Sharks Knysna Lagoon
Mireille Duhon
We had an interesting visitor into the Knysna lagoon recently, a whale shark Rhincodon typus. Whale sharks are very large, slow-moving filter-feeders which have a circumpolar distribution through all tropical and warm water, between 30N and 35S. The distribution of whale sharks is temperature dependent, and they are rarely sighted in areas with a surface water temperature less than 21C. This is probably why the whale shark ended up in Knysna lagoon, it was searching for warmer water. Whale sharks have a unique colouration of white or yellow spots, and horizontal and vertical stripes on a grey-blue upper surface. The underside is white or yellowish in colour. The largest whale shark ever recorded was 20m in length and weighed 42 tons! Most whale sharks are a smaller, with 12m being a more average length, with males reaching maturity between 7-9m while females are sexually mature at roughly 9m in length. The whale shark that stranded in Knysna was roughly 4m and at this size would have been an immature individual. As with other shark species, male whale sharks have claspers while females do not. Little is known about the reproduction of whale sharks, but a mature female caught in Taiwan had roughly 300 young in her uterus at varying stages of development! Size at birth is between 55 and 64cm, although a free-swimming individual of 46cm has been recorded. Whale sharks are, despite their large size, relatively harmless. They do not act aggressively towards humans when approached, and there are many ecotourism ventures focused on whale shark interactions. Whale sharks are listed as Endangered according to IUCN, with a decreasing population. Vessel strikes, bycatch by fisheries, and focussed fisheries for meat and fins, even tourism if incorrectly managed all play a part in a drop in whale shark numbers.
The Knysna lagoon, or estuary, is connected to the Indian Ocean via the Knysna Heads. Catches include White Steenbas, White Mussel Cracker, Garrick or Leervis, Cob or Kabeljou, Grunter, Elf or Shad, and a variety of different skates. Recommended bait includes bloodworms, moonshine, prawns (Knysna has both pink/sand and mud prawns), cuttlefish, mullet, and pencil bait. Many of these can be found fresh, in the lagoon.
Groenvlei, also called Lake Pleasant, is situated on your left between Knysna and Sedgefield, on the N2, coming from Knysna. It is one of a few natural lakes in South Africa with bass. It is not clear how the Largemouth bass ended up in the lake, but it is a favored fishing spot with bass fishing lovers.
The lake, managed by Cape Nature, is only about 4km wide and 1km long, the average depth is between 3.4 to 5.2 meters deep, with exceptional holes as deep as 7 meters. It is surrounded by grass and reeds, with random grass patches and shallow islands inside the lake. It is in these grass beds that Largemouth Bass, Tilapia, Blue Gill, and Carp can be found.
Shore angling is very limited due to the reeds that surround the vlei, but good catches have been made from the jetties and boats. Only electric motors are allowed on the lake, outboard motors must always be lifted clear of the water.
The Sedgefield train bridge is just north of the N2 at Swartvlei estuary. A well-liked spot by local fishermen, catches reported here include Cob, Grunter, Garrick, Stompneus, Mallet & Tilapia. The best bait for this area is sardines, prawns, cuttlefish & mullet (as live bait).
With the success of local fishermen in bagging some of the most prized species in the estuaries and offshore, the area is fast becoming a popular fly-fishing destination. Listed species caught include the Spotted Grunter, Garrick (Leervis), Giant Kob, Bonito and Shad.
Popular spots are the Knysna lagoon (around Leisure Island), and Sedgefield and Goukamma lagoons when the mouths are open. When the mouths are closed (even at high tide) there is no tidal movement and the feeding banks and drop-offs are too deep to fish.
The Southern Cape coast offers some of the best rock and surf fishing in the country. In the Knysna area popular beaches are Noetzie, Coney Glen, the Heads, Brenton-on-Sea, Buffalo Bay, Goukamma and Sedgefield, Swartvlei & Myoli beaches.
Swartvlei and Myoli are excellent beach fishing spots and Cape stumpnose, Blacktail (yes from the sand on Myoli), Shad and late afternoons, towards nighttime, Cob. Best bait to use especially for Cob is fresh cuttlefish. This bait is also highly preferred by non-edible species like the smooth-hound shark, the spotted gulley shark, blue rays, duckbill rays and ragged-tooth sharks. If caught, please remove the hook gently and place them back into the water. The area is popular for Kob, Garrick, Elf, Belman, Grunter, Bronze Bream, White Steenbras, White Musselcracker and Galjoen. Smaller species like Blacktail, Karanteen (Strepie) and Cape Stumpnose can also be found.
c80f0f1006