these key life functions, causing behavioural and physiological changes, masking their ability to detect sound, and even leading to injury and death. For example, very loud sounds can cause marine mammals to panic and ascend too quickly, resulting in decompression sickness and tissue damage from gas bubble lesions.

To reduce noise pollution in the marine environment, policies are needed to mitigate propeller noise from ships, sonar equipment, seismic air guns, pile driving, and construction. Quieter technologies must also be developed to help improve the ocean soundscape and enable the recovery of marine life.

Chemical pollution

Agricultural runoff

Agricultural runoff is a significant contributor to chemical pollution in oceans. When large tracts of land are plowed, the exposed soil can erode during rainstorms, carrying agricultural fertilizers and pesticides into the sea. This nonpoint source pollution can make river and ocean water unsafe for humans and wildlife, and it has led to the closure of beaches in some areas.

Air pollution

Some water pollution starts as air pollution, which settles into waterways and oceans. For example, dirt and silt from fields or construction sites can run off into waterways, harming fish and wildlife habitats.

Oil spills

Oil spills are another source of chemical pollution in oceans. While large spills tend to dominate headlines, consumers account for most of the oil pollution in oceans, including oil and gasoline that drips from cars and trucks. In addition, nearly half of the estimated one million tons of oil that enters marine environments each year comes from land-based sources such as factories, farms, and cities.

Sewage

More than 80% of the world's wastewater flows back into the environment without being treated or reused. This sewage can include metals, solvents, and toxic sludge, which can be harmful to humans and the environment.

Radioactive substances

Radioactive waste is any pollution that emits radiation beyond what is naturally released by the environment. It is generated by uranium mining, nuclear power plants, and the production and testing of military weapons. Radioactive waste can persist in the environment for thousands of years, making disposal a significant challenge.

Manufactured chemicals

More than 140,000 new chemicals have been invented and manufactured in the past 75 years, and these synthetic chemicals are often produced from fossil fuels. Many of these chemicals are used in the manufacture of plastics, and others are incorporated into millions of consumer goods and industrial products. However, the majority of manufactured chemicals have never been tested for safety or toxicity, and their potential to damage ecosystems or harm human health is unknown.

Plastic pollution

Plastic pollution is a significant and rapidly increasing component of ocean pollution. An estimated 8 million metric tons of plastic waste are tossed into the oceans each year, and this waste can persist in the environment for up to a millennium. Plastic pollution can entangle marine life, be ingested by fish and other organisms, and interfere with navigation safety.

Pharmaceuticals and personal care products

More than 10,0000 chemicals are used in the manufacture of pharmaceuticals and personal care products, and these products can enter the oceans through wastewater systems, rivers, and other routes. Some of these chemicals have the potential to accumulate in fish and shellfish species consumed by humans, posing risks to human health.

Sewage and wastewater

Untreated sewage contains harmful bacteria such as E. coli, which can infect water bodies and cause diseases. Other harmful solids and chemicals in sewage can also damage bodies of water that support wildlife. For example, fertilizers encourage algae growth, which blocks sunlight and affects water quality. Bacteria in sewage also use up oxygen in the water as they decompose the organic material in the wastewater, resulting in a lack of oxygen in the water that kills fish. Sewage also causes the water to appear dark and murky, which affects the ability of fish to breathe and see.

According to the National Oceanic and Atmospheric Administration (NOAA), 80% of marine litter comes from land-based sources via storm drains, sewers, and other routes. Sewage released into rivers and oceans can cause a threat to both human health and the environment. Contamination of the coastal marine environment by sewage has been linked to significant numbers of infectious diseases, including gastroenteritis and upper respiratory disease. It has also been associated with the consumption of contaminated seafood, causing illnesses such as diarrhoea, cholera, dysentery, typhoid, and hepatitis A.

To address the issue of sewage and wastewater pollution, treatment plants for wastewater and laws against pouring untreated sewage directly into the environment have been implemented. Additionally, organizations such as the National Oceanic and Atmospheric Administration (NOAA) work with other agencies to develop ways to control sewage pollution and protect marine ecosystems.

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