Canadians living in Sarnia, the largest city on Lake Huron, react to Donald Trump's threat to tear up the Great Lakes agreements and conventions between the US and Canada. "If Mr. Trump wants to move that border, he is going to have a big fight on his hands," says local resident Jan Casbourn. "He is breaking the tradition of this long standing cooperative arrangement over the Great Lakes," adds Mary Baxter of Western University. IMAGES AND SOUNDBITES