All is not lost at Verlorenvlei

Translated from Afrikaans the name Verlorenvlei means "lost marsh", strange name for a marsh - what or who has lost something? Or did someone get lost here? It certainly cannot mean that this beautiful marsh-like lake was lost at some stage? Oloff Bergh, the VOC official, visited the lake in 1682 and called it Zandrivier.  When Simon van der Stel came this way on route to the Koperberge in the Namaqua, he mistakenly thought the river was a tributary of the Olifant's river and called it Zeekoe Vallei (Hippopotamus marsh). It was Jan Rhenius though, who renamed the swamp to its original Khoisan name “quaecoma” which means “lonely swamp” or “lost marsh”.

Verlorenvlei is one of the largest natural wetlands on the west coast of South Africa and is one of only few coastal freshwater lakes in our country.  It`s catchment covers about 1890km2 and consists of four main tributaries: the Kruis, Bergvallei, Hol and Krom Andries rivers, which have their sources in the Olifant's river - and and Swartberge.  All four of them flow into the 30km long Verlorenvlei river.

The lake itself is about 13.5km long and 1.4km wide and is linked to the ocean at Eland's bay by a small, shallow channel of 2,5 km long.  A rocky sand-covered bar at the mouth and other artificial obstructions make it a virtually closed system. Normally the mouth is closed and the channel consists of a few stagnant saline pools. After the rains the lake overflows into the channel and tidal exchange takes place.  The lake is not really deep at any point, a maximum of 4.5m and an average of about 3m.  Depending on the water levels, the salinity levels can become as high as 40 parts per thousand, east of the railway bridge, and as low as 0.5 parts per thousand at Redelinghuys.

Verlorenvlei occurs at the transition between fynbos and Karoo vegetation types and holds a high diversity of plant species.  Rare plants include Ferraria foliosa, Ferraria densepunctulata, Cullumia floccosa.  Cerycium venoum was found here earlier, but it is thought that this plant is now extinct.

About 190 bird species exist here, from which 75 are water birds.  The wetland occasionally hosts more than 4000 birds; the highest number recorded in a single count was 11 891.  The number includes birds like Greater and Lesser Flamingos, Little Bittern, Great Crested Grebe, Red-knobbed Coot, African Marsh Harrier and different duck species.  At times at least 26% of the Western Cape's Great White Pelicans can be seen here. We also have 4 or 5 African Fish Eagle breeding pairs here.  If you are lucky, you can see up to 1256 Pied Avocet, 478 Great White Pelican and more than 750 Greater Flamingos.

Quite a few fish species are living here, among others the indigenous Cape Kurper, Cape Galaxias and Berg River Redfin.  One of the redfin species was just described here and renamed after the lake: the Verlorenvlei Redfin Pseudobarbus Verloreni.

Threatened and interesting mammal species are also present at the lake: Grant`s golden mole, De Winton`s golden mole, Van Zyl`s golden mole, Cape gerbil, Cape spiny mouse, honey badger, striped polecat and aardwolf.  A few wild cats species are here as well: leopard, caracal and African wild cat.

The Verlorenvlei lies within the ranges of quite a few reptiles like the speckled padloper, Namaqua dwarf adder, many-horned adder, coastal legless skink, Knox`s desert lizard, namaqua plated lizard, Namaqua dwarf chameleon and many more. More than 25 reptile species endemic to South Africa are found here! I have said this a few times before: it is incredible how wide the bio diversity of this unknown part of our country is! 

In spite of the fact that this lake is one of the most important estuarine /lacustrine systems in South Africa, it only reached formal protection status as Ramsar area in 2011. The lack of formal protection for so long exacerbates the threats that influence the estuary from further upstream. Large scale potato and wheat production takes place in the catchment area and a lot of water is therefor extracted from the system.  Apart from the extraction of ground and surface water, these agricultural activities can cause heightened ground erosion which in turn leads to heightened sediment in the estuary.  Nitrification also happens where increased nutrients levels lands into the river. The raised sediment and nutrients in the marsh, stimulates the growth of Phragmites Australis reed, contributing to a loss of open water habitat and further altering the ecology of the estuary.

Except from the invasive human structures like a rubble causeway at the railway bridge, fences, powerlines across some sections of water and jetties and pumphouses in the water body itself, there is also a lot of invasive alien flora like Acacia cyclops living here.

Uncontrolled recreational activities in the estuary can lead to the disturbance of wildlife, especially birds.  Recreational activities should be kept to a minimum and limited to certain zones to reduce disturbance.

The marsh' endemic fish population is also under threat because of illegal gill-netting and invasive alien fish species like Carp and Mozambique tilapia which compete with the endemic species for food and shelter.

Veld fires in and around Verlorenvlei lead to erosion and raised levels of sedimentation. This is a very specific problem for Verlorenvlei because it has a very narrow mouth and this can cause the mouth to silt closed in such a way that even a flood cannot cut through the excess sediment.

The solid waste and water that seeps from the municipal dump - only a few hundred meters from the marsh -  can lead to microbial contamination, toxins enter the system and nutrients levels can be changed. The dumping of rubble in unauthorised areas can furthermore lead to loss of habitat.

Open mining of wolframite and molibdeen were being proposed for the upper catchment area of the Verlorenvlei at Metonshoek.  These mining activities will most likely need a lot of fresh water and further it will hold high risks for pollution of the fresh water flowing into the marsh. A lot of opposing by organisations like Friends of the marsh and Verlorenvlei Coalition caused the Western Cape High Court to recently grant an interdict brought by the Berg River Municipality to halt the drilling.  This all happened after Bongani Minerals started illegal drilling in Moutonshoek Valley in March 2012, contravening the Land Use Planning Ordinance. 

It has been stopped... for now... But will it last?
http://verlorenvlei.co.za/myn-verdwyn/
https://www.farmersweekly.co.za/agri-news/south-africa/verlorenvlei-mining-halted-for-now/