This is the stoy of a seal that passed 6 months with a Frisbee around his neck:
Seal Survives Six Months at Sea in England with a Frisbee Around Its Neck | Maritime Herald
From the news:
They managed to trap him with a net while doing her best to return to the sea. But he was so weak and hurt that his efforts were in vain. Due to the complexity of the wound caused by the plastic on her neck, she was immediately transferred to the East Winch Wildlife Center, a unit of the Society for the Prevention of Cruelty to Animals (RSPCA). “He was undernourished when the vets saw him, he had not been able to feed himself because of the obstruction that the frisbee generated, we had never seen such a wound and we thought that he would not be able to recover,” said the head of the centre, Alison Charles.