Animals And Pollution: A Toxic Relationship

Plastic pollution is one of the most damaging environmental issues of our time. It is everywhere and in everything, and it never goes away. It is toxic and can kill wildlife, make them more susceptible to disease, and cause blockages in their digestive systems, leading to starvation, malnutrition, and even death.

Plastic waste affects marine life such as whales, sea turtles, seals, and seabirds, as well as land animals including elephants, hyenas, zebras, tigers, camels, and cattle. It also disrupts habitats, making it hard for some species to live and breed naturally, leading to depletions in populations.

Plastic can take hundreds of years to break down into smaller pieces, which can be ingested by animals. It can also release harmful chemicals into the surrounding soil and groundwater, contaminating the food we grow and consume.

The impact of plastic pollution on wildlife is a grave concern that demands immediate attention and concerted efforts to reduce, recycle, and properly dispose of plastic waste.

Air pollution

Impact on Respiratory System

One of the most significant ways air pollution affects animals is through its impact on their respiratory system. Birds, in particular, are highly susceptible due to their efficient respiratory systems and the time they spend in the open air. Studies have shown that long-term exposure to air pollution can lead to lung failure, inflammation, and respiratory diseases such as asthma and bronchitis in birds. Additionally, high levels of nitrogen dioxide (NO2) and nitrogen oxide (NO) gases released by vehicles, power plants, and factories can cause direct and irreversible lung damage in birds, leading to population decline.

Toxic Chemicals and Diseases

The toxic chemicals present in air pollution also affect animals at a cellular level. Pollutants can cause DNA damage, leading to mutations and cancerous cell growth. Air pollution has been linked to an increased risk of acute cardiovascular events and the development of coronary artery disease in animals. Studies have also shown that domesticated and wild animals exposed to polluted air over extended periods have a higher risk of developing tumours.

Behavioural Changes

Impact on Food Sources

Impact on Reproduction

Water pollution

Sources of Water Pollution

Effects on Aquatic Life

Eutrophication and Dead Zones

Excess nutrients, such as nitrogen and phosphorus, from agricultural runoff and sewage, can lead to eutrophication, where algae blooms deplete oxygen levels in the water, creating "dead zones" where aquatic life cannot survive. This phenomenon has been observed in the Gulf of Mexico, resulting in the death of various species, including marine life, birds, and land animals.

Algal Blooms

Pollution from excess nutrients, pesticides, and fertilizers can also cause harmful algal blooms, which produce toxins that poison aquatic organisms, including seabirds, fish, sea turtles, dolphins, manatees, and sea lions. These blooms not only harm wildlife but also pose risks to humans who come into contact with or consume fish and shellfish from contaminated waters.

Marine Debris

Solid debris, such as plastic bags and cans, often ends up in oceans, entangling, suffocating, and starving marine animals. Discarded fishing gear and other debris harm over 200 different species of marine life. Additionally, microplastics, which are tiny plastic particles, can be ingested by marine organisms, leading to health issues and potential accumulation of toxins in larger fish species.

Ocean Acidification

The absorption of carbon pollution from burning fossil fuels is making oceans more acidic, impacting the ability of shellfish and coral to build shells and potentially affecting the nervous systems of various marine species, including sharks and clownfish.

Preventing Water Pollution

To address water pollution, it is essential to reduce plastic consumption, properly dispose of chemicals and non-biodegradable items, maintain vehicles to prevent fluid leaks, and practice eco-friendly landscaping and farming methods that minimize the use of pesticides and fertilizers. Additionally, supporting policies and regulations that protect water sources and investing in wastewater treatment and green infrastructure are crucial steps towards mitigating water pollution and preserving aquatic ecosystems.

Climate change pollution

Habitat Loss

Animals are losing their native habitats as climate change makes wild spaces more vulnerable to extreme weather events, such as storms, droughts, and wildfires. Warmer temperatures also affect vegetation, food sources, and access to water. Ecosystems may become uninhabitable for certain animals, forcing them to migrate outside of their usual patterns in search of more livable conditions. This can lead to a cascade of environmental changes that disrupt the synchronization between migratory birds and their food sources, reducing their reproductive success. For example, the wood thrush, the official bird of Washington, DC, may lose its regional population within the century due to changes in habitat and food availability.

