Tern IDs in Bar Harbor

I got some terns in Petit Manan Island (a puffin watching island near Bar Harbor), ME last week. We could not go any closer, so the photos are tiny. Is it possible to identify them?

Thanks,
Cui

Some more photos here.

Thanks,
Cui

Mostly Common Terns or unidentifiable; in the first post, first pic, the left-most bird is an Arctic Tern.

Resin

I'm so glad that I got both. Two lifers :)

Thanks,
Cui

There's Roseates on Manan too, but only a few, and none visible in your pics.

Resin

Yeah... Just out of curiosity, which traits can be used to identify a Roseate Tern in this scenario? I guess you find the Arctic Tern based on the color of its primaries?

Thanks,
Cui