Some critics regard this excellent and memorable poem as an allegory concerning man's relationship with nature and the way that man so often kills nature in her various manifestations casually and callously, with no thought for the wider consequences of what he does. In the poem, we can see that the Mariner kills the albatross as something of a joke or to divert himself. He imposes his mastery over nature, and shows this mastery by killing an innocent creature that actually was something of a friend to the sailors.
The punishment that the Mariner and the other sailors endure as a result of this reckless and thoughtless act clearly indicates the way in which abusing our power over nature and killing heedlessly has massive consequences, as we are seeing today in our own world. Interestingly, the Mariner is only able to redeem himself and free himself from the albatross that hangs around his neck by blessing nature in another form, as the spontaneous blessing that springs to his mouth when he sees the water snakes illustrates.
The end of the poem presents us with the moral of the story as the Mariner sees it, which of course explicitly relates to nature and our relationship with it:
He prayeth best, who loveth best
All things both great and small;
For the dear God who loveth us,
He made and loveth all.
Clearly this stanza points towards what our relationship with nature should be like and the way that it is essential to love all creatures and recognise God's handiwork in all of the created order. It is the Mariner who has been forced to learn this lesson through his horrific experience.