1. Areaとzone 特別保護地区の「地区」は?

特別保護地区の訳語でこれまで使ったことがある英訳はspecial protection areaと special protection zoneの二通りありました。Areaとzoneはどう違うのでしょう。検索すると、いくつか似たような例が出てきました。たとえば、ダイオキシンの爆発事故のあった場所で: The exposed area was later divided up into zones based on exposure levels. Zone A was the most heavily contaminated area and Zone B had the next highest contamination.
zone : A zone is an area that has particular features or characteristics.
war zone, disaster zone, time zoneといった例が。
area : An area is a particular part of a town, a country, a region, or the world.
A particular area is a piece of land or part of a building that is used for a particular activity….
An area is a particular place on a surface or object, for example on your body.

南極条約では特別保護地区をspecially protected areas (SPA)としています。