Pollution's Impact On Marine Life: A Prezi Overview

Marine pollution is a pressing issue that poses a significant threat to the health and well-being of our planet. With oceans covering 71% of the Earth's surface and providing habitats for a diverse range of species, the impact of pollution on marine life is a crucial topic. The pollution in our oceans comes primarily from land-based sources, including runoff from farms, littering, and industrial activities, and it affects marine organisms in a variety of ways. From entanglement and ingestion of plastic debris to the depletion of oxygen in seawater, marine life is under immense pressure. This paragraph will explore the effects of pollution on marine organisms and highlight the urgent need to address this global issue.

Plastic pollution

The impacts of plastic pollution on marine organisms are varied and far-reaching. One of the primary ways plastics harm marine life is through ingestion. Sea turtles, for example, often mistake plastic bags for jellyfish, their staple diet, and seabirds have been known to eat plastic because it releases a chemical that smells like their natural food. This ingestion of plastic can lead to suffocation, starvation, and toxic contamination. Research indicates that half of sea turtles worldwide have ingested plastic, and a recent study found that ingesting just 14 pieces of plastic increases a sea turtle's risk of death. Young turtles are especially vulnerable as they are less selective about what they eat and tend to drift with currents, just as plastic does.

Another way plastic harms marine life is through entanglement. Large items of plastic, such as discarded fishing nets, can entangle marine mammals and fish, leading to starvation, injury, and increased vulnerability to predators. This issue is particularly acute for large marine mammals such as whales, which are highly vulnerable to entanglement in ghost fishing gear. An estimated 300,000 whales, dolphins, and porpoises die each year from this cause.

In addition to the direct impacts on marine organisms, plastic pollution also has socio-economic effects. It negatively impacts tourism, fisheries, shipping, and human health. For example, plastic waste can encourage the growth of pathogens in the ocean, and corals that come into contact with plastic have an 89% chance of contracting disease.

To address plastic pollution, practical approaches include preventing the accumulation of plastic pollutants, reducing, recycling, and reusing plastic, raising awareness, and holding producers and manufacturers responsible.

Chemical contamination

Marine pollution is a pressing issue that encompasses various types of pollution, including chemical contamination, that severely disrupts marine ecosystems. Chemical contamination refers to the introduction of harmful man-made chemical contaminants into the ocean. These contaminants include pesticides, herbicides, fertilizers, detergents, oil, industrial chemicals, and sewage.

The effects of chemical contamination on marine organisms are complex and far-reaching. For instance, nutrient-rich fertilizers used in agriculture often end up in local streams and estuaries, leading to excessive algae growth that deprives the water of oxygen, creating "dead zones" uninhabitable for marine life. Some chemical contaminants, like the insecticide DDT, have climbed high into the food webs, even endangering species like the bald eagle.

Additionally, certain chemicals, such as PFAS, accumulate in the blood of both humans and marine mammals, with unknown long-term consequences. Pharmaceuticals ingested by humans but not fully processed by our bodies also end up in aquatic food webs, potentially impacting marine wildlife.

The persistence of chemical pollutants in the marine environment poses a significant challenge. Many of these contaminants cannot be easily broken down and may increase in concentration as they move up the food web. This poses a long-term threat to marine ecosystems, even after efforts to reduce pollution are implemented.

Understanding the full scope of chemical contamination's impact on marine organisms requires further research. However, it is clear that these contaminants severely disrupt marine ecosystems and the organisms that inhabit them. Addressing this issue through responsible chemical use and the enforcement of regulations is crucial for protecting the marine environment.

Oil spills

For marine birds, oil spills can destroy the water-repellency of their feathers, leaving them vulnerable to the elements. Juvenile sea turtles can become trapped in oil and mistake it for food. Dolphins, whales, and other marine mammals can inhale oil, which can affect their lungs, immune function, and reproduction. Oil can also poison birds and animals that try to clean themselves after coming into contact with it.

The type of oil spilled is also a significant factor. Light oils, such as fuel oils, are very volatile and will evaporate quickly. However, they present hazards as they can ignite or explode, and are toxic to both animals and plants. Heavy oils, on the other hand, can persist in the environment for months or years if not removed. They can smother organisms and lead to chronic health issues like tumors.

Noise pollution

Anthropogenic noise, or human-caused noise, has significantly increased in the ocean due to activities such as shipping, seismic surveys, explosions, construction, and the use of sonar devices. These noises can travel long distances underwater, leading to increased noise levels in many coastal and offshore habitats. The loudest underwater noise comes from naval sonar devices, which work similarly to echolocation, a type of sound used by whales and dolphins.

• Temporary or permanent hearing loss
• Behavioural and physiological changes
• Masking, or the ability to detect sound being overlapped or covered by another sound
• Injury and death

Very loud sounds can cause panic in marine mammals, leading to decompression sickness and tissue damage from gas bubble lesions. It can also alter their behaviour, causing them to move away from the noise, adjust their activities to avoid noisy times, or increase their anti-predatory behaviour. Noise pollution can also interfere with communication, masking the sounds produced by marine wildlife and leading to changes in individual and social behaviour, altered metabolisms, and hampered population recruitment.

To reduce noise pollution in the marine environment, policies and technologies that reduce propeller noise from ships, sonar equipment noise, and construction noise are needed. Quieter technologies and better management of soundscapes can also help improve the ocean soundscape and enable the recovery of marine life.

Light pollution

ALAN interferes with the natural light patterns that marine organisms have evolved to rely on for critical physiological and behavioural processes. These natural light cues include the light's intensity, colour, frequency, and spatial orientation. For example, marine organisms use natural light cues for spawning, daily and long-distance migration, foraging, predation, rest, and camouflage.

ALAN comes from a variety of sources, including coastal development (e.g. buildings, streetlights, ports), vessels (e.g. fishing boats, oil rigs), and offshore infrastructure. The use of LED lighting exacerbates the problem, as LEDs produce shorter wavelengths of light that penetrate deeper into the water.

ALAN has been shown to impact a wide range of marine organisms, including sea turtles, zooplankton, clownfish, sea urchins, and coral reefs. For example, ALAN disrupts the nesting and migration behaviours of sea turtles, lures zooplankton to the water's surface, and inhibits the reproduction of clownfish and coral reefs.

The specific effects of ALAN vary depending on the wavelength and intensity of the light, as well as the species and life stage of the organism. Shorter wavelength blue and green light is more easily detected by marine organisms and penetrates deeper into the water.

Addressing ALAN requires reducing the use, duration, intensity, and spectral composition of artificial light. Strategies include reducing the number of lights, using motion-sensitive lights, and installing limited-angle lights or shields to prevent light spill.

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