Water Pollution: A Deadly Threat To Animal Life

Water pollution is a critical environmental issue that poses a significant threat to marine life. The impact of plastic pollution on marine animals is devastating, with millions of tons of plastic waste entering the ocean each year. While it is challenging to estimate accurately, it is believed that plastic pollution kills at least 100,000 marine animals every year, including dolphins, whales, and turtles. This number is likely an underestimate, as it only accounts for a few observed species. The true toll of water pollution on animal life is likely much higher, with plastic pollution affecting marine ecosystems and wildlife in various ways, including entanglement, ingestion, and chemical contamination.

Ingesting plastic

Marine animals often mistake plastic for food, ingesting it and causing blockages in their digestive systems, which can lead to starvation and death. For example, sea turtles frequently mistake plastic bags for jellyfish, and once ingested, the plastic blocks their digestive systems, causing them to starve. Similarly, a juvenile sperm whale was found dead on a Spanish beach in 2018 with 30 kilograms of plastic in its digestive tract. The cause of death was inflammation from the plastic, coated in various toxins, which likely caused immense suffering.

Even animals that do not rely on eyesight to find prey are at risk of ingesting plastic. Dolphins, whales, and toothed whales use echolocation to find their prey, but plastic bags filled with water can sound similar to their prey. As a result, it is estimated that 56% of the planet's whale, dolphin, and porpoise species have consumed plastic.

The toxins present in plastic can also lead to internal deterioration and poisoning, exacerbating the detrimental effects of plastic pollution on animal populations. These toxins can be transferred up the food chain, threatening species higher up, such as dolphins, whales, and even humans.

While it is challenging to determine the exact number of deaths caused by plastic ingestion, it is estimated that over 100,000 marine mammals die each year from ingesting or becoming entangled in plastic. This number includes vulnerable species such as sea turtles, whales, dolphins, and coral reefs. In addition, approximately 1 million seabirds die annually from ingesting plastic, as it blocks their intestinal tracts.

Entanglement in plastic

Marine animals are affected by plastic pollution in several ways, including entanglement, ingestion, and chemical contamination. While it is challenging to estimate the number of marine animals that die from plastic pollution, the impact is significant.

Marine animals, such as whales, dolphins, sea turtles, seabirds, and fish, can become entangled in plastic debris, such as discarded or lost fishing nets and nylon filaments. This entanglement can lead to severe injuries, suffocation, drowning, and, in some cases, death. The trapped animals may also suffer from infections and starvation, further reducing their chances of survival.

The problem of entanglement is not limited to large marine creatures. In New Zealand, for example, a southern black-backed gull was found caught in a nylon fishing line, and a fur seal was trapped in discarded netting. These incidents highlight that even smaller animals are vulnerable to entanglement, and it is not just a problem for marine mammals.

The impact of entanglement on marine animals has been recognized for decades, yet the full extent of the problem remains unknown due to the challenges in quantifying and studying these incidents. However, it is clear that plastic pollution, including entanglement, poses a significant threat to marine biodiversity.

The magnitude of the problem is evident from the increasing annual input volumes of plastic waste into the natural environment. Millions of tons of plastic waste enter the ocean each year, and the amount of plastic in the ocean is growing rapidly. This plastic waste does not only affect marine animals but also has negative impacts on tourism, fisheries, shipping, and human health.

Chemical contamination

While it is challenging to estimate the number of animals that die from water pollution due to chemical contamination, it is evident that it has a detrimental impact on various species. Chemical contamination is one of the ways plastic pollution affects marine animals, and given the vast amount of plastic waste entering the ocean each year, the impact on marine life is significant.

Plastic debris in the ocean, including discarded fishing gear, poses a severe threat to marine animals, leading to entanglement, ingestion, and chemical contamination. Abandoned fishing nets and gear, known as "ghost fishing equipment," account for a significant portion of the plastic pollution in the oceans. This ghost equipment continues to entangle and trap marine creatures, leading to injuries, drowning, and fatalities.

