Bluefin tuna are a unique and massive species. They can grow to more than ten feet in length and weigh more than 1,500 pounds. Their feats are similarly epic. A bluefin can cross the Atlantic Ocean in just over a month, dive up to 3,000 feet in a matter of minutes, and swim at speeds comparable to some racehorses. The bluefin tuna is a delicacy in certain parts of the world—in Japan, some bluefin tuna can fetch up to $100,000 for a single fish.

Sadly, perhaps because of its exceptionalism, the bluefin has been fished to the brink of extinction in many places. In the Gulf of Mexico, for example, longline fishing operations that target yellowfin—the canned tuna found in grocery stores—also exact a heavy price on local bluefin populations. In the past three decades, bluefin populations in the Gulf have plummeted to their lowest point ever.

In 2005, conservation groups filed a petition with the federal government that requested closure of the Gulf’s yellowfin fishery during bluefin spawning season. The government refused. Earthjustice challenged the agency’s decision, which was made without taking into account critical scientific data on the bluefin population’s health and road to recovery.