How Pollution Harms Coastal Areas And Ecosystems

Pollution of coastal areas is a pressing issue, with over 80% of marine pollution originating from land-based sources. Human activities, such as oil production and transportation, and waste disposal, have detrimental effects on the environment and human health. Oil spills cause severe damage to coastal ecosystems, while agricultural emissions contribute to the pollution of coastal zones. Plastic pollution is another significant concern, with an estimated 8 million tons of plastic waste entering the oceans annually. This waste originates from sources like solid waste dumped along coastlines, broken-down ships, and discarded fishing gear, leading to economic losses and biodiversity loss. Urbanization also plays a role in marine pollution, as seen in China's coastal areas, where rapid development has impacted the economy and living standards.

Oil spills and oil byproducts

The magnitude of harm to wildlife varies depending on factors such as the extent of the spill, the duration of exposure, and the proximity of different species to the spill. Oil can cause immediate health issues and long-term physiological and behavioral changes in marine and coastal wildlife. Small doses can lead to skin irritation, immune system alterations, reproductive or developmental damage, and liver disease. When large amounts of oil enter the water, the likelihood of chronic effects like cancer increases, and direct mortality becomes more widespread.

Oil spills can impact wildlife through ingestion, inhalation, or direct contact. They can also cause changes in foraging locations by depleting food sources, leading to increased competition and susceptibility to predation. The persistence of oil and its byproducts in the environment is a significant concern, as they can remain in low-energy environments like kelp holdfasts for years, hindering the recovery of affected ecosystems.

Coastal areas are particularly vulnerable to oil spills due to the presence of petrochemical industries and the transport of oil products through pipelines or vessels. Spills from coastal facilities, such as marine terminals and tank farms, account for a significant portion of the total spills associated with petroleum transportation. The Niger Delta in Nigeria, a hub for oil and gas production, is a notable example of a region suffering from recurrent oil spills and the ineffective management of the associated environmental impacts.

Overall, oil spills and their byproducts have severe and long-lasting effects on coastal areas, damaging ecosystems, and leading to economic losses. The persistence of oil in the environment and its impact on wildlife highlight the importance of effective prevention, response, and mitigation strategies to protect vulnerable coastal regions from the detrimental effects of oil pollution.

Nonpoint source pollution

Nonpoint source (NPS) pollution is any source of pollution that does not meet the point-source definition under the Clean Water Act. NPS pollution is caused by rainfall or snowmelt moving over and through the ground, carrying natural and human-made pollutants to bodies of water. As the runoff moves, it picks up and carries away pollutants, depositing them into lakes, rivers, wetlands, coastal waters, and groundwater.

NPS pollution can be caused by a variety of activities, including those on working farms and ranches, such as runoff from farm fields, livestock facilities, construction sites, and the use of fertilizers and pesticides, which can contaminate water with nutrients and sediment. Forestry activities, such as the removal of streamside vegetation, road construction, timber harvesting, and mechanical preparation for tree planting, can also impact water quality.

Coastal waterways may become contaminated with pollutants generated from activities at marinas, such as boat cleaning, fueling operations, and marine head discharge. Urban runoff is another significant source of NPS pollution, as water flowing through storm drains and pipes can carry pollutants directly to lakes and streams without being treated.

The effects of NPS pollution can be detrimental to aquatic life. Sediment, for example, can cause water to become cloudy, making it difficult for aquatic organisms to see and feed properly. It can also damage fish gills and the breathing of aquatic insects, reduce sunlight penetration, and affect plant growth. Additionally, sediments can carry other pollutants, such as metals and toxic chemicals, further exacerbating the problem.

Efforts to address NPS pollution are ongoing, with states, tribes, and territories working to identify categories of NPS pollution sources and implement practices to reduce their impacts.

Point source pollution

Point-source pollution is a type of pollution that comes from a single, identifiable place. It is one of the two main categories of pollution, the other being non-point-source pollution, which comes from multiple places at once and is more challenging to identify and address. Point-source pollution includes air and water pollution.

