Protected area type: Special Protection Areas
Feature type: 
  • Species
  • Marine
  • Antrim
Council: Ards and North Down

Belfast Lough is a large intertidal sea lough situated at the mouth of the River Lagan on the east coast of Northern Ireland. The inner part of the lough comprises a series of mudflats and lagoons and the outer lough is restricted to mainly rocky shores with some small sandy bays. 

The Belfast Lough open water area comprises the marine area below the mean low water mark. Seawards it extends to a national boundary between the eastern limits on the north and south shores of the Outer Belfast Lough Area of Special Scientific Interest at Kilroot and Horse Rock respectively. The boundary towards the head of the lough is a notional line between Greencastle on northern shore and Holywood Bank on the southern shore.

Water depths within the site are generally between 1m and 10m. Shallow waters, less than 5m in depth, dominate the area with deeper waters confined to the central area of the lough, east of a line between Greenisland and Cultra.


The site qualifies under Article 4.2 of the Directive (79/409/EEC) as it supports an internationally important wintering population of great crested grebe.

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