Ecosystem threat status

Lara van Niekerk; Andrew L. Skowno; Kerry Sink; Linda R. Harris

More than 54% of South Africa’s estuaries are relatively healthy, but this amounts to only 18% of total estuarine extent, comprised mostly of small estuaries. Concerning overall, more than 70% of estuarine area is significantly modified.

59%
of 22 ecosystem types
Threatened

23%
of 22 ecosystem types
Critically Endangered

18%
of 22 ecosystem types
Endangered

18%
of 22 ecosystem types
Vulnerable

Ecosystem threat status assessment

The estuarine realm is one of the most threatened in South Africa, in terms of both number of ecosystem types and by area.

About 59% of the 22 estuary types are threatened with 23% Critically Endangered, 18% Endangered and 18% Vulnerable. Of total estuarine area, 99% is threatened with 1% Critically Endangered, 57% Endangered and 41% Vulnerable.

Multiple interventions are required to avoid further decline in health. These include protection of freshwater inflow to estuaries and the sea, restoration of water quality, reduction in fishing effort and avoidance of mining, infrastructure development and crops in the estuarine functional zone.

Figure 1. LARA PLEASE ADD THE CAPTION HERE

Table 1. LARA PLEASE ADD CAPTION HERE

		Critically Endangered	Endangered	Vulnerable	Least Concern
Cool Temperate	Type	0	24	9	0
	Extent (km²)	0	1 214	41	0
	Percentage	0	97	3	0
Subtropical	Type	1	9	121	0
	Extent (km²)	28	3 813	4 758	0
	Percentage	0	44	55	0
Tropical	Type	0	0	2	0
	Extent (km²)	0	0	163	0
	Percentage	0	0	100	0
Warm Temperate	Type	0	3	67	54
	Extent (km²)	0	430	7 224	780
	Percentage	0	5	86	9

