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Location South Africa, KwaZulu-Natal
Central coordinates 32o 29.00' East  28o 1.00' South
IBA criteria A1, A2, A3, A4i, A4iii
Area 167,700 ha
Altitude 0 - 180m
Year of IBA assessment 2001

BirdLife South Africa



Summary Situated c. 80 km north of Richards Bay, Lake St Lucia is a subtropical coastal estuary with a long narrow channel to the sea. The lake system is about 70 km long, and, excluding The Narrows, between 3 km and 18 km wide for most of its length. It is the largest estuarine system in Africa, with a water surface area that varies from 225-417 km2. The St Lucia system supports over 350 bird species and is the most important breeding area for waterbirds in South Africa.

Site description Situated c.80 km north of Richards Bay, Lake St Lucia is a subtropical coastal estuary with a long narrow channel to the sea. Located on the north-eastern KwaZulu-Natal coastal plain, the system is bounded by the Umfolozi river and its associated swamps in the south, and by the Mkuze river and Ozabeni in the north. The lake system is about 70 km long, and, excluding The Narrows, between 3 km and 18 km wide for most of its length. It is the largest estuarine system in Africa, with a water surface area that varies from 225–417 km². The mean depth is less than 1 m, and the water turbidity is high because the substrate is mainly fine silt. Hydrological conditions in the lake vary seasonally and in the long-term, with long periods of hypersalinity that result in large changes in the composition and abundance of plant, invertebrate and bird species.

Mangrove-fringed tidal banks extend into the estuary, where the mangroves Avicennia and Bruguiera are common, as is saltmarsh rush Juncus. Islands, estuarine mudflats and shallows are frequent. Aquatic vegetation (Potamogeton, Ruppia and Zostera) develops in the lake after prolonged periods of low salinity. Tall beds of reed and sedge, primarily Phragmites, Sporobolus, Scirpus, Cyperus and Typha, dominate the marginal vegetation. Surrounding these, above the water-table, are fringes of open vlei grassland. The grasslands and swamp flood seasonally, during longer-term wet cycles, to surround the patches of bush and forest on higher ground. The dry sand-forest around False Bay is never flooded, and dominants include Terminalia, Newtonia, Balanites, Dialium, Sclerocarya, Acacia and Strychnos. On the eastern shores, the coastal sand-dunes hold dune forest that runs parallel to the seashore in a band between one and three kilometres wide. The western shores hold the Dukuduku State Forest, a particularly dense and extensive patch of coastal forest, with trees of Trema, Ficus, Albizia and Ekebergia. There are also freshwater pans, vleis, reedbeds and sedge swamps. Extensive pine Pinus plantations occur around much of the estuary.

To the north of St Lucia, the Mkuze river, which forms the northern and eastern borders of Mkuzi Game Reserve (IBA ZA043), forms a massive wetland complex after it leaves the reserve, before it drains into the northern portion of Lake St Lucia. It contains large beds of reed Phragmites and papyrus Cyperus, marsh with sedges and grass, nutrient-rich pans with good floating, fringing and emergent vegetation, swamp-forest of Ficus, Voacanga, Ilex, Urera and Syzygium, and dense, short coastal grassland (interspersed with muddy creeks and narrow channels). To the north of the main swamp are Muzi, Mpempe and Mdlanzi pans, which are long, narrow cut-off lakes with predominantly bare shorelines. Tall woodland or thicket surrounds these pans where the water-table permits. Further east, in the Ozabeni area, the soil becomes progressively more sandy, and open grassland dominates. Surrounding the marginal vegetation are fringes of open vlei grassland. Apart from isolated clumps, the only real forest in this area is a broad strip of swamp-forest associated with the Mbazwane Stream. The whole Mkuze Swamps and Ozabeni area holds a very diverse mosaic of wetland vegetation and appears to be largely undisturbed.

