New evidence shows that Atlantic cod off Nova Scotia are recovering from their dramatic collapse two decades ago — and that the ecosystem is recovering with them. That suggests major changes to marine ecosystems can be reversed with time, says a Canadian study published Wednesday in the scientific journal Nature. It also “bodes well” for other cod populations further north along the East Coast that have yet to recover (such as ours!), says the study, led by researcher Kenneth Frank at the Bedford Institute of Oceanography in Dartmouth, N.S. In 2010, the Northwest Atlantic Fisheries Organization’s scientific council reported that the cod population in the Grand Banks, an underwater plateau southeast of Newfoundland, had grown 69 per cent since 2007. However, that was still just 10 per cent of what the stocks were in the 1960s. Can the rejuvenation continue?