The application for a mataitai reserve, which forbids commercial fishing, was lodged by Otakou runanga in October 2008 and was being assessed by the Ministry of Fisheries (MFish).
Runanga manager Hoani Langsbury said MFish had requested further information before the application was forwarded to the minister.
However, information relating to the customary use of the area was stored in the cordoned-off Te Waipounamu House, the central Christchurch headquarters of Ngai Tahu.
The building was near the off-centre Hotel Grand Chancellor, which was badly damaged in the February 22 earthquake, he said.
Until that information could be safely retrieved, it was likely to cause a delay for the application.
MFish Spatial Allocations team leader Randall Bess said it was "not known when the minister will consider the application or when a decision may be made".
Since 2000, MFish had received 36 mataitai applications, including 19 in 2008, and 25 of those applications were still being assessed.
Nineteen mataitai have been established since 1998, and Fisheries Minister Phil Heatley has declared nine of those reserves.
