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Year of most recent IBA criteria assessment: 2007

Populations of IBA trigger species

Species	Current IUCN Red List Category	Season	Year(s) of estimate	Population estimate	IBA Criteria Triggered
Northern Gannet Morus bassanus	LC	breeding	2004	32,094 breeding pairs	A4ii, B1ii, B2, C3
A4iii Species group - seabirds	n/a	breeding	1999-2001	31,611 breeding pairs	A4iii, C4

Note: This table presents the IBA criteria triggered and the species that triggered then at the time of assessment, the current IUCN Red List category may vary from that which was in place at that time.

For more information about the IBA assessment process and criteria please click here

Threats to the site (pressure)
Threat Level 1	Threat Level 2	Timing	Scope	Severity	Result
Biological resource use	fishing & harvesting aquatic resources - unintentional effects: large scale	happening now	whole area/population (>90%)	slow but significant deterioration	high
Climate change and severe weather	habitat shifting and alteration	likely in long term (beyond 4 years)	majority/most of area/population (50-90%)	moderate to rapid deterioration	medium

Condition of key/trigger populations (state)
Scientific	Common	TargetPop	ActualPop	Units	Remaining	Result
Morus bassanus	Northern Gannet	33000	32094	breeding pairs	98	favourable
Species group - seabirds	A4iii	33510	31611	breeding pairs	95	favourable

Conservation actions taken at site (response)
Conservation Designation	Management Planning	Conservation Action	Result
Whole area of site (>90%) covered by appropriate conservation designation	A comprehensive and appropriate management plan exists that aims to maintain or improve the populations of qualifying bird species	Substantive conservation measures are being implemented but these are not comprehensive and are limited by resources and capacity	high

For more information about IBA monitoring please click here

Protected Area	Designation	Area (ha)	Relationship with IBA	Overlap with IBA (ha)
West Wales Marine / Gorllewin Cymru Forol	Site of Community Importance (Habitats Directive)	737,614	protected area contains site	0
Pembrokeshire Marine/ Sir Benfro Forol	Site of Community Importance (Habitats Directive)	138,038	protected area overlaps with site	11
Pembrokeshire Marine / Sir Benfro Forol	Marine Protected Area (OSPAR)	0	protected area overlaps with site	0
Pembrokeshire Coast	National Park	61,476	protected area overlaps with site	11
Grassholm/Ynys Gwales	Site of Special Scientific Interest (UK)	12	protected area overlaps with site	9
Grassholm Island	National Nature Reserve	11	protected area overlaps with site	11
Grassholm	Marine Protected Area (OSPAR)	1,700	protected area overlaps with site	0
Grassholm	Nature Reserve	8	protected area overlaps with site	0
Grassholm	Special Protection Area (Birds Directive)	1,774	protected area contains site	11
Grassholm	RSPB Reserve	11	is identical to site	11

IUCN Habitat	Habitat detail	Extent (% of site)
Grassland		-
Coastline	Sea cliffs and rocky shores, Rock stacks and islets	-
Marine Coastal/Supratidal		-

For further information about the habitat classification please click here.

Land-use	Extent (% of site)
nature conservation and research	-
tourism/recreation	-

For further information about the land use classification please click here.

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Recommended citation
BirdLife International (2023) Important Bird Areas factsheet: Grassholm. Downloaded from http://www.birdlife.org on 27/03/2023.