Ocean Pollution: Our Health At Risk

Ocean pollution is a serious threat to human health and well-being. It is caused by human activity and affects more than 3 billion people. The toxins in the ocean make landfall and enter the human body mainly through the consumption of contaminated seafood.

The toxins in the ocean include mercury, pesticides, industrial chemicals, petroleum wastes, agricultural runoff, and manufactured chemicals embedded in plastic. These toxins are especially harmful to people in coastal fishing communities, small island nations, indigenous populations, and people in the high Arctic.

The effects of ocean pollution on human health include an increased risk of cardiovascular disease, dementia, behavioural changes, reproductive issues, and cancer.

Mercury pollution: Mercury is released into the ocean through coal combustion and small-scale gold mining. It is the metal pollutant of greatest concern in the oceans

Mercury is a heavy metal that cycles through the atmosphere, water, and soil in various forms, and it has been identified as a global pollutant. The largest source of mercury in the oceans is atmospheric deposition, which introduces three types of mercury: gaseous elemental mercury (Hg0), inorganic mercury (Hg2+/HgII), and particle-bound mercury (Hg(P)). Mercury is released into the ocean through coal combustion and small-scale gold mining, which are the two largest anthropogenic sources of mercury emissions.

Coal combustion has tripled since 1970 and is responsible for 21% of global mercury emissions, estimated at 2220 tonnes per year. Despite a growing number of countries moving away from coal, global demand is expected to remain steady over the next five years. Mercury is released from coal-fired power plants and coal washing. Up to 95% of mercury releases from power plants can be reduced by improving coal and plant performance and optimizing control systems for other pollutants.

Small-scale gold mining, also known as artisanal gold mining, is the largest single anthropogenic source of mercury emissions, and it involves the use of elemental mercury. Mercury is mixed with gold-containing materials to form an amalgam, which is then heated to vaporize the mercury and obtain the gold. This process can lead to significant mercury exposure and health risks for miners and their communities. The Minamata Convention on Mercury recognizes the risks of using mercury in small-scale gold mining and calls upon nations to reduce or eliminate mercury use in this sector.

Mercury pollution in the ocean has become widespread, accumulating in high levels in predator fish, and posing documented risks to infants, children, and adults. It can bioaccumulate in marine food chains in the form of highly toxic methylmercury, which can cause severe health issues for humans who consume contaminated seafood. The United States Environmental Protection Agency (EPA) states that mercury consumption can result in loss of peripheral vision, weakened muscles, impaired hearing and speech, and deteriorated movement coordination. Infants and developing children are especially vulnerable, as mercury exposure inhibits brain and nervous system development, damaging memory, cognitive thinking, language abilities, attention, and fine motor skills.

To address mercury pollution, the following actions are recommended:

• Banning coal combustion and transitioning to renewable energy sources
• Reducing and eliminating mercury use in small-scale gold mining
• Implementing policies for proper treatment and disposal of industrial mercury waste
• Promoting public awareness about the importance of reducing mercury emissions and properly disposing of mercury-containing items

Plastic pollution: Plastic waste is the most visible component of ocean pollution. It kills marine life and breaks down into harmful microplastics

Plastic waste is the most visible component of ocean pollution. It is a global crisis, with billions of pounds of plastic in the oceans, making up about 40% of the world's ocean surfaces. At current rates, plastic is expected to outweigh all the fish in the sea by 2050.

Plastic waste in the ocean kills marine life. It has impacted at least 267 species worldwide, including 86% of all sea turtle species, 44% of all seabird species, and 43% of all marine mammal species. Marine animals are killed by ingesting plastic, or by getting entangled in it. Plastic waste also breaks down into harmful microplastics.

Microplastics are small plastic particulates that measure less than 5mm in size. They are invisible in water and will either float or sink, depending on what they are made of. Microplastics that float accumulate in large oceanic currents called gyres, while those that sink are mistaken for food by sea life.

Microplastics are ingested by marine life, impacting the entire food chain. They are consumed by fish and other marine animals, which are then eaten by larger predators, including humans. Microplastics can also absorb toxins, which are then transferred to the fatty tissues of the organisms that ingest them.

The problem of plastic pollution in the oceans is growing. The amount of plastic debris in the oceans is increasing, and the production of plastic is expected to increase by 40% over the next decade. Urgent action is needed to address this crisis.

Oil spills: Oil spills and chemical wastes threaten the microorganisms in the sea that produce oxygen

Oil spills and chemical waste are a major threat to the health of marine microorganisms, which are responsible for producing a large portion of the world's oxygen. Oil spills can have both acute and chronic effects on marine life, including microorganisms. Acute toxicity refers to the immediate short-term effects of exposure to a toxicant, while chronic toxicity refers to the long-term effects of continuous exposure or the long-term sublethal effects of acute exposure.

