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Discovery of a viable population of Coelacanths (Latimeria
Chalumnae Smith, 1939) at Sodwana Bay, South Africa
Pieter Venter, Peter Timm, Gilbert Gunn, Etienne le Roux, Christo
Serfontein, Pieter Smith, Erna Smith, Martin
Bensch, Dennis Harding and Phillip Heemstra*
Following many requests to Science in Africa for more
detailed information on the coelacanth dicovery, Dr Heemstra provides the
following in-depth look and takes a look to the future of the Sodwana Bay
coelacanth..
“Other scientists are more cautious, but I am optimistic that there is a coelacanth population off the African
mainland, perhaps off central Mozambique, northern Natal or the Transkei. New submersible technology and
renewed access will hopefully answer these intriguing questions in the near future.”
– Mike Bruton1, March 1992
 On October 28th 2000, Pieter Venter, Peter Timm and Etienne le Roux were near the end of an eight-minute
initial exploratory dive to 104 m in the Jesser Canyon at Sodwana Bay, in the St Lucia Marine Reserve on the north
coast of South Africa (Fig. 1). As they were about to ascend, the first author (PV) saw a large, pinkish eye
reflecting the beam of his underwater light. He approached, and underneath an overhang he saw a fish about two
metres long. After a few seconds he realised, much to his surprise, that the pale blue fish with its unusual lobed
fins was a coelacanth. He summoned Peter Timm, and they saw two more coelacanths. Timm, who was
concerned with their ascent, was unable to confirm the sighting. But later, on the surface, Venter convinced him
that these fish were coelacanths, and the divers then decided to arrange an expedition to do additional dives with
a video camera to record the presence of this species.
On November 27th a dive was planned to 115 m with a 15 minute bottom time; the divers were Pieter
Venter,
Gilbert Gunn and cameramen Christo Serfontein and Dennis Harding. The support divers were Pieter Smith, Martin
Bensch and Etienne le Roux. After searching caves along the wall of the canyon for 12 minutes, three coelacanths
were sighted and filmed with the video camera (Figs 2 & 3) at a depth of 108 m. The largest fish was between
1.6 and 1.8 m in length, and the other two coelacanths were about 1.5 and 1.0 m. The water temperatures at
the bottom for the October and November dives were 17C and 18C respectively.
 After 15 minutes, the divers started their ascent as planned, but at a depth of 70 to 60 m, some problem
involving Harding and Serfontein resulted in their uncontrolled ascent to the surface. Harding lost consciousness
soon after surfacing and was rushed to the beach. Efforts to resuscitate him were unsuccessful. Serfontein was
also unconscious when he reached the surface, but with the assistance of Pieter Smith, he regained
consciousness and was able to descend immediately to a depth of 32 m to resume his decompression schedule. After 134 minutes in the sea,
Serfontein was taken to the beach, administered oxygen and transported to Richards
Bay for 6 hours of treatment in a decompression chamber.
DISCUSSION
The fossil record of coelacanths,[2] comprising some 120 species arrayed in about 47 genera and three or four
families, extends from the Middle Devonian (380 million years ago) to the end of the Cretaceous (70 million years
ago), when the coelacanths were thought to have died out, along with the dinosaurs and many other fossil
groups. The first fossil coelacanth was described in 1836, and the group is now well known in the literature on
fossil fishes. The genus name Coelacanthus (meaning “hollow spine”) refers to the hollow neural and haemal
spines of the vertebrae that connect to the tubular pterygiophores supporting the dorsal and ventral caudal fin
rays [3]. Three extinct species are known from South African fossils, one in KwaZulu-Natal, one from the Free State,
and one from Grahamstown [2,4]. Most fossil coelacanths are known from marine deposits, but a few were adapted
to freshwater. They attained their maximum diversity (in number of species) in the Triassic Period (some 200
million years ago), but disappeared from the fossil record at the end of the
Cretaceous [2]. Consequently, the
zoological world was astounded when a living coelacanth (Latimeria chalumnae
Smith, 1939) was discovered off
the Chalumna River near East London[5] in December 1938. Coelacanths have changed little over the past 380
million years. The skeleton of Macropoma mantelli, which is known from the Upper Cretaceous, is virtually identical
to that of the living coelacanth and differs little from the skeleton of most Devonian coelacanths
[2].
Although only a single specimen of Latimeria chalumnae has been caught off South Africa, the discovery of this
first specimen did much to put South Africa and J.L.B. Smith on the ichthyological map of the world. Thanks to
the efforts of J.L.B. and Margaret Smith, Marjorie Courtenay-Latimer, French anatomists, and more recently, Hans
Fricke’s observations and films of coelacanths in their natural habitat at Grand Comoro, we have learned much
about this fascinating fish [6-10]. Since 1952, when the “home” of the coelacanth was discovered in the Comoros,
more than 180 coelacanths have been caught with hook and line in depths of 35– 600 m on the steep volcanic
slopes of Grand Comoro and Anjouan Island [8,9]. A gravid coelacanth was trawled off the central coast of
Mozambique [10] and a specimen was also caught in a shark net near Toliara on the southwest coast of Madagascar
[11]. The recently discovered coelacanths near Manado at the northern end of Sulawesi, Indonesia seem to be a
separate species [12].
