Pollution's Impact: Devastating Sea Life And Ecosystems

Oceans are among the most valuable natural resources on Earth, governing the weather, cleaning the air, helping feed the world, and providing a living for millions. However, human activities are causing significant harm to the health of marine ecosystems. Oceans are being flooded with two main types of pollution: chemicals and trash. Eighty percent of marine pollution comes from land-based sources, including runoff from farms, factories, and cities, as well as littering, storm winds, and poor waste management. Chemical pollution, such as fertilisers and pesticides, can cause harmful algal blooms, which can be toxic to wildlife and humans, and deplete oxygen levels in the water, creating dead zones where marine life cannot survive. Trash pollution, particularly plastic, can entangle and injure marine animals, be mistaken for food, and release toxic chemicals as it breaks down, which then accumulate in the tissues of organisms that ingest them, including humans. Marine debris also interferes with navigation safety and can pose threats to human health.

Oil spills

Sea turtles are vulnerable to oil spills at all life stages. Juvenile sea turtles can become trapped in oil and mistake it for food, while adults can inhale oil fumes and swallow oil when breathing at the ocean surface.

The effects of oil spills are long-lasting and can have irreversible impacts on delicate marine ecosystems. Even with cleanup efforts, only a fraction of the oil is typically removed, and the technologies used can sometimes be hazardous.

Marine debris

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

Plastics are one of the most common types of marine debris, with plastic debris accounting for 92% of individual encounters between organisms and debris. As plastics break down into microplastics, they are ingested by marine organisms, leading to internal injuries, intestinal blockage, starvation, and death. Microplastics also absorb toxic chemicals, further threatening the health of marine life and humans who consume seafood.

Derelict fishing gear, such as nets, ropes, and lines, can entangle marine animals, leading to injury, suffocation, and death. It can also damage marine habitats and create hazards for navigation.

Abandoned and derelict vessels obstruct navigational channels, harm the environment, and disrupt commercial and recreational activities. They may also release hazardous substances, posing immediate or future threats to wildlife and habitats.

The impact of marine debris is far-reaching, affecting hundreds of marine species, degrading habitats, interfering with navigation, causing economic losses, and threatening human health and safety. It is essential to address this issue through increased public awareness, behavioural changes, and a shift towards a more sustainable economy.

Carbon emissions

When carbon dioxide dissolves in seawater, it forms carbonic acid, increasing the ocean's acidity. This process has detrimental effects on marine organisms that rely on calcium carbonate to develop and maintain their shells and skeletons, such as mussels, clams, oysters, and coral. The decrease in ocean carbonate levels caused by rising acidity threatens the survival of these animals, disrupting food chains and the livelihoods of people who depend on the ocean for income and food sources.

The impact of carbon emissions on the ocean's acidity is rapidly worsening. If greenhouse gas emissions continue to increase, the surface waters of the ocean could become much more acidic by the end of the century. This increased acidity contributes to the bleaching of coral reefs and impairs the sensory abilities of some fish, making it harder for them to sense predators or hunt prey.

The ocean plays a crucial role in mitigating climate change by absorbing excess heat and carbon dioxide emissions. However, the increasing levels of greenhouse gases have negatively affected the ocean's health, reducing its ability to act as a carbon sink and safeguard life on Earth. It is essential to address the root cause of the problem by reducing unabated carbon dioxide emissions from the burning of fossil fuels.

The effects of carbon pollution on the ocean are far-reaching and have significant implications for marine life, ecosystems, and human communities. By understanding the impact of carbon emissions on the ocean, we can emphasize the importance of emissions reduction and work towards sustainable solutions to protect the health and resilience of our oceans.

Noise pollution

Marine mammals, such as whales, dolphins, and porpoises, are particularly affected by noise pollution. They rely on sound to communicate, locate mates and prey, avoid predators, navigate, and defend their territories. Noise pollution can disorientate animals, especially those that rely on echolocation like dolphins and toothed whales, and interfere with their natural behaviours. It can also cause hearing loss, stress responses, and even death.

The impact of noise pollution on the marine ecosystem is complex and interconnected. For example, if a whale strands on a beach due to sudden intense noise from human activity, its body will remain on land instead of sinking to the seafloor. This disrupts the food chain as sea-floor-dwelling animals that rely on the whale's body for food lose a key food source.

Noise levels in the ocean have increased dramatically over the past few decades, with sources of noise in the marine environment not being regulated at an international level. There is a growing concern that noise proliferation poses a significant threat to marine ecosystems and the survival of marine mammals, fish, and other ocean wildlife.

To reduce noise pollution in the marine environment, policies need to be implemented to mitigate propeller noise from ships, sonar equipment, seismic air guns, pile-driving, and construction. Additionally, quieter technologies, such as 'marine vibroseis' for seismic surveys and alternatives to conventional pile-driving, need to be developed and adopted.

Chemical contamination

• Industry: Factories and industrial waste can allow waste products to flow into streams and rivers, which eventually reach the sea.
• Farming: Pesticides and herbicides are sprayed onto food crops to control insects and weeds. These chemicals are often toxic and can easily find their way into freshwater streams and rivers, which eventually flow into the sea.
• Medicine: Some medicines contain harmful chemicals, which can enter the sea through sewage treatment plants.
• At home: Many household cleaning, washing, and polishing products contain chemicals that can be harmful to wildlife and marine environments.

Frequently asked questions