Global warming is raising seawater temperatures off Japan, allowing migratory fish to stay north longer.

A study appearing in the journal Nature last May found that warming ocean temperatures have moved the distribution of fish preferring cold seas farther to the north and into deeper offshore waters, making it likely that reduced quantities of fish will be harvested in low-latitude seas.

In the study, “Signature of ocean warming in global fisheries catch” (Cheung, William et al.), sea surfa