Ocean Pollution: Harming Marine Life And Coastal Communities

Ocean pollution is a pressing issue that poses a threat to marine life and human health. The oceans, covering over 70% of the Earth's surface, are essential for the survival of all life on the planet, providing over 97% of the world's water supply and 70% of the oxygen we breathe. However, human activities have led to the contamination of these waters with various pollutants, including plastic, oil, carbon emissions, and toxic chemicals. Marine debris, such as plastic, accounts for billions of pounds of trash in the ocean each year, with plastic pollution being the most prominent factor. This pollution originates from both land-based and ocean-based sources, with a significant amount coming from nonpoint source pollution, such as runoff from septic tanks, vehicles, farms, and other inland activities. The impact of this pollution is widespread, affecting marine ecosystems, coastal economies, and human health. Marine animals, such as fish, birds, and mammals, suffer entanglement, ingestion of plastic, and habitat destruction, leading to devastating consequences for entire species. Additionally, toxic chemicals like mercury, pesticides, and heavy metals contaminate water supplies and the food chain, causing health issues in humans, including hormonal, reproductive, nervous system, and kidney problems. Addressing ocean pollution requires collective efforts to reduce, recycle, and responsibly manage waste, as well as enforce regulations and promote sustainable practices.

Marine life

Sea turtles, for instance, often mistake plastic bags for jellyfish, a primary treat for turtles. Turtles may also choke on plastic or sustain internal injuries, sometimes dying as a result. In addition, research indicates that half of sea turtles worldwide have ingested plastic. Furthermore, plastic pollution on beaches is affecting their reproduction rates by altering the temperature of the sand where incubation occurs.

Another species affected by plastic pollution is the Hawaiian monk seal, which is already endangered. The primary threat to these seals is entanglement in fishing gear, which can cause infection or total immobility. In addition, there is a high amount of plastic found in their pup nurseries.

Marine mammals such as whales and dolphins have also been found with plastic in their stomachs. They can also get trapped in lines or nets, leading to drowning or starvation.

Plastic pollution is not only harmful to marine animals that ingest it or become entangled in it. It also affects animals that feed on or near the ocean, such as seabirds. Research suggests that 60% of seabirds have ingested plastic, while other estimates put this number closer to 90%. The ingestion of plastic reduces the storage volume of the stomach, leading to starvation.

In addition to the direct harm caused by plastic ingestion or entanglement, marine life is also affected by the depletion of oxygen in seawater caused by ocean pollution. As excess debris in the ocean slowly degrades over many years, it consumes oxygen, leading to the death of ocean animals such as penguins, dolphins, whales, and sharks.

Furthermore, excess nitrogen and phosphorus in seawater can also cause oxygen depletion, creating dead zones where very little marine life can survive.

The consequences of ocean pollution on marine life are far-reaching and often deadly. While some animals die from entanglement or ingestion of plastic, others suffer from cancer, behavioral changes, and reproductive issues due to exposure to toxic chemicals.

Human health

Ocean pollution is a complex mixture of toxic metals, plastics, manufactured chemicals, petroleum, pesticides, fertilizers, pharmaceutical chemicals, agricultural runoff, and sewage (See figure). Eighty percent of ocean pollution arises from the land and it reaches the oceans through rivers, runoff, deposition from the atmosphere, and direct dumping, such as pollution from waste water treatment plants and discarded waste. Ocean pollution is heaviest near the coasts and most highly concentrated along the coastlines of low-income and middle-income countries.

The most hazardous ocean pollution is plastic waste, which enters the seas at a rate of more than 10 million tons each year. Plastic waste kills marine life and breaks down into microplastic particles that contain multiple toxic chemicals – carcinogens, neurotoxins, and endocrine disruptors – which interfere with hormones and can cause cancer, birth defects, and reduced fertility. When humans eat seafood contaminated with these materials, they ingest millions of microplastic particles and the many chemicals they carry.

Mercury is another major ocean pollutant, with coal burning in homes and industry being the primary source. Mercury accumulates to high levels in predatory fish, such as tuna, and can cause brain injury, reduced IQ, and increased risk of autism, ADHD, and other learning disorders in infants exposed in the womb through their mothers' consumption of contaminated fish. Adult exposure to mercury increases the risk of heart disease and dementia.

Petroleum pollutants from oil spills threaten the marine microorganisms that produce much of the Earth's oxygen by reducing their capacity for photosynthesis. Coastal pollution increases the frequency of harmful algal blooms, which produce powerful toxins that accumulate in fish and shellfish and can cause dementia, amnesia, paralysis, and death in humans who eat contaminated seafood. When inhaled, these toxins can cause asthma.

The combination of coastal pollution and sea surface warming encourages the spread of dangerous pathogens such as Vibrio cholerae, the causative agent of cholera. The health impacts of ocean pollution disproportionately affect indigenous peoples, coastal communities, and vulnerable populations in the Global South.

The environment

Oceans are among the Earth's most valuable natural resources. They cover more than 70% of the planet's surface, provide over 97% of the world's water supply, and produce over 70% of the oxygen we breathe. They are home to most of the life on Earth, from microscopic algae to the blue whale, the largest animal on the planet.

However, human activity is causing significant harm to the oceans. Every year, billions of pounds of trash and other pollutants enter the ocean. The majority of this waste comes from human activities along coastlines and far inland. For example, nonpoint source pollution occurs as a result of runoff from septic tanks, vehicles, farms, and other sources. Point source pollution, on the other hand, comes from a single source, such as an oil or chemical spill.

