Sea Life's Pollution Battle: Understanding The Devastating Impact

Marine life is under threat from a range of pollutants, from plastic to oil and carbon emissions. The ocean is a dumping ground for human waste, and our behaviour has resulted in contaminated seafood, dead zones, and compromised biodiversity. It is estimated that up to 13 million metric tons of plastic end up in the ocean each year, threatening marine ecosystems and the people who depend on them. Plastic pollution is particularly harmful, with at least 800 species worldwide affected by it. Marine animals suffer from entanglement and ingestion of plastic, which can lead to suffocation, starvation, and drowning. In addition, chemical pollution causes dead zones in the ocean, depleting the oxygen in seawater and creating an uninhabitable environment for plant and animal life. Noise pollution from human activities such as shipping and oil exploration also harms marine life, altering the underwater acoustic landscape and harming marine species. The impact of pollution on marine life is widespread and devastating, and urgent action is needed to address this crisis.

Plastic pollution

One of the primary ways plastic pollution harms sea life is through ingestion. Many marine animals, from seabirds to whales and fish, mistake plastic waste for food. This can lead to starvation, as their stomachs become filled with indigestible material, or internal injuries and death. Research indicates that half of all sea turtles worldwide have ingested plastic, and a recent study found that sea turtles that ingest just 14 pieces of plastic have an increased risk of death. Not only does this impact the individual animals, but it also has broader ecological implications, as plastic pollution has been found to affect reproduction rates by altering the temperatures of the sand where incubation occurs.

In addition to ingestion, entanglement in plastic debris is another significant issue. Large items of plastic, such as discarded fishing nets and six-pack rings, can trap and entangle marine mammals and fish, leading to starvation, injury, and increased vulnerability to predators. It is estimated that plastic contributes to the death of more than 100,000 marine mammals every year, including endangered species such as Hawaiian monk seals and Pacific loggerhead sea turtles.

The impact of plastic pollution extends beyond the individual animal level. Plastic waste can encourage the growth of pathogens in the ocean, with studies showing that corals that come into contact with plastic have an 89% chance of contracting diseases compared to a 4% likelihood for corals that do not. Additionally, floating plastic items can transport invasive species, further threatening marine ecosystems, biodiversity, and the food web.

Another concerning aspect of plastic pollution is the presence of microplastics, tiny particles of plastic that result from the breakdown of larger plastic items. These microplastics are easily consumed by marine animals and can enter the food chain, leading to potential health risks for both marine life and humans. Microplastics have been found in various sources of food and water, including seafood, drinking water, salt, and beer. The long-term impacts of microplastics are still being studied, but they pose a significant risk to the health of our planet and all its inhabitants.

Addressing plastic pollution requires a multifaceted approach, including improved waste management systems, increased recycling, and reduced usage of disposable packaging and single-use plastics. It is essential to tackle this issue at its source to prevent further harm to sea life and our planet.

Mercury pollution

Mercury is a heavy metal that cycles through the atmosphere, water, and soil. Due to its natural cycle, irrespective of which part of the world releases mercury, it could affect another part of the world, making it a global concern. Mercury is released through both natural and anthropogenic processes. Natural processes include volcanic activities and land emissions through the soil. On the other hand, anthropogenic sources of mercury emission include artisanal and small-scale gold mining, fossil fuel burning, and primary production of non-ferrous metals.

Mercury enters the ocean in different ways, including atmospheric deposition, rivers, estuaries, sediments, and hydrothermal vents. Atmospheric deposition is the largest source of mercury in the oceans. Mercury can be widely dispersed across the globe when deposited in water and air, so even remote parts of the world can quickly suffer elevated levels of this toxic material. The ocean acts as a "storage closet" for mercury, and the total anthropogenic mercury released into the ocean is estimated to be around 80,000 to 45,000 metric tons. Two-thirds of this amount is estimated to be found in waters shallower than 1000 meters, where much of the consumable fish live.

Mercury can bioaccumulate in marine food chains in the form of highly toxic methylmercury, which poses health risks to humans who consume seafood. About 66% of global fish consumption comes from the ocean, so it is crucial to monitor and regulate oceanic mercury levels to prevent mercury from reaching humans through seafood consumption. Mercury can be absorbed by touch, inhalation, or consumption, and it builds up in the body with each exposure. It is challenging to remove, and high levels of mercury can lead to mercury poisoning, which is unpleasant and potentially fatal.

Methylmercury, the harmful form of mercury, can easily cross biological membranes and accumulate to harmful concentrations in the exposed organism. This bioaccumulation results in high levels of mercury in top predator fishes, which can have detrimental effects on humans and fish-eating wildlife. Methylmercury levels in predatory fish are typically more than one million times higher than in the water they inhabit.

