Mercury

The bits and pieces of overwhelming information a consumer receives from the internet or social media about the benefits and potential risks of eating fish can cause confusion and lead to misunderstandings. The consumer is often faced with a dilemma: on the one hand, the consumption of fish – mainly due to omega-3 fatty acids (see Myth and Truth/Fact No. 2) – contributes positively to the normal functioning of the body and, therefore, should be consumed in large quantities; meanwhile, there are consumer associations, national authorities in countries issuing advice, and urging attention towards the consumption of certain species of fish from specific areas.

The World Health Organization ranks mercury (Hg) among the 10 chemicals that raise significant public health concerns. Evidence of widespread mercury (Hg) pollution of the environment – as a result of human activity – led to the recent Minamata Convention, an International Treaty designed to protect human health and the environment from pollutive emissions and releases of mercury via human-based activities. As consumers, we acknowledge the EU’s effort to ban the use of thermometers, sphygmomanometers and other instruments containing mercury.

In the marine environment, inorganic mercury is converted by microorganisms, and through methylation, into methylmercury, which is the most common form of mercury found in the sea (90%). In turn, methylmercury is dispersed into the marine environment very rapidly and then bioaccumulates. Although the concentration of mercury in fish is often well below the legal limit proposed by the European Food Safety Authority, predatory fish, such as swordfish and sharks, have been reported to contain significantly higher concentrations of mercury. Larger predatory fish live longer and are at a higher food-chain level (food-chain level defines the position of an organism in the ecosystem -), thus, usually accumulating larger amounts of mercury.

About a decade ago (2012), the US National Food and Drug Administration (FDA) and the United States Environmental Protection Agency (USEPA) issued a tuna consumption warning. The warning stated that some tuna species, which tend to bioaccumulate more mercury than others, potentially increase the risk of exposure to mercury toxicity for the population that consumes them in large amounts.

The increase in the intake of Hg-contaminated foods, which exceeds the permissible limits set by the World Health Organization, has been linked by all researchers to the frequent consumption of large tuna species. Canned tuna of the large species of yellowfin tuna* (thunnus albacores*) and white or longfin tuna (thunnus alalunga) contains medium levels of mercury. Meanwhile, canned tuna, of the smallest species of tuna such as Skipjack (Katsuwonus pelamis), contains less than one third of the mercury concentration of the above species. At TRATA we use Skipjack tuna exclusively and control the concentration of mercury in each batch of tuna, by maintaining much lower acceptance limits than those set by European legislation. At the same time, we contribute to the rational and sustainable management of catches, since the Skipjack tuna species does not belong to the official Red List of endangered species published by the International Union for Conservation of Nature (IUCN). In contrast, other tuna species, such as yellowfin tuna and white or longfin tuna, are classified as “almost endangered species”.

So, feel free to fully enjoy the juicy pieces of Skipjack TRATA tuna. It also helps sustainable fishing.