Dolphin Bycatch Ethics in Tuna Fishing

The history of dolphin bycatch in tuna fishing and the ongoing challenges of dolphin-safe certification systems.

Key Facts

Eastern Pacific tuna purse seine fishing killed millions of dolphins before 1972 Marine Mammal Protection Act reforms.
Dolphins associate with yellowfin tuna in the eastern Pacific, leading to their historical capture in tuna sets.
The dolphin-safe label was created in 1990 and has been contentious regarding its actual welfare standards.
ETP-method tuna fishing with dolphins has lower overall bycatch of other species than non-dolphin-set alternatives.
Stress and injury from net encirclement affect dolphins even when observable mortality is eliminated.
FAD-associated fishing avoids dolphin encirclement but has high juvenile tuna and bycatch rates of other species.

Welfare Considerations

Dolphin bycatch in tuna fishing represents one of conservation history's most significant welfare achievements through the dramatic reduction of dolphin mortality from the 1960s to today. However, the remaining welfare challenges are more nuanced than mortality statistics suggest. Encirclement of dolphins in purse seine nets causes stress responses even when dolphins escape or are backdown-released. The dolphin-safe label does not guarantee no dolphin interaction, only no intentional encirclement, and standards vary by market. The comparison between dolphin set tuna (lower overall bycatch but dolphin stress) and non-dolphin set alternatives (dolphin-safe label but higher bycatch of other species) illustrates the complexity of welfare decisions across species.

What You Can Do

Research tuna certification standards in your market to understand what dolphin-safe actually guarantees.
Support tuna fishing reform that considers welfare impacts across all species, not only charismatic dolphins.
Choose tuna from fisheries with documented low overall bycatch rates including sea turtles and non-target fish.
Reduce overall tuna consumption to lower demand pressure on all fishing methods.