Pollution's Deadly Impact On Animals

Plastic pollution is a critical environmental issue that is having a devastating impact on marine animals. Approximately 8 to 10 million tons of plastic enter the ocean each year, and it is estimated that 100,000 marine animals die from plastic pollution annually. Marine animals are affected by plastic pollution in several ways, including entanglement, ingestion, and chemical contamination. Entanglement in abandoned fishing gear, for example, can lead to drowning, while ingestion of plastic can cause blockages in the digestive system, resulting in starvation. Plastic pollution also affects the reproductive systems of marine animals and can introduce toxic additives into the food chain.

Ingesting plastic

Marine animals are the most susceptible to ingesting plastic. The ocean is inundated with plastic, accounting for 80% of all ocean debris. Only 1% of this waste floats in surface waters, with the majority sinking and breaking down into microplastics. As a result, marine animals from various depths of the ocean, including plankton, shellfish, birds, fish, marine mammals, and sea turtles, ingest plastic debris.

The ingestion of plastic has detrimental effects on marine animals, leading to loss of nutrition, internal injury, intestinal blockage, and even death. Larger pieces of plastic can obstruct their gastrointestinal tract, causing starvation as the animal is unable to excrete the foreign object. In some cases, plastic is ground into small pieces in the stomach and then scattered, as seen in the northern fulmar, which spreads millions of plastic pieces annually.

Sea turtles, in particular, are vulnerable to ingesting plastic bags and sheeting, mistaking them for their jellyfish prey. This debris can get stuck in their digestive systems, creating a false sense of fullness. A similar fate befell a young green turtle that washed up on the coast of Brazil in 2010, with over 3000 pieces of plastic in its gut and stomach.

Whales, the ocean's gentle giants, are also victims of plastic ingestion. A juvenile sperm whale stranded on a Spanish beach had nearly 30 kilograms of plastic in its digestive tract, causing fatal inflammation. Abandoned fishing gear, or "ghost fishing equipment," poses another threat to marine mammals, entangling and drowning them.

The impact of plastic ingestion extends beyond marine life. Corals, vital to marine ecosystems, face negative consequences when they ingest or adhere to plastic. Waxworms and other organisms possess the unique ability to break down plastics, offering a potential solution to reduce plastic waste. However, the key to combating plastic pollution lies in rethinking how we produce, use, and manage plastics to reduce their overall presence in the environment.

Entanglement in fishing gear

Marine animals, such as whales, dolphins, seals, sea lions, and sea turtles, often become entangled in fishing gear and other marine debris as they swim or while on the beach. This entanglement can lead to drowning, starvation, physical trauma, and infections. It is a significant cause of death for hundreds of thousands of marine mammals and sea turtles worldwide annually.

Fishing gear that is lost, abandoned, or deliberately jettisoned contributes to this issue. This "ghost fishing equipment" continues to ensnare marine creatures, leading to devastating consequences. The impact of entanglement is not limited to large marine animals, as even smaller dolphins, seals, sea lions, and sea turtles can become entangled and require assistance.

To address this issue, organizations like NOAA Fisheries and the IWC Entanglement Response Network provide training and coordination for disentanglement efforts. They work with partners to prevent entanglements, rescue entangled animals, and gather data to inform strategies for reducing entanglement risks. The public plays a crucial role by reporting sightings of entangled animals and participating in community clean-up efforts to remove potential hazards from the ocean and beaches.

The loss and abandonment of fishing gear have become one of the most visible signs of growing marine pollution. It is estimated that 8 million tons of plastic enter the oceans annually, with a significant portion being abandoned fishing gear. This pollution has severe consequences for marine life, and the impact on animal deaths is likely underestimated.

Chemical contamination

Endocrine-disrupting chemicals (EDCs) are a significant category of contaminants that interfere with natural hormone functions. These chemicals can have far-reaching consequences for both wildlife and humans. EDCs have been linked to reproductive issues, developmental problems, and growth impairments in fish and wildlife. They can also accumulate in the blubber of marine mammals, such as seals, impacting their survival during their first year of life. Additionally, EDCs have been implicated in disorders in other animals, including birds, amphibians, and mammals, leading to widespread feminization or de-masculinization of male vertebrate wildlife.

