The Dark History Of Marine Pollution

Marine pollution, a pressing global issue, is primarily caused by human activities, with approximately 80% of marine waste originating from land-based sources. This pollution comprises a mixture of chemicals and trash, including plastic debris, oil spills, and nutrient runoff from farms and other industrial activities. The consequences of marine pollution are dire, threatening marine biodiversity and human well-being. Each year, an estimated 8-10 million metric tons of plastic waste enter the oceans, endangering and killing marine life, contaminating seafood, and leading to negative health outcomes for humans.

Marine pollution is mostly caused by human activities

Marine pollution is predominantly caused by human activities, with 80% of marine pollution originating from land-based activity. One of the main causes of marine pollution is nonpoint source pollution, which occurs due to runoff from various human activities. This includes the use of fertilisers on farms, which can lead to the runoff of chemicals into waterways that eventually flow into the ocean. Nutrient pollution, such as excess nitrogen and phosphorus in seawater, can cause oxygen depletion, creating "dead zones" where marine life struggles to survive. These nutrients can also stimulate the growth of harmful algal blooms, which can be toxic to marine life and humans.

Another significant contributor to marine pollution is plastic waste. Plastic debris can injure and kill marine animals through ingestion, entanglement, or suffocation. It can also transport pollutants through ocean currents and accumulate in ocean gyres, forming patches of floating plastic. Microplastics, tiny plastic particles, are ingested by marine organisms, causing toxic chemicals to be absorbed into their tissues. These toxins then migrate up the food chain, eventually reaching humans through seafood consumption. The use of disposable and single-use plastic items, such as shopping bags, packaging, and plastic bottles, has been a significant driver of plastic pollution in the oceans.

Point source pollution, or pollution from a single source, is another form of marine pollution caused by human activities. This includes oil spills and chemical spills, which can have devastating impacts on marine life. Marine transportation and global shipping activity have contributed to both chemical pollution and noise pollution, affecting marine ecosystems, particularly species that rely on sound for survival, such as whales and dolphins.

Littering, illegal dumping, poor waste management, and stormwater discharge also contribute to marine debris. While some pollution may be unintentional, such as trash being blown into the ocean by storm winds, human activities along coastlines and inland play a significant role in marine pollution. Overall, the cumulative effects of these human activities have far-reaching consequences for marine ecosystems and human health.

Oil spills are a major cause of marine pollution

Oil spills can ensnare and suffocate marine animals by permeating their gills, and they can also damage the insulating and waterproofing properties of feathers and fur, causing animals to die from hypothermia. Oil spills can also make seafood unsafe to eat, and they can have a significant impact on the fishing industry, often leading to the immediate suspension of commercial fishing.

Cleanup activities can never remove 100% of the spilled oil, and scientists must be careful that their actions do not cause additional harm. After the Exxon Valdez oil spill in 1989, it was found that high-pressure, hot-water hoses used to clean up beaches caused more damage than the oil alone. The Oil Pollution Act of 1990 established that those responsible for oil spills can be held accountable for paying for cleanup and restoration.

Oil spills first became a major environmental problem in the 1960s due to intensified petroleum exploration and production on continental shelves and the use of supertankers. While spills from wrecked or damaged supertankers are now rare due to stringent shipping and environmental regulations, thousands of minor and several major oil spills are still reported each year.

Plastic pollution is a key driver of biodiversity loss

Marine pollution refers to the harmful presence of chemicals and trash in the ocean. Most marine pollution (80%) originates on land and is caused by human activities. Marine pollution has far-reaching consequences, affecting human health and marine ecosystems.

Plastic pollution is a significant contributor to marine pollution and a key driver of biodiversity loss. Plastics are found everywhere, even in the deepest parts of the oceans. In 2021, global plastic production was estimated at 390.7 million metric tons, with an annual increase of 4%. At least 14 million tons of plastic end up in the ocean each year, and plastic constitutes 80% of all marine debris, from surface waters to deep-sea sediments.

Plastic pollution affects all land, freshwater, and marine ecosystems. It has significant negative consequences for ecosystems and biodiversity, impacting a wide range of areas, including climate change, human health, and human rights. The persistence of plastic and its toxicity pose a severe threat to biodiversity. It endangers ecosystems, plant species, and animal species, hindering their capacity to provide essential services to humanity.

Plastic debris in the ocean injures and kills marine life through ingestion, entanglement, and toxic impacts. It has impacted at least 267 species worldwide, including sea turtles, seabirds, and marine mammals. Floating plastics also act as a transport mechanism for invasive alien species, which is a leading cause of biodiversity loss and species extinction.

