Year in the Wild Blog

Seahorses and sewerage…the delicate balance of Knysna estuary

Knsyna is famous not only for its indigenous forests, but also its estuary, which is the biggest – and most ecologically important – in the country. According to several scientific studies relating to birds, fish and plants, it ranks higher than all other estuaries in terms of its natural importance.

Incredibly, according to research supplied by SANParks, it hosts 43% of all of South Africa’s estuarine natural life – all the more incredible, because the Knysna estuary is just 1 800 hectares in size,  and is home to some rare, endemic species that aren’t found anywhere else in the world – including the Knysna sea horse.

This sea horse is found here as well as in the nearby Swartvlei. It is one of six seahorses found in SA, and is the only species in the world that is on the IUCN’s endangered list – largely because of encroachment on its natural habitat by urban and industrial development. Adults grow to a maximum of seven cm long, and somewhat bizarrely, it’s the males which give birth to the tiny young, carrying them in a special pouch until they are ready to be released.

The estuary is also very important to South Africa’s fishing industry – it contributes 22% of the nation’s estuarine value to commercial fishing, and is the country’s most important nursery to line fish like red stumpnose, cob, white steenbras and spotted grunter. As a source of food to local people, several hundred people rely on it for putting foods on their plate every night.

Then of course, there are the tourists who flock here during summer and school holidays. According to marine ranger Shamley Titus – who took me round the estuary this morning on the SANParks patrol boat – there can be as many as 500 boats on the estuary at any one time during summer. “That’s a lot of boats for what is quite a small area.”

Shamley took me down to the famous “heads”, where the waters of the estuary empty into the ocean. In times past, these iconic rock promontories have claimed many a yacht and ship, as the vessels need to pass through what is a relatively narrow gap to escape the rough ocean, and find sanctuary in the calm waters of the lagoon.

Shamley told me how the lagoon is visited by several kinds of sharks, especially ragged tooth sharks, but also whales, especially southern-rights.

But the Knysna estuary is heavily developed – houses, restuarants and marinas all crowd the sensitive marsh areas, which are so important for breeding fish and birds. And of course, there’s Thesen Island, which is a serious eye-sore, built right in the middle of the lagoon. However, the development is now under strict control, and SANParks have a tough job trying to conserve one of South Africa’s most precious waterways.

Recently, the town’s sewerage works sprung a leak, and thousands of liters of contaminated water was allowed to pour into the estuary. The eco-system  took a hammering as e-coli levels rocketed. The water works have since been upgraded, and this sort of thing shouldn’t happen again, but who knows…it’s just one example of the challenges involved in managing a national park which lies in one of South Africa’s most popular tourist towns.

The Knysna "heads"...the entry to the estuary.

 

The estuary...a highly utilised holiday destination, yet - ecologically - it's ranked as the country's most important.

 

The view up the lagoon from the "heads"...

 

Fish eagle! The resident Knysna specimens are adept at catching sea fish out of the salt-water estuary

 

Can you think of a more majestic animal than a fish eagle in flight? Ja, sure we can...leopard and elephant...both of which, by the way, also survive in the forests of Knysna. Long may that last.

 

The fish eagle we saw was divebombed by some seagulls...who clearly don't like competition!

 

Great cormorant...

A tern perching on a pole in the lagoon

A grey heron looking for breakfast...the estuary is a good birding-site, but pollution and human intrusion into their habitat is inevitable.

 

Soaring fish eagle...

 

Little egret...

 

Shamley Titus on the SANParks patrol boat in the Knysna estuary

Lekker by die see...a local woman casts a line for her dinner.

 

The Knysna sea horse...I photographed these in the sea tank at the Garden Route NP's head office on Thesen Island

 

The male sea horse gives birth to plenty of young...but most die. This baby is dead...thanks to SANParks receptionist Geneve Lupacchini for loaning me her fingertips for the photo!

 

 

The beaches and coastline here are some of the most photogenic in the country...this one is near Buffel's Bay, in the Goukamma Nature Reserve, a CapeNature area.

 

The entrance to the town at Buffel's Bay...to the west of Knysna

Thanks again to my sponsors for making it all possible. CapeNature, South African National Parks, Ezemvelo KZN Wildlife, Eastern Cape Parks, iSimangaliso Wetland ParkFord, Total, Evosat, Conqueror TrailersVodacom, Digicape, Lacie, Frontrunner, Safari Centre Cape TownK-Way, EeziAwnNational Luna, Nokia , Goodyear, Global Fleet Sales, HetznerClearstream Consulting and Escape Gear.

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