Pesticides are another significant source of chemical contamination, with approved pesticides used in agriculture and other industries ending up in ecosystems like the Arctic, where they endanger the entire ecosystem. Polar bears, for example, are affected by toxic pesticide contamination, which impacts their behaviour and hormonal balance, making it difficult for them to survive in an increasingly hostile environment. Similarly, pesticides act as endocrine disruptors in drinking water sources and aquatic habitats, posing profound risks to imperiled species.

Furthermore, chemical pollution weakens the immune system of animals, making them more susceptible to infections and diseases. This is evident in the case of harbour porpoises in the UK, where chemical accumulation has increased their risk of infectious diseases by 41%. Additionally, toxic chemicals have been linked to increased cancer rates, reproductive issues, and various health problems in both animals and humans.

The impact of chemical contamination extends beyond individual species, threatening entire ecosystems and food chains. For example, mountaintop removal coal mining poisons animals and taints the drinking water of downstream communities. Uranium mining leaves a toxic and radioactive footprint, contaminating aquatic ecosystems and threatening fish and wildlife. The toxins from these activities can accumulate in the food chain, causing deformities and reproductive issues for aquatic species.

Oil spills

One of the most affected groups of animals during oil spills are birds. Oil can coat birds' feathers, leaving them unable to fly and causing them to lose their insulating properties, leading to death by hypothermia. Oiled birds also face increased risks of dehydration and exhaustion. In addition, when birds attempt to clean themselves, they can ingest the oil, leading to poisoning. A study conducted after the Cosco Busan oil spill in California's San Francisco Bay revealed that a significant number of dead bird carcasses were missed by search teams, indicating that the actual number of bird deaths from oil spills is often underestimated.

Sea otters are another animal highly vulnerable to oil spills. Oil strips away the insulating properties of their fur, making them susceptible to hypothermia. Sea turtles are also at risk, as oil can cause a range of health problems, including damaging their gills and reducing their ability to get enough oxygen. Marine mammals, such as dolphins and bottlenose dolphins, are also at high risk due to the time they spend near the surface of the water, where oil floats. Oil can cause severe health issues in these mammals through inhalation, ingestion of oiled food, or direct contact.

The exact number of animal deaths from oil spills is challenging to determine due to the vast areas affected and the difficulty in recovering and counting carcasses. Oil spills can have lasting consequences, and the true extent of their impact may not be fully understood for months or even years.

Microplastics

The extensive production and use of plastics have led to the proliferation of microplastics in water, air, soil, and various living organisms worldwide. Poor waste management, particularly in highly populated areas with inadequate waste systems, contributes to the spread of microplastics. Rain and wind carry plastic waste from landfills, streets, and urban areas into rivers and streams, which eventually flow into the oceans. Additionally, microplastics can leech into soil and water sources from landfills and other environments, contaminating the food we grow and impacting wildlife.

Marine animals, including whales, dolphins, seals, sea turtles, fish, and birds, are particularly vulnerable to the harmful effects of microplastics. They mistake plastic bags for jellyfish or squid and consume them, leading to intestinal blockages and damage. Microplastics can also introduce poisonous substances into their bodies and carry other pollutants, enhancing their negative effects. Abandoned fishing gear, such as nets and lines, entangle and trap marine animals, preventing them from finding food, shelter, or swimming to the surface for air.

Terrestrial animals are also severely impacted by microplastics. Frogs, toads, salamanders, and newts are among the most sensitive groups affected by plastic pollution in freshwater habitats. Microplastics can be ingested at different stages of their development, hindering their feeding processes and causing physical harm. Additionally, microplastics shed from synthetic clothing during washes can be discharged into the environment, further contributing to the problem.

The accumulation of microplastics in the environment and living organisms has raised concerns about long-term health consequences. While the data on the impact of microplastics is still evolving, the potential hazards to animal health are significant and widespread.

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