email a friend
printable version
Location South Africa, Western Cape
Central coordinates 18o 5.00' East  33o 25.00' South
IBA criteria A1, A4i, A4ii, A4iii
Area 273 ha
Altitude 0 - 19m
Year of IBA assessment 2001

BirdLife South Africa



Summary Dassen Island, South Africa's second largest coastal island lies 9 km from the mainland between Saldanha Bay and Cape Town. This island reaches 19.2 m above sea level at its highest point. Owing to its proximity to the mainland and offers sanctuary to a variety of land and seabirds. The most important resident is the African Penguin Spheniscus demersus.

Populations of IBA trigger species

Species Season Period Population estimate Quality of estimate IBA Criteria IUCN Category
African Penguin Spheniscus demersus resident  8,000-9,000 breeding pairs  A1, A4ii  Endangered 
African Penguin Spheniscus demersus winter  30,000 individuals  A1, A4ii  Endangered 
Cape Cormorant Phalacrocorax capensis resident  13,767-48,000 breeding pairs  A1, A4i  Endangered 
Cape Cormorant Phalacrocorax capensis winter  30,000-100,000 individuals  A1, A4i  Endangered 
Bank Cormorant Phalacrocorax neglectus resident  30-50 breeding pairs  A1  Endangered 
Bank Cormorant Phalacrocorax neglectus winter  50-200 individuals  A1, A4i  Endangered 
Crowned Cormorant Microcarbo coronatus resident  80-175 breeding pairs  A1, A4i  Near Threatened 
Crowned Cormorant Microcarbo coronatus winter  400 individuals  A1, A4i  Near Threatened 
African Oystercatcher Haematopus moquini resident  100 breeding pairs  A1, A4i  Near Threatened 
African Oystercatcher Haematopus moquini winter  221-436 individuals  A1, A4i  Near Threatened 
Ruddy Turnstone Arenaria interpres winter  416 individuals  A4i  Least Concern 
Kelp Gull Larus dominicanus breeding  5,000-7,500 breeding pairs  A4i  Least Concern 
Kelp Gull Larus dominicanus winter  12,000-18,000 individuals  A4i  Least Concern 
Hartlaub's Gull Larus hartlaubii breeding  30-100 breeding pairs  A4i  Least Concern 
Hartlaub's Gull Larus hartlaubii winter  250 individuals  A4i  Least Concern 
Greater Crested Tern Thalasseus bergii breeding  3,038 breeding pairs  A4i  Least Concern 
Greater Crested Tern Thalasseus bergii winter  400-7,000 individuals  A4i  Least Concern 
A4iii Species group - seabirds winter  50,000-99,999 individuals  unknown  A4iii   
A4iii Species group - seabirds resident  100,000-499,999 individuals  unknown  A4iii   
A4iii Species group - waterbirds breeding  20,000-49,999 individuals  unknown  A4iii   

IBA Monitoring

2013 very high not assessed high
unset
Medium - based upon reliable but incomplete / partially representative data

Climate change and severe weather habitat shifting and alteration happening now some of area/population (10-49%) slow but significant deterioration medium
Climate change and severe weather storms and floods happening now some of area/population (10-49%) slow but significant deterioration medium
Energy production and mining renewable energy likely in short term (within 4 years) some of area/population (10-49%) moderate to rapid deterioration medium
Human intrusions and disturbance recreational activities happening now some of area/population (10-49%) slow but significant deterioration medium
Human intrusions and disturbance work and other activities happening now small area/few individuals (<10%) no or imperceptible deterioration low
Natural system modifications other ecosystem modifications happening now small area/few individuals (<10%) slow but significant deterioration low
Pollution garbage and solid waste happening now some of area/population (10-49%) slow but significant deterioration medium
Residential and commercial development housing and urban areas happening now small area/few individuals (<10%) no or imperceptible deterioration low
Transportation and service corridors flight paths happening now some of area/population (10-49%) slow but significant deterioration medium
Transportation and service corridors shipping lanes happening now whole area/population (>90%) moderate to rapid deterioration very high
Transportation and service corridors utility & service lines happening now small area/few individuals (<10%) no or imperceptible deterioration low

Rocky areas   0 0 good (> 90%) good (> 90%) favourable

Spheniscus demersus African Penguin 30000 16000 individuals 54 unfavourable
Hydrobates leucorhous Leach's Storm-petrel 5 5 breeding pairs 100 favourable
Pelecanus onocrotalus Great White Pelican 550 450 breeding pairs 82 near favourable
Phalacrocorax neglectus Bank Cormorant 50 70 breeding pairs 100 favourable
Phalacrocorax capensis Cape Cormorant 13767 765 breeding pairs 6 very unfavourable
Microcarbo coronatus Crowned Cormorant 175 280 breeding pairs 100 favourable
Haematopus moquini African Oystercatcher 436 280 individuals 65 unfavourable
Larus dominicanus Kelp Gull 7500 1739 breeding pairs 24 very unfavourable
Larus hartlaubii Hartlaub's Gull 100 1327 breeding pairs 100 favourable
Thalasseus bergii Greater Crested Tern 3038 1477 breeding pairs 49 unfavourable

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 

Protected areas

Protected area Designation Area (ha) Relationship with IBA Overlap with IBA (ha)  
Cape West Coast UNESCO-MAB Biosphere Reserve 378,240 protected area contains site 273  
Dassen Island Other Area 257 protected area contains site 273  

Habitats

IUCN habitat Habitat detail Extent (% of site)
Unknown   -
Coastline Sand dunes & beaches; Scree, boulders and bare rock; Sea cliffs & rocky shores; Shingle & stony beaches  major
Rocky areas   major

Land use

Land-use Extent (% of site)
unknown -
unknown -

Contribute  Please click here to help BirdLife conserve the world's birds - your data for this IBA and others are vital for helping protect the environment.

Recommended citation  BirdLife International (2014) Important Bird Areas factsheet: Dassen Island. Downloaded from http://www.birdlife.org on 26/11/2014

To provide new information to update this factsheet or to correct any errors, please email BirdLife