Mercury levels in tuna have remained stable for years!

Scientists say that despite controls introduced decades ago to limit polluting substances, high mercury levels in tuna persist.

Mercury, which has toxic properties, is released through the mining and burning of coal and mixes into the ocean, accumulating in fish.

Although mercury levels in the atmosphere have dropped significantly, it is stated that they have remained stable in tuna since 1971.

Experts say that mercury from very old periods is hidden in the depths of the ocean and mixes into the waters where tuna swim.

Mercury that enters marine ecosystems turns into methylmercury, the most dangerous form of this substance.

It accumulates in tuna when they consume contaminated marine life.

Tuna is one of the most consumed fish by humans worldwide, and when eaten, this element is passed on to humans.

Mercury is particularly dangerous for unborn babies and young children. It can also lead to cardiovascular diseases in adults.

Concerns regarding mercury have led to steps being taken worldwide to reduce activities that release this chemical into the atmosphere.

The main activities that lead to mercury emissions are listed as follows:

Coal and gold mining

Coal burning

Industrial activities

Waste processing

Even the cremation of bodies with amalgam dental fillings causes an increase in the total amount in the air.

The restrictions imposed have enabled atmospheric levels to drop by approximately 90 percent since 1990.

Researchers examined data obtained from nearly 3,000 tuna muscle samples taken from various species caught in the Pacific, Atlantic, and Indian Oceans, which account for 94 percent of the global tuna catch, to see if these actions had an impact on mercury levels in tuna.

The new study contrasts with other research showing that mercury levels in some tuna species have decreased.

Scientists found that, with the exception of an increase in the northwest Pacific in the late 1990s, mercury levels in tuna remained stable between 1971 and 2022.

This is thought to be linked to increased mercury emissions in Asia, triggered by rising coal consumption.

Researchers state that there is a massive amount of old mercury in the depths of the ocean and that the stable levels may be due to emissions from decades or centuries ago.

Anne Lorrain from the French National Research Institute for Sustainable Development said, "Even with a major reduction in mercury emissions, the results show that we need to be patient to see a change in tuna mercury levels."

"In general, this situation is similar to carbon dioxide (CO2) emissions: if we largely stop emissions, CO2 in the atmosphere will slowly stabilize and eventually begin to decrease."

The study was published in the journal Environmental Science & Technology Letters.

News Source: BBC