The Marine Life of Maputaland

An exploration of the coral reefs of Sodwana Bay -
South Africa's spectacular marine park

Wolfgang E. Grulke
September 1997

The coastal waters around South Africa teem with a vast variety of life. Washed by the southern extremities of the Atlantic and Indian Oceans, these coasts harbour a unique diversity of marine life: from popular game fish to some of the most dramatic shark experiences; from gastropods (including some of the rarest cowries in the world) to nudibranchs (with hundreds of yet unnamed species). In the west are the cold kelp forests around Cape Town where the Benguella current sweeps icy water up into the Atlantic Ocean from the Antarctic. On South Africa's most northerly east coast are the tropical Indian Ocean reefs off northern Maputaland, an area fabled (on land) for its hundreds of bird species and dramatic large mammals such as the white and black rhinos. Off the east coast of southern Africa lie many islands that are home to spectacular marine habitats. Together they form the southernmost reaches of the tropical West Indian Ocean. These islands include the Comoros islands (the only known Western Indian home of the dragon moray - see pictures #534 and #535), Aldabra (the world's largest raised coral atoll and a World Heritage Site), Reunion, Mauritius and Madagascar.

This article focuses primarily on one of these areas - the tropical coral reefs off the South Africa's Maputaland coast at Sodwana Bay.

While the reefs of Sodwana along Maputaland's remote coastline are fabled for some of the larger marine denizens such as whale sharks, turtles, ragged-tooth sharks (see pictures #548 to #551) and (for the fisherman) marlin and sailfish, it is in the detail that the real beauty of these reefs lies. The Sodwana reefs are home to an astonishing variety of marine creatures - a biodiversity that compares with the best in the world, and much of it yet to be discovered.

This may be surprising when you consider the pressure that a large number of divers puts on these reefs - this is the most-dived location in South Africa. Yet these reefs continue to surprise. During one seven-day period in July we photographed a new species of ghost pipefish (see picture #572) and three new species of nudibranch, all unknown to science, right on Two-Mile reef at the centre of diving at Sodwana - such is the diversity of life here. Sodwana really deserves more respect that is often accorded it. It is one of the world's great dive sites - dive it with someone who knows the area and respects its inhabitants - it will be an experience to treasure.

Across the Makatini Flats

The rough car ride across the unpredictable dirt roads of the Makatini Flats is the last jarring obstacle to the beauty of the Maputaland coast. Often fabled to be far worse than they actually are, these roads wind somewhat irrationally across the wide dry coastal plain to the high coastal sand dunes and dune forests.

The coastal dunes are so dominant that it's easy to forget that they are just travelling ridges of sand temporarily halted by the grip of vegetation. Along the base of these tall rugged dunes stretch mile upon mile of desolate sandy beaches - transversed only by the occasional turtle track or buck spoor - or, at holiday periods, by the tyre tracks of scores of 4-wheel-drive vehicles. These varied tracks are strange companions in the hot Maputaland sand - sand that can reach a daunting temperature of around 45 degrees centigrade at midday in summer.

The coastline is typified by long arching bays and some Pleistocene sandstone platforms, some exposed only at low tide. The rock pools created by the violent wave action typical of this coast create unique micro-worlds for a variety of marine life. At low tide we have found rays and moray eels trapped in small pools that are also home to a large variety of nudibranchs and juvenile reef fish.

Along the Maputaland coast the south-flowing Agulhas current hits the continental shelf only a few kilometres off-shore, providing deep water very close to land, and conditions very conducive to large pelagic fish, some of which (notably marlin and sailfish) are abundant at various times of the year making this one of the most popular areas in SA for serious sport fishing.

The World's most southerly coral reefs?

Much of the popular literature claims that Sodwana has "the most southerly coral reefs in the world"! Almost every article written in the past ten years refers to this fictional distinction. The reefs at Sodwana are not even South Africa's most southerly, that distinction belonging to Raggie Reef just south of Leadman's Shoal, near St. Lucia. Leadman's shoal is located at about 28 degrees south. The world's most southerly coral reefs are in fact located at almost 32 degrees south, at Lord Howe Island off the New South Wales coast of Australia.

Coral reefs exist only in a very narrow band of geographic circumstance. They require the water temperature to be warm (and to vary no more than between 16 and 36 degrees centigrade), clean (no rivers carrying silt and other detritus into the sea) and to be bathed in consistent strong sunlight. The Maputaland reefs certainly fulfil those criteria and the reefs off this coast display a high biodiversity that attracts more than 60 000 divers per year.

There are no true coral reefs (i.e. reefs created by coral growth - the reefs here are rocky reefs) along the Maputaland coast, although solitary corals thrive on offshore rocky reefs and in some sheltered pools all along the coast, in the constant favourable conditions. The constant rough wave action and the lack of really sheltered areas along the Maputaland coast most likely explains the absence of any true fringing reefs. The southernmost fringing reefs on the African coast occur in southern Mozambique just south of Inhaca island.

