The Bozo of Mali are people of the water. For generations, they have lived along the banks of the Niger river, fishing for their livelihood. But climate change and drought have brought lower water levels and fewer fish - driving young Bozo men to leave their villages in search of work. Gala is one of these men. Like many young Bozo, he has moved to the capital, Bamako, and works as a sand fisher - dredging up sand and gravel by hand from the river's banks and bottom, and using large wooden pirogues to ferry it ashore. Here, it will be loaded into trucks and used for bricks, concrete mix and tiling - all to feed the construction boom in the country's largest city.