german island borkum in the waddenzee

biological borkum brackish channels coast coastal dry dutch ebb ebbtide energy environment environmental europe european flat flora german germany groningen gully gutter habitats holland interactions intertidal island landscape low marsh marshes mill mills mud mudflats natural nature netherlands outdoor outdoors outside physical plant plants pole poles reserve salt sand sandbanks sandbars sandy sea shoals shore tidal tide undisturbed vegetation wadden waddenzee water wet wetland wetlands windmills wndmill