Arctic Fever, by Bruce Barcott, is free in the Kindle store. This isn't marked as a Single, but from the length and publisher (OnEarth Magazine), it appears that it is quite similar to this classification. Most likely, it's a feature article length piece.
Book Description
Strange things are happening north of the Arctic Circle as sea ice melts and old boundaries dissolve, tearing at ancient strands of one of the planet's most fragile food webs.