Seal center Pieterburen has already rescued 12 seals tangled in nets and other sea pollution on Dutch shores this year. That’s over three times as many as in the same period last year, the rescue center said. The most recent rescue was on Vlieland on Thursday. On Tuesday, rescuers freed a young gray seal from a big net on Ameland. In all of last year, Pieterburen’s seal wardens only had to rescue 38 seals from entanglement in litter.