Land Pollution's Impact On Our Oceans

Atmospheric pollution from land sources significantly impacts the ocean, accounting for 80% of marine pollution. This pollution arises from various human activities, including runoff from farms, vehicles, and construction sites, as well as littering and poor waste management practices. Atmospheric pollutants, such as carbon dioxide, pesticides, chemical waste, and plastic waste, are carried by wind or washed into the ocean, endangering marine life and human health. The degradation of plastic waste, for instance, releases toxic chemicals absorbed by small organisms, which then move up the food chain to larger predators and humans. Additionally, carbon dioxide absorption by seawater leads to ocean acidification, potentially affecting marine ecosystems and food chains. To address these issues, international agreements and regional regulations have been implemented, and strategies such as carbon capture and storage are being explored to reduce atmospheric pollution from land sources that harm the ocean.

Atmospheric pollution from littering

The ocean is severely affected by atmospheric pollution from land sources. Eighty percent of marine pollution comes from land-based sources, threatening marine life, especially in coastal waters and biologically productive areas. Land-based pollutants include pesticides, chemical waste, cleaning agents, petroleum products, mining waste, garbage, and sewage. These pollutants can have devastating effects on marine ecosystems and wildlife.

One significant way in which littering contributes to atmospheric pollution is through the burning of waste. It is estimated that over 40% of the world's litter is burned in the open air, releasing toxic emissions into the atmosphere. These emissions not only cause respiratory issues and other health problems but also contribute to the formation of acid rain. The incineration of litter can release various harmful substances, including carbon dioxide (CO2), nitrogen oxides, sulfur dioxide, and particulate matter. These pollutants can have both local and global impacts on air quality and climate change.

Littering also indirectly affects atmospheric pollution by contributing to the degradation of ecosystems and the release of greenhouse gases. As litter accumulates in natural environments, it can alter soil composition and nutrient levels, disrupt drainage systems, and increase flooding. The decomposition of organic waste in litter, such as food scraps and yard waste, produces methane, a potent greenhouse gas. Methane emissions contribute to the warming of the atmosphere, leading to climate change, which, in turn, affects the oceans.

Additionally, littering directly impacts the ocean through the improper disposal of plastic waste. Plastic pollution has become one of the most pressing environmental issues, with approximately 8 million tons of plastic waste entering the oceans annually. Plastic waste can be carried by wind and waterways into the ocean, where it breaks down into microplastics. These microplastics are ingested by marine organisms and can work their way up the food chain, potentially reaching humans through seafood consumption. Plastic pollution also ensnares marine creatures, leading to injuries and deaths, and smothers coral reefs, disrupting the delicate balance of underwater habitats.

To address the issue of atmospheric pollution from land sources, including littering, a multifaceted approach is necessary. Public education and community engagement in cleanup activities are crucial for raising awareness and reducing littering incidents. Additionally, stricter waste management regulations, sustainable product design, and global collaboration are essential for reducing the production of litter and mitigating its environmental impact on the oceans and the atmosphere.

Ocean acidification

When carbon dioxide dissolves in seawater, the water becomes more acidic and the ocean's pH drops. In the past 200 years, ocean water has become 30% more acidic, faster than any known change in ocean chemistry in the last 50 million years. The pH of surface ocean waters has fallen by 0.1 pH units since the Industrial Revolution, from 8.2 to 8.1. This corresponds to a 26-30% increase in ocean acidity.

The impacts of ocean acidification vary across species. While some algae and seagrass may benefit from higher CO2 concentrations, increasing the acidity harms other species such as molluscs, corals, and some plankton varieties. The shells and skeletons of these organisms may become less dense and strong, making them more susceptible to damage and slowing their recovery rate.

The consequences of ocean acidification extend beyond marine ecosystems, impacting human societies that depend on the goods and services provided by these ecosystems. Food security is at risk, with commercially and ecologically important marine species expected to be affected. The loss of molluscs such as oysters and mussels alone could result in global annual costs exceeding US$100 billion by 2100. Coastal protection and tourism are also vulnerable, with coral reefs providing vital protection from storms and cyclones and attracting significant tourism revenue.

Addressing ocean acidification requires a focus on reducing global greenhouse gas emissions and implementing adaptation strategies at the local level, such as improving water quality and developing sustainable fisheries management practices.

Nonpoint source pollution

One example of nonpoint source pollution is when rainfall flows across a parking lot and picks up oil leaked by parked or passing cars. This runoff then empties into a stream, which eventually leads to a lake, river, or ocean, carrying pollutants with it. The pollutants in this runoff can have harmful effects on the environment, economy, and human health. For instance, they can lead to mass die-offs of fish, making water look dirty, and rendering it unsafe for human consumption. This can result in financial losses for the fishing industry and a decline in tourism as coastal areas become less appealing to visitors.

Another example is the use of nitrogen-based fertilizers in agricultural operations, which can migrate to rivers and estuaries and ultimately reach the sea. Here, they promote harmful algal growth and create dead zones by depriving marine areas of oxygen, making it impossible for marine life to exist. Nonpoint source pollution also includes excess fertilizers, herbicides, and insecticides from agricultural lands and residential areas; oil, grease, and toxic chemicals from urban runoff and energy production; sediment from improperly managed construction sites, crop and forest lands, and eroding streambanks; and bacteria and nutrients from livestock, pet wastes, and faulty septic systems.

The effects of nonpoint source pollution vary and may not always be fully assessed, but it is considered the leading cause of water quality issues. Efforts to control and reduce nonpoint source pollution are ongoing, with organizations like NOAA's Office for Coastal Management working with states to address this issue.

Intentional discharge

Ships are major contributors to ocean pollution, especially when crude oil spills occur. Crude oil lasts for years in the ocean and is difficult to clean up.

Atmospheric pollution is often caused by littering. Atmospheric pollution includes single-use plastics (such as plastic bags) and styrofoam containers, which can take hundreds of years to biodegrade. Atmospheric pollution is carried by wind to the ocean.

Deep-sea ocean mining also causes ocean pollution and ecosystem disruption at the lowest levels of the ocean. Drilling for substances such as cobalt, zinc, silver, gold, and copper creates harmful sulfide deposits deep in the ocean.

Oil spills

The effects of oil spills on marine life are wide-ranging and devastating. Oil spills can harm marine animals like fish and shellfish, as well as other species such as marine birds, sea turtles, and mammals. Oil destroys the insulating ability of fur-bearing mammals like sea otters, and the water-repelling abilities of a bird's feathers, exposing them to harsh elements. Many birds and animals swallow oil when trying to clean themselves or eat oiled prey, which can cause gastrointestinal irritation, ulcers, bleeding, diarrhoea, and digestive complications. It can also cause reproductive or developmental damage, liver disease, and even cancer.

The magnitude of harm caused by an oil spill can vary depending on factors such as the amount of exposure, the pathway of exposure, the age and health of the animal, and the type of synthetic chemicals used to clean up the spill. While nature can help to disperse and break down oil over time, the process is slow and unreliable, and the damage caused by oil spills can persist for years.

Frequently asked questions