Estuaries are one of the most important features of the South African coastline; they are tranquil areas of high productivity and play a vital role in the life cycles of many plants and animals – especially as a nursery for fish. Situated at the interface between fresh and marine waters, estuaries are among the most biologically productive ecosystems in the world and are of great ecological and economic importance.

These words were written by Dr Anina Lee in The Village NEWS of 30 October 2019. Friends of the Bot River Estuary and Environs (Botfriends) fully agree with this ecological appreciation of both estuaries and wetlands as high-value ecosystems.

The Bot River Estuary is the largest in the Overstrand. Its surroundings include large badly-degraded wetland areas. We are highly concerned about the conservation of these environmental assets. Among the most serious threats are the aggressive and rapid spread of invasive alien vegetation at the expense of the indigenous fynbos, and the pollution and drying up of the wetlands.

This is why the Botfriends have come up with community-driven activities in alien clearing and wetland preservation. About 30 ha have been cleared thus far with our private resources. Significant as this is, these efforts need to be scaled up urgently. This is why the Botfriends have come up with a plan to deal with large parts of the area south of the R43, from Rooisand to Hawston.

This area once boasted high biodiversity and many wetlands. Alien invasion has dried up the wetlands and increased the fire risk. Several sections have been abandoned, including demarcated green areas. Efforts towards controlling the invasive species have been limited and have sometimes compounded rather than relieved the problems. If not eradicated properly, for example when infested areas are just mowed or clearing is not followed up, aliens regrow fast and suppress the fynbos vegetation more vigorously than before.

The shore of the Bot River Estuary near the mouth. On the dune to the right side, fynbos vegetation has already recovered a year after alien clearing by Botfriends. The spot to the left in the foreground was cleared a few months ago. Here fynbos is beginning to gain an advantage over the aliens. The patch with vigorous regrowth of Port Jackson Willow (Acacia saligna) between these two spaces needs follow-up treatment to prevent the aliens from out-competing the slower growing fynbos. Behind this recently treated space to the left, the dense woody vegetation shows uncontrolled Port Jackson and Australian Myrtle (Leptospermum laevigatum) having suppressed fynbos. PHOTO: Klaus Schmitt

The Paddavlei near Hawston has changed from an open water body to a polluted swamp that is a quarter of its original size. In 2018, a fire in an alien-infested area adjacent to Fisherhaven could not be controlled even with helicopter support. It occurred under gentle wind conditions. Higher wind could have caused a disaster similar to the great Betty’s Bay fire of 2019.

Rehabilitating the wetlands will increase their water-holding capacity and the inflow to the Bot River Estuary, a declared RAMSAR site. It will also enhance the water quality through the wetlands’ filtering function. In addition, these wetlands fall within three biodiversity corridors between the estuary and the mountains. Protected corridors allow free spread and movement of indigenous flora and fauna. Such ecosystem services become ever more important, as climate change is a reality and South Africa is a hotspot. Here warming will most likely be twice the global average, while rainfall will be scarcer and more erratic, and more extreme events will likely result in further runoff and flooding.

The Botfriends Alien Clearing Project aims to (1) remove alien plants in the Bot River environs, (2) re-establish wetlands in the Bot River area and demarcate three biodiversity corridors, (3) reduce the fire risks to manageable proportions, (4) contribute towards an environmental management strategy for a greater area that involves the relevant stakeholders.

While clearing areas in and around Fisherhaven, Botfriends have tested the effectiveness and cost-efficiency of different methods. Our team can serve as the nucleus for further expansion of a clearing workforce. An area of about 3 000 ha has been identified as a priority for further clearing and a project proposal has been drawn up for submission to potential donors. Meanwhile we continue with our own limited resources, aiming to involve more local roleplayers and contributors, both private and communal. All contributions are welcome, be it in the form of financial donations, fundraising ideas, labour, advice or logistics.

Financial contributions to the alien clearing project will be tax-deductible. For further information, please contact Michael Austin at botvlei@gmail.com or visit www.botfriends.org.za.

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