The “dolphin safe” fishing methods espoused by the Earth Island Institute — and defended by Mary McGrory [op-ed, Feb. 2] — actually exact a heavy toll on our marine environment.

As much as some would like to frame this debate in terms of first-graders and “Flipper” reruns, someone has to ask the frank question “How much is a dolphin worth?” According to the Inter-American Tropical Tuna Commission, for every dolphin saved by our outdated methods, 27 sharks, 382 mahi-mahis and more than 1,000 other caught-and-discarded fish are sacrificed. Worse, more than 25,000 small tuna also perish with each haul, fish too young to reproduce. Kill enough juveniles, even unintentionally, and the next generation of adult fish just isn’t there.

Mexico has developed a dolphin-friendly program of its own, based on methods that are “not having a significant adverse impact on any depleted dolphin stock,” according to the tuna commission. Mexican tuna are every bit as “dolphin safe” as anyone else’s, and they’re mostly premium yellowfin, which tastes better.

Even Greenpeace supports Mexico’s tuna industry. Ditto for Environmental Defense. So why is the Earth Island Institute clinging to a system that could put the entire global tuna industry in dry dock?