The Devastating Impact Of Water Pollution On Fish

Water pollution is a pressing issue that poses a significant threat to marine life, with plastic pollution being a major contributor. While it is challenging to determine the exact number of fish killed by water pollution annually, estimates indicate that plastic pollution alone kills around 100,000 marine mammals each year. The impact of plastic pollution on fish and other marine creatures is twofold: ingestion of plastic and entanglement in abandoned fishing gear and nets. Additionally, water pollution from sewage spills and industrial discharges has led to mass fish deaths, with recent reports highlighting a tenfold increase in fish mortality rates in England's rivers since 2020.

Sewage pollution

While it is difficult to know the exact number of fish killed by water pollution annually, plastic pollution is estimated to kill 100,000 marine mammals each year, with 81 out of 123 marine mammal species known to have ingested or become entangled in plastic. The impact of sewage pollution on fish populations is significant and has led to mass fish killings. Sewage pollution can cause reduced oxygen levels in the water, which is the most common cause of fish kills. Low oxygen levels can be caused by various factors, including drought, high temperatures, and increased organic loads from sewage and other sources.

In recent years, there has been a concerning increase in fish kills linked to sewage pollution in UK waterways. According to Environment Agency (EA) data, the number of fish deaths attributed to sewage pollution escalated from 26,690 in 2020-2021 to 116,135 in 2023-2024, a 176% increase. This rise in fish kills coincides with a surge in sewage spills, which increased by 54% from 2022 to 2023.

Water companies have been implicated in these fish kills, with Southern Water and Thames Water identified as the primary contributors to sewage pollution incidents in 2023-2024. Anglian Water has also faced legal repercussions, including fines, for instances of river pollution that resulted in the deaths of thousands of fish. Despite the efforts of organizations like the Angling Trust and Fish Legal, which advocate for stronger enforcement and combat sewage pollution, the number of prosecutions against water companies has decreased.

Plastic ingestion

While it is difficult to know the exact number of fish that die each year from water pollution, plastic pollution is a significant contributor to the problem. Plastic ingestion by fish is a growing problem and a major concern for marine life and human health.

The foraging strategy of fish was also found to be related to plastic ingestion, with fish higher up on the food chain and predatory fish being the most likely to consume plastic. Pelagic species, such as lanternfishes, showed the greatest plastic ingestion at depths of 100-200 meters. These species may contribute significantly to the movement of microplastics throughout the water column due to their extensive biomass and vertical migratory behavior.

The effects of ingested plastic on wild fish are largely unknown, but correlative evidence suggests that plastic debris can contaminate fish tissues with persistent organic pollutants. These pollutants can have toxic effects on fish and other marine life, and they can also impact human health when ingested through fishery products. Microplastics in fish have been found to reach the gastrointestinal tract, causing oxidative stress, cytotoxicity, and translocation to other tissues. They can also release chemical substances and act as carriers of microorganisms, with potentially harmful additives such as polybrominated diphenyl ethers (PBDE) and bisphenol A (BPA).

While the impact of plastic ingestion on fish mortality is not fully understood, it is clear that plastic pollution, including microplastics, poses a significant threat to marine life and the health of ecosystems. The increasing rate of plastic consumption by fish and the widespread presence of plastic pollution in our oceans highlight the urgent need for further research and effective solutions to address this growing problem.

Abandoned fishing gear

While it is challenging to determine the exact number of fish killed by water pollution each year, plastic pollution is a significant contributor to aquatic life deaths. Abandoned fishing gear, also known as derelict or ghost fishing gear, is a substantial source of plastic pollution in oceans and waterways. This gear, which includes lines, nets, pots, traps, and floats, can have devastating consequences for marine life and the environment.

Derelict fishing gear can ensnare marine creatures, leading to injuries, infections, and drowning. It is estimated that 640,000 tonnes of the 8 million tonnes of plastic that enter the oceans annually are from ghost fishing equipment. This abandoned gear continues to trap and kill various species, including fish, crustaceans, marine mammals, sea turtles, and seabirds. The impact of ghost fishing is not limited to wildlife; it also damages sensitive seafloor habitats, such as coral reefs and seagrass beds, and interferes with vessels by entangling their rudders and propellers.

