Whale Health Crisis: Plastic Pollution's Impact

Plastic pollution is a pressing issue that poses a significant threat to marine life, including whales. With an estimated 12 million tonnes of plastic waste entering the oceans each year, it is no surprise that whales, as filter feeders, are ingesting large quantities of plastic fragments and microplastics. This consumption of plastic exposes whales to toxic chemicals and can lead to critical obstructions in their digestive systems, reduced fertility, and even death. The impact of plastic pollution on whale populations is a growing concern, and it is essential to address this issue to protect these majestic creatures and the health of our oceans.

Plastic ingestion blocks whales' digestive tracts

Plastic ingestion is a serious threat to whales, blocking their digestive tracts and causing intestinal trauma, which can lead to death. In 2008, a sperm whale stranded on the California coast was found with a ruptured stomach caused by a huge amount of plastic waste, including fishing nets and other synthetic debris. Another sperm whale, stranded on the same coast, had a large plug of wadded plastic blocking its digestive tract and was suffering from starvation.

In 2017, a whale was found dead in Norway with more than 30 whole plastic bags in its stomach. The 2-ton whale had no food in its stomach, only plastic, and had to be euthanized. This is a common issue, with previous studies finding plastic bags and other plastic items in whales' stomachs, causing critical obstructions in their digestive systems.

Whales are filter feeders, meaning they consume large quantities of water and strain out small prey. In the process, they inadvertently swallow plastic fragments and microplastics, which can accumulate and block their digestive tracts. Microplastics are small pieces of plastic less than 5mm in size, which can be manufactured or the result of larger plastics breaking down.

The ingestion of plastic and microplastics can also expose whales to toxic chemicals, further endangering their health. These toxins can accumulate within the animals and interfere with their ability to absorb nutrients correctly. The toxic substances found in plastic and microplastics include heavy metals and phthalates, which can alter hormones regulating growth, development, metabolism, and reproductive functions.

Plastic toxins alter whales' hormones

Whales are ingesting plastic in alarming quantities, exposing them to toxic chemicals. Whale sharks and fin whales, for example, are ingesting hundreds of pieces of plastic every day. As filter feeders, they consume large quantities of small prey by straining them from the ocean water, swallowing hundreds to thousands of cubic meters of water daily. This means they are likely to ingest substantial amounts of microplastic floating in the water.

Microplastics are small pieces of plastic less than 5mm in size. They are either manufactured, such as the microbeads added to health and beauty products, or the result of larger plastics breaking down over time. These plastics are pervasive in marine environments and are known to harbor toxic substances such as heavy metals and phthalates.

Since many animals are known to eat microplastics, scientists are concerned about the toxic substances within them and their ability to accumulate within the animals, potentially blocking their ability to absorb nutrients. Professor Maria Cristina Fossi of the University of Siena states that "exposure to these plastic-associated toxins pose a major threat to the health of these animals since it can alter the hormones, which regulate the body's growth and development, metabolism, and reproductive functions, among other things."

Indeed, David Attenborough, in an episode of Blue Planet II, highlights the plight of a pod of pilot whales feeding in the Atlantic Ocean, far from land. The whales become entangled in plastic bags, and a mother whale is filmed carrying her dead baby calf in her mouth. Attenborough suggests that the calf may have been poisoned by drinking its mother's milk, which was contaminated by toxic plastic in the food chain.

The impact of plastic pollution on whales underscores the urgent need to address this global environmental crisis.

Plastic pollution reduces whale fertility

Plastic pollution is having a devastating impact on whales, with ingestion of plastic causing poisoning and death. Plastic pollution also reduces whale fertility, with toxic substances contained within the plastic altering hormones that regulate reproductive functions.

A recent study published in the journal Trends in Ecology & Evolution found that whales and whale sharks are ingesting microplastics in alarming quantities. These tiny particles of plastic, less than 5mm in size, are pervasive in marine environments and are known to harbour toxic substances. While the study focused on the potential for these microplastics to cause hormone disruption, other studies have found plastic bags and other plastic debris in whales' stomachs, causing critical obstructions in their digestive systems and even death.

The impact of plastic pollution on whale fertility is a serious concern, as many filter-feeding whale species are already endangered and have low reproductive rates. Whale sharks, for example, are listed as vulnerable, with a population of only around 7,000 in 2016. Manta rays, another species affected by plastic pollution, typically give birth to a single offspring every two to five years.

The problem is particularly acute in areas of high pollution, such as the Mediterranean Sea, where animals may also suffer from psychological stress, further increasing the risk of health problems and reducing fertility.

With an estimated 12 million tonnes of plastic waste entering our oceans each year, the problem is only getting worse. Plastic pollution is a global issue that requires a global solution. Urgent action is needed to reduce the impact on whale populations and the marine environment as a whole.

Plastic debris entangles whales

Plastic debris in the ocean is a critical threat to whales, and entanglement is one of the two primary ways in which it harms them. The problem of plastic pollution in the oceans has been created within a single generation, and it will require a global effort to solve it.

Whales are among the more than 240 wildlife species known to have ingested plastic, which can cause internal injuries and even death. Plastic debris in the ocean takes the form of discarded fishing gear, packing loops, six-pack carriers, plastic bags, and microplastics, among other things. All of these items pose a severe risk of entanglement to whales and other marine life.

Fishing gear made of plastic, such as nets and ropes, is especially dangerous. Every year, 300,000 whales, dolphins, and porpoises become entangled in these items and die slow and painful deaths from suffocation, starvation, or exhaustion. This abandoned fishing gear, often referred to as "ghost gear," can continue to trap marine animals for years, decimating populations of whales and other species.

Even microplastics, tiny plastic particles measuring less than 5mm, have been found inside whales and their prey. While these particles break down into invisible toxic compounds over time, they can still disrupt the development and reproductive health of whales and other marine life.

The problem of plastic pollution in the oceans is a global one, and it will require a coordinated international response to address it effectively. Reducing plastic production and improving waste management practices are crucial steps in mitigating the impact of plastic pollution on whales and other marine life.

Plastic ingestion causes intestinal trauma in whales

Whales are dying from ingesting plastic pollution in the ocean. A review of research literature from the last two decades reveals hundreds of cases in which cetaceans (an order including 80-odd species of whales, dolphins and porpoises) have been sickened or killed by marine litter. Ingestion of plastic is a serious cause of disability and death for these creatures.

Another example is the case of two sperm whales that stranded on the California coast in 2008. One of the whales had a ruptured stomach, while the other had a large plug of wadded plastic blocking its digestive tract, leading to starvation. These cases highlight the severe intestinal damage that plastic ingestion can cause in whales.

Whales are particularly vulnerable to ingesting plastic due to their feeding behaviours. Deep-diving toothed whales, such as sperm whales, rely on echolocation to find food in the darkness. However, plastic debris like shopping bags can bear similar "echoes" to those of their prey, leading them to mistakenly ingest plastic. Additionally, whales are suction feeders, making it difficult for them to distinguish between prey and plastic once it is in their mouths.

The impact of plastic ingestion on whales' intestinal health is not fully understood, and scientists are still working to measure the full extent of the problem. However, it is clear that plastic ingestion causes intestinal trauma in whales, leading to severe health consequences and even death.

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