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

Tuna, and in particular large tuna species, are apical predators that accumulate mercury because they occupy high levels in the food chain. They are therefore indicators of mercury concentration in the oceans, and especially in the food chain. Another factor to take into account is the harmfulness of mercury for human health, which is counterbalanced by selenium, whose concentration in tuna is also high. 

The journal in which the study is published has a high impact factor and its first author has numerous publications on the subject.