Plastic Pollution's Impact On Marine Life

Plastic pollution is a pressing issue that poses a significant threat to marine life. With billions of pounds of plastic entering our oceans each year, the problem has become a global crisis. Plastic pollution affects a wide range of marine ecosystems and species, from seabirds to sea turtles, seals, whales, and other marine mammals. The impact of plastic pollution on marine life is twofold: ingestion and entanglement. Marine animals often mistake plastic waste for food, leading to internal injuries, starvation, and even death. Additionally, they can become entangled in discarded fishing gear and other plastic debris, resulting in immobilization, suffocation, and increased vulnerability to predators. The durability of plastic, which prevents it from biodegrading, further exacerbates the issue. As plastic breaks down into smaller microplastics and nanoplastics, they are more easily consumed by marine organisms, leading to toxic contamination and adverse health effects. Addressing plastic pollution requires collective efforts, including reducing plastic production, improving waste management, and transitioning to more sustainable alternatives.

Plastic ingestion by marine animals

Marine animals ingesting plastic is a significant issue that affects hundreds of species and has a devastating impact on marine wildlife. Research indicates that at least 800 species are affected by marine debris, with plastic accounting for 80% of this litter. This includes fish, seabirds, sea turtles, and marine mammals.

One of the primary ways in which plastic harms marine life is through ingestion. Marine animals may mistake plastic for food, as it often floats on the water's surface and takes on an odour similar to their natural prey. For example, sea turtles often mistake plastic bags for jellyfish, and plastic debris for seaweed. Seabirds are also highly susceptible to ingesting plastic, as they feed from the ocean's surface. Adults may inadvertently feed plastic to their chicks, causing detrimental effects on their growth and survival.

The ingestion of plastic can lead to intestinal injuries, starvation, and death. It can also cause toxic contamination, as microplastics have the ability to absorb toxins, which can then be transferred to the fatty tissues of the organisms that ingest them. This contamination can spread up the food chain, eventually reaching human seafood eaters. A recent study found that a quarter of fish at markets in California had plastic in their guts, mostly in the form of plastic microfibres.

Furthermore, the impact of plastic ingestion on marine wildlife is not limited to physical harm. Plastic pollution has also been found to affect the reproduction rates of sea turtles by altering the temperature of the sand where incubation occurs.

The issue of plastic ingestion by marine animals is widespread and devastating, with research indicating that half of all sea turtles worldwide have ingested plastic. Urgent action is needed to address this crisis and protect marine ecosystems and the humans that depend on them.

Entanglement in plastic debris

Large plastics, such as fishing gear, six-pack rings, and plastic bottles, pose a severe risk of entanglement for marine mammals and fish. These items can trap and restrict the movement of marine creatures, leading to starvation, injuries, and increased vulnerability to predators. For instance, discarded fishing nets can smother and break coral reefs, hindering their healthy growth. The entanglement of large whales can result in exhaustion and infection rather than immediate drowning, as they are typically strong enough to pull gear off the ocean floor. However, it is considered a primary cause of human-caused mortality in right whales, humpback whales, and gray whales.

Smaller plastics, measuring between 5 and 10 mm, can also cause harm. These plastic fragments can float on the water's surface, tricking seabirds and other marine species into consuming them, which can lead to suffocation, starvation, and toxic contamination. Microplastics, measuring less than 5 mm, are invisible to the naked eye, making it easy for marine life to mistake them for food. They can adsorb toxins, which then transfer to the fatty tissues of the organisms that ingest them.

The impact of plastic pollution on marine life is not limited to entanglement. Marine animals also suffer from ingestion of plastic, which can lead to intestinal injuries and death. Additionally, microplastics can adsorb and concentrate toxic compounds from seawater, further endangering marine life.

The accumulation of plastic in the oceans has become a global crisis. With every bit of plastic ever made still existing, according to the EPA, the problem is only growing. As plastic pollution continues to increase, it is essential to address this issue at its source by reducing the use of single-use plastics and promoting recycling and reusable alternatives.

Plastic pollution in marine birds' nests

Marine birds are highly susceptible to plastic pollution. Seabirds, in particular, are at risk of ingesting plastic debris, which they mistake for prey. This is due to their high ingestion rates of contaminated prey, such as fish and shellfish. It is estimated that by 2050, 99% of seabird species will have ingested plastic debris.

The ingestion of plastic can lead to starvation, as it reduces the storage volume of the stomach. It can also cause blockages in the digestive tract, ulcers, and perforations of the gut. In addition, plastic debris can contain toxic chemicals that can be passed on to the birds, leading to reproductive issues and reduced growth rates.