Table 2. NEEDS A CAPTION

Estuary name	Estuary type	Estuary functional type	Threat status
Durban Bay	Subtropical Estuarine Bay	SubTrop	Critically Endangered
Bot/Kleinmond	Cool Temperate Estuarine Lake	CTemp	Endangered
Buffels	Cool Temperate Arid Predominantly Closed	CTemp	Endangered
Diep/Rietvlei	Cool Temperate Large Temporarily Closed	CTemp	Endangered
Disa	Cool Temperate Large Temporarily Closed	CTemp	Endangered
Eerste	Cool Temperate Large Temporarily Closed	CTemp	Endangered
Groen	Cool Temperate Arid Predominantly Closed	CTemp	Endangered
Groot Berg	Cool Temperate Predominantly Open	CTemp	Endangered
Heuningnes	Warm Temperate Estuarine Lake	WTemp	Endangered
Jakkals	Cool Temperate Large Temporarily Closed	CTemp	Endangered
Klein	Cool Temperate Estuarine Lake	CTemp	Endangered
Langebaan	Cool Temperate Estuarine Lagoon	CTemp	Endangered
Mbashe	Subtropical Large Fluvially Dominated	SubTrop	Endangered
Mzimvubu	Subtropical Large Fluvially Dominated	SubTrop	Endangered
Olifants	Cool Temperate Predominantly Open	CTemp	Endangered
Orange	Cool Temperate Large Fluvially Dominated	CTemp	Endangered
Palmiet	Cool Temperate Large Temporarily Closed	CTemp	Endangered
Richards Bay	Subtropical Estuarine Lake	SubTrop	Endangered
Silwermyn	Cool Temperate Large Temporarily Closed	CTemp	Endangered
Sout (Noord)	Cool Temperate Arid Predominantly Closed	CTemp	Endangered
Sout (Wes)	Cool Temperate Large Temporarily Closed	CTemp	Endangered
Spoeg	Cool Temperate Arid Predominantly Closed	CTemp	Endangered
St Lucia	Subtropical Estuarine Lake	SubTrop	Endangered
Swartlintjies	Cool Temperate Arid Predominantly Closed	CTemp	Endangered
Swartvlei	Warm Temperate Estuarine Lake	WTemp	Endangered
Touw/Wilderness	Warm Temperate Estuarine Lake	WTemp	Endangered
Uilkraals	Cool Temperate Predominantly Open	CTemp	Endangered
Verlorenvlei	Cool Temperate Estuarine Lake	CTemp	Endangered
Wadrift	Cool Temperate Arid Predominantly Closed	CTemp	Endangered
Wildevoëlvlei	Cool Temperate Large Temporarily Closed	CTemp	Endangered
Zand	Cool Temperate Large Temporarily Closed	CTemp	Endangered
Zeekoei	Cool Temperate Estuarine Lake	CTemp	Endangered
iMfolozi/uMsunduze	Subtropical Large Fluvially Dominated	SubTrop	Endangered
iNhlabane	Subtropical Estuarine Lake	SubTrop	Endangered
uMhlathuze	Subtropical Estuarine Lake	SubTrop	Endangered
uMvoti	Subtropical Large Fluvially Dominated	SubTrop	Endangered
uThukela	Subtropical Large Fluvially Dominated	SubTrop	Endangered
Bira (Bhirha)	Warm Temperate Large Temporarily Closed	WTemp	Vulnerable
Bob’s Stream	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
Breede	Warm Temperate Predominantly Open	WTemp	Vulnerable
Buffalo	Warm Temperate Predominantly Open	WTemp	Vulnerable
Buffels (Oos)	Cool Temperate Small Temporarily Closed	CTemp	Vulnerable
Bulolo	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
Bulungula	Subtropical Large Temporarily Closed	SubTrop	Vulnerable
Bulura (Bulurha)	Warm Temperate Large Temporarily Closed	WTemp	Vulnerable
Bushmans	Warm Temperate Predominantly Open	WTemp	Vulnerable
Cebe	Warm Temperate Large Temporarily Closed	WTemp	Vulnerable
Cefane	Warm Temperate Large Temporarily Closed	WTemp	Vulnerable
Cintsa	Warm Temperate Large Temporarily Closed	WTemp	Vulnerable
Coega (Ngqurha)	Warm Temperate Large Temporarily Closed	WTemp	Vulnerable
Duiwenhoks	Warm Temperate Predominantly Open	WTemp	Vulnerable
East Kleinemonde	Warm Temperate Large Temporarily Closed	WTemp	Vulnerable
Gamtoos	Warm Temperate Predominantly Open	WTemp	Vulnerable
Goda	Warm Temperate Large Temporarily Closed	WTemp	Vulnerable
Goukamma	Warm Temperate Large Temporarily Closed	WTemp	Vulnerable
Goukou	Warm Temperate Predominantly Open	WTemp	Vulnerable
Gouritz	Warm Temperate Predominantly Open	WTemp	Vulnerable
Gqunqe	Warm Temperate Large Temporarily Closed	WTemp	Vulnerable
Gqunube	Warm Temperate Predominantly Open	WTemp	Vulnerable
Gqutywa	Warm Temperate Large Temporarily Closed	WTemp	Vulnerable
Great Fish	Warm Temperate Predominantly Open	WTemp	Vulnerable
Great Kei	Warm Temperate Large Fluvially Dominated	WTemp	Vulnerable
Groot Brak	Warm Temperate Large Temporarily Closed	WTemp	Vulnerable
Gxara (Gxarha)	Warm Temperate Large Temporarily Closed	WTemp	Vulnerable
Gxulu	Warm Temperate Large Temporarily Closed	WTemp	Vulnerable
Gxwaleni	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
Hartenbos	Warm Temperate Large Temporarily Closed	WTemp	Vulnerable
Hluleka	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
Ingo	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
Kaaimans	Warm Temperate Predominantly Open	WTemp	Vulnerable
Kabeljous	Warm Temperate Large Temporarily Closed	WTemp	Vulnerable
Kariega	Warm Temperate Predominantly Open	WTemp	Vulnerable
Kasouga	Warm Temperate Large Temporarily Closed	WTemp	Vulnerable
