The ferry operator Stena is reducing its Belfast services as a result of the coronavirus pandemic.
The firm, which normally operates seven ships on 138 sailings a week from Belfast, has temporarily berthed one ship and cut sailings to 108 a week.
Earlier this week, the firm said it would furlough staff and make redundancies across its UK and Ireland operations.
Stena sails from Belfast to Heysham, Liverpool and Cairnryan.
It is understood freight volumes have fallen since the crisis began but that non-freight traffic has collapsed.
On Monday, Stena said it would furlough 600 employees and make 150 redundant across the UK and Ireland.
The number of positions affected in Belfast is still to be confirmed.
Stormont ministers have been talking to the UK Department of Transport about a support package for freight and ferry services but nothing has yet been agreed.
On Tuesday the Irish government said it was making up to €15m (£13.2m) available to support continued operations on five ferry routes.
They are Dublin to Cherbourg and Rosslare to Fishguard, Pembroke, Cherbourg and Bilbao.
The operators are Irish Ferries, Stena Line and Brittany Ferries.
Transport Minister Shane Ross said: "The five routes in question are of strategic importance to Ireland.
'They ensure the robustness and resilience of Ireland's lifeline supply chain which is critically important at this time for the movement of goods, including food and medical supplies, into and out of Ireland."
On Tuesday, three more coronavirus-related deaths were announced in Northern Ireland, bringing its total number of NI deaths in the pandemic to 73.