Condition

Estuarine realm

Lara van Niekerk1, 2 , Andrew L. Skowno3 , Kerry Sink3, 2 , Linda R. Harris2

1. Council for Scientific and Industrial Research

2. Institute for Coastal and Marine Research

3. South African National Biodiversity Institute

Published

November 11, 2025

Overall, estuaries are Moderately (59%) to Poorly (32%) protected in South Africa, less than 1% of area is well protected. From a ecosystem types perspective about 9% are Well protected, 36% Moderate, 41% Poorly, and 14% Not Protected.

00%
of 220 ecosystem types
Threatened
00%
of 220 ecosystem types
Well Protected
00%
of 220 ecosystem types
Not protected
00%
of 50 taxa assessed
Threatened
Figure 1. South Africa’s Protected Area network.

Ecosystem protection level assessment

Overall, estuaries are Moderately (59%) to Poorly (32%) protected in South Africa, less than 1% of area is well protected. From an ecosystem types perspective about 9% are Well protected, 36% Moderate, 41% Poorly, and 14% Not Protected.

Since 2011 there has been erosion of protection in historical protected areas caused by removal of no-take restrictions and developing commercial fisheries in Marine protected Areas (MPAs). This is further exasperated by increased illegal gillnetting in protected areas in KZN.

An investment in estuarine protection is needed in ecosystem types that are Not Protected or to advance Poorly Protected ecosystem types towards Well Protected. Ecosystem types in the Tropical and Warm Temperate biogeographical region are the best protected, while ecosystem types in the Cool Temperate are least protected.

Opportunities to improve ecosystem protection level

Figure 2. Estuarine ecosystem type protection level.

There is an opportunity to improve the protection level of some of the Poorly or Moderately Protected ecosystem types to Well Protected through improved estuarine management and ecosystem restoration to reduce ecosystem degradation.

Several under protected ecosystem types can advance to Well Protected solely with improved management of fishing and water quality. For example, 32% of types and 10% of area can be well protected if fishing effort in just 3 estuaries are better controlled – Langebaan, Knysna and Kosi.

The global support for 30% protection target (2030 Global Biodiversity Framework Target 3) represent a unique opportunity to garden international support and present funding opportunities to advance estuary protection. Conservation agencies around the coast are in the process to evaluate and extend estuarine protection with local community support, e.g. Olifants Estuary and Verlorenvlei (CapeNature).

Ongoing efforts to develop OECMs and stewardship approaches for estuaries present an opportunity for bottom-up conservation models to be developed that can be used to protect and arrest the ongoing decline in Blue Carbon habitats. It is less clear, if this mechanism will also be able to protect invertebrates, fish and birds. However, there is no doubt that increased community engagement in protection will create an environment of trust and present opportunities for strengthening protection over time, either as a ‘stepping stone’ for increase formal protection over time or as a sufficient measure one its own.

Summary

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References

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Approach

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#INSERT TABLE WITH HEALTH CATEGORIES: est_ets_cat.csv

Protection Level is an indicator developed in South Africa that measures the representation of ecosystem types within the protected area network. The extent of each ecosystem type within the network is expressed as a proportion of the total extent. Four categories of Ecosystem Protection Level are calculated per ecosystem type (n= 22).

  • Well Protected: 100% of the PA target within PA network; AND only A&B condition estuaries contribute; AND areas under heavy and very heavy fishing pressure are excluded from contributing

  • Moderately Protected: 50% to 99% of PA target within the PA network; and A&B condition estuaries contribute 100%, C & D condition estuaries contribute 30% and E&F condition estuaries contribute 10%

  • Poorly Protected: 5% to 49% of PA target within the PA network; and A&B condition estuaries contribute 100%, C & D condition estuaries contribute 30% and E&F condition estuaries contribute 10%

  • Not Protected: less than 5% of PA target within the PA network; and A&B condition estuaries contribute 100%, C & D condition estuaries contribute 30% and E&F condition estuaries contribute 10%

The PA target was historically set at 20% for marine and estuarine ecosystems, but with the adoption of the 30% targets for Target 3 of the Global Biodiversity Framework - the protected areas target was increased to 30% in the EPL calculations (previous time points (2018) were recalculated using this higher target). Ecosystem condition data (van Niekerk et al., 2025) for each time point allow for only good condition estuaries without heavey fishing pressure (especially systems under severe gill-netting pressure) to be considered representative for Well Protected status; while for Moderately Protected, Poorly Protected and Not Protected the condition of the estuaries is used to calculate their contribution to meeting targets such that higher integrity / condition estuaries contribute more to meeting protected areas targets than low integrity / condition estuaries.

Technical documentation

Code repositories

#INSERT ANDREW’S EPL FILE

Key Publications

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Key publications

Jordaan, M.S., et al. 2020. Protected areas and endemic freshwater fishes of the Cape Fold Ecoregion: missing the boat for fish conservation? Frontiers in Environmental Science 8:502042. doi: 10.3389/fenvs.2020.502042

References

1. Rutherford, M.C. et al. 2006. Biomes and bioregions of Southern Africa. In Mucina, L. & M.C. Rutherford (eds), The vegetation of South Africa, Lesotho and Swaziland. Strelitzia 19: 30–51. South African National Biodiversity Institute, Pretoria.