The Reefs and Marine Life of Sodwana Bay

Even though these are not the classical 'barrier reefs' Sodwana has offered us some of the most spectacular marine life experiences anywhere. Though there are many less-known and less-visited reefs, the most popular, and most easily accessible, reef in the Sodwana area is Two-Mile Reef where many South African divers have their first sea dive. The pressure on the marine life of this reef is enormous but it is a large and varied environment that delivers excellent dive experiences time after time. Further from the launch site at Jesser Point are Five-Mile, Seven-Mile and Nine-Mile Reefs, all offering highly unique environments. Accessibility depends completely on sea conditions at the time and expert local skippers decisions are best adhered to - they know the sea conditions in these parts intimately.

The magnificent coral tree at Nine-Mile Reef (see slides #540 and #541) should be protected as a national monument! This spectacular hard coral Tubastrea micrantha is one of the most profound features of the Maputaland reefs and its marine inhabitants are always an intense pleasure to observe. An entire dive can be spent in the proximity of this magnificent coral head - always taking extreme care not to touch it. My greatest fear is that one reckless diver will destroy hundred of years of growth in one capricious moment. Look inside the coral head - in between the complex branching corals. Here you will see a large number of dark grey mature domino damsels (it's only when they are immature that they display the characteristic 'domino' markings!), several species of crab and many smaller coral fish. Just like London's Piccadilly, if you stay here for long enough the (marine) world will pass by you! In addition to schools of lemonfish, Moorish idols and snappers, we have frequently seen cuttlefish swimming casually by in an emotional display of changing colours. In the walls of Nine-Mile Reef there are many overhangs and caves where you will encounter the occasional large moray. There is one particularly bold individual that has swum alongside us, completely in the open - unusual behaviour for a moray during daytime hours.

A much closer reef, Quarter-Mile, is where in the summer months pregnant raggedtooth sharks can be viewed in intimate close-up. This shallow and somewhat bland reef is also a favourite hunting-ground for large rays and guitarfish.

Some of the shallower reefs, such as Stringer reef, appear to be nurseries for the larger reefs. Many juveniles of the typical Indo-Pacific reef fish are found here. Also, the paperfish Taenianotus triacanthus is to be found here. They tend to keep close to their favourite sites which makes these cryptic relatives of the scorpionfish somewhat easier to find. In the sponge-covered walls you will find blennies peering out at you from their holes in the wall as you pass. There are several species of cleaner shrimp and cleaner wrasse busy caring for their customers. A large variety of rockcods are usually found queuing for their services. There are several magnificent anemones wedged in cracks in the rock with their attendant clown fish. Above the reef a dizzying variety of sea goldies and wrasse feed constantly.

Sodwana is in fact an excellent site to observe a large variety of rockcods. Here you will find ....pics

Sponge reef is an interesting deep reef for those interested in the smaller invertebrates that make their home amongst the wide variety of sponge species on this reef. It is here too that you can occasionally see the rare map puffer - one of the largest of the pufferfish whose beautifully patterned body is usually more than half a metre in length.

Through the rolling Indian Ocean Breakers!

To get to this prolific marine life off Maputaland can be rough! This is no Caribbean or Maldives. Because of the lack of fringing reefs the trip out to your dive site usually starts with a boat ride through rough rolling waves. The coast is directly exposed to the best and worst the Indian Ocean can throw at it. The occasional high swell conditions may be caused by tropical cyclones in the Mozambique channel or propagated by storms thousands of kilometres out to sea. To some 'fair weather divers' whose experience is limited to the relative comfort of some of the world's more glamorous dive sites this is often somewhat of a surprise. Personally I find each boat ride through the breakers an exciting and exhilarating start to the dive experience. It's as much a part of diving at Sodwana as the time spent underwater. The ride back to shore is usually much easier and after a dive one can often frolic with dolphins or the occasional whale shark - the world's largest fish.

The area between Mbibi and Cape Vidal is one of transition between the true tropical marine fauna to the north and the subtropical fauna, typified by the southern Natal and Transkei coasts. Northern Maputaland is the only area of South Africa to have a truly tropical marine environment, and is populated large by typical Indo-Pacific marine life. The local amaThonga people use the marine resources extensively, including fish, mussels, red bait, even some species of nudibranch, limpets, sea urchins and molluscs.

In terms of marine fishes, Margaret Smith (wife of the late JLB Smith - who first identified a living coelacanth) commented that the Maputaland coast is unlike any other in the world. It is the only location that has tropical Indo-Pacific fishes, Southern Ocean fishes, European fishes that reach there via the African west coast, circumglobal fishes, deep sea fishes and endemic South African species.

Five species of sea turtle occur along this coast (the hawksbill, green, olive ridley, loggerhead and leatherback turtles). In an emotional nesting ritual the turtles drag themselves up on the beach at night to lay their eggs. At certain times of the year tourists are able to share the experience with almost with perfect planning - courtesy of the Parks Board who have been managing a turtle protection and research programme since the early 1960's. The entire marine resources around Sodwana form part of the Sodwana Bay National Park that was established as a marine reserve in 1950!