Mercury is one of the most serious contaminants threatening aquatic ecosystems. It is a global pollutant that ultimately makes its way into every aquatic ecosystem. It is a potent neurological poison in fish, wildlife, and humans. According to the United States Environmental Protection Agency (EPA), mercury consumption can result in loss of peripheral vision, weakened muscles, impaired hearing and speech, and deteriorated movement coordination. The developing brains and nervous systems of infants and children are particularly vulnerable to mercury exposure, which can lead to damage to memory, cognitive thinking, language abilities, attention, and fine motor skills.

To address the issue of mercury pollution, international action plans have been proposed to minimize anthropogenic mercury emissions and clean up existing mercury pollution. Reducing the usage of coal power, minimizing small-scale artisanal gold mining, properly treating industrial mercury waste, and implementing policies are crucial steps in the long-term plan to reduce mercury emissions. Public awareness is critical in achieving the goal of minimizing mercury pollution and protecting marine life and human health.

Coastal pollution

One of the primary sources of coastal pollution is nonpoint source pollution, which occurs due to runoff from land-based activities. This includes contributions from septic tanks, vehicles, farms, livestock ranches, and timber harvest areas. When large areas of land are plowed, the exposed soil can be washed away during rainstorms, carrying agricultural fertilizers and pesticides into nearby waterways and, ultimately, the ocean. This form of pollution can render river and ocean water unsafe for humans and wildlife, leading to beach closures and adverse effects on shellfish-growing waters. Nonpoint source pollution is challenging to address, requiring costly restoration and protection efforts.

Another significant contributor to coastal pollution is oil and chemical spills from boats, airplanes, cars, trucks, and even lawnmowers. These spills can have devastating and long-lasting consequences for delicate marine ecosystems. Additionally, chemical discharges from factories, raw sewage overflows, and stormwater runoff add to the toxic mix, fuelling the growth of harmful algal blooms and creating aquatic dead zones.

Plastic pollution is also a pervasive issue in coastal areas. Single-use plastic items, such as bags, water bottles, straws, and containers, persist in the environment for hundreds to thousands of years. They pollute beaches, entangle marine life, and are ingested by various species, including fish, whales, turtles, and seabirds. Plastic waste breaks down into smaller pieces over time, making it extremely difficult to retrieve from the ocean. The ingestion of plastics and microplastics can lead to toxic contamination and has been linked to the deaths of over 100,000 marine mammals annually.

Addressing coastal pollution requires a multifaceted approach, including improved waste management practices, the reduction of single-use plastics, and the implementation of policies and technologies to target specific pollution sources. By recognizing the impact of human activities on coastal environments and taking collective action, we can work towards safeguarding the health of our oceans and the life they sustain.

Oil spills

Direct Effects of Oil Spills on Wildlife:

Indirect Effects of Oil Spills on Wildlife:

Factors Influencing the Impact of Oil Spills:

The amount of exposure to oil, the pathway of exposure, and the age and health of the animal all influence the degree of harm caused by an oil spill. The longer the oil is present at the surface, the greater the likelihood of exposure for surface-dwelling species. The type of synthetic chemicals used to clean up the spill can also impact the magnitude of harmful effects.

Susceptibility of Wildlife to Oil Spills:

The vulnerability of wildlife to oil spills changes over time. Initially, species that spend time at the surface, such as whales, manatees, and dolphins, are most at risk. As the oil washes ashore, shorebirds and marine mammals that live at the ocean's edge are affected. Finally, benthic species, like crabs and oysters, are impacted once the oil particles mix throughout the water column.

Noise pollution

Marine animals rely on sound to communicate, locate mates and prey, avoid predators, navigate, and defend their territories. Noise pollution can cause a variety of negative effects, including temporary or permanent hearing loss, behavioural and physiological changes, masking (when an animal's ability to detect sound is overlapped or covered by another sound), injury, and death.

Very loud sounds can cause panic in marine mammals, leading to decompression sickness and tissue damage from gas bubble lesions. It can also alter their behaviour, causing them to move away from the noise, adjust their activities to avoid noisy times, or increase their anti-predatory behaviour.

Sources of noise pollution in the ocean

The major sources of noise pollution in the ocean include shipping, recreational boating, and energy exploration. Other sources include military sonars or seismic surveys, propellers, pile driving, offshore wind farms, naval exercises, marine tourism, commercial fishing, and oil and gas exploration.

The impact of noise pollution on marine ecosystems and biodiversity

Ways to reduce noise pollution

Some measures to reduce noise pollution include implementing policies to reduce propeller noise from ships, mitigating the sounds of sonar equipment, seismic air guns, pile driving, and construction, and developing quieter technologies.

Frequently asked questions