Even with all of these big questions on our plate, we can't forget about the importance of nature in "Annabel Lee." It's not something the speaker makes a big deal of, but nature is everywhere in this poem. The sea is the biggest example, but we also hear about the wind and the clouds and the stars and the moon. Sometimes it's a quiet, steady presence in the background, but like everything else in this poem, nature is always a little bit scary and threatening. You never quite imagine that sea being sunny and pretty, do you?
The natural world plays an ambiguous role in this poem. It threatens the speaker, and kills his beloved Annabel Lee, but it also comforts him by bringing her back in the moon and the stars.
The poem is built around the central image of the sea, and the feeling and the sound of the ocean give it structure and meaning.