April 10, 2025
A toxic tide: The hidden impact of oil pollution
BY: Sophie Fresson
Topics: Oil and Gas
Dr. Rosie Williams is a research scientist, at ZSL’s Institute of Zoology, working on the Cetacean Stranding Investigation Programme, focusing on the impacts of chemical pollutants on marine mammals. We spoke with Rosie about the devastating effects of oil pollution on marine wildlife and repercussions for human health.
Right now, the government is asking the public to help them decide on the future of Big Oil in UK seas. Help them make the right choice for our ocean and future here.
Q: What impacts can oil have on marine wildlife?
Oil pollution affects marine life in multiple ways. The most visible impact is the physical smothering of animals, like seabirds covered in thick, black oil. This prevents them from flying, keeping them stranded and vulnerable. For fish, oil can clog their gills, making it difficult for them to extract oxygen from the water.
Beyond the physical damage, toxic chemicals in oil spills pose a serious threat. Some compounds found in oil are carcinogenic, meaning they can cause cancer. Others can disrupt reproductive systems, leading to fertility issues, stillbirths, or developmental defects in marine species. These chemicals also suppress immune systems, making animals more susceptible to disease. Some chemicals interfere with hormone regulation, which can lead to a variety of health and behavioural problems, such as reduced predator evasion or impaired hunting abilities.
The consequences of oil spills are far-reaching, harming wildlife and, in turn, the ecosystems they support. Vulnerable habitats like coral reefs and mangroves are particularly susceptible to impacts that can cascade through entire ecological communities.
Q: Can you tell us more about the toxic chemicals in oil spills?
Many chemicals in oil are known as endocrine disruptors, which interfere with the body’s hormone system. These compounds can mimic natural hormones, binding to receptors and disrupting essential physiological processes, including immune function, metabolism, and reproduction.
A particularly concerning group of pollutants are the persistent organic pollutants. These chemicals meet four key criteria: they are long-lasting in the environment, highly toxic, they accumulate in tissues, and they can travel long distances. Within the oil industry, polycyclic aromatic hydrocarbons (PAHs) are a major concern. PAHs are released through oil spills and a byproduct called produced water – the wastewater generated during oil extraction.
Q: What is produced water, and why is it concerning?
Produced water is the wastewater that comes up to the surface with oil and gas during extraction. A recent review found over 1,000 toxic chemicals in produced water, including heavy metals, PAHs, and other persistent pollutants. Given the vast number of toxic substances, understanding their full impact is extremely challenging.
We have strong evidence that benthic (seafloor-dwelling) communities near oil rigs experience much higher levels of toxic chemical contamination than those in unaffected areas. These contaminated sites also show a significant reduction in species diversity. Since benthic communities are a crucial part of the marine food web, this pollution can have far-reaching consequences, potentially affecting larger animals like marine mammals.
Q: How does the oil industry contribute to noise pollution?
Oil and gas companies rely on seismic surveys to locate new reserves. These involve ships firing seismic airguns into the ocean, sending shockwaves through the water to map the seafloor. The problem is, this noise pollution is incredibly disruptive to marine life.
Many marine species, including whales and dolphins, rely on sound for navigation, communication, and hunting. Loud industrial noise can cause disorientation, separation from their pods, or even strandings. And the reality is that noise pollution affects a wide range of wildlife beyond just marine mammals. New research is continually revealing just how critical sound is to the ocean ecosystem, and oil industry activities are a significant source of harmful noise pollution.
Q: What about human health? Are we at risk from these pollutants?
Absolutely. Many of these pollutants don’t just stay in the ocean; they make their way into the food chain. Industrial chemicals accumulate in seafood, which is a key part of human diets. For example, persistent organic pollutants have been found in people, and we know these chemicals can cause serious health effects.
The UK’s NHS guidelines recommend that young women and those planning to have children limit their intake of oily fish like salmon. Why? Because these fish accumulate high levels of industrial pollutants, which could be passed on to future generations. That alone should be a massive red flag.
Personally, I have changed my own seafood consumption habits. I avoid fish species known to accumulate the highest levels of toxins. It’s frustrating that this is a decision we’re forced to make due to pollution caused by industry.
Q: How much does this pollution worry you?
A lot. I love the ocean and its wildlife, so I find it deeply concerning from an environmental perspective. But beyond that, I’m worried about how these pollutants affect human health. Industrial pollution has taken away our ability to safely eat food from the ocean, and that makes me angry.
Q: What do you think needs to happen next?
The oil industry needs to take greater responsibility for its environmental impact. At the very least, governments should properly monitor and enforce regulations around oil spills and produced water releases. There should be heavy fines for companies that pollute our oceans.
Dr. Williams’ insights paint a stark picture of the widespread and lasting impacts of oil pollution. From harming marine life to threatening human health, the dangers of oil spills and produced water cannot be ignored. Stronger regulations, corporate accountability, and a transition away from fossil fuels are all necessary steps to protect our ocean for future generations. Take action here. Read more about the oil and gas industry’s chronic pollution in our Sea Slick report here.
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