Local Eco Warrior

Louw Claassens
Knysna Seahorses
Seahorse Photo Credit: Dave Harasti

For the past several years, Louw Claassens, the Director of the Knysna Basin Project, has spent a considerable amount of time underwater. She has quite literally immersed herself in the study of the teeny, tiny Knysna seahorse (Hippocampus capensis) – our town’s iconic estuarine species. Her ground breaking research recently earned her a PhD from Rhodes University. Her dissertation covered fascinating aspects of the population ecology, habitat use and behaviour of this rare species within the residential marina of Thesen Island.

Her interest in these incredibly well camouflaged little creatures began after a chance meeting during a field trip with well known local Professor Brian Allanson, founder of the Knysna Basin Project (KBP). At the time, she was studying for a Masters degree in Aquatic Health at the University of Johannesburg. The experience so inspired her that after graduating, she moved to Knysna and shifted her field of study, making the research of the Knysna Estuary’s most celebrated aquatic resident her primary mission.

Knysna seahorses are rare due to their small geographical range. They are found in only three estuaries: Knysna, Swartvlei and Keurbooms. They are unique in that they are the only known true estuarine seahorse species in the world. They are classified by the International Union for the Conservation of Nature (IUCN) as endangered which makes the study and protection of the species critical. Louw’s study of seahorses is also extremely valuable because they serve as an indicator species, which means that they are extremely susceptible to changes in their environment. A flourishing Knysna seahorse population could therefore, be indicative of a healthy Knysna Estuary or vice versa.

Few people are aware of the importance of the health of the Knysna Estuary. It is the most significant in South Africa in terms of species biodiversity and the protection of fauna and flora in the Knysna Estuary alone would ensure that 42% of South Africa’s estuarine biodiversity is conserved.

Claassens feels strongly that a lot more needs to be done to manage our estuary. Which is why her passion and dedication extends far beyond her love of seahorses. She is a passionate conservationist who understands that everything in nature is connected and if the custodians of our local environment want to conserve our precious estuarine fauna and flora, they need to implement holistic management practises. “The research we do will hopefully be used to guide and assists the various management authorities with implementing effective conservation strategies, in order to ensure the sustainable conservation of the Knysna Estuary. The time has come to use scientific research to effectively manage the environment we depend on”, says Claassens.

Looking forward, the KBP will soon be welcoming several honours and masters students and together they will be researching very important aspects of aquatic health. “Included in our studies, says Louw, “is the monitoring of sites within the surrounding localised catchments in an attempt to identify specific pollution sources. You cannot manage what you don’t know – and through continuous and adaptive monitoring, we can provide the insights needed to effectively manage our catchments.”

A serious algal bloom known as Ulva lactuca, has been invading the Knysna estuary in recent years and is evidence that all is not as it should be. Human settlements lead to an excess of nutrients to enter the estuarine bay and it causes havoc on the system. In this case the algal bloom is displacing eelgrass, which is critical habitat for many species. Another project will focus on the study of micro-plastics in our environment. This is a serious concern around the world and scientists are eager to learn about the threats that they pose. Knowledge, after all, is power!

We would just like to say ‘hats off’ to Louw Claassens and all the other dedicated scientists and conservation heroes from the Knysna Basin Project whose work will hopefully help authorities implement sound conservation strategies in the future.