Between December and January, the banks of Cambodia's waterways spring to life as fish season kicks in. The shift in climate from wet to dry causes the flow of the Tonle Sap River to reverse. This unique natural phenomenon brings with it a mass migration of fish and is the peak period for Cambodia's army of fishermen. The tonnes of tiny fish netted are then bought by prahok makers, who dedicate the next few days to meticulously making batches to stock up the country's supplies for the next 12 months.