By Edward Carver The Emperor Seamount Chain is a massive and richly biodiverse set of underwater mountains stretching about 3,000 kilometers (1,900 miles) south from the Aleutian Islands in the northwest Pacific. From the 1960s until the 1980s, bottom trawlers plied the area aggressively, decimating deep-sea coral communities and fish stocks, and removing biomass to a degree not observed on any other seamounts in the world. Fishing has decreased greatly since then, but one Japanese trawler has remained active on the seamounts in recent years — and, to conservationists’ disappointment, that tra…