Understanding Ocean Pollution: Three Key Human Factors

Ocean pollution is a pressing environmental issue that poses a grave threat to the health and well-being of our planet. Oceans cover 70% of the Earth's surface and are pivotal to the health of our ecosystem, including humans and land-dwelling animals. While the exact amount of pollution in the oceans is hard to measure, a recent study estimates that the world's oceans are polluted by roughly 171 trillion plastic particles, weighing around 2.3 million tons. This paragraph will discuss the three main causes of ocean pollution.

Nonpoint source pollution

Agricultural practices, such as the use of fertilizers, can also contribute to nonpoint source pollution. When excess nutrients, usually nitrogen and phosphorus, enter bodies of water, they act as fertilizers, causing high levels of algae growth. This restricts sunlight and oxygen from entering the water, affecting aquatic plants and ecosystems. Forestry practices, boating, and marinas are other human activities that impact nonpoint source pollution.

The effects of nonpoint source pollution are far-reaching and can severely impact the environment, human health, and local economies. It can make water unsafe for humans and wildlife, leading to beach closures and affecting industries like shellfish farming and coastal tourism. Nonpoint source pollution can also contaminate soil and air, impacting the physical and environmental well-being of coastal areas.

To address nonpoint source pollution, various programs and initiatives have been developed. The US Environmental Protection Agency (EPA) has created fact sheets and resources to help the public, homeowners, and specific industries like agriculture and forestry reduce their impact. NOAA's Office for Coastal Management also works with states through the Coastal Nonpoint Pollution Control Program to reduce and prevent polluted runoff.

Industrial waste

In the 1970s, 17 million tons of industrial waste was legally dumped into the ocean. In the 1980s, this figure decreased to 8 million tons, but the waste included acids, alkaline waste, scrap metals, waste from fish processing, flue desulphurization, sludge, and coal ash. The dumping of industrial waste into oceans was only regulated in the early 1970s, and illegal dumping still occurs today. Rivers, canals, and harbors are dredged to remove silt and sand buildup, and about 20-22% of dredged material is dumped into the oceans, with the remainder going into other waters, landfills, or used for development. Dredged material is the most common type of toxic waste dumped into the ocean, and about 10% of it is polluted with heavy metals, hydrocarbons, nutrients, and organochlorines from pesticides.

Manufacturing plants in many areas release toxic waste into the ocean, including mercury. While it has been banned in the USA, sewage also contributes to ocean pollution. Trade openness and industrialization have been shown to have a significant positive impact on marine pollution. To minimize the environmental effects of trade and industrial operations, developed and developing nations should promote sustainable industrial practices and enforce stricter regulations in international trade.

Oil spills

Further, many birds and animals ingest oil when trying to clean themselves, which can poison them. Oil can also mix into the water column, exposing fish, shellfish, and corals. Adult fish may experience reduced growth, enlarged livers, changes in heart and respiration rates, fin erosion, and impaired reproduction. Fish eggs and larvae are especially sensitive to the impacts of oil spills. Even when the impacts are not immediately lethal, oil can accumulate in fish and shellfish, making them unsafe for human consumption.

The Oil Pollution Act of 1990 established that those responsible for oil spills can be held accountable for cleanup and restoration costs. This process, called Natural Resource Damage Assessment (NRDA), involves federal, state, and tribal agencies working with the responsible party to select restoration projects and recover funds, often through legal settlements. Over the last 30 years, these efforts have helped secure over $9 billion to restore the ocean and Great Lakes.

Atmospheric pollution

Plastic pollution is the primary type of ocean pollution, with an estimated 171 trillion plastic particles polluting the world's oceans. These microplastics, tiny plastic particles of 0.2 inches or smaller, are ingested by marine animals or entangle them, leading to the deaths of approximately 100,000 marine creatures annually. Plastic bags, water bottles, drinking straws, and yogurt containers are all examples of single-use plastics that end up in the ocean. The lightweight nature of plastic bags allows them to travel great distances, recently being found at a depth of 10,975 meters in the Mariana Trench.

Another consequence of atmospheric pollution is nutrient pollution, caused by excess nutrients, typically nitrogen and phosphorus, entering water bodies. These nutrients act as fertilisers, promoting excessive algae growth that restricts sunlight and oxygen from reaching aquatic plants. As a result, plants decay, further reducing oxygen levels and creating "dead zones" in the ocean. Agricultural runoff and wastewater generated from lawns are the primary sources of these excess nutrients, with 415 dead zones currently identified worldwide.

In addition to plastics and nutrients, atmospheric pollution also includes noise pollution, which is increasingly generated by human activities. The constant noise from commercial ships, sonar devices, and industrial processes creates an acoustic "smog" that interferes with the communication and behaviours of marine wildlife. This noise pollution can lead to temporary or permanent deafness in marine animals, impacting their ability to feed, avoid prey, and reproduce. High-intensity sonar used by the U.S. Navy and seismic blasts from ships searching for offshore oil and gas have been linked to mass whale strandings and may push some species towards extinction.

Furthermore, atmospheric pollution can result from the use of certain chemicals and products. For example, sunscreen and insect repellents that people apply to their skin can wash off into the ocean, contributing to chemical pollution. While this may be unintentional, it can have detrimental effects on marine life. Similarly, industrial waste and fossil fuel combustion release toxic chemicals and pollutants into the atmosphere, which eventually find their way into the ocean, impacting both marine ecosystems and human health.

Chemical contamination

Ocean pollution, also known as marine pollution, is a combination of chemical contamination and trash. Chemical contamination occurs when chemicals are washed, blown, or intentionally dumped into the ocean. While the exact amount of chemical pollution in the ocean is challenging to measure, it is one of the leading causes of ocean pollution, with 80% of marine pollution originating on land due to human activity.

Industrial activities are a major source of chemical ocean pollution. Manufacturing plants release toxic waste, including mercury and crude oil, into the ocean. Industrial waste was commonly dumped in the ocean in the mid-1900s before regulations were implemented. Even today, some companies continue to illegally dispose of chemicals directly into the ocean. For example, a Los Angeles company, Montrose, was found to have disposed of large amounts of DDT and other toxic chemicals into the ocean for many years. These chemicals have had detrimental effects on the health of marine species and animals higher up in the food chain, such as California sea lions and condors.

Agricultural activities also contribute to chemical ocean pollution. Excess nutrients, such as nitrogen and phosphorus from fertilizers, enter water bodies and act as fertilizers, causing excessive algae growth. This algae growth restricts sunlight and oxygen from reaching aquatic plants, negatively impacting marine ecosystems. Pesticides used in agriculture, such as DDT, can also find their way into the ocean, posing a threat to both environmental and human health. While DDT use is now banned or restricted in most developed nations, its use remains unregulated in many underdeveloped countries.

In addition to industrial and agricultural sources, chemical ocean pollution also comes from pharmaceutical, health, and body care products. These products can enter the ocean through sewage leaks and ineffective water treatment processes. Sun cream, for instance, is an increasing concern, especially in environmentally sensitive habitats such as coral reef systems. Individual humans are now direct sources of sun cream contamination in the oceans, with river systems and water treatment processes also contributing to the issue.

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