South Africa has one of the biggest kelp forests in the world. Kelp is a marine alga and not a true plant and species range from shorter-growing “bottom kelp” to much taller species. This ecosystem serves as food and shelter for many marine species and is one of the richest habitats on earth.
The canopy of these forests can be seen from the shore on the surface of the water and looks like a shiny green mass but once you go below the surface an enchanting new world opens up.
A Kelp forest above the water looks like a tangle of shiny green leaves
In the beginning, when I just started entering kelp forests as a snorkeler and later a new Open Water scuba diver, the kelp felt like a scary dark place that would entangle me. But, if you stay calm and just go with the back-and-forth sway of the surge, the kelp opens up and becomes a serene place. The slippery leaves lightly flow over your body with the movement of the water. If you slow your breathing and listen, you can hear the crackling of the kelp and when you look up, you see a mesmerizing scene of sun rays trickling down through the tall trees. A whole new world to explore and get lost in.
The importance of kelp forests
These are some of the world’s most diverse ecosystems and are extremely rich in marine life and biodiversity, containing about 14 000 different species. They function as nurseries for various fish species and provide shelter for numerous animals from predators and storms. They are home to many different species of fish, marine animals, invertebrates, urchins, rock lobsters, sea otters and the Cape Fur Seals. They purify the water since kelp thrives on the waste products produced by its inhabitants.
A cuttlefish hiding in the kelp forest
These forests are incredibly important as they help preserve the health of the oceans. Kelp can grow as fast as one to two feet a day which means that they can absorb huge amounts of carbon through photosynthesis. Kelp forests play a vital part in reducing carbon emissions as they can capture and sequester carbon faster than land forests. Efforts to restore and enhance kelp and seagrass beds to store more “blue carbon” are increasingly seen as a pivotal tool to help counter the effects of a warming ocean and world.
Wide Range of Uses
Kelp is cut into thin slices and cooked as a pasta substitute
Kelp has a wide range of uses. Many species of seaweed and kelp have wonderful health benefits and are consumed by humans raw or cooked in sushi, sauces and salads. I have tried it as a thinly sliced pasta substitute and it tasted great. There are many suggested benefits of kelp like aiding in digestion and promoting healthy nails and blood vessels, it may also help with diabetes and weight management. Though these benefits have not yet been proven through research.
Different species of edible seaweeds found on the South African coast
There are a growing number of pre-packaged seaweed and kelp products available in stores. It also forms part of many products such as pharmaceuticals, toothpaste, shampoos and puddings. It’s widely used to stabilize and improve the texture of foods.
The hollow float of kelp can be used to cook food on a fire
Kelp reduces coastal erosion by serving as a buffer for storm-driven waves and surges. Shallow kelp beds protect the shoreline by keeping the sediment in place and preventing it from being swept away.
Distribution and recent spread
South Africa’s swaying underwater forest extends for about 1 000km more or less parallel to the shoreline from the west coast to the southern coast where it reaches De Hoop Nature Reserve. It extends about 100m offshore.
The main algal species in South Africa are Ecklonia maxima and Laminaria pallida
Laminaria pallida prefer to stay in regions where there are rocky shores, this allows the laminaria to attach. Due to the height of the Laminaria, they provide protection for creatures that the open ocean does not often give. Invertebrates are just one of the organisms that live among the algae. Sea snails and other invertebrates feed on the blades (leaves) of the laminaria. Other organisms, such as sea urchins, feed on the holdfasts, which can kill the algae.
Ecklonia maxima is a dominant west coast species that forms extensive kelp beds from just north of Luderitz in Namibia to Papenkuilsfontein about 10 km west of Cape Agulhas, and very recently recorded also from Koppie Alleen, De Hoop, indicating a recent range extension of some 70 km.
The kelp anchors itself by attaching itself to a rock or other kelp. The hollow stipe and gas-filled float enable the kelp to float near or on the water surface enabling it to soak up more sunlight.
The southeasterly wind feeds the Cape Peninsula in summer by bringing upwellings of nutrient-rich waters from the cold depths of the ocean, fertilising the kelp, and allowing them to grow into giant forests. Wave action and water movement are also vital for kelp growth because they stir up the nutrients and enable the plants to absorb these nutrients through their fronds.
A Pyjama shark or Striped catshark swimming over the lower bottom growing algae
Enjoy and Preserve
Kelp forests are truly wonderful to explore and I encourage anyone who gets the chance to dive in these mystical forests to grab the opportunity. Take people with you to appreciate and fall in love with the serenity these places offer.
We Protect what we Love. Join the movement!
by Madelein Wolfaardt