Database release:

For Special Protection Areas (SPA),
Proposed Sites for Community Importance (pSCI),
Sites of Community Importance (SCI) and
for Special Areas of Conservation (SAC)



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1.1 Type


1.2 Site code


1.3 Site name

Mulroy Bay SAC

1.4 First Compilation date


1.5 Update date


1.6 Respondent:

Name/Organisation:National Parks and Wildlife Service, Department of Culture, Heritage and the Gaeltacht

1.7 Site indication and designation / classification dates

Date site proposed as SCI:2001-08
Date site confirmed as SCI: No information provided
Date site designated as SAC:2019-11
National legal reference of SAC designation:607/2019


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2.1 Site-centre location [decimal degrees]:


2.2 Area [ha]


2.3 Marine area [%]


2.4 Sitelength [km] (optional):

No information provided

2.5 Administrative region code and name

NUTS level 2 code Region Name
IE01Border, Midland and Western

2.6 Biogeographical Region(s)

Atlantic (0.00 %)


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3.1 Habitat types present on the site and assessment for them

Annex I Habitat types Site assessment
Code PF NP Cover [ha] Cave [number] Data quality A|B|C|D A|B|C
      RepresentativityRelative SurfaceConservationGlobal
1140  info      119.93  0.00 
1160  info      3169.66  0.00 
1170  info      42.7891  0.00 
  • PF: for the habitat types that can have a non-priority as well as a priority form (6210, 7130, 9430) enter "X" in the column PF to indicate the priority form.
  • NP: in case that a habitat type no longer exists in the site enter: x (optional)
  • Cover: decimal values can be entered
  • Caves: for habitat types 8310, 8330 (caves) enter the number of caves if estimated surface is not available.
  • Data quality: G = 'Good' (e.g. based on surveys); M = 'Moderate' (e.g. based on partial data with some extrapolation); P = 'Poor' (e.g. rough estimation)

3.2 Species referred to in Article 4 of Directive 2009/147/EC and listed in Annex II of Directive 92/43/EEC and site evaluation for them

Species Population in the site Site assessment
G Code Scientific Name S NP T Size Unit Cat. D.qual. A|B|C|D A|B|C
      MinMax  Pop.Con.Iso.Glo.
BA052Anas crecca    93  93   
BA050Anas penelope    190  190   
BA046Branta bernicla    89  89   
BA149Calidris alpina    223  223   
BA130Haematopus ostralegus    300  300   
M1355Lutra lutra          DD 
BA070Mergus merganser    10  10   
BA048Tadorna tadorna    24  24   
  • Group: A = Amphibians, B = Birds, F = Fish, I = Invertebrates, M = Mammals, P = Plants, R = Reptiles
  • S: in case that the data on species are sensitive and therefore have to be blocked for any public access enter: yes
  • NP: in case that a species is no longer present in the site enter: x (optional)
  • Type: p = permanent, r = reproducing, c = concentration, w = wintering (for plant and non-migratory species use permanent)
  • Unit: i = individuals, p = pairs or other units according to the Standard list of population units and codes in accordance with Article 12 and 17 reporting (see reference portal)
  • Abundance categories (Cat.): C = common, R = rare, V = very rare, P = present - to fill if data are deficient (DD) or in addition to population size information
  • Data quality: G = 'Good' (e.g. based on surveys); M = 'Moderate' (e.g. based on partial data with some extrapolation); P = 'Poor' (e.g. rough estimation); VP = 'Very poor' (use this category only, if not even a rough estimation of the population size can be made, in this case the fields for population size can remain empty, but the field "Abundance categories" has to be filled in)

3.3 Other important species of flora and fauna (optional)


Population in the site


Group CODE Scientific Name S NP Size Unit Cat. Species Annex Other categories
     MinMax C|R|V|PIVVABCD
Aeolidiella alderi                     
Cygnus olor    117  117             
Dercitus bucklandii                     
Drachiella spectabilis                     
Gobius couchi                     
Halecium muricatum                     
Haminoea navicula                     
Limaria hians                     
Lithothamnion corallioides                     
Lithothamnion glaciale                     
Odonthalia dentata                     
Paracentrotus lividus                     
Parerythropodium coralloides                     
Raspailia aculeata                     
Sarcodictyon roseum                     
Stellata grubii                     
Zostera marina                     
  • Group: A = Amphibians, B = Birds, F = Fish, Fu = Fungi, I = Invertebrates, L = Lichens, M = Mammals, P = Plants, R = Reptiles
  • CODE: for Birds, Annex IV and V species the code as provided in the reference portal should be used in addition to the scientific name
  • S: in case that the data on species are sensitive and therefore have to be blocked for any public access enter: yes
  • NP: in case that a species is no longer present in the site enter: x (optional)
  • Unit: i = individuals, p = pairs or other units according to the standard list of population units and codes in accordance with Article 12 and 17 reporting, (see reference portal)
  • Cat.: Abundance categories: C = common, R = rare, V = very rare, P = present
  • Motivation categories: IV, V: Annex Species (Habitats Directive), A: National Red List data; B: Endemics; C: International Conventions; D: other reasons


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4.1 General site character

Habitat class % Cover

Total Habitat Cover


Other Site Characteristics

Mulroy Bay is an extremely sheltered, narrow inlet situated in the north west of Ireland. It is approximately 20 km in length and 2 km wide at the mouth. The bay is the most convoluted of the marine inlets in north-west Ireland. It has three significant narrows only 100 - 150 m across, where the current is very strong (3 - 5 knots). Mulroy Bay is a galcial fiard. The Moross peninsula, which separates the North Water from the Broad Water, is a large glacial drumlin. Bedrock is principally metamorphic quartzite, limestone and schist and gneiss, with intrusive granite at the mouth. Some small islands are included in site.

