This video says about itself:
Lower Tiligul Estuary (Liman). Ukraine. May 17, 2015.
From the Netherlands Journal of Geosciences, May 2016:
During the Pleistocene [Ice Age], the coastal marine bivalve mollusc Mya arenaria became extinct in northwest Europe. The species remained present in North America. Datings of Mya shells found in northern Denmark and the southern Baltic Sea suggest that repopulation of northwest European coasts already occurred before Columbus’ discovery of America (1492), possibly facilitated by Viking (Norse) settlers at Greenland and northeast North America.
In this paper we report on findings of M. arenaria at five locations in the coastal landscape of the Netherlands: polders reclaimed from the Wadden Sea and the former estuaries of Oer-IJ and Old Rhine. The shells from four of these locations also date before 1492 AD.