Our Gabions, Terramesh® System and Reno Mattresses were used to build an ecobelt
We successfully built an ecobelt around the Thesen Island Marina while preserving the lives of endangered Knysna seahorse – Hippocampus capensis. There was the need to protect the island against the erosive forces of fluctuating tide levels and associated wave actions in line with the Knysna Estuary environment. This was successfully carried out using our Gabions, Terramesh® System and Reno Mattresses to achieve the “no net loss of salt marsh.”
An endangered species
Currently, seahorses are facing great challenges like overexploitation and habitat degradation. So much weight is placed on their physiological ability to survive climate changes. With their biological and ecological constraints, as well as their poor swimming skills, a disturbance to the natural lifestyle of seahorses would have an adverse effect on them.
The Knysna seahorse, Hippocampus capensis Boulenger, is South Africa’s only endemic seahorse species and is found in only three adjacent estuaries situated on the southern Cape coast. It was the first (and is still the only) seahorse species to be listed as endangered on the IUCN Red Data List of Threatened species with habitat loss identified as a major threat.
The challenge was how to successfully build a much-needed shoreline and offshore protection of the Thesen Island Marina in South Africa without distorting the natural habitat of this lovely and sensitive sea animal.
Reproducing the perfect natural habitat
Our Gabions and Reno Mattresses were used to recreate the perfect natural habitat for the seahorses because they presented the best option due to their flexibility in meeting with the geometrical constraints of the canal embankments, durability under harsh marine environments and ability to lend themselves favourably to environmental rehabilitation.
The camouflage strategy and sparse distribution associated with structurally complex habitats of seahorses imply that not all habitats are equally suitable for them.
At Maccaferri, we are not just engineers; we understand the importance of preserving this endangered species, which is why it was quite comforting to see this sea creature (as can be seen in the video) continues to lead a sheltered life; live and reproduce close to Gabions.
For the first time ever in South Africa, we were able to successfully transplant indigenous salt marsh plants on a large scale and replanted and established them at simulated heights and natural conditions.
The Knysna Estuary is an estuarine bay situated on the southern Cape coast of South Africa. Thesen Islands Marina is a 90.60 ha residential marina estate located on Thesen Island in the bay regime of the estuary.
Special thanks to our client, THESEN ISLAND DEVELOPMENT COMPANY for entrusting us with this project. We started this project in August 2000 and successfully completed it in December 2003.
For more information on this project, you can download our Case History.