Air Pollution's Impact On Marine Life And Oceans

Marine pollution is a pressing issue, with the ocean absorbing around 30% of CO2 emissions, causing ocean acidification and damaging marine wildlife. Air pollution is a contributing factor, carrying iron, carbonic acid, nitrogen, silicon, sulfur, pesticides, and dust particles into the ocean. The atmosphere is a pathway for pollution to reach the ocean, with vessels also contributing significantly through the dumping of pollutants and exhaust gases. Marine debris, such as plastic waste, poses dangers to marine life, with microplastics entering the food chain and having toxic effects. Chemical pollution from agricultural runoff and industrial waste also has detrimental consequences for marine environments and human health.

Ocean acidification

The pH of the ocean naturally fluctuates within limits due to various processes, and marine organisms have adapted to these usual changes. However, the rapid increase in atmospheric CO2 concentrations, primarily from the burning of fossil fuels and land use change, has accelerated ocean acidification. Since the beginning of the industrial era, the ocean has absorbed approximately 525 billion tons of CO2, with at least 22 million tons absorbed daily. This has resulted in a 30% rise in seawater acidity since the pre-industrial era.

The consequences of ocean acidification are already being observed. Some marine species, particularly those with shells or calcium carbonate structures, are struggling to adapt. For example, the shells of some animals are dissolving, and branching and cold-water corals are having difficulty maintaining their fragile structures. Additionally, ocean acidification may disrupt marine food chains. Some plants and algae may thrive in acidic conditions, but commercially valuable shellfish like oysters, clams, and shrimp could find it challenging to build and maintain their shells. This could have implications for food supply, as these organisms are consumed by larger animals, including humans.

The overall effects of ocean acidification are expected to be negative, with potential extinctions and significant alterations to marine ecosystems. While some species may adapt, the rapid pace of change doesn't leave much time for adaptation. Furthermore, the details of the biological impacts are still uncertain, and the full scope of the consequences is yet to be understood.

Addressing ocean acidification requires a focus on reducing CO2 emissions. Substantial reductions in emissions would allow the Earth system to recover from human-induced acidification and restore balanced ocean chemical conditions. Policies and initiatives, such as the European Green Deal and the Marine Strategy Framework Directive, aim to tackle this issue and restore marine ecosystems.

Marine debris

Additionally, plastic ingestion is a significant issue. Marine animals may mistake plastic debris for food or accidentally consume it along with their meals. Plastic ingestion can lead to intestinal blockage, internal injuries, starvation, and death. Seabirds are particularly vulnerable to plastic ingestion, with plastic found in 90% of seabirds in a recent study. Furthermore, microplastics, which are plastic particles less than 5 millimetres in diameter, have been detected in various marine species, including plankton and whales. These microplastics are consumed by small organisms, which are then eaten by larger animals, leading to the transfer of toxic chemicals up the food chain and potentially into the human food supply.

The sources of marine debris include dumping, improper waste management, littering, and extreme natural events such as hurricanes and typhoons. Major marine debris events caused by natural disasters have brought national and international attention to the issue. While prevention and cleanup efforts are challenging, they are not impossible. Solutions include increasing public awareness, changing individual behaviours, and transitioning to a more sustainable economy with reduced pollution and waste. The "3Rs" (reduce, reuse, recycle) and an additional "R" (refuse) are essential in combating marine debris.

Chemical pollution

Marine pollution is a growing concern, with the ocean being flooded with various types of pollution, including chemicals. Chemical contamination, or nutrient pollution, 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. This increases the concentration of chemicals, such as nitrogen and phosphorus, in the coastal ocean, promoting the growth of toxic algal blooms that can harm wildlife and humans.

Oil spills, such as the Deepwater Horizon disaster, introduce crude oil into the ocean, which is toxic to marine life and challenging to clean up. Ships and marine transportation further contribute to chemical pollution through their ballast, bilge, and fuel tank operations. Atmospheric pollution, including carbon dioxide emissions, also plays a role in chemical pollution of the ocean, leading to ocean acidification, which affects marine organisms that depend on calcium particles in seawater for shell formation.

The presence of microplastics in the ocean is another significant concern. Microplastics, formed from the breakdown of plastic debris, are ingested by small organisms, leading to the absorption of toxic chemicals into their tissues. These toxins then migrate up the food chain, eventually reaching humans. PFAS (per- and polyfluoroalkyl substances), persistent chemicals circulated through the air and water, have also been detected in various marine organisms, including seals, polar bears, and dolphins, indicating their widespread impact on marine ecosystems.

Additionally, historical events have contributed to chemical pollution in marine environments. Since World War II, nations have disposed of chemical weapons in seas like the Baltic Sea, raising concerns about environmental contamination. The Fukushima Daiichi nuclear disaster in 2011 released radioactive toxins into the ocean, affecting the benthic food web and the entire marine food chain.

Noise pollution

Marine pollution is a pressing issue, encompassing various forms of contamination, including chemical and plastic waste pollution. However, the impact of noise pollution on marine environments is a less understood area.

The impact of noise pollution on marine life is evident, with studies showing a decline in cetacean populations (whales and dolphins) in areas with high noise pollution. For example, increased ship noise has caused bottlenose dolphins to simplify their vocal calls, potentially reducing the information content of their communication. Marine animals may also flee their original habitats due to harsh noises, leading to injuries or death.

The cumulative effects of concentrated noise pollution pose a unique risk to localized ecosystems. The increase in global shipping activity has contributed to a rise in ambient noise levels, particularly in the low-frequency range, which can propagate over long distances with minimal attenuation. This rise in ambient noise levels has the potential to impact the health and functioning of marine ecosystems.

To address this issue, policies and regulations are needed to reduce propeller noise from ships and mitigate the sounds of sonar equipment, seismic air guns, and construction. Quieter technologies and more efficient ship designs can also play a crucial role in reducing noise pollution and improving the ocean soundscape, allowing for the potential recovery of some marine life.

Oil spills

Marine pollution is a pressing issue, with oil spills being one of the most emotive and well-known events that cause it. Oil spills can have devastating effects on marine environments, wildlife, and coastal communities. The chemical constituents of oil are poisonous and can harm organisms through internal exposure, such as ingestion or inhalation, and external exposure, such as skin and eye irritation.

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