Natural Disasters

The frequency and intensity of natural disasters such as droughts, wildfires, and hurricanes have increased due to climate change. These events cause catastrophic loss of life and habitat for both wildlife and humans. Australia's Black Summer bushfires (2019-2020) burned 186,000 square kilometers and are estimated to have killed or displaced three billion koalas, kangaroos, and other animals.

Human-Wildlife Conflict

Climate change intensifies human-wildlife conflict through habitat loss and extreme climate events, forcing people and animals to share increasingly crowded spaces. As ecosystems change, both humans and animals roam farther in search of food, water, and resources, leading to conflicts that often result in devastating consequences for the animals involved. For example, jaguars sometimes prey on domestic animals, leading to retaliatory killings that further decline their already dwindling populations.

Extinction

The combination of challenges created by climate change could lead to the extinction of many animal species, particularly those already vulnerable or near extinction. The North Atlantic right whale, for instance, is on the brink of extinction, with an estimated 336 individuals remaining—the lowest count in 20 years. A warming ocean and conflicts with humans (such as vessel strikes) contribute to the threat faced by this species.

Changes in Food Chains and Invasive Species

Invasive species are one of the top five dangers to ecosystems, and climate change provides new opportunities for them to spread and thrive in new environments. This can lead to the extinction of animals, increased competition for resources, a reduction in biodiversity, and the spread of diseases. Warmer temperatures have also altered the timing of plant blooming and expansion, affecting the migration patterns of animals that depend on these plants for food.

Loss of Water Supply

Droughts and high temperatures are causing crucial water supplies to dry up, posing a significant risk to wildlife, especially in hot climates. Animals may need to travel farther to find water, putting them in a vulnerable position. Additionally, climate change can affect water quality, increasing the risk of pollutants, pathogens, and sediments in water sources, which can lead to disease outbreaks.

Bioaccumulation

As one moves higher up the food chain, the concentration of pollutants increases significantly due to biomagnification. This is the process by which toxins are passed from one trophic level to the next (and thereby increase in concentration) within a food web.

Top-level predators such as bears and eagles are particularly susceptible to the bioaccumulation of these types of air pollutants. For example, mercury is of great enough concern that it is recommended we limit how often we eat certain types of fish that may contain high levels of heavy metal.

Marine debris

There are three main types of marine debris that impact wildlife: plastics, derelict fishing gear, and abandoned and derelict vessels.

Plastics and Microplastics

Plastics are one of the most extensive types of marine debris, commonly used in many items. As society has found new uses for plastic, the variety and quantity of plastic items found in the marine environment has increased dramatically.

Plastics are now known to break down into smaller components called microplastics, which can be ingested by wildlife such as sea turtles, seabirds, and marine mammals. This ingestion leads to loss of nutrition, internal injury, intestinal blockage, starvation, and death. Seabirds are especially vulnerable to plastic pollution; a recent study found plastic in 90% of seabirds. In addition to ingestion, other debris such as packing bands, balloon strings, and rubber bands can lead to entanglement.

Derelict Fishing Gear

A second highly visible and impactful form of marine debris is derelict fishing gear (DFG), which has numerous impacts on the environment, including damaging marine habitats, entangling marine species, creating hazards to navigation, and ghost fishing of commercially important species. One of the most notable types of impacts from this type of marine debris is wildlife entanglement. Derelict nets, ropes, lines, or other fishing gear can wrap around marine life, leading to injury, illness, suffocation, starvation, and death.

Abandoned and Derelict Vessels

Abandoned and derelict vessels (ADVs) are a third highly visible type of marine debris, with thousands littering our nation's coastal waters. ADVs threaten oceans, coasts, and waterways by obstructing navigational channels, causing harm to the environment, and diminishing commercial and recreational activities. ADVs may pose an immediate or future threat to wildlife and wildlife habitats from the release of hazardous substances.

Impact on Marine Animals

The effects of marine debris on marine animals are widespread and deeply concerning. One of the most disturbing consequences is the ingestion of plastic by animals, who often mistake plastic debris for food, leading to dire consequences. Plastic debris can cause blockages in the digestive systems of animals, leading to starvation, malnutrition, and even death. It can also accumulate toxins over time, posing additional health risks to animals that consume them.

Another consequence of marine debris is entanglement, which disrupts the ability of animals to move, hunt, and feed, impacting their overall survival and reproductive success. Entangled animals may also get abrasions from the debris, resulting in dangerous infections. If movement is restricted, animals may not be able to feed, and air-breathing fauna may drown if entangled underwater.

Frequently asked questions