Pollution's Impact: Turtles' Plight And Fight

Pollution poses a significant threat to turtles, particularly sea turtles, which are vulnerable to a range of pollutants at all stages of their life. From eggs to adults, turtles face risks from toxic metals, PCBs, petroleum products, and agricultural and industrial runoff. These pollutants can cause immediate harm or build up over time, leading to immunosuppression, disease, and death. Additionally, plastic pollution in the ocean, often mistaken for food, can cause intestinal blockages, malnutrition, and even pierce the intestinal wall, resulting in internal bleeding. Light and noise pollution also impact turtles, driving them away from critical habitats. With nearly all species of sea turtles classified as endangered, addressing the impact of pollution is crucial for their survival.

Plastic ingestion: turtles eat plastic, confusing it for food, which can cause intestinal blockages and even death

Sea turtles often mistake plastic for their natural food sources, such as jellyfish and seaweed. This is because plastic bags and fishing nets resemble their staple foods.

Plastic ingestion can cause intestinal blockages, malnutrition, reduced growth rates, and even death. It can also trick turtles into feeling full, causing them to neglect to seek out other food sources and ultimately starve. Intestinal blockages can also lead to malnutrition and reduced growth rates.

Research conducted by the Commonwealth Scientific and Industrial Research Organisation (CSIRO) and the University of the Sunshine Coast (USC) found that a turtle had a 22% chance of dying if it ate just one piece of plastic. Once a turtle had ingested 14 plastic items, there was a 50% likelihood that it would die.

Globally, it is estimated that approximately 52% of all sea turtles have eaten plastic.

Entanglement: turtles can get trapped in plastic debris, fishing nets, and other waste, leading to injury or drowning

Entanglement is a significant threat to turtles, as they can become trapped in plastic debris, fishing nets, and other waste, leading to injury or drowning. Turtles are vulnerable to entanglement at all stages of their lives, from eggs to hatchlings to adults. The accumulation of plastic and debris at nesting beaches can entangle female turtles as they attempt to nest, and it can also trap hatchlings trying to reach the sea.

Turtles are strong swimmers, but when they become entangled in plastic or fishing gear, they can be weighed down and unable to surface, leading to drowning. Even if they manage to stay afloat, entanglement can prevent them from escaping predators or hunting, reducing their chances of survival.

The types of debris that turtles can become entangled in vary widely and include lost fishing nets, plastic twine, nylon fishing line, six-pack rings from canned drinks, plastic packaging straps, plastic balloon strings, kite strings, plastic packaging, and discarded anchor lines and seismic cables.

Research by the University of Exeter found that 91% of turtles entangled in discarded fishing gear died. The same research also surveyed 106 marine experts, 84% of whom had directly witnessed the death of turtles due to plastic entanglement.

Entanglement in plastic and other debris can have devastating consequences for turtles, causing injuries, choking, and drowning. It is a significant contributor to the decline in global turtle populations and highlights the urgent need to address plastic pollution in our oceans.

Oil spills: oil from spills accumulates in important sea turtle habitats and can impact turtles at all stages of life

Oil spills are a significant threat to sea turtles, as the oil accumulates in important sea turtle habitats and can impact turtles at every stage of their life. Sea turtles' habitats often overlap with areas likely to be affected by offshore oil exploration and production. Oil spills occur due to intentional discharge from vessels, vessel groundings, the transport of oil products, and runoff from land-based sources.

Oil from spills far offshore gathers along convergence zones, which are crucial areas for young sea turtle development. These zones are where ocean currents meet, and they are vital for the growth of young turtles. The oil from these spills also washes up on beaches, damaging nesting habitats and affecting nests, adult female turtles, and hatchlings making their way to the water.

Sea turtles are vulnerable to oil pollution through direct contact or by ingesting contaminated food. Oil can build up in their tissues over time, leading to immunosuppression and disease. One such disease is fibropapillomatosis (FP), which causes cauliflower-shaped tumors on sea turtles' external soft parts and internal organs. FP can impair a turtle's movement, vision, and breathing, making them more susceptible to predators and collisions with boats.

