Some of the world's largest seafood companies, including Clearwater Seafoods, High Liner Foods, Nomad Foods, Mowi, Leroy and Thai Union, showed a sharp drop in value, driven by a decline in the value of China's yuan and global market jitters.

Canada-based seafood giant Clearwater Seafoods' market cap dropped around 3.5 percent between Aug. 1-6 to $251 million (€223.4 million), to recover slightly to $253 million (€225.2 million) on Aug. 7.

North American frozen seafood processor High Liner Foods' market cap took a much harder hit, plummeting over 15 percent to $225 million (€200.2