Understanding Coastal Pollution: Major Us Contributors

The United States' coastal pollution is a pressing issue that poses significant risks to both the environment and human health. With over 80% of marine pollution originating from land-based sources, human activities play a pivotal role in the degradation of coastal ecosystems. From industrial and agricultural practices to urban runoff and plastic waste, a multitude of factors contribute to the worsening state of US coastal waters. As a result, unique beach habitats are destroyed, marine life is harmed, and public health is threatened. This complex issue demands immediate attention and a comprehensive approach involving scientific research, policy interventions, and collective action to mitigate the detrimental effects of coastal pollution and protect the delicate balance of our ocean ecosystems.

Plastic and other trash

Plastic debris can be ingested by marine animals, leading to health issues and even death. Microplastics, for instance, are consumed by fish and other species that filter their food from the water, potentially entering the human food chain and impacting human health. Plastic waste also contributes to the depletion of oxygen in seawater, as oxygen is consumed during the degradation process.

The United States is one of the top 20 countries responsible for the majority of plastic pollution globally. This pollution comes from various sources, including runoff from land, accidental or intentional discharges from vessels, and waste from industrial, agricultural, and urban activities. Runoff pollution occurs when rain or snowmelt carries pollutants, such as fertilizers, pesticides, chemicals, motor oil, and trash, from the ground into storm drains, rivers, and eventually the ocean. Discharges from vessels, such as recreational boats and commercial ships, can also contribute to plastic and trash pollution in coastal areas.

In addition to plastic, other trash items commonly found in coastal areas include detergent bottles, crates, buoys, combs, water bottles, and fishing gear. These items can have detrimental effects on marine life, birds, and other species that mistake them for food or become entangled in them. The accumulation of trash in coastal areas not only harms the environment but also impacts the economic potential of these regions, as polluted beaches may reduce property values and inhibit community economic growth.

To combat plastic and trash pollution, several measures have been proposed and implemented. These include transitioning from fossil fuels to renewable energy, banning straws and plastic bags to reduce plastic usage, and increasing protected ocean areas to preserve ecosystems and fish stocks. Additionally, organizations like the National Oceanic and Atmospheric Administration (NOAA) work with government agencies to develop strategies for controlling and reducing coastal pollution.

Oil spills

One of the largest oil spills in US history was the Deepwater Horizon spill in 2010, which released approximately 134 million gallons of oil into the Gulf of Mexico. This spill had a significant impact on the entire Gulf of Mexico, from deep-sea communities to over 1,300 miles of shoreline. The spill was caused by an explosion on the oil drilling rig, which tragically killed 11 workers.

Another notable oil spill was the Exxon Valdez oil tanker spill in Prince William Sound, Alaska, in 1989. This spill released over 11 million gallons of oil, causing widespread environmental damage. In response to this disaster, the US government enacted the Oil Pollution Act (OPA) in 1990, which strengthened the government's ability to prevent and respond to oil spills. OPA also required oil tankers to be double-hulled, providing additional protection to the cargo tank and reducing the risk of oil spills during accidents.

California has also been the site of several large oil spills, including the 1969 Union Oil drilling rig platform blowout off the coast of Santa Barbara, which spilled approximately 4.2 million gallons of crude oil. This spill was a catalyst for the modern environmental movement and led to the enactment of the California Oil Spill Prevention and Response Act in 1990. More recently, in October 2021, a pipeline from an Amplify Energy oil platform leaked oil into the ocean and onto beaches in Orange County, California.

The impacts of oil spills on wildlife can be severe. Oil is toxic when ingested and can impair the waterproofing of birds' feathers, affecting their ability to float, swim, or fly. Oil spills can also have economic impacts, as they often result in beach closures and losses to the recreational fishery industry.

Agricultural pollution

Agricultural runoff, also known as non-point source pollution, is a major factor in agricultural pollution. This occurs when rainwater or melting snow carries sediment, nutrients, pesticides, and other pollutants from agricultural lands into neighbouring waterways. These pollutants can eventually make their way into coastal waters, impacting estuarine and coastal ecosystems. The high use of fertilisers in agriculture, for example in California's San Joaquin Valley, contributes to this runoff, as excess nutrients in the water can stimulate algal blooms, creating "dead zones" where oxygen concentrations approach zero, suffocating species such as shrimp and clams.

Nitrogen and phosphorus are particularly important in stimulating algal growth. In coastal saltwater, nitrogen is typically the limiting factor for algae, and agricultural drainage is a significant source of nitrogen entering surface waters. Phosphorus from agricultural lands can also be dissolved in surface runoff, contributing to the excess nutrients that fuel algal blooms.

In addition to water pollution, agricultural activities contribute to air pollution. The heavy use of manures and fertilisers can release gases such as nitrogen oxides and ammonia. These gases can have negative impacts on sensitive ecosystems, including national parks, when present in high concentrations.

The United States Environmental Protection Agency (US-EPA) has implemented measures to address point source pollution, which is easier to identify and control. However, non-point source pollution, including agricultural runoff, remains a challenge due to its diffuse nature and the difficulty in measuring and regulating it.

Industrial pollution

Direct discharges of pollutants into the ocean and coastal waters from industrial facilities have been reduced in recent decades due to the Clean Water Act and other federal regulations, as well as advancements in waste treatment. However, industrial pollution still persists and has significant impacts on coastal ecosystems.

Industrial organic chemicals, pesticides, and trace metals are toxic pollutants that contaminate marine environments. These pollutants can have adverse effects on marine organisms, even at low concentrations. They can affect the reproductive, immune, and endocrine systems of marine life, leading to potential population declines. Some toxic substances have been banned from manufacture and use, but previously released materials can remain in the environment for extended periods, continuing to cause harm.

Additionally, nutrient pollution, particularly from nitrogen and phosphorus, has been recognized as a key threat to coastal environments. Increased loadings of these mineral nutrients can lead to eutrophication, hypoxia, reductions in seagrass beds and corals, and potentially toxic algal blooms. These blooms have been on the rise in recent decades, impacting not only the United States but also Europe, Japan, and China.

Urban pollution

Nonpoint source pollution is a major challenge in urban areas, as it is difficult to track and control. It can come from various sources, including everyday activities such as driving cars, trucks, and other vehicles, as well as industrial, agricultural, and marine activities. The impact of nonpoint source pollution is significant, with over one-third of shellfish-growing waters in the United States adversely affected, leading to economic losses and health risks for humans and marine life.

Communities of color in the United States are disproportionately affected by urban air pollution, with 7.5 times higher pediatric asthma rates and 1.3 times higher premature mortality rates compared to mostly-white communities. This disparity is attributed to systemic racism and redlining, resulting in communities of color being located near factories, congested roadways, or shipping routes with polluted air.

To address urban pollution, the United States Environmental Protection Agency (EPA) has developed guidance and best management practices (BMPs) to control nonpoint source pollution in coastal waters. These practices include techniques such as bioretention, green infrastructure, and stormwater permit programs. Additionally, organizations like the National Oceanic and Atmospheric Administration (NOAA) work with federal and state agencies to monitor, assess, and limit pollution, as well as provide educational resources to raise awareness about the issue.

While progress has been made in reducing emissions from transportation, power plants, and manufacturing, climate change continues to pose challenges. Extreme heat, drought, and wildfires contribute to spikes in particle pollution, especially in the western United States, affecting the air quality of metropolitan areas and endangering public health.

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