Micro-estuary – a new estuary type recognised for South African conditions

Abstract

Ezemvelo KwaZulu-Natal Wildlife embarked on a programme to identify all the estuaries within the KwaZulu-Natal (KZN) province. Following an aerial survey along the coastline in 2012, images of all the visible inlets and estuaries were captured. Among these are a number of areas where flows of freshwater to the sea appeared to be present but which were not among the estuaries that had previously been named. There are already well defined and recognised estuary types being managed in South Africa in terms of existing environmental legislation. Following the initial survey and the observation that there are coastal inlets/freshwater outlets that are potentially small estuaries that had not been included among them prompted a further investigation into whether some of these inlets were in fact features that should be classified in some way or other. Based on a rapid qualitative assessment, 181 sites were classified as either a “micro-estuary”, “freshwater seep”, “hard-structure freshwater outflow point” or as sites that had been considerably modified by engineered structures. A total of 61 of these 181 sites are included in a new classification as micro-estuaries. Most of these systems are in a degraded condition and require intensive rehabilitation to restore them to their historical ecological function. This study emphasises the urgency of accepting “micro-estuary” as a new estuarine type to provide formal protection against further deterioration. This is the first study to provide a description and spatially define these smaller systems present along the KZN coast.

Keywords:

• KwaZulu-Natal
• estuarine
• rapid assessment
• ecological function

ACKNOWLEDGEMENTS

Ezemvelo KwaZulu-Natal Wildlife provided funding/logistical and technical support for this project. Ms Alicia Gomez, Ms Nonzuzo Dlamini, Mr Santosh Bachoo, Mr Thobani Lizwe Khomo and Mrs Vasha Chetty are thanked for their assistance in the field. Mrs Ronel Schulz is thanked for her assistance with logistics.

Authors’ contributions: B.E was the project leader; G.C.B., M.N. and A.M. were the researchers; G.C.B. and M.N. wrote the manuscript; A.M. and J.C. made methodological contributions to the manuscript.

DISCLOSURE STATEMENT

The authors declare they have no competing interests.

Additional information

Funding

The Micro-estuaries project was funded by internal Ezemvelo KZN wildlife operational funds. No external funding sources where utilised during the course of this investigation.