Relinkage of the Mfolozi River to the St. Lucia estuarine system urgent imperative for the long-term management of a Ramsar and World Heritage Site

The St. Lucia Estuary was separated from the Mfolozi River in the early 1950s following canalisation of the Mfolozi floodplain swamp that resulted in the deposition of large amounts of sediment in the estuary. A separate Mfolozi River mouth has been maintained artificially since then and the deleterious consequences in terms of freshwater supply to the St. Lucia system are now becoming fully apparent, especially following the latest drought. Fish and penaeid prawn stocks in Lake St. Lucia have collapsed and the loss of this major southern African estuarine nursery area for these faunal components has had a significant impact on fish and prawn catches in adjacent coastal waters. It is therefore imperative that a re-linkage of the Mfolozi River to the St. Lucia system occurs so that the health and conservation status of the St. Lucia ecosystem, which is a Ramsar and World Heritage Site, can be assured. This review of the major findings presented at a recent scientific workshop explores the need for, and consequences of, a reconnection between the Mfolozi River and St. Lucia Estuary and makes some preliminary suggestions towards the achievement of that goal. Foremost amongst these proposals is to use the subsiding Mfolozi floodplain as a sink for excess sediment carried by the Mfolozi River before it enters the St. Lucia system, as well as various strategies in terms of reconnection options.