Keiskamma	Warm Temperate Predominantly Open	WTemp	Vulnerable
Keurbooms	Warm Temperate Predominantly Open	WTemp	Vulnerable
Kiwane (Khiwane)	Warm Temperate Large Temporarily Closed	WTemp	Vulnerable
Klein Brak	Warm Temperate Large Temporarily Closed	WTemp	Vulnerable
Knysna	Warm Temperate Estuarine Bay	WTemp	Vulnerable
Kobonqaba (Khobonqaba)	Warm Temperate Predominantly Open	WTemp	Vulnerable
Kosi	Tropical Estuarine Lake	Tropical	Vulnerable
Kowie	Warm Temperate Predominantly Open	WTemp	Vulnerable
Krom	Cool Temperate Small Temporarily Closed	CTemp	Vulnerable
Kromme	Warm Temperate Predominantly Open	WTemp	Vulnerable
Ku-Amanzimuzama	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
Ku-Bhula (Mbhanyana)	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
Ku-Mpenzu	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
Kwa-Suku	Subtropical Large Temporarily Closed	SubTrop	Vulnerable
Kwanyambalala	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
Kwanyana	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
Kwelera (Kwelerha)	Warm Temperate Predominantly Open	WTemp	Vulnerable
Kwenxura (Kwenxurha)	Warm Temperate Large Temporarily Closed	WTemp	Vulnerable
Lourens	Cool Temperate Small Temporarily Closed	CTemp	Vulnerable
Lupatana	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
Lwandilana	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
Lwandile	Subtropical Large Temporarily Closed	SubTrop	Vulnerable
Maalgate	Warm Temperate Large Temporarily Closed	WTemp	Vulnerable
Maitland	Warm Temperate Large Temporarily Closed	WTemp	Vulnerable
Mapuzi	Subtropical Large Temporarily Closed	SubTrop	Vulnerable
Mbotyi	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
Mdikana	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
Mdumbi	Subtropical Predominantly Open	SubTrop	Vulnerable
Mendu	Warm Temperate Large Temporarily Closed	WTemp	Vulnerable
Mendwana	Warm Temperate Predominantly Open	WTemp	Vulnerable
Mgwalana	Warm Temperate Large Temporarily Closed	WTemp	Vulnerable
Mgwegwe	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
Mgwetyana	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
Mkozi	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
Mkweni	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
Mncwasa	Subtropical Large Temporarily Closed	SubTrop	Vulnerable
Mnenu	Subtropical Large Temporarily Closed	SubTrop	Vulnerable
Mngazana	Subtropical Predominantly Open	SubTrop	Vulnerable
Mngazi	Subtropical Large Temporarily Closed	SubTrop	Vulnerable
Mntafufu	Subtropical Predominantly Open	SubTrop	Vulnerable
Mnyameni	Subtropical Large Temporarily Closed	SubTrop	Vulnerable
Morgan	Warm Temperate Large Temporarily Closed	WTemp	Vulnerable
Mpahlane	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
Mpahlanyana	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
Mpako	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
Mpande	Subtropical Large Temporarily Closed	SubTrop	Vulnerable
Mpekweni	Warm Temperate Large Temporarily Closed	WTemp	Vulnerable
Msikaba	Subtropical Predominantly Open	SubTrop	Vulnerable
Mtakatye	Subtropical Predominantly Open	SubTrop	Vulnerable
Mtata	Subtropical Predominantly Open	SubTrop	Vulnerable
Mtati (Mthathi)	Warm Temperate Large Temporarily Closed	WTemp	Vulnerable
Mtentu	Subtropical Predominantly Open	SubTrop	Vulnerable
Mtentwana	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
Mtolane	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
Mtonga	Subtropical Large Temporarily Closed	SubTrop	Vulnerable
Mtumbane	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
Mzamba	Subtropical Predominantly Open	SubTrop	Vulnerable
Mzimpunzi	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
Mzintlava	Subtropical Predominantly Open	SubTrop	Vulnerable
Nahoon	Warm Temperate Predominantly Open	WTemp	Vulnerable
Ncera (Ncerha)	Warm Temperate Large Temporarily Closed	WTemp	Vulnerable
Nenga	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
Ngqwara (Ngqwarha)	Warm Temperate Large Temporarily Closed	WTemp	Vulnerable
Nkanya	Subtropical Large Temporarily Closed	SubTrop	Vulnerable
Nkodusweni	Subtropical Large Temporarily Closed	SubTrop	Vulnerable
Nqabara/Nqabarana	Warm Temperate Predominantly Open	WTemp	Vulnerable
Nqakanqa	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
Ntlonyane	Subtropical Large Temporarily Closed	SubTrop	Vulnerable
Ntlupeni	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
Nxaxo/Ngqusi	Warm Temperate Large Temporarily Closed	WTemp	Vulnerable
Nyara (Nyarha)	Warm Temperate Large Temporarily Closed	WTemp	Vulnerable
Old Woman’s	Warm Temperate Large Temporarily Closed	WTemp	Vulnerable
Onrus	Cool Temperate Small Temporarily Closed	CTemp	Vulnerable
Piesang	Warm Temperate Large Temporarily Closed	WTemp	Vulnerable
Qinira (Quinirha)	Warm Temperate Large Temporarily Closed	WTemp	Vulnerable
