Live lobster can be purchased in Seattle. It's not like Teller, Alaska.
If you travel with them, consider
1. put them in a bag with some paper towels dampened with sea water.
2. Alaska Airlines will not allow the lobsters to travel in the cabin as pets because they are not among the listed species (dog, cat, bird, etc.)
3. Consider bringing them as carry on (but not as a pet). Water is not allowed beyond 3 oz. in a hand lotion container. However, frozen (not liquid) cold packs are allowed. You can bring 3 oz. of sea water and then splash the lobsters.
Until recently, lobsters could be transported as emotional support animals but no longer on AS, DL, UA, AA, WN and a number of other airlines. It would be abusive to the policy to claim they are emotional support animals even though people could say "if my lobster is out of my sight, I get anxiety", "where's my lobster dinner?"