17-year-old Hereiti lives on the largest of the Cook Islands in the South Pacific Ocean. She says the ocean is the ‘lifeblood’ of her community, and that when it is ‘healthy’, the people are too. But she worries that rising sea levels and pollution are threatening the health of the ocean. ‘Life Below Water’ is goal 14 of the UN’s sustainable development goals, a set of targets announced in 2015 to transform lives around the world by 2030. The UN wants to conserve and sustainably use the oceans, and significantly reduce marine pollution by 2025. In 2015, world leaders agreed to 17 global goals (officially known as the Sustainable Development Goals or SDGs). Five years on, there is more work than ever to do. Reaching these goals has the power to create a better world by 2030, through ending poverty, fighting inequality, and addressing the urgency of climate change. See