For centuries, cod were so abundant in the waters off New England that fishermen used to say they could walk across the Atlantic on the backs of them, and generations of men from places like Gloucester, Massachusetts, spent their entire lives chasing the coveted fish. In recent decades, scientists raised alarms about overfishing and the warming ocean. In 2014, the National Oceanic and Atmospheric Administration reported that the cod population had plummeted to as little as 3 percent of what it would take to sustain a healthy population. They banned virtually all cod fishing throughout the region. Fishermen were infuriated. They challenged the findings and accused the government of trying to destroy their livelihood. Many cod fishermen were forced to sell their boats and abandon a way of life that had supported their families for generations. In 2016, officials estimated there were fewer than 200 cod fishermen left in the fleet, and they’re now in the fight of their lives, struggling to hold fast to a tradition that has endured for centuries.