Reacción a "Reactions: mercury concentration in tuna has not been reduced in the last decades"

The presence of mercury in the marine environment has been of concern to scientists, administrations and consumers for decades. Many studies have shown the concentrations in different marine species and regions of the world, with the aim of warning about the health of marine ecosystems and human exposure through seafood. 

The study by Médieu et al. shows the evolution of mercury concentration in some tuna species over more than five decades. It is a solid piece of work that has involved the review of numerous previous investigations and, in conclusion, calls on the authorities to take action to further decrease mercury concentrations in marine organisms. If this can be achieved, it will undoubtedly contribute to improving ecosystem and human health. 

One of the most important reflections that can be read in the article refers to future changes in climate, as this may result in changes in the kinetics of methylmercury in food webs. It is therefore essential to continue studying the hydrodynamic characteristics and mercury concentrations in tuna and other fish species, but not only at the muscular level, but in all tissues, in order to know the bioaccumulation and biomagnification in important tissues and organs such as the liver, kidney or brain. 

Spain is an important country in the aquaculture of Atlantic bluefin tuna (Thunnus thynnus), a migratory species but which is farmed (fattening), and for which the biological cycle has been closed in marine cages and land-based tanks. For this reason, efforts to investigate the importance of mercury in this species are all the more necessary.