Is there an academic\ethical reason for omitting place names in environmental science papers?
I can think of a few reasons for which it might be sensible for names to be withheld, usually relating to not attracting large numbers of the public to a place. For example, a rare bird's nesting site, an endangered seal's haul-out area, or other places of delicate ecology.

However, it would seem reasonable for the authors to make the location known to other researchers on request, as otherwise there is no way to verify or reproduce their findings.