One of the biggest factors affecting the oceans is plastic pollution. Plastic waste, such as single-use plastic bags, water bottles, and fishing gear, accounts for a significant portion of the trash in the ocean. It is estimated that there are 15-51 trillion pieces of plastic in the world's oceans, and at current rates, plastic is expected to outweigh all the fish in the sea by 2050. Plastic pollution harms marine life, including fish, birds, marine mammals, and sea turtles, and can also interfere with human health. Microplastics, which are tiny plastic particles, are easily ingested by marine life and can cause physical harm and toxic exposure. As microplastics move up the food chain, they can pose risks to human health as well.

In addition to plastic pollution, other forms of ocean pollution include chemical, light, and noise pollution. Chemical pollution, such as oil, mercury, lead, pesticides, and other heavy metals, can contaminate water supplies and the food chain. Light pollution, caused by artificial light at night, disrupts the normal cues associated with circadian rhythms in marine organisms, affecting their migration, reproduction, and feeding patterns. Noise pollution, generated by ships, sonar devices, and oil rigs, interrupts underwater communication for marine mammals like whales and dolphins, disrupting their migration, communication, hunting, and reproduction patterns.

The impact of ocean pollution on marine ecosystems and human health is severe and far-reaching. It is essential to address this issue through individual and collective action, including reducing plastic consumption, encouraging recycling, and supporting environmental advocacy groups and sustainable practices.

The economy

Marine plastic pollution has significant economic and societal repercussions. Industries like tourism, fishing, and real estate are heavily dependent on marine environments, and pollution can severely impact these economic opportunities.

In the United States, the tourism and recreation sector is the largest employer in the ocean and Great Lakes economy, with the sector contributing $124 billion to gross domestic product (GDP). Marine debris can deter tourists from visiting beaches, leading to a decline in tourism spending and a decrease in local jobs. A study found that doubling marine debris on beaches in coastal Alabama resulted in a loss of $113 million in tourism revenue and nearly 2,200 jobs. Conversely, reducing marine debris can boost tourism spending and create jobs. For example, decreasing marine debris on Ohio's shorelines was estimated to generate an additional $217 million in tourism revenue and over 3,700 jobs.

Marine debris also impacts commercial and recreational fisheries. It can interfere with fishing gear, reduce catches, and create safety and navigation hazards. Lost fishing gear can damage sensitive habitats and continue to catch species, a process known as "ghost fishing," resulting in financial losses for fishers. Additionally, lost lines, nets, and traps incur replacement costs for fishers. A study found that removing derelict crab pots from the Chesapeake Bay could increase the harvest of blue crabs by 38 million pounds, resulting in a revenue increase of $33.5 million.

The economic impact of marine plastic pollution extends beyond local communities. It is estimated to cost the global economy $19 billion annually, with the potential to triple by 2040. The United States lost $255 million in revenue due to plastic pollution in 2018, and polluted waters can cause real estate prices to drop by up to 25%. The economic damage to marine ecosystems due to plastic pollution is significant, amounting to nearly $13 billion, according to the UN Environment Program (UNEP).

The food chain

Ocean pollution is having a devastating impact on the food chain, with toxic chemicals and plastic waste contaminating water supplies and our food sources. The ocean is a vital source of oxygen and water for the planet, and its health is essential for all life on Earth.

Bioaccumulation and Biomagnification

Bioaccumulation is the process by which toxins accumulate in the tissues of animals over time. This occurs when an animal consumes polluted food or absorbs chemicals through its skin. Instead of expelling the toxins, the animal stores them in its fatty tissues. As a result, predators that consume these contaminated animals also ingest the toxins, leading to biomagnification, where toxins are concentrated at higher levels in the food chain. This can have severe health consequences for animals and humans, including hormonal issues, reproductive problems, nervous system damage, and an increased risk of cancer.

Microplastics

Microplastics are a significant contributor to ocean pollution, with plastic debris found in swirling convergences that make up about 40% of the world's ocean surfaces. These tiny plastic particles are ingested by marine life, including fish, birds, and seals, and can cause physical harm and toxic exposure. As larger animals consume contaminated prey, microplastics move up the food chain, eventually reaching humans through seafood consumption. The effects of microplastics on human health include digestive issues, immune system dysfunction, and long-term risks like cancer.

Chemical Contaminants

Various chemical contaminants, such as oil, mercury, lead, pesticides, and industrial waste, are released into the ocean through direct dumping, runoff, and atmospheric deposition. These toxins can accumulate in the tissues of marine organisms, making them unsafe for consumption. For example, heavy metals like mercury can build up in fish tissues, posing a danger to both wildlife and humans who consume them. Oil spills can coat the feathers of seabirds and the gills of fish, impairing their movement, feeding abilities, and breathing.

Eutrophication

Eutrophication, or the overabundance of nutrients in a body of water, is another consequence of ocean pollution. Agricultural runoff carrying high levels of nutrients can lead to fish kills due to oxygen depletion, disrupting the food chain. This has immediate and far-reaching impacts, affecting both small and large marine ecosystems.

Loss of Key Species

Ocean pollution can also lead to the loss of key species in the food chain. For example, pesticides have been implicated in the deaths of over 30% of honeybees in the United States between 2006 and 2009. Honeybees play a crucial role in pollination, and their decline can result in reduced availability of fruits, vegetables, and berries for both humans and animals.

In summary, ocean pollution has far-reaching consequences for the food chain, impacting the health and survival of various species, including humans. It is crucial to address this issue through sustainable practices, responsible waste management, and collective action to protect the health of our oceans and the planet.

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