To address the plastic pollution crisis, there have been positive efforts, such as bans on certain single-use plastics. However, a global plastics treaty is essential due to the transboundary nature of plastic pollution. The treaty should aim to reduce plastic production, phase out harmful subsidies, eliminate harmful products and chemicals, and implement strong national plans and rigorous reporting and compliance mechanisms.

Marine debris includes plastic items like shopping bags and bottles

Marine pollution is caused majorly by human activities along coastlines and far inland. One of the biggest sources of pollution is nonpoint source pollution, which occurs as a result of runoff from septic tanks, vehicles, farms, and timber harvest areas. Another source is point source pollution, which is caused by oil or chemical spills, or discharge from faulty factories or water treatment systems.

Marine debris is a significant contributor to marine pollution, and plastic items like shopping bags and bottles are a large part of this. Plastic marine debris is a problem due to its prevalence in our daily lives. Plastic items are often single-use and designed to be thrown away or recycled. During cleanups, single-use plastic items are the most common type of marine debris found, including shopping bags, beverage bottles, bottle caps, and other plastic bags.

Plastic debris in the ocean injures and kills marine life, impacting at least 267 species worldwide, including sea turtles, seabirds, and marine mammals. Animals mistake plastic for food or become entangled and strangled by plastic bags and discarded fishing nets. Plastic debris has also been found to transport pollutants and invasive species through ocean currents.

The impact of plastic marine debris is long-lasting as plastic does not break down like natural materials, instead fragmenting into smaller pieces that are difficult to locate and clean up. Preventing plastic from entering the ocean is crucial, as once plastic pollution enters marine ecosystems, it can be challenging to fully remove it. Outreach and education are essential to raising awareness and changing behaviours related to plastic use and disposal.

Additionally, plastic pollution has indirect effects on human health. Small organisms ingest toxins from plastic debris, which are then passed on to larger predators, including seafood that humans consume. These toxins can have detrimental long-term health effects, including cancer and birth defects.

Chemical contamination, or nutrient pollution, is a concern for health

Marine pollution is a pressing issue, with far-reaching consequences for both human health and marine ecosystems. Chemical contamination, or nutrient pollution, is a significant concern within this broader issue.

Chemical contamination of the oceans occurs due to human activities, such as the use of fertilisers on farms, which leads to the runoff of chemicals into waterways that eventually flow into the ocean. This type of pollution can also occur through oil spills, or from nonpoint sources such as septic tanks, vehicles, farms, and factories. The increased concentration of certain chemicals, specifically nitrogen and phosphorus, in coastal areas promotes the growth of algal blooms, also known as "red tides". These blooms can be toxic to marine life and, in some cases, even humans. For example, phytoplankton will absorb methylmercury, a bacteria-converted mercury that finds its way down to the ocean's surface. This mercury then moves up the food chain, from zooplankton to small fish, and eventually to larger fish that humans consume, such as swordfish, which contain very high mercury loads.

Nutrient pollution from human activities, such as agriculture, has led to a tenfold increase in global fertiliser use since the mid-20th century. This has resulted in a significant rise in nitrogen discharges from rivers into the sea. When excess nitrogen and phosphorus are present in seawater, they cause oxygen depletion, creating ""dead zones" where marine life struggles to survive. This not only impacts fisheries but also tourism, as these zones are detrimental to the health of marine ecosystems.

Furthermore, plastic pollution in the ocean has gained significant attention due to its alarming impact on marine life and its ability to transport and accumulate pollutants. Floating plastics in the oceans collect pollutants on their surfaces and distribute them through ocean currents. Marine life that ingests these plastics coated with pollutants can absorb these toxins into their bodies, and these toxins can then migrate up the food chain, eventually reaching humans. Microplastics, tiny plastic particles less than 0.2 inches in diameter, have been detected in various marine species, including plankton and whales.

Personal care products also contribute to chemical contamination in the ocean. For instance, oxybenzone, a common ingredient in sunscreens, has been found to negatively affect coral health and reproduction. Additionally, pharmaceutical pollutants, such as ibuprofen, painkillers, anti-depressants, and antibiotics, have been recognised as an emerging issue, with the potential to accumulate in fish and shellfish consumed by humans. These chemical contaminants can impact marine species through endocrine disruption and neurotoxicity, affecting their reproductive abilities and offspring survival rates.

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