The seal has been given the temporary name Black Jack, although a contest to pick a name is being held. He is the third black seal to show up in the Netherlands in 35 years. They say he is black due to melanism, an increased amount of black or nearly black pigmentation, and the opposite of albinism. Black Jack will hopefully be strong enough to go back into the sea in three months’ time.
Any link you click in this article has nice pics! Funny how the name has to have black in it.