Concerns have been raised about a temporary school and sanitation issues at the site and the Department of Conservation is investigating after a seal was skinned and eaten.
Tents, campervans and cars have been seen across the area near the beach during the occupation.
Last month Wellington City Council contractors demolished and removed some makeshift structures there.
The debris, including wooden pallets and corrugated iron, was taken to the Southern Landfill.
McCarthy said police have engaged Kahungungu Whānau Services, to ensure the appropriate Whanau Ora support is in place for those who may need it during their exit from Mahanga Bay.
"Police are continuing to engage with the people occupying Mahanga Bay, and we continue to work with other agencies - including Wellington City Council, Niwa and Linz - to reach a peaceful resolution."
Members of the occupation have been approached for comment.