Additionally, oil spills contribute to marine pollution, affecting the sensitive habitats that sea turtles depend on for survival. These habitats include seagrass beds, mangroves, and coral reefs. The impact of oil spills on these habitats can have long-lasting effects on sea turtle populations.

Light and noise pollution: light and noise drive turtles away from critical habitats and can cause disorientation and hearing damage

Light and noise pollution are significant threats to sea turtles, causing them to abandon critical habitats and endangering their survival. Sea turtles are highly sensitive to both light and noise, and the impact of these pollutants can be far-reaching.

Unfiltered lights along coastlines can disorient hatchlings and deter adult turtles from nesting. Coastal lighting can disrupt the natural behaviour of sea turtles, causing them to avoid suitable habitats and endangering their nesting activities. This disruption can have a cascading effect on the turtle population, as fewer nesting sites mean fewer successful hatchlings.

Noise pollution, particularly persistent and abrupt low-frequency noise, can also disturb sea turtles. Sources such as seismic tests for energy exploration can impact their hearing and may even cause hearing damage. The loud and sudden nature of these noises can startle turtles and cause them to flee from their habitats, impacting their nesting and feeding behaviours.

The combination of light and noise pollution can be especially detrimental, as it can create a persistent and stressful environment for sea turtles, affecting their overall health and reproductive success. These pollutants can drive turtles towards less suitable habitats, further endangering their survival and the survival of their offspring.

Additionally, light and noise pollution can have indirect effects on sea turtle populations. For example, these pollutants can impact the prey species that sea turtles rely on for food, reducing their availability and altering their distribution. This can lead to a decline in the food sources available to sea turtles, further endangering their health and reproductive success.

The impact of light and noise pollution on sea turtles highlights the importance of responsible coastal development and the need for measures to mitigate these pollutants. By reducing light and noise pollution, we can help protect sea turtles and ensure the long-term survival of these ancient mariners.

Chemical pollution: toxic metals and other chemicals can build up in turtles' organs and tissues, leading to immunosuppression and disease

Sea turtles are vulnerable to chemical pollution at all stages of their life. Pollutants such as toxic metals, including mercury, cadmium, and lead, as well as chemicals like PCBs, can build up in the organs and tissues of turtles, leading to immunosuppression and disease.

Toxic metals are known to accumulate in the liver, kidneys, and other tissues of sea turtles. For example, a study on loggerhead turtles from the Mediterranean Sea found that mercury tended to be higher in the liver than in other organs and tissues. Similarly, cadmium was found at high levels in the kidneys, and lead was found at high levels in muscle tissue. These toxic metals can bioaccumulate and biomagnify in the food chain, leading to higher concentrations in the tissues of older turtles.

The accumulation of pollutants in turtle tissues can lead to immunosuppression, making turtles more susceptible to diseases such as fibropapillomatosis (FP). FP causes cauliflower-shaped tumors on the external soft parts and internal organs of sea turtles, impacting their vision, breathing, and feeding abilities. It also creates drag, slowing them down and making them more vulnerable to predators and boat collisions.

In addition to toxic metals, chemicals like PCBs (polychlorinated biphenyls) also pose a significant threat to sea turtles. PCBs were banned from production in the US in 1979, but they persist in the environment and have been found in sea turtle eggs. Ingestion of these chemicals can lead to depressed immune systems, illness, disease, and impaired reproduction.

The impact of chemical pollution on sea turtles is not limited to direct harm but also includes indirect effects on their habitats. For example, oil spills and urban runoff of chemicals contribute to marine pollution, affecting sensitive habitats that sea turtles depend on, such as seagrass beds, mangroves, and coral reefs.

The build-up of toxic metals and chemicals in sea turtles can have far-reaching consequences, affecting their health, reproduction, and overall population dynamics. It is crucial to address these pollution sources and reduce the input of contaminants into marine ecosystems to protect sea turtle populations and their habitats.

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