It is effectively an eastern suburb of the larger town of Amlwch.
Anglesey County Council were unsure why the population had dropped (or even whether it had been miscounted).
[1] Prior to the 2013 county council elections, Amlwch Port was one of the 40 electoral wards to the Isle of Anglesey Council.
It ceased to be a county ward as a result of The Isle of Anglesey (Electoral Arrangements) Order 2012.
[2] Media related to Amlwch Port at Wikimedia Commons