The measure of removable is
conceptualized as shallow or high depth. Species with depth ranges
between zero and 200 meters are classified as ‘shallow ¼ 0’, and
species with depth ranges between 247 and 2047 meters are
classified as ‘deep ¼ 1’. Data regarding depth ranges of species were
collected from www.sealifebase.org, which is an international
database of marine species.3