Qolora (Qolorha)	Warm Temperate Large Temporarily Closed	WTemp	Vulnerable
Qora (Qhorha)	Warm Temperate Predominantly Open	WTemp	Vulnerable
Quko	Warm Temperate Large Temporarily Closed	WTemp	Vulnerable
Ratel	Cool Temperate Small Temporarily Closed	CTemp	Vulnerable
Rocky Bay	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
Rooiels	Cool Temperate Small Temporarily Closed	CTemp	Vulnerable
Schuster	Cool Temperate Small Temporarily Closed	CTemp	Vulnerable
Seekoei	Warm Temperate Large Temporarily Closed	WTemp	Vulnerable
Shixini	Warm Temperate Predominantly Open	WTemp	Vulnerable
Sikatsha	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
Sikombe	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
Sinangwana	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
Sir Lowry’s Pass	Cool Temperate Small Temporarily Closed	CTemp	Vulnerable
Sout (Oos)	Warm Temperate Predominantly Open	WTemp	Vulnerable
Steenbras	Cool Temperate Small Fluvially Dominated	CTemp	Vulnerable
Sundays	Warm Temperate Predominantly Open	WTemp	Vulnerable
Sundwana	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
Swartkops	Warm Temperate Predominantly Open	WTemp	Vulnerable
Thsani	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
Tyolomnqa	Warm Temperate Large Temporarily Closed	WTemp	Vulnerable
Van Stadens	Warm Temperate Large Temporarily Closed	WTemp	Vulnerable
West Kleinemonde	Warm Temperate Large Temporarily Closed	WTemp	Vulnerable
Xora	Subtropical Predominantly Open	SubTrop	Vulnerable
aMahlongwa	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
aManzanamtoti	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
aManzimtoti	Subtropical Large Temporarily Closed	SubTrop	Vulnerable
aMatigulu/iNyoni	Subtropical Predominantly Open	SubTrop	Vulnerable
iBhobhoyi	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
iBilanhlonhlo	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
iDombe	Subtropical Large Temporarily Closed	SubTrop	Vulnerable
iFafa	Subtropical Large Temporarily Closed	SubTrop	Vulnerable
iKhaba	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
iKhandalendlovu	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
iKhoshwana	Subtropical Large Temporarily Closed	SubTrop	Vulnerable
iKongeni	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
iLovu	Subtropical Large Temporarily Closed	SubTrop	Vulnerable
iMbizana	Subtropical Large Temporarily Closed	SubTrop	Vulnerable
iMpenjani	Subtropical Large Temporarily Closed	SubTrop	Vulnerable
iMvutshini	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
iNgane	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
iNjambili	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
iNkomba	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
iNonoti	Subtropical Large Temporarily Closed	SubTrop	Vulnerable
iSandlu	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
iSezela	Subtropical Large Temporarily Closed	SubTrop	Vulnerable
iSiphingo	Subtropical Predominantly Open	SubTrop	Vulnerable
iSiyaya	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
iSolwane	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
iZimbokodo	Subtropical Large Temporarily Closed	SubTrop	Vulnerable
iZinkwazi	Subtropical Large Temporarily Closed	SubTrop	Vulnerable
iZotsha	Subtropical Large Temporarily Closed	SubTrop	Vulnerable
oHlangeni	Subtropical Large Temporarily Closed	SubTrop	Vulnerable
uMahlongwane	Subtropical Large Temporarily Closed	SubTrop	Vulnerable
uMakhosi	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
uMbango	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
uMbhoyibhoyi	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
uMdesingane	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
uMdlotane	Subtropical Large Temporarily Closed	SubTrop	Vulnerable
uMdloti	Subtropical Large Temporarily Closed	SubTrop	Vulnerable
uMfazezala	Subtropical Large Temporarily Closed	SubTrop	Vulnerable
uMgababa	Subtropical Large Temporarily Closed	SubTrop	Vulnerable
uMgobezeleni	Tropical Estuarine Lake	Tropical	Vulnerable
uMhlabashana	Subtropical Large Temporarily Closed	SubTrop	Vulnerable
uMhlali	Subtropical Large Temporarily Closed	SubTrop	Vulnerable
uMhlanga	Subtropical Large Temporarily Closed	SubTrop	Vulnerable
uMhlangomkhulu (North) (Mhlangamkulu)	Subtropical Large Temporarily Closed	SubTrop	Vulnerable
uMhlangomkhulu (South) (Umhlangankulu)	Subtropical Large Temporarily Closed	SubTrop	Vulnerable
uMhlungwa	Subtropical Large Temporarily Closed	SubTrop	Vulnerable
uMkhomazi	Subtropical Predominantly Open	SubTrop	Vulnerable
uMkhumbane	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
uMlalazi	Subtropical Predominantly Open	SubTrop	Vulnerable
uMnamfu	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
uMngeni	Subtropical Predominantly Open	SubTrop	Vulnerable
