The 'Trench', applied to both the kingdom and its inhabitants, escaped the destruction of Atlantis in DC Comics' "Aquaman" #1 (Nov. 2011) as created by Geoff Johns.
DC's "New 52" then rebooted the continuity, with Johns introducing the Trench' into a new timeline, making them antagonists.
"...the 'Trench' had been inhabitants of 'Atlantis' before that continent was destroyed and submerged by 'Atlan', the 'Dead King'.
"Only three major groups of old Atlantis survived that event, including 'Aquaman' and the 'Atlanteans', the 'Xebelians', in the 'Bermuda Triangle' and the 'Trench', who were thrown deep into the 'Marianas Trench', where they adapted their traits and powers..."
In director James Wan's "Aquaman", the 'Trench' are one of