ALIEN VEGETATION

The Swartkops estuary and its two adjacent valley thickets (Swartkops Nature Reserve and Aloes Nature Reserve) have, over the years, been infested with a variety of aliens. These all tend to overwhelm the indigenous vegetation so they need to be eradicated or, at the very least, kept in check. These include: Jointed cactus, Prickly pear, Agave, Yucca, Port Jackson and Rooikrantz to name a few.

Jointed Cactus

Around 2018 the jointed cactus had spread so much that the popular Flamingo trail walk in the Swartkops Nature Reserve had to be abandoned. At that point, the ZC decided that something had to be done so we started a program to eliminate it.

First year we tried poisoning, but we soon abandoned it: too expensive and not effective.  Also worried about the environmental impact of the poison.

We then tried infesting it with the Cochineal bug. It was largely successful but did not eliminate it completely.

From 2019 we resorted to removing the remaining cacti by hand: dig roots out using fork, use tongs to place roots and branches in bucket. When full, empty bucket into strong plastic bag. Carry bags to the estuary bank for collection by boat.

Our biggest headache was what to do with the full bags of cactus? Cannot go to landfill as it will just spread from there! Tried burning; impractical and costly. Enviroserve then came to the rescue and have kindly buried it. We are deeply grateful to them.

For the first two years we used ZC staff and Wessa Stewards on a year’s practical training with us. However, for the last 3 years we have also enlisted a group of persons from Redhouse and Bluewater Bay who care about the environment and they have enthusiastically joined in the eradication program.

In this time, we have mostly eradicated all the cactus from the banks of the estuary from Bar None north of Redhouse right down to the robots at John Tallantin. We also removed cactus in Perseverance Industrial as well as the horse-fields behind the Swartkops Police Station, the steps at Tippers Creek and along the lower banks of the Chatty-river before it flows under the M19.

We estimate we have removed in excess of 1200 bags in the last 5 years; our peak effort was in 2021 when we removed 495 bags working twice a week.

We have made extensive use of both our boats to transport the cactus teams to and from the estuary banks and collected full bags.

Agave and Yucca

Now that most of the cactus has been removed, we have turned our attention since 2022 to other aliens. We targeted Agave and Yuccas which were proliferating almost beyond control in two areas: first was the open area bordered by the old railway line and Amsterdamhoek road and the next was a huge stand of mainly Agave behind the Scout Hall in Tippers Creek.

We were greatly assisted by a local Amsterdamhoek resident who used his Land-rover to winch out the bigger plants and to transport to the local tip. We collected the seeds in bags which we took to Enviroserv for disposal.

Prickly Pear

Its early stages but we also turning our attention to the prickly pear in the Aloe Reserve. In this instance the ZC is embarking on a program of biological control;  infesting the prickly pear that is accessible in the valley thickets with pieces of plant already infested with the Cochineal bug.  Any small plants or parts of plants are dug up and put on top of bushes so they cannot take root.