Alohou Papa stands in the middle of the bustling market in Togoville and blows hard on a bright red whistle to catch everyone's attention. "It's 9 o'clock. The village chief is sending me to announce that bartering can now start," he cries. "No arguing and no provocation," he tells traders and buyers. Every Saturday on the northern shore of Lake Togo, some 65 kilometres (40 miles) east of the capital, Lome, Togoville runs a lively traditional barter market.