On World Wildlife Day, we highlight the severe impact that mercury pollution poses to wildlife inside and outside our oceans, particularly those at the top of the food chain.
When mercury released into the environment, it can bioaccumulate in the food chain, with predators at the top, such as marine mammals, seabirds, and large predatory fish, being particularly vulnerable.
Mercury can enter the ocean through a variety of sources, including atmospheric deposition, runoff from land, and industrial discharges. Once there, it can be converted to methylmercury, a highly toxic form that is easily absorbed by marine organisms.
When smaller organisms such as plankton and small fish consume methylmercury-contaminated food, the toxin accumulates in their bodies. As larger predators consume these smaller organisms, the concentration in the body increases, a process known as biomagnification.
Marine mammals such as dolphins, whales and seals are particularly susceptible to mercury contamination due to their position at the top of the food chain. High levels of mercury in these animals can lead to reproductive failure, behavioral changes, and even death.
Large predatory fish such as tuna and swordfish are also vulnerable to mercury contamination. High levels of mercury in these types of fish can lead to developmental abnormalities, to reduced reproductive success and, in some cases, to impaired growth.
Humans around the world who consume contaminated seafood can be exposed to methylmercury, which can cause a range of health problems, including neurological damage, developmental delays in children, and cardiovascular disease.
Mercury pollution poses a significant threat to marine wildlife. Reducing mercury emissions and implementing strategies to reduce exposure in wildlife and humans is critical to protecting the health of our oceans and the animals that rely on them.