This video from Ecomare museum on Texel island in the Netherlands says about itself (translated):
January 7 2016
For the rehabilitation seals Ute, Jelle and Dave, today was a day of celebration. They went safe and sound back to the Wadden Sea. Jelle and Dave were found in September, Ute in November.
These three common seals had been starving because of lungworm infection. After recovery in Ecomare, they could be freed again.
Seroprevalence of Antibodies against Seal Influenza A(H10N7) Virus in Harbor Seals and Gray Seals from the Netherlands: here.
Seals in motion. How movements drive population development of harbour seals and grey seals in the North Sea: here.