The Canadian Press There’s growing evidence that the number of great white sharks is on the rise along Canada’s East Coast, where plans are in the works to post warning signs for beachgoers for the first time. Fred Whoriskey, director of the Ocean Tracking Network at Dalhousie University in Halifax, says the population of these apex predators appears to be growing because of successful conservation measures and a rapidly growing food supply, mainly grey seals. “We’re probably seeing more animals here, though we don’t know how many,” he said in an interview. “No one has a handle on the northwest Atlantic white shark population …. (But) I’ve spoken to a lot of lobstermen who are seeing things that they have not seen for 40, 50 years on the water. That…