The problem of abandoned fishing gear is widespread and affects even remote and protected marine areas. For example, in the Papahānaumokuākea Marine National Monument, the largest fully protected marine conservation area, over 50 metric tons of marine debris, primarily consisting of derelict fishing gear, washes up on its shores annually. This debris severely impacts vulnerable species, such as the endangered Hawaiian monk seal and the threatened Hawaiian green sea turtle.

To address the issue of abandoned fishing gear, organizations like the NOAA Marine Debris Program have initiated projects to remove and prevent derelict fishing gear from entering the ocean. The program has been successful in removing over 848 metric tons of derelict fishing gear from the monument's shorelines. Additionally, the Fishing for Energy partnership provides fishers with a free solution for disposing of old, derelict, or unusable fishing gear, recycling or converting it into energy.

Furthermore, some fisheries have implemented innovative methods to manage the risk of losing gear and reduce ghost fishing. For instance, MSC-certified fisheries in Alaska and Normandy have introduced biodegradable escape panels and rings in their cod fishing pots and lobster fishery pots, respectively, to minimize the impact of lost gear on ecosystems. These fisheries also monitor gear loss and assess its ecological consequences to maintain their certification.

Water company negligence

While it is challenging to determine the exact number of fish killed by water pollution annually, plastic pollution is a significant contributor to aquatic life deaths. It is estimated that plastic pollution kills 100,000 marine mammals each year, with 81 out of 123 marine mammal species known to have ingested or become entangled in plastic. The issue extends beyond marine mammals, with plastic also affecting fish, turtles, and other creatures.

Water companies play a crucial role in maintaining water quality and can be held accountable for negligence resulting in water pollution and subsequent harm to aquatic life. Although they are typically government-operated, water companies generally do not have governmental immunity and can be sued for damage caused by their negligence. Their duties include properly installing, maintaining, and repairing their infrastructure, such as reservoirs, dams, pumps, and pipes, to prevent water-related damage to property and the public.

If a water company fails to fulfil these duties and their negligence leads to water pollution, they can be held liable. For instance, if they do not address a reported issue promptly or fail to investigate signs of a potential leak, such as persistent wetness or depressed ground, they may be found negligent. In such cases, those affected can seek compensation and, if necessary, take legal action with the support of a qualified property lawyer.

To establish negligence, evidence must be presented demonstrating the water company's failure in installation, maintenance, or repair. Additionally, enlisting the aid of an expert witness familiar with water utility operations can strengthen the case by explaining how the company's actions or inactions led to negligence. While a water company is not expected to regularly dig up its pipes for inspection, they are obligated to respond to reported problems and make timely repairs.

It is important to note that the impact of plastic pollution in our oceans extends beyond the death of marine life. Plastic pollution also disrupts marine ecosystems, endangers species, and has long-term effects on the environment. While the exact number of fish deaths due to water pollution may be unknown, the cumulative impact of plastic pollution on our oceans is undoubtedly devastating.

Ocean pollution

Plastic pollution in the oceans has devastating consequences for marine ecosystems. Marine animals, including fish, can become entangled in abandoned fishing gear and other plastic debris, leading to injury, infection, and death by drowning. The impact of ingestion is equally dire, as plastic can cause internal damage and be fatal. With an estimated 8 to 10 million tons of plastic entering the oceans yearly and over 46,000 pieces of plastic in every square mile of ocean, the magnitude of the problem is immense.

The fishing industry is a significant contributor to ocean pollution, with an estimated 640,000 tons of the annual plastic influx attributed to abandoned fishing gear. This includes nets, lines, and other equipment that continue to ensnare and kill marine life long after they have been discarded. The impact of the fishing industry extends beyond pollution, as their use of large nets can trap and drown not only fish but also turtles, sharks, and small whales.

The impact of ocean pollution on fish is not limited to immediate death. Plastic pollution can have insidious effects on fish populations over time. For example, plastic particles can remain in the bodies of smaller fish, potentially impacting their health and reproductive success. This, in turn, can have cascading effects on the ecosystem, as fish play a crucial role in the food chain.

Addressing ocean pollution requires a multifaceted approach. Reducing plastic use and improving waste management practices are essential steps. Individuals can play a role by recycling, reusing, and refusing single-use plastics. Additionally, advocating for better sewage treatment practices and holding water companies accountable for pollution incidents can help mitigate sewage pollution, as evidenced by the alarming rise in fish deaths linked to sewage pollution in England's rivers. By addressing these issues, we can work towards mitigating the devastating impact of ocean pollution on fish populations and marine ecosystems as a whole.

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