Wild Dolphin Bycatch in Purse Seine Fisheries

Dolphin bycatch in tuna purse seine fisheries was one of the original animal welfare crises that galvanized the modern conservation movement.

Key Facts

In the 1960s and 70s, yellowfin tuna fisheries in the Eastern Tropical Pacific killed an estimated 500,000 dolphins annually
Fishermen set purse seine nets on dolphin schools because tuna associate with dolphins in this region
The Marine Mammal Protection Act of 1972 was partly a response to public outrage over dolphin bycatch
Fishing on floating objects (FADs) and fish aggregating devices has largely replaced dolphin-setting but creates different bycatch problems
The dolphin-safe tuna label was created in 1990, though its standards and enforcement have been debated
Eastern spinner dolphin and spotted dolphin populations have not fully recovered despite decades of reduced mortality
Observer programs on fishing vessels are essential for monitoring bycatch levels

Welfare Considerations

Dolphins encircled in purse seine nets experience extreme stress - the animals panic, attempt to escape, and can suffer for extended periods before being released or drowned. Even released dolphins may die from capture myopathy. The scale of historical dolphin bycatch - millions of deaths over decades - represents one of the largest marine mammal welfare disasters in history.

What You Can Do

Choose tuna products from fisheries that do not set on dolphins (pole-and-line or FAD-free)
Learn about the dolphin-safe label limitations and look for more specific sourcing information
Support observer programs that monitor bycatch in commercial fisheries
Advocate for strong enforcement of dolphin-safe certification standards
Donate to oceanic conservation organizations monitoring dolphin population recovery