Furthermore, plastic pollution also poses a risk of entanglement for marine birds, which can result in injuries, drowning, and suffocation.

While plastic pollution affects all marine birds, some species are more vulnerable than others. For example, the Balearic shearwater and the Newell's shearwater are among the Critically Endangered species with the highest exposure risk to plastic pollution.

To address the issue of plastic pollution in marine birds' nests, it is crucial to reduce plastic waste and improve waste management practices. It is also important to increase international collaboration to tackle this global issue effectively.

Plastic's impact on marine food chains

Plastic pollution is a pressing issue that affects all marine ecosystems and has a detrimental impact on marine life. It disrupts the natural food chain and poses a significant threat to various species, from small organisms to large marine mammals. The effects of plastic pollution on marine food chains can be observed through the following aspects:

Ingestion and Entanglement:

The most visible and direct impact of plastic pollution on marine life is the ingestion of plastic waste and entanglement in discarded plastic items. Marine animals, such as seabirds, fish, turtles, and marine mammals, often mistake plastic debris for food. Floating plastic bags, fragments, and pellets resemble their natural prey or floating algae, leading them to consume these harmful substances. Additionally, larger plastic items, such as discarded fishing gear, nets, and six-pack rings, can entangle marine creatures, restricting their movement, causing injuries, and making them more vulnerable to predators.

Starvation and Internal Injuries:

When plastic is ingested, it fills the stomachs of marine animals, leading to a false sense of fullness and subsequent starvation. Plastic can also cause internal injuries, intestinal damage, and blockages within their digestive systems. These injuries can be fatal and impair the animals' ability to swim or fly, further increasing their vulnerability.

Toxic Contamination:

Microplastics, due to their microscopic size, are easily consumed by small marine organisms and can make their way up the food chain to larger predators and, eventually, humans. These microplastics have the ability to adsorb toxins, which then transfer to the fatty tissues of the organisms that ingest them. This toxic contamination can have long-term health effects, and scientists are still working to understand the full extent of these impacts.

Disruption of Food Sources:

Plastic pollution also affects the food sources of marine life. For example, discarded fishing nets can smother and break coral reefs, preventing their healthy growth and reducing the availability of food and habitats for various marine species. Additionally, plastic debris can transport invasive alien species, which can further disrupt native ecosystems and contribute to biodiversity loss.

Bioaccumulation and Biomagnification:

Apex predators and marine mammals at the top of the food chain are particularly vulnerable to the cumulative impact of microplastics and the bioaccumulation of toxic chemicals found in plastics. As toxins build up in the fatty tissues of animals that consume contaminated prey, the concentration of these toxins increases as you move up the food chain. This process, known as biomagnification, has been observed in species such as orcas, which have been found with high levels of chemicals in their fatty tissues and breast milk.

Addressing plastic pollution in marine environments is crucial to mitigating these impacts on marine food chains and preserving the delicate balance of marine ecosystems.

Plastic pollution in marine mammals

Marine mammals are among the worst affected by plastic pollution. It is estimated that plastic pollution kills 100,000 marine mammals each year. Of the 123 marine mammal species, 81 are known to have eaten or become entangled in plastic.

Marine mammals, such as whales, seals, dolphins and porpoises, are vulnerable to ingesting plastic because it can look like prey to them. For example, a plastic bag floating in the water can resemble a jellyfish or squid, the staple diet of many marine mammals. Unnatural objects like plastic waste may also confuse the sonar used by toothed whales and some dolphin species to find their prey, leading them to mistakenly interpret plastic as food.

In 2010, a California grey whale washed up dead on the shores of Puget Sound with more than 20 plastic bags, a golf ball, small towels, duct tape and surgical gloves in its stomach. Another example is a sperm whale that died on a Spanish beach due to an inflammation of its abdominal tissues caused by ingesting nearly 30 kilograms of plastic, including shopping bags, fishing nets and a jerry can.

Marine mammals also face the threat of entanglement in plastic-based fishing gear, such as nets, ropes and pots, which is estimated to kill 300,000 whales, dolphins and porpoises annually. This plastic debris can restrict their movement, leading to starvation, injury and vulnerability to predators. It can also cause drowning, as marine mammals cannot breathe underwater.

The impact of plastic pollution on marine mammals is not limited to physical harm. Microplastics, or plastic particles smaller than 5mm, can be ingested by marine mammals and accumulate in their bodies. These microplastics have the ability to adsorb toxins, which can then be transferred to the fatty tissues of the organisms that consume them. The long-term impacts of microplastics are still being studied, but they pose a significant threat to the health of marine mammals and the ecosystems they inhabit.

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