4.2 Quality and importance

Mulroy Bay has high conservation interest due to very important examples of large shallow inlets and bays, reefs and mudflats. It has a wide range of communities from exposed coast to ultra sheltered areas. The tide swept communities of the main channel, and the sheltered and extremely sheltered communities in the Broad Water and North Water, are unusual in Ireland. Broad Water is hydrographically and biologically unusual, being isolated from the open sea and subject to a reduced tidal range. Several species are present which are at or near the northern limits of their range (Dudresnaya verticillata, Aeolidiella alderi and Stolonica socialis) or the southern limits of their range (Odonthalia dentata). The rich Limaria hians beds in the Moross Channel are unique in Ireland, and the low shore rapids at Broadwater are unusually species rich (81 species). Additional rare algal species (Ascophyllum nodosum var mackii, Fucus ceranoides var ramosissima and Codium bursa) have been found in the bay which were not found by BioMar. Additional rare faunal specimens include the scarce octocoral Parerythropodium corallioides and a species of parasitic copepod new to Britain and Ireland. A large intertidal area of mudflats and sandflats occurs around Island Roy and Carrickart. Lutra lutra occurs within the site. The site supports wintering waterfowl in low numbers.

4.3 Threats, pressures and activities with impacts on the site

The most important impacts and activities with high effect on the site

Negative Impacts
RankThreats and pressures [code]Pollution (optional) [code]inside/outside [i|o|b]
Positive Impacts
RankActivities, management [code]Pollution (optional) [code]inside/outside [i|o|b]

Rank: H = high, M = medium, L = low
Pollution: N = Nitrogen input, P = Phosphor/Phosphate input, A = Acid input/acidification,
T = toxic inorganic chemicals, O = toxic organic chemicals, X = Mixed pollutions
i = inside, o = outside, b = both

4.4 Ownership (optional)

No information provided

4.5 Documentation (optional)

Brennan, A.T. (1945). Notes on the distribution of certain marine algae on the west coast of Ireland. Irish Naturalists' Journal, 8: 252-254.Charlesworth, J.K. (1924). The glacial geology of the north-west of Ireland. Proc. Roy. Ir Acad. 36B 174-314.Fahy, E. (1983). Feeding ecology of feral rainbow trout Salmo gairdneri Richardson in Mulroy Bay, an Atlantic sea lough. Irish Naturalists' Journal, 21(3): 103-107.Gibb, D.C. (1957). The free-living forms of Ascophyllum nodosum (L.) le Jol. Journal of Ecology 45: 49-83.Holmes, J.M.C., and Gotto, R.V. (1987). Some ascidicolous copepods new to British and Irish waters. Irish Naturalists' Journal, 22(8): 340-343.Minchin, D. (1981). The escallop Pecten maximus in Mulroy Bay. Fisheries Bulletin (Dublin), 1: 21pp.Minchin, D. (1988). Couch's goby, Gobius couchi (Teleostei: Gobiidae), from Irish waters. Journal of Fish Biology 33: 821-822.Minchin, D., Duggan, C.B and King, W. (1987). Possible effects of organotins on scallop recruitment. Marine Pollution Bulletin 18(11): 604-608.Morton, O. (1978). Some interesting records of algae from Ireland. Irish Naturalists' Journal, 19(7): 240-242.Parkes, H.M. (1958a). A general survey of the marine algae of Mulroy Bay, Co. Donegal (to be continued). Irish Naturalists' Journal, 12(12): 324-330.Parkes, H.M. (1958a). A general survey of the marine algae of Mulroy Bay, Co. Donegal II. Irish Naturalists' Journal, 12(12): 324-330.Picton, B.E. (1985). Anthozoans (Coelenterata: Anthozoa) new to Ireland and new records of some rarely recorded species. Irish Naturalists''Journal, 21(11): 484-488.Praeger, R.L. (1894). Fauna of Mulroy Bay, Donegal. Irish Naturalist. 3: 113-114.Sheard, J.W. (1968). The zonation of lichens on three rocky shores of Inishowen, Co. Donegal. Proceedings of the Royal Irish Academy, 66B: 101-112.Somerfield, P. (1985). A study of Haminea navicula (Da Costa) and its environment, the Wee Sea, County Donegal. Mod. Theses, Zoology, Trinity College, Dublin.


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6.1 Body(ies) responsible for the site management:

No information provided

6.2 Management Plan(s):

An actual management plan does exist:

No, but in preparation

6.3 Conservation measures (optional)

No information provided



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