Now the Haringvliet was cut off from the sea there was no tide and the sea water was slowly replaced with fresh water from the rivers. Some pants and animals could adapt to their new environment but for some species these changes were fatal. Crabs and marine fish can not be found in the Haringvliet anymore. Before the Haringvliet was closed this area was one great nature reserve. For years a small island, the Scheelhoek, was the sanctuary of klutes. It was the biggest colony of Europe. More than 1500 couples came here every spring to nest. In winter shores of the Haringvliet was a safe place for tenths of thousands wild geese. Nowadays some places are preserved for this wild life. With this dam it only takes a half hour ride to get to the Haringvliet from Rotterdam. Because there is no tide the Haringvliet is used for recreational purposes. Almost every day of the year one can find there yachts, surfers, or other water sports activities.