Ingestion of plastic is another critical issue. Marine animals, such as sea turtles, often mistake plastic bags for jellyfish or other prey, leading to blocked digestive systems and starvation. Additionally, the toxic chemicals present in plastic, such as BPA, can cause internal deterioration, poisoning, and reproductive issues in marine wildlife. These chemicals can also impair the growth of fish, especially when exposed to warmer water temperatures.

The impact of chemical contamination from plastic pollution extends beyond individual animals to entire ecosystems. Coral reefs, for example, are vulnerable to plastic pollution, which can cause disease and bleaching. This, in turn, affects the fish and other marine animals that depend on the coral reef as their habitat. The destruction of coral reefs can have far-reaching consequences for the biodiversity and health of marine ecosystems.

Water pollution from chemical contamination also affects freshwater sources, such as lakes and rivers. In the United States, for instance, tap water is contaminated in almost every state, and only 31% of US waters have been tested. The presence of toxic PFAS chemicals in tap water has been detected in numerous locations, posing risks to both human and animal health.

While the exact number of animal deaths due to chemical contamination in water pollution is challenging to determine, it is clear that the impact is widespread and devastating. The growing magnitude of plastic pollution and chemical contaminants in our water systems underscores the urgency of addressing this critical environmental issue to protect marine life and ecosystems.

Ocean dead zones

Dead zones are typically found in coastal areas and the Great Lakes, with no part of the world being immune. The second-largest dead zone in the world is located in the northern Gulf of America, formerly known as the Gulf of Mexico. In 2024, this hypoxic zone spanned 6,705 square miles and was the 12th largest ever measured in almost four decades.

The primary human-induced cause of dead zones is nutrient pollution, particularly from agricultural runoff. Fertilizers, pesticides, and other excess nutrients from land-based activities wash into waterways, stimulating excessive growth of algae. As the algae die and decompose, they consume oxygen, leading to oxygen depletion in the water. This process, known as eutrophication, can result in the mass killing of fish and other marine life.

Climate change variables also contribute to the formation of dead zones. Warmer waters hold less oxygen, and climate-related factors such as ocean acidification, changing storm patterns, and rising sea levels can further exacerbate the problem. Additionally, reduced oceanic mixing due to higher temperatures makes it more challenging to replenish oxygen in depleted areas.

The impact of dead zones extends beyond ecological concerns. They can potentially destroy economies by affecting the availability of seafood, which is a crucial source of income and food for many communities. Therefore, addressing the issue of ocean dead zones requires collective efforts to reduce nutrient pollution, promote sustainable agricultural practices, and mitigate the effects of climate change.

Direct poisoning

One of the primary sources of direct poisoning is plastic pollution. Plastic waste in oceans and waterways is ingested by marine animals, such as sea turtles, whales, and birds, leading to starvation and internal injuries. Plastic can block digestive systems, creating a false sense of fullness and resulting in the animal's starvation. Additionally, ingested plastic can cause internal lacerations and release toxins, leading to infections and suffering. For example, in 2018, a juvenile sperm whale washed up dead on a Spanish beach, with nearly 30 kilograms of plastic in its digestive tract. The cause of death was inflammation caused by the ingested plastic, which was coated in various toxins.

Another form of direct poisoning is the consumption of polluted water. Nutrient pollution, including nitrates and phosphates, and excess nitrogen and phosphorus, can contaminate surface water and groundwater. This type of pollution is often caused by farm waste, fertilizer runoff, and sewage discharge. The excess nutrients promote the growth of algae, leading to eutrophic dead zones where aquatic life cannot survive due to a lack of oxygen. Additionally, certain species of algae produce toxins that directly poison aquatic organisms, including fish, seabirds, sea turtles, and marine mammals such as dolphins and manatees. These toxins can also cause reproductive issues and impair the health of marine life, contributing to population declines and the extinction crisis.

The impact of direct poisoning from water pollution is far-reaching and devastating for marine ecosystems. It is important to address this critical environmental issue and find effective solutions to reduce plastic pollution and nutrient contamination in our oceans and waterways.

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