Even as weak commodity prices depress export prices, sluggish demand growth in the rich world may limit emerging economies' export volumes.

ECONOMIST: Uncertain prospects

Even when the sharks are found closer to the ocean surface, they spend their time in the cool-temperature, plankton-rich waters that limit underwater visibility and make diving difficult.

CNN: Scientists discover winter home of world's second-biggest fish

One key to achieving Agrimonde's proposal is convincing people in rich countries to limit their waste and meat consumption and create more even distribution of animal products in diets around the world.

CNN: French report suggests new ways to feed the future