Key Biodiversity See Box and Tables 2 and 3 for key species. The St Lucia system supports over 350 bird species and is the most important breeding area for waterbirds in South Africa, with at least 48 breeding species recorded. Owing to its subtropical position, several bird species reach the southern limits of their ranges at St Lucia. Owing to the variability of the system, the lake may often hold very important numbers of a species in some years and almost insignificant numbers in others. At times, Lake St Lucia holds extremely large numbers of Pelecanus rufescens, P. onocrotalus, Platalea alba, Anas smithii, A. undulata, Recurvirostra avosetta and Phoenicopterus minor. Phoenicopterus ruber bred here in 1972, when some 30,000 birds and 6,000 nests were recorded owing to an increase in food, produced by a period of low salinity that followed a long hyper-saline period. St Lucia also holds the only breeding population of Ephippiorhynchus senegalensis in KwaZulu-Natal and is one of only three breeding sites for Mycteria ibis in KwaZulu-Natal. The lake can hold over 80% of South Africa’s breeding population of Sterna caspia. The colony of Pelecanus onocrotalus is the only known breeding colony in south-east Africa. Large numbers of Palearctic migrant waders occur in summer.

Forests on the eastern shores of Lake St Lucia hold Circaetus fasciolatus. In winter the coastal forest also holds small numbers of the globally threatened Zoothera guttata. In wet years, the flooded grassland between St Lucia and Cape Vidal supports Macronyx ameliae. Three restricted-range species are common here—Apalis ruddi, Nectarinia neergaardi (100–150 breeding pairs) and Hypargos margaritatus—and all occur in sand-forest thickets surrounding the lake.

The Mkuze swamps and Ozabeni areas are less well known. However, the area is thought to be excellent for waterbirds, particularly rails (Rallidae). Swampy backwaters with overhanging vegetation are home to Gorsachius leuconotus, Podica senegalensis and Scotopelia peli. The open flood-plain and flooded grasslands with dunes hold Anthus brachyurus, Turnix hottentotta, Caprimulgus natalensis, Centropus grillii and Macronyx ameliae. Although seldom recorded, Botaurus stellaris almost certainly occurs widely in the very extensive reedbeds.

Non-bird biodiversity: As befits a World Heritage Site, St Lucia has a wealth of Red Data and endemic species. Endemic to the IBA are the plants Kalanchoe luciae, Rhus kwazuluana and a new species of Aloe, and five species of butterfly. The mammal Diceros bicornis (CR) has been reintroduced.

Populations of IBA trigger species

Species Season Period Population estimate Quality of estimate IBA Criteria IUCN Category
Yellow-billed Duck Anas undulata winter  503-1,706 individuals  A4i  Least Concern 
Cape Shoveler Spatula smithii winter  110-512 individuals  A4i  Least Concern 
Greater Flamingo Phoenicopterus roseus breeding  6,000 breeding pairs  A4i  Least Concern 
Greater Flamingo Phoenicopterus roseus winter  6,317-30,000 individuals  A4i  Least Concern 
Lesser Flamingo Phoeniconaias minor winter  common  A1  Near Threatened 
African Spoonbill Platalea alba resident  200-500 breeding pairs  A4i  Least Concern 
African Spoonbill Platalea alba winter  426-1,577 individuals  A4i  Least Concern 
Great White Pelican Pelecanus onocrotalus resident  500-1,500 breeding pairs  A4i  Least Concern 
Great White Pelican Pelecanus onocrotalus winter  1,550-3,978 individuals  A4i  Least Concern 
Southern Banded Snake-eagle Circaetus fasciolatus resident  1998  present  A1, A3  Near Threatened 
Pied Avocet Recurvirostra avosetta winter  1,265-3,460 individuals  A4i  Least Concern 
Grey-headed Gull Larus cirrocephalus winter  733-1,332 individuals  A4i  Least Concern 
Caspian Tern Hydroprogne caspia breeding  180-300 breeding pairs  A4i  Least Concern 
Caspian Tern Hydroprogne caspia winter  158-572 individuals  A4i  Least Concern 
Brown-headed Parrot Poicephalus cryptoxanthus resident  1998  present  A3  Least Concern 
Mangrove Kingfisher Halcyon senegaloides resident  1998  present  A3  Least Concern 
Zululand Batis Batis fratrum resident  1998  present  A3  Least Concern 
Four-coloured Bush-shrike Telophorus quadricolor resident  1998  present  A3  Least Concern 
Rudd's Apalis Apalis ruddi resident  1998  present  A2, A3  Least Concern 
Black-bellied Glossy-starling Lamprotornis corruscus resident  1998  present  A3  Least Concern 
Spotted Ground-thrush Zoothera guttata winter  present  A1  Endangered 
Mouse-coloured Sunbird Nectarinia veroxii resident  1998  present  A3  Least Concern 
Neergaard's Sunbird Nectarinia neergardi resident  1998  present  A1, A2, A3  Near Threatened 
Pink-throated Twinspot Hypargos margaritatus resident  1998  present  A2, A3  Least Concern 
A4iii Species group - waterbirds winter  20,000-49,999 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

