A Canadian woman and a pediatric cardiologist from Georgia won the men’s and women’s contests at Key West’s annual Conch Shell Blowing Contest this weekend, using different techniques to impress the judges.   Brian Cardis of Macon, Georgia, played the Jimmy Buffett song “Fins” on a a pink-lined conch shell with holes so it can be played like a flute, while Carol Whiteley of Ontario, Canada, blew a long, loud blast with her shell to best other competitors.    Other winners included Michael and Georgann Wachter, a couple from Avon Lake, Ohio, who performed a conch-shell-and-vocal duet parodying Elvis Presley’s “Hound Dog” that drew cheers and laughter from spectators.