Seafood is a part of the human diet and harvesting of marine species provides a source of income to millions. Products from marine species are used as food additives, animal feed, fertiliser, clothing, jewellery and cosmetics. But development, overfishing, pollution and introduction of exotic species in marine habitats have jeopardised marine ecosystems and biodiversity. Construction activities, sewage and pollution from industries in large cities threaten coastal ecosystems. Oil spills and release of waste from tankers at major ports also threaten marine life.