Fish farms, like the one above, account for over half of the world's fish supply (Credit: USDA NRCS CA/ CC-BY-2.0/ Wikimedia Commons)

Fish farming is a form of aquaculture in which fish are raised in enclosures to be sold as food. They account for over half of the world's fish supply and are vital for meeting the needs of an ever-growing human population. However, fish farms currently face a big challenge — waste management.