Porbeagles – one of Canada’s most populous sharks – travel all the way to the Sargasso Sea to give birth. Pregnant females leave their usual haunts on the Georges Bank shared by Canada and the US to travel the thousands of kilometres to their nursery. Lovers of cold water, the porbeagles dive more than a kilometre down, swimming underneath the Gulf Stream. This takes them to a safe destination, avoiding the active fishery off eastern Canada and the US. Porbeagles have been subject to fishing since the 1960s, when the Norwegians started to fish them. Their meat is popular in Europe. Overfishing caused the population to drop to an all-time low about five years ago, but scientists raised the alarm. Fishers and scientists cooperated to impose an 80% cut to the catch quota (and a further 10% cut), with good results. The population is beginning to rise and is hoped to remain sustainable. — From a presentation at the CSEE conference this week by Steven Campana of the Department of Fisheries and Oceans’ Bedford Institute of Oceanography