By swimming, diving, eating, excreting and dying, tuna mix water layers, store carbon and cycle nutrients that fuel the whole ocean food chain. This includes the primary producers in the ocean, plankton, which play a crucial role in oxygen production and carbon sequestration.

Tuna biology is complex, and maintaining stocks at sustainable level requires significant scientific intervention by Regional Fisheries Management Organisations. Despite these interventions, many tuna stocks are currently at low biomass levels, which results in more young fish, but with lower numbers of large, adult spawning fish. Recent research has highlighted that fish populations with many large individuals and high biomass fisheries are better for stocks, ocean health and communities, and retain the social and economic benefits to emerging economies. 

WWF’S global tuna strategy aims to bring the exploitation of tuna for food and as a source of revenue by industrial and artisanal fisheries into balance with their fundamental role in ecosystem
maintenance.