uMphambanyoni	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
uMsimbazi	Subtropical Large Temporarily Closed	SubTrop	Vulnerable
uMthavuna	Subtropical Large Temporarily Closed	SubTrop	Vulnerable
uMthente	Subtropical Large Temporarily Closed	SubTrop	Vulnerable
uMthwalume	Subtropical Large Temporarily Closed	SubTrop	Vulnerable
uMuntongazi	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
uMuziwezinto	Subtropical Large Temporarily Closed	SubTrop	Vulnerable
uMvuzi	Subtropical Large Temporarily Closed	SubTrop	Vulnerable
uMzimayi	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
uMzimkhulu	Subtropical Predominantly Open	SubTrop	Vulnerable
uMzumbe	Subtropical Large Temporarily Closed	SubTrop	Vulnerable
uSetheni	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
uThongathi	Subtropical Large Temporarily Closed	SubTrop	Vulnerable
uVunguza	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
uVuzana	Subtropical Small Temporarily Closed	SubTrop	Vulnerable
Baakens	Warm Temperate Small Temporarily Closed	WTemp	Least Concern
Beechamwood	Warm Temperate Small Temporarily Closed	WTemp	Least Concern
Blind	Warm Temperate Small Temporarily Closed	WTemp	Least Concern
Blinde	Warm Temperate Small Temporarily Closed	WTemp	Least Concern
Bloukrans	Warm Temperate Small Fluvially Dominated	WTemp	Least Concern
Boknes	Warm Temperate Small Temporarily Closed	WTemp	Least Concern
Cunge	Warm Temperate Small Temporarily Closed	WTemp	Least Concern
Cwili	Warm Temperate Small Temporarily Closed	WTemp	Least Concern
Elands	Warm Temperate Small Fluvially Dominated	WTemp	Least Concern
Elandsbos	Warm Temperate Small Fluvially Dominated	WTemp	Least Concern
Gericke	Warm Temperate Small Temporarily Closed	WTemp	Least Concern
Grant's	Warm Temperate Small Temporarily Closed	WTemp	Least Concern
Groot (Oos)	Warm Temperate Small Fluvially Dominated	WTemp	Least Concern
Groot (Wes)	Warm Temperate Small Temporarily Closed	WTemp	Least Concern
Gwaing	Warm Temperate Small Temporarily Closed	WTemp	Least Concern
Haga-haga	Warm Temperate Small Temporarily Closed	WTemp	Least Concern
Hickman's	Warm Temperate Small Temporarily Closed	WTemp	Least Concern
Hlaze (iHlanze)	Warm Temperate Small Temporarily Closed	WTemp	Least Concern
Hlozi	Warm Temperate Small Temporarily Closed	WTemp	Least Concern
Imtwendwe (Mtwendwe)	Warm Temperate Small Temporarily Closed	WTemp	Least Concern
Jujura (Jujurha)	Warm Temperate Small Temporarily Closed	WTemp	Least Concern
Klipdrif (Oos)	Warm Temperate Small Temporarily Closed	WTemp	Least Concern
Klipdrifsfontein	Warm Temperate Small Temporarily Closed	WTemp	Least Concern
Ku-Nocekedwa	Warm Temperate Small Temporarily Closed	WTemp	Least Concern
Kwa-Goqo	Warm Temperate Small Temporarily Closed	WTemp	Least Concern
Kwazlelitsha (Kwazwedala)	Warm Temperate Small Temporarily Closed	WTemp	Least Concern
Lilyvale	Warm Temperate Small Temporarily Closed	WTemp	Least Concern
Lottering	Warm Temperate Small Fluvially Dominated	WTemp	Least Concern
Matjies	Warm Temperate Small Temporarily Closed	WTemp	Least Concern
Mcantsi	Warm Temperate Small Temporarily Closed	WTemp	Least Concern
Mlele	Warm Temperate Small Temporarily Closed	WTemp	Least Concern
Mtana	Warm Temperate Small Temporarily Closed	WTemp	Least Concern
Mtendwe	Warm Temperate Small Temporarily Closed	WTemp	Least Concern
Ncizele	Warm Temperate Small Temporarily Closed	WTemp	Least Concern
Nebelele	Warm Temperate Small Temporarily Closed	WTemp	Least Concern
Ngadla	Warm Temperate Small Temporarily Closed	WTemp	Least Concern
Ngculura (Ngculurha)	Warm Temperate Small Temporarily Closed	WTemp	Least Concern
Ngogwane	Warm Temperate Small Temporarily Closed	WTemp	Least Concern
Ngoma/Kobule	Warm Temperate Small Temporarily Closed	WTemp	Least Concern
Ngomane (East)	Warm Temperate Small Temporarily Closed	WTemp	Least Concern
Noetsie	Warm Temperate Small Temporarily Closed	WTemp	Least Concern
Nqinisa	Warm Temperate Small Temporarily Closed	WTemp	Least Concern
Papkuils	Warm Temperate Small Temporarily Closed	WTemp	Least Concern
Riet	Warm Temperate Small Temporarily Closed	WTemp	Least Concern
Ross' Creek	Warm Temperate Small Temporarily Closed	WTemp	Least Concern
Rufane	Warm Temperate Small Temporarily Closed	WTemp	Least Concern
Shelbertsstroom	Warm Temperate Small Temporarily Closed	WTemp	Least Concern
Sihlontlweni	Warm Temperate Small Temporarily Closed	WTemp	Least Concern
Slang	Warm Temperate Small Temporarily Closed	WTemp	Least Concern
Storms	Warm Temperate Small Fluvially Dominated	WTemp	Least Concern
Timba	Warm Temperate Small Temporarily Closed	WTemp	Least Concern
Tsitsikamma	Warm Temperate Small Temporarily Closed	WTemp	Least Concern
Tweekuilen	Warm Temperate Small Temporarily Closed	WTemp	Least Concern
Zalu	Warm Temperate Small Temporarily Closed	WTemp	Least Concern