Oil spills can directly kill marine organisms and disrupt marine communities and ecosystems. It destroys the insulating ability of fur-bearing mammals and the water repellency of bird feathers, leading to hypothermia and death. Oil can also affect the lungs, immune function, and reproduction of dolphins and whales, who inhale it. In addition, many birds and animals ingest oil when trying to clean themselves, which can poison them.

Oil spills also have sublethal effects on marine life, including reduced growth, enlarged livers, changes in heart and respiration rates, fin erosion, and reproduction impairment in adult fish. Even when lethal impacts are not observed, oil can make fish and shellfish unsafe for human consumption. Juvenile sea turtles can mistake oil for food and become trapped in it. Oil entered the sea through small amounts released over long periods or through point sources, such as natural seeps, leaking pipelines, and offshore production discharges.

The long-term effects of oil spills are complex and depend on various factors, including the type of oil, the amount released, the location, and the timing. Recovery from oil spills can take years or decades and is challenging to assess due to the natural variability of marine ecosystems. Oil spills can have lasting impacts on marine communities and ecosystems, including the removal of keystone predators and changes in community composition.

Overall, oil spills and chemical waste pose a significant threat to the health and well-being of marine microorganisms, which play a crucial role in producing oxygen for the planet. The effects of oil spills can be both acute and chronic, directly killing marine life and disrupting ecosystems, as well as having sublethal impacts on reproduction and growth. The long-term consequences of oil spills are complex and challenging to recover from, highlighting the importance of prevention and effective response strategies to protect marine life and human health.

Coastal pollution: Industrial waste, agricultural runoff, pesticides, and human sewage increase the frequency of harmful algal blooms

Coastal pollution is a significant contributor to the increase in harmful algal blooms (HABs). HABs are "red tides", "brown tides", and "green tides" that occur when toxin-producing algae grow excessively in ocean waters. Industrial waste, agricultural runoff, pesticides, and human sewage are all contributors to the increase in HABs. These blooms produce toxins associated with dementia, amnesia, neurological damage, and rapid death.

Industrial waste, agricultural runoff, pesticides, and human sewage are all contributors to the increase in HABs. HABs are the result of eutrophication, which occurs when there is an overabundance of nutrients in a body of water. Nitrogen and phosphorus are the primary nutrients responsible for eutrophication, and they can come from a variety of sources, including industrial waste, agricultural runoff, and human sewage.

When these nutrients enter coastal waters, they fuel the growth of toxin-producing algae. These algae can produce potent toxins that have been linked to a range of health issues, including dementia, amnesia, neurological damage, and rapid death. People are typically exposed to these toxins by consuming contaminated fish and shellfish.

The increase in HABs poses a significant threat to both marine life and human health. It is crucial to address coastal pollution and implement measures to reduce the frequency and severity of HABs to protect the health and well-being of coastal communities and the marine ecosystem.

Climate change: Warmer sea temperatures increase the spread of marine microbes that cause disease

Warmer sea temperatures increase the spread of marine microbes that cause disease. This is due to the fact that temperature is a fundamental driver of marine communities. As the ocean warms, the metabolic rates of marine microbes increase, and their interactions within the microbial food web are altered.

Heterotrophic bacteria occupy a central position in the marine microbial food web, and their metabolic activity and interactions with other compartments within the web are regulated by temperature. As sea temperatures rise, key ecosystem processes such as bacterial production, respiration, growth efficiency, and bacterial-grazer trophic interactions are likely to change.

For example, warming increases bacterial respiration and bacterial losses to their grazers, leading to an increase in the bacterial-grazer biomass flux within the microbial food web. This can have a significant impact on the carbon cycle in a warmer ocean, as microbes play a crucial role in carbon cycling.

In addition, warming can also affect the distribution and abundance of marine microbes. Some studies have predicted that warmer temperatures will lead to a more oligotrophic ocean, with a higher proportion of picophytoplankton and higher bacterial respiration. This can further impact the food web and nutrient cycling in marine ecosystems.

Furthermore, the increase in sea temperatures can also have implications for human health. Warmer waters can promote the growth of harmful algal blooms, which produce toxins associated with dementia, amnesia, neurological damage, and rapid death. These toxins can accumulate in seafood, posing risks to human health when consumed.

Overall, the rise in sea temperatures due to climate change has significant implications for the spread of marine microbes and their potential impact on both marine ecosystems and human health.

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