Spurred by scientific discoveries on the benefits of omega-3 fatty acids on human health (Galli/Risé 2009), the consistent rise of global per capita fish consumption (FAO 2016: 2) has dramatically bred overfishing. Particularly, tunas are often caught through unsustainable practices that lead to bycatch and push marine species to the brink of extinction. This “tuna crisis” is bioethically relevant as it calls on companies and consumers to reflect upon “the responsibility to maintain the generative ecology of the planet, upon which life [...] depends” (Post 2004: xi). Generally uninformed of what lies behind tuna cans or sashimi menus, consumers must rely on the investigations carried out by environmental organisations to make ethical purchasing choices. Against this backdrop, this paper analyses the knowledge dissemination strategies (Garzone 2006) whereby environmental organisations try and influence the dietary and purchasing choices of tuna lovers. The analysis focuses on three “tuna guides” issued by Greenpeace in the USA, Australia and Italy. Adopting a Cultural Discourse Studies perspective (Shi-xu 2015), the contrastive examination unveils few differences and numerous similarities in the texts analysed. This discursive uniformity is determined by Greenpeace authorship and the global nature of the tuna crisis, but also by the discursive conventions of environmental activist culture (Horton 2004), which promote local solutions to global crises. American, Australian and Italian cultural specificities are, therefore, only apparently stifled by these discursive conventions, as total homogenisation is thwarted by the constraints of the local markets and by language, which reveals cultural specificities through idioms and puns.