Agriculture and aquaculture annual & perennial non-timber crops - shifting agriculture happening now majority/most of area/population (50-90%) very rapid to severe deterioration very high
Agriculture and aquaculture livestock farming and ranching (includes forest grazing) - nomadic grazing happening now some of area/population (10-49%) moderate to rapid deterioration high
Agriculture and aquaculture wood and pulp plantations (includes afforestation) - small-holder plantations happening now some of area/population (10-49%) moderate to rapid deterioration high
Biological resource use fishing & harvesting aquatic resources - unintentional effects: subsistence/small scale happening now majority/most of area/population (50-90%) very rapid to severe deterioration very high
Biological resource use hunting & collecting terrestrial animals - intentional use (species being assessed is the target) happening now some of area/population (10-49%) slow but significant deterioration medium
Biological resource use hunting & collecting terrestrial animals - persecution/control likely in long term (beyond 4 years) some of area/population (10-49%) slow but significant deterioration medium
Climate change and severe weather storms and floods likely in short term (within 4 years) majority/most of area/population (50-90%) slow but significant deterioration medium
Climate change and severe weather temperature extremes likely in short term (within 4 years) some of area/population (10-49%) slow but significant deterioration medium
Energy production and mining renewable energy happening now some of area/population (10-49%) very rapid to severe deterioration high
Human intrusions and disturbance recreational activities happening now some of area/population (10-49%) moderate to rapid deterioration high
Human intrusions and disturbance work and other activities happening now some of area/population (10-49%) moderate to rapid deterioration high
Pollution agricultural & forestry effluents - nutrient loads happening now some of area/population (10-49%) moderate to rapid deterioration high
Pollution garbage & solid waste happening now small area/few individuals (<10%) slow but significant deterioration low
Residential and commercial development housing and urban areas happening now some of area/population (10-49%) slow but significant deterioration medium
Residential and commercial development tourism and recreation areas happening now some of area/population (10-49%) moderate to rapid deterioration high
Transportation and service corridors flight paths happening now small area/few individuals (<10%) slow but significant deterioration low
Transportation and service corridors utility & service lines happening now some of area/population (10-49%) slow but significant deterioration medium

Forest   0 0 moderate (70-90%) moderate (70-90%) unfavourable
Wetlands (inland)   0 0 moderate (70-90%) moderate (70-90%) 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  The conservation measures needed for the site are being comprehensively and effectively implemented  high 

Protected areas

Protected area Designation Area (ha) Relationship with IBA Overlap with IBA (ha)  
Cape Vidal State Forest 8,288 protected area contained by site 8,288  
Greater St Lucia Wetland Nature Reserve Provincial Nature Reserve 213,358 protected area overlaps with site 49,897  
iSimangaliso Wetland Park World Heritage Site 239,566 protected area contains site 167,700  
Sodwana Bay National Park 452 protected area contained by site 452  
St. Lucia System Wetlands of International Importance (Ramsar) 155,500 protected area contained by site 155,500  
Turtle Beaches/Coral Reefs of Tongaland Wetlands of International Importance (Ramsar) 39,500 protected area is adjacent to site 0  

Habitats

IUCN habitat Habitat detail Extent (% of site)
Grassland Grassland - edaphic, wet  -
Wetlands (inland) Estuarine waters; Intertidal mud, sand or salt flats; Mangroves; Rivers & streams  -
Forest Lowland forest - undifferentiated; Woodland - mixed; Woodland - riparian  -

Land use

Land-use Extent (% of site)
nature conservation and research 10%
agriculture -
water management 70%

References Barnes (1995), Berruti (1980a,b, 1983), Breen et al. (1993), Cowan (1995), Cowan and Marneweck (1996), Day et al. (1954), Millard and Broekhuysen (1970), Porter and Forrest (1974), Lawson (1987), Robson and Horner (1996), Taylor, P.B. (1997a,b), Taylor, R.H. (1982), Whitfield (1977), Whitfield and Blaber (1978, 1979a,b), Whitfield and Cyrus (1978).

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Recommended citation  BirdLife International (2015) Important Bird Areas factsheet: Lake St Lucia and Mkuze Swamps. Downloaded from http://www.birdlife.org on 29/07/2015

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