It was the muddy water that caught Stefan Talke’s eye. In the mid-2000s Talke was a postdoctoral scholar at Utrecht University, studying the river Ems that empties into the North Sea between Germany and the Netherlands. Decades earlier, engineers had begun dredging parts of the Ems so that newly built ships could navigate it from a shipyard upriver.But those changes also changed the rhythm with which tides ebbed and flowed into the river from the sea. Those shifting tides stirred up sediment from the river bottom and muddied its waters. Over the last 120 years the tidal range – the distance between high and low tide – has quintupled in the Ems estuary.
Source: How humans are altering the tides of the oceans – BBC Future