Air pollution from industrial sources, such as factories and power plants, can release pollutants like carbon monoxide, heavy metals, sulfur dioxide, nitrogen dioxide, and particulate matter into the atmosphere. These emissions contribute to the formation of acid rain, which is considered non-point-source pollution due to the long-range movement of pollutants.

Water pollution from point sources can include factories, power plants, municipal sewage treatment plants, and some farms. These sources discharge effluent, or wastewater containing chemical pollutants, into bodies of water like rivers, lakes, or oceans. Oil refineries, paper mills, and auto plants that use water in their processes are also included in this category. The Clean Water Act in the United States defines municipal separate storm sewer systems and industrial stormwater discharges (e.g., construction sites) as point sources.

Point-source pollution has significant environmental and economic impacts. For instance, the release of nutrients from municipal wastewater treatment plants can cause rampant algae growth in water bodies, leading to ecological disruptions. Pollution from oil exploration and production activities, including oil spills, can severely damage coastal ecosystems and result in economic losses for coastal communities.

Efforts to combat point-source pollution include regulatory measures such as the Clean Air Act and the Clean Water Act in the United States, which have improved air and water quality over the last 50 years. Additionally, campaigns like UNEP's #CleanSeas urge governments and industries to reduce plastic use and packaging and encourage consumers to change their disposable habits to prevent irreversible damage to marine environments.

Microplastics and marine debris

Marine debris and microplastics are significant contributors to coastal pollution. Marine debris is defined as any persistent solid material disposed of or abandoned in the ocean or on the shore, including plastic, glass, metal, rubber, paper, and lost or discarded fishing gear. Plastic is the most prevalent type of marine debris, and it can come from a variety of sources, such as larger plastic pieces that have broken apart, resin pellets used in manufacturing, or microbeads found in health and beauty products. These microplastics, plastic particles smaller than five millimeters, can be harmful to aquatic life and birds, which may mistake them for food.

Microplastics are of particular concern due to their potential to adsorb and transport toxic chemicals, such as PCBs, PBDEs, and PFOA, in the marine environment. These toxins can bioaccumulate in food chains, posing risks to marine ecosystems and biodiversity, and potentially human health. While there is still much to learn about the impacts of microplastics, research suggests that the ingestion of microplastics by marine life can lead to various adverse effects, including DNA damage, oxidative stress, and inflammation.

The continuous growth in solid waste generation and the slow degradation rate of plastics contribute to the increasing litter problem in coastal areas. Human activities on land are the primary sources of marine pollution, with an estimated 8 million tons of plastic waste entering the oceans annually. This pollution has severe economic impacts, with coastal communities facing increased costs for beach cleaning, public health, and waste disposal. It also disrupts the fishing industry, leading to damaged gear and reduced, contaminated catch.

To address the issue of marine debris and microplastics, global efforts are being made to reduce plastic use and improve waste management. For instance, the UNEP's Global Programme of Action for the Protection of the Marine Environment has been active since 1995, providing guidance to authorities on preventing and controlling marine degradation. The #CleanSeas campaign, launched in 2017, urges governments and industries to reduce plastic use and packaging and encourages consumers to change their disposable habits.

Algal blooms

There are many sources of nutrient pollution. Most excess nutrients enter waterways via agricultural runoff, especially from animal manure and chemical fertilisers that get washed from farms by rain. Other sources include leaked waste from animal feedlots, stormwater runoff from urban and suburban areas, and discharges from wastewater treatment facilities. Even if you do not live near a body of water, nutrients from your home and yard can make their way into nearby lakes, rivers, and oceans. For example, extra fertiliser on your lawn can wash off during rainstorms and run downhill into a nearby stream.

Climate change is expected to increase the growth of harmful algal blooms in fresh, salt, and brackish water. Warmer temperatures and increased nutrient runoff from more intense rainfalls may lead to more frequent and severe algal blooms in coastal areas. In addition, increased drought conditions can lead to decreased water flow, creating stagnant or slow-moving water bodies that are more favourable for algal blooms.

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