Some thoughts on Sodwana - 'the two of us'

Sodwana does not have the spectacular sea walls or the water clarity of the Red Sea. It does not have the romance of the Seychelles or Maldives or South Sea islands. But, take the time to get to know the spectacular detail of the coral reef life on this profusion of reefs and you will be hooked for life. That's why we keep coming back - although we tend to time our visits to avoid the peak holiday periods, and weekends if we can. There's nothing like a few days in mid-week, in Southern Africa's mid-winter from May to August, when you can be almost alone on the reefs. Alone, that is, with some of the greatest profusion of marine life on the planet. It brings to mind the meaning of the word Sodwana - 'just the two of us'.

Slide captions

Slide numbers refer to those on the copyright notice at the bottom of each slide. The numbers in brackets refer to old numbers that may be found on other parts of the slide frame.

Note: the term 'rockcod' can be replaced by 'grouper' in many parts of the world.

#532 (was 105)

Honeycom moray eel Gymnothorax favagineus in its lair

#533 (was red 23)

Geometric moray eel Siderea grisea in its lair

#534 (was green 104) and #535

First ever photographs in western Indian Ocean of dragon moray eel Muraena pardalis

#536 (was 421)

The magnificent coral rockcod Cephalopholis miniata

#537 (was 438)

This rockcod Epinephelus fasciatus appears quite startled at the attention of the camera.

#538

Unidentified rockcod with cleaner wrasse.

#539

The rare striped-fin rockcod Epinephelus posteli with orange encrusting sponge. This is a very rare rockcod species found only in Maputaland, Mozambique and Madagascar. It is easily identified by its fleshy protuberances that give it the appearance of a vampire. Its bright red colour is not so easily apparent under water.

#540 (was 169)

Divers silhouetted while photographing coral head Tubastrea micrantha at 9-Mile Reef

#541 (was 420)

Intense fish life in and around 9-Mile Reef coral head Tubastrea micrantha. In between the complex branching corals can be seen a large number of dark grey mature domino damsels (it's only when they are immature that they display the characteristic 'domino' markings!)

#542 (was 129)

A school of coachmen Heniochus acuminatus over coral heads on 9-Mile Reef.

#543 (was 419)

The spanish dancer nudibranch Hexabranchus sanguineus found during the day in a cave the shallow Jesser Point rock pools at Sodwana Bay.

#544 (was 411)

An unidentified species of Glossodoris sp. Nudibranch.

#545 (was 156)

The rare Christmas parrotfish Calotomus carolinus. Note its unusually irregular teeth plates!

#546 (was 149)

An amber parrotfish Scarus rubroviolaceus in its terminal male phase, note the unusually long trailing tail fins.

#547

Th three-spot angelfish Apolemichthys trimaculatus showing off its beautiful blue lips.

#548

Large female pregnant ragged-tooth shark Carcharias taurus (named 'Raggie' for short) buzzing divers at Quarter-Mile Reef. (Suggest you crop really tight around shark and single diver)

#549

Large female pregnant ragged-tooth shark Carcharias taurus (natural light)

#550

"Raggies in the Mist" A group of large female pregnant ragged-tooth sharks Carcharias taurus congregating on a sandy bottom.

#551

Large female pregnant ragged-tooth shark Carcharias taurus displaying its ominous teeth. (Crop tight around shark)

#552

The beautiful blue-spotted ribbon-tail ray

#553

The beautiful blue-spotted ribbon-tail ray

#554

Graphic image "Anemone fingers"

#555

Graphic image "Anemone mouth"

#556

Close up of the brilliant sea star Protoreaster lincki

#557

Close up of one arm of the brilliant sea star Protoreaster lincki showing tube feet extended.

#558

Beautiful graphic image of the nosestripe anemonefish Amhiprion akallopisos in its host anemone.

#559

Black wire coral tendril with bright yellow polyps extended.

#560

Graphic image of the back of the crown-of-thorns sea star Acanthaster planci

#561

A colourful group of colonial ascidians.

#562

A rare luminescent sea urchin Astropiga radiata or Echinothrix calamaris???

#563

A textile cone hunting the reef at night.

#564

The crown squirrelfish Sargocentron diadema

#565

A school of crescent-tailed bigeye Priacanthus hamrur

#566

A close-up of the crescent-tailed bigeye Priacanthus hamrur

#567

A juvenile emperor angelfish Pomacanthus imperator in the rock-pools at Mbibi.

#568

A bright orange-banded brittle star wrapped around a deep orange sponge.

#569

The sea goldie Anthias squamipinnis - the top fish is in the process of transforming into a dominant male.

#570

A juvenile rock-mover wrasse Novaculichthys taeniourus. These juvenile fish are very seldom seen and often mistaken for a drifting bit of seaweed.

#571

A first photograph of a new species of ghost pipefish Solenostomus sp., a relative of the sea horse, photographed at Sodwana Bay. Phil Heemstra, curator of Marine Fishes at the JLB Smith Institute of Ichthyology comments: "This Solenostomus species is most interesting as it does not appear to be any of the two species known from the western Indian Ocean. In fact it does not appear to be any of the three species known world-wide. The combination of snout depth, caudal peduncle depth/length and configuration of caudal fin does not match any of the three new species. It is probably a new species."