The Ciénaga de Mallorquín is a swamp north of #Barranquilla, a city on Colombia’s Caribbean coast. Historically a source of food, wood and flood protection, the swamp had become a magnet for litter and pollution, with knock-on impacts on water quality and the abundance of fish. So the city launched an ambitious plan to restore the degraded ecosystem - deploying pollutant-absorbing algae, cleaning up the waterways and even launching an education programme which demonstrates the importance of the