* Lobster: Seals do eat lobsters, but it's not a primary food source. Lobsters are typically found in deeper waters and are more difficult to catch for seals.
* Mussels: Seals do eat mussels! They are often found in shallow coastal waters where seals frequent, making them an easier prey.
So, the answer is: Seals eat both lobster and mussel, but mussels are a more common part of their diet.