Biota of South African wetlands
in relation to the
Ramsar Convention

GI Cowan (ed)

1999

Department of Environmental Affairs and Tourism. Pretoria

ISBN 0-621-29461-6

Introduction

The ecological significance of wetlands arises from the fact that the wetness associated with these habitats exercises a major influence on the species composition of wetland biota. Consequently, many animals are wholly or partially dependent on wetlands for refuge, feeding and breeding purposes (Begg 1986).

In terms of the Ramsar Convention, three groups of criteria for selecting wetlands for designation to the List of Wetlands of Intemational Importance were accepted at the Third Conference of Contracting Parties held in Montreux, 1990. At the Fifth Conference of Contracting Parties held in Brisbane, 1996 a fourth criterion was accepted. The four groups of criteria accepted are:

1. Criteria for representative or unique wetlands
2. General criteria based on plants or animals
3. Specific criteria for using waterfowl
4. Specific criteria for using fish

In terms of Criterion 2: General criteria based on plants or animals, a wetland should be considered internationally important if:

1. it supports an appreciable assemblage of rare, vulnerable or endangered species or subspecies of plant or animal, or an appreciable number of individuals of any one or more of these species; or
2. it is of special value for maintaining the genetic and ecological diversity of a region because of the quality and peculiarities of its fauna and flora; or
3. it is of special value as the habitat of plants or animals at a critical stage of their biological cycles; or
4. it is of special value for its endemic plant or animal species or communities.

Aims of this publication

This publication aims to give some indication of the range of fauna and flora found in South Africa's wetlands. Rather than attempting to list the biota found in each wetland or wetland system, this section works from the biota to the wetlands where the aims are:

• To provide an idea of the range of species found in our wetlands
• To indicate their red data status
• To indicate what habitats they are likely to be found

As far as possible a standardized format was followed for each group of biota, where the scientific nomenclature was followed by the common names where available, habitat, status in terms of the South African Red Data Books, or in cases where these are unavailable, the IUCN red data list (1996), and an indication as to whether the species are endemic to the country or not. Some authors included biogeographical province in their tables. It was not possible to standardize habitats throughout, given the requirements ofthe biota. The greatest problems were encountered in trying to limit the animals dependant on the marginal areas, for example riparian forest and hygriphilous grassland. Standardization, where used, tended to use only the upper limits of wetland classification.

Habitats

The Convention on Wetlands (Ramsar 1971) defines wetlands as: "areas of marsh, fen, peatland or water, whether natural or artificial, permanent or temporary, with water that is static orflowing, fresh, brackish or salt, including areas of marine water the depth of which at low tide does not exceed six metres" (Article 1. 1). These areas may also include adjacent riparian and coastal zones (Article 2. 1). Based on this definition, a classification system has been developed for use in the Convention. This system has been adapted for use in South Africa (Cowan 1998). At the upper limit wetland habitats are classified into marine, estuarine, riverine, lacustrine, palustrine and endorheic wetland systems. However, using this definition and classification to define wetland habitats raises a number of questions, particularly when determining species which occupy those habitats considered marginal to wetlands such as the marine habitats, coastal islands, riparian forest habitats and hygriphilous grasslands. Riparian forests in savanna areas stand out as a distinctive habitat, dependant on the rivers. Many of the species found here are considered forest species rather than wetland species, the division between the two groups being difficult to define at times. Similarly, wet or hygriphilous grasslands are some of the more difficult habitats to define, especially with South Africa's erratic rainfall pattem. Many ofthese habitats are ephemeral. Given this difficulty, the criteria used to determine wetland species were based on whether it was dependant on water, wetland flora or other wetland fauna for any major part of its life cycle (eg breeding, feeding, moulting). Many species utilize wetland habitats opportunistically (eg swallows roosting in reedbeds) orjoin other species (eg cattle egrets in heronries) which could qually utilize habitats other than wetlands for the same purposes.

Results

Tables for the following groups of fauna and flora are presented: aquatic plants, marine molluscs, amphipods, crabs, odonata, fish, amphibia, reptiles, birds and mammals. This is by no means a complete coverage of South Africa's wetland biota, and hopefully similar summaries of other biota's status will become available soon. Table I summarizes the available data, and supplements it with information from literature which has became recently available.

Table 1 Number of wetland species, number of species listed in the Red Data Books, and the number of endemics per taxon in South Africa.

Taxon	No. species	No. Red Data species	No. endemics
Plants	350	57	36
Molluscs (marine)	268	-	64
Molluscs (freshwater)	86	-	-
Amphipods	42	-	-
Crabs	41	-	8
Ephemeroptera	91	-	-
Odonata	153	8	30
Simulidae	39	-	-
Trichoptera	151	-	-
Fish	244	39	78
Amphibia	102	15	44
Reptiles	36	10	10
Birds	234	24	10
Mammals	44	17	1

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	This page is maintained by the South African Wetlands Conservation Programme and was last updated on 13 September 1999.

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