Approach

The 2025 assessment of South Africa’s 22 estuarine ecosystem types was conducted using the 2024 IUCN guidelines for red listing ecosystems and drawing from previous estuarine NBA assessments.

The IUCN RLE (Ver 2) framework was applied and following criterion were assessed:

Criterion A2b (current rate of decline in ecosystem extent); based on land cover change rates between 1990 and 2022 - projected forward to 2040.
Criterion A3 (historical reduction in ecosystem extent), based on land cover 2022
Criterion B3 was applied to the estuary types that occur at 5 or fewer locations - and for which there is ongoing decline defined as: a) between t1 and t2, fishing pressure shifts from M to H OR H to VH, OR b) PES class A, B and C extent declined by >1%, OR extent of H and VH Fishing pressure at year of assessment is greater than 30% of type extent. This captures increasing or sustained gill-netting pressures, and steady decline in ecosystem condition as triggers. The rating applies to the whole type and is scaled by estuarine extent.
Criterion D1 was applied using fishing pressure scores for each estuary. The scores were converted to an index 0-1 and aligned to severity rating (1 highest severity - 100%; 0 lowest severity - 0%). The rating applies to the whole type and is scaled by estuarine extent.
Criterion D3 was applied to the Estuarine Ecological State Class (PES) data such that severity of biotic disruption of >= 90% was assumed for PES classes E-F; Severity >=70% was assigned to PES classes D-F; Severity >=50% was assigned to PES classes C-F. The rating applies to the whole type and is scaled by estuarine extent.

Each of the 22 estuary ecosystem types were assigned to one of the four risk categories: Critically Endangered, Endangered, Vulnerable and Least Concern. The highest risk category for these two criteria is selected as the threat / risk status for each river type.

A more detailed explanation of the assessment method can be found at RLE explanation page.

Technical documentation

Code repositories

Threat status assessment

Key publications

Recommended citation

Van Niekerk, L., Skowno, A.L., Sink, K., & Harris, L.R. 2025. Ecosystem threat status: Estuarine realm. National Biodiversity Assessment 2025. South African National Biodiversity Institute. http://nba.sanbi.org.za/.