This video says about itself:
Eurasian Oystercatcher (Haematopus ostralegus) in winter plumage feeding November 2007, Brouwersdam (Zeeland), The Netherlands.
From Vroege Vogels radio in the Netherlands:
Oystercatchers eat Japanese oysters
26 February 2008 14:29
Wadden Sea biologist Gerhard Cadee has discovered on Texel that oystercatchers have discovered how to eat Japanese oysters. Until recently, it was supposed that this oyster, present numerously since 2000 in the Wadden Sea, was not a fit source of food fort mollusc eating birds. Regularly, Cadee rides his bike along the Wadden Sea dike of Texel. There he saw how herring gulls and oystercatchers have found alternatives for eating clams.
After clam colonies have disappeared because of over-fishing, at first the birds changed to eating American jack knife clams. This long mollusc invaded the Wadden Sea in the 1980s.
Later, the birds learned how to eat [Japanese] oysters. Herring gulls can smash the thick oyster shells by dropping them from high in the sky. Oystercatchers look for unattached oysters of about 6 centimeter, put them vertically on a solid bottom, and then get their bills inside.
sSee also here.