The 28-year-old is believed to be the first woman to hold such a role within the Northern Ireland Fisheries Harbour Authority.
She succeeds Michael Young, who has moved down the coast to Carlingford Harbour in Co Louth.
Rooney will be sharing her harbour duties with her existing role as station officer for Kilkeel Coastguard.
“Safety is a big priority for me so combining that with my great passion for the water hopefully will bring success for the harbour,” she says.
The Irish News has more on the story HERE.