Fishing vessels from Northern Ireland landing catch in the Republic face restrictions around landing times, officials have said.
Availability of inspectors is one factor, a lead on the Department of Agriculture, Environment and Rural Affairs Department (DAERA) fishery transition team said.
Dublin has designated extra ports to receive fishermen from Northern Ireland.
It is part of the Northern Ireland Protocol which prevents a hard land border on the island post-Brexit.
Owen Lyttle, director of marine and fisheries at Stormont’s Agriculture Department, said: “These ports came into operation on February 1, this week.
“In some of those ports there are restrictions in place to do with … limited opening times.”