In May 1991, a project organised by Prof M.N. Bruton (then Director of the J.L.B. Smith Institute of
Ichthyology) brought Prof Hans Fricke and his submersible JAGO to South Africa to look for coelacanths and
survey the faunal diversity in depths of 50-400 m along the coast of the Eastern Cape Province Fifteen dives
totalling 23h 45 min were carried out at depths of 35-110 m in the Tsitsikamma National Park on the Eastern Cape
coast, and 8 dives totalling 23h 30 min were done to depths of 370 m on the continental shelf and slope off the
Chalumna River Mouth. No coelacanths were sighted during the survey, nor were large caves
seen off the
Chalumna River, as the friable sandstone terraces of the slope in this region is not conducive to formation of
caves; in several places, the roofs of overhangs were seen to have collapsed after being eroded too far.
The continental shelf off the coast of northern KwaZulu-Natal is narrow (approximately 3 km wide, with a shelf
break at –45 to –70 m, and along this coast there are some 13 canyons that begin at depths of –30 to –40 m
within 1 or 2 km of shore and plunge to depths of –650 m within 8 km of
shore.[13] The beachrock/aeolianite walls
of the Jesser Canyon where the Sodwana coelacanths were sighted are evidently more sturdy and suited to cave
formation than the slope sedimentary rock off the Chalumna River. The sheltered habitat of this V-shaped canyon
is also less exposed to the strong Agulhas Current than the lower relief slope off the Eastern Cape Province. The
similar canyons along the coast of northern KwaZulu-Natal and Mozambique are also likely to be suitable habitat
for coelacanths.
Because of the difficulty in sampling and observing fishes in rough bottom habitats below depths of 50 m, the
fish fauna of these habitats is poorly known. This discovery of a small population of coelacanths at a depth of 104
m at Sodwana Bay, a popular dive site in South Africa, emphasises how little we know about life in the oceans and
the need for further exploration and survey work to assess the fish diversity of southern Africa and the Western
Indian Ocean.
The sighting of juvenile (1 m) and adult (1.6 to 1.8 m) coelacanths on two separate dives implies a viable
population of Latimeria chalumnae in a marine protected area (St Lucia Marine Reserve), and this is good news for
the conservation of this apparently endangered species. The Minister of the Department of Environmental Affairs
and Tourism has acted swiftly to legislate for the protection of the population, and a management plan is being
prepared by the KwaZulu-Natal Nature Conservation Service in collaboration with the Marine and Coastal
Management division of the Department of Environmental Affairs and Tourism.
We express our condolences to family and friends of our fellow diver, Mr Dennis Harding. We are grateful to Mr
André Slade of Inner Space Developments, for the use of his underwater video equipment. We thank Robin
Stobbs. M.N. Bruton and Eric Anderson for their useful comments on the manuscript.
What Now?
Expeditions are being planned to study our population of the coelacanth. Phil Heemstra is trying to organise for the
submersible Jago and Hans Fricke, famous for taking the first photographs of the coelacanth living in its natural
habitat in the Comoros, to visit South Africa as soon as possible. Fortunately, the population lives within a
protected area, and with the announcement of the discovery, the government have promised to enact legislation
to protect these special fish from disturbance. This legislation has now been enacted and it is now illegal to
disturb, attempt to catch, locate or film the fish without a permit issued for that specific purpose. In an
interesting development, Africam who brought us Shark Cam, Wreck Cam and Whale Cam to the Internet are
thinking hard about the engineering challenges and possible benefits to science and the general public and the
possible negative impacts on the coelacanths of installing an underwater "Coelacanth Cam" to film them and send
this imagery to the Internet for the world to view.
Their habitat is - perhaps fortunately - far too deep for regular SCUBA diving, as at those depths, the oxygen in
the air becomes deadly. To see such a renowned fish is a great temptation to all, but if scores of divers attempt
to see this remarkable species, we don't know what effect it will have on them. Another consideration is the
health of the people trying to see them - already, there has been the tragic loss of a life, and if other dives are
conducted, more deaths may result, particularly if done by inexperienced divers. Diving to these depths cannot be
taken lightly; it takes a lot of training, special gas mixtures and a lot of equipment and surface backup to safely
undertake. The nearest recompression chamber is in Richard's Bay; the deeper the dive the greater the risk of
decompression related problems, which can result in death or permanent disability. The great temptation to go and
see these fish must be resisted as far as possible. As more information on our population becomes available, we
will bring it to you here! The question in my mind at least is how far south do they extend? Perhaps others are
lurking in deep water further south along our coastline.
For Further Information a Reference list is
provided below:
1. Bruton M.N. (1992). The mingled destinies of coelacanths and men. ICHTHOS, Newsletter Soc. Friends
J.L.B.Smith Inst. Ichthyol. 33, 1-3.
2. Forey P. (1998). History of the Coelacanth Fishes. Chapman & Hall.
3. Agassiz, L. (1836). Recherches sur les poissons fossiles. Neuchâtel, Switzerland, Vol. 2, Part 2, 1-136.
4. Anderson M.E., Long J.A., Evans F.J., Almond J.E., Theron J.N. and Bender P.A. (1999). Biogeographic affinities
of Middle and Late Devonian
fishes of South Africa. Rec. W. Austr. Mus. Suppl. 57, 157-168.
5. Smith J.L.B. (1939). A surviving fish of the Order Actinistia. Trans. Roy. Soc. S. Afr. 27(1), 47-50.
6. Fricke H., Schauer J., Hissmann K., Kasang L. and Plante R. (1991). Coelacanth
Latimeria chalumnae
aggregates in caves: first observations in
the resting h[ab]itat and social behaviour. Envir. Biol. Fishes 30, 281-285.
7. Fricke H.[W]. and Hissman K. (1994). Home range and migrations of the living coelacanth
Latimeria chalumnae. Mar. Biol. 120, 171-180.
8. Bruton M.N. and Stobbs R.E. (1991). The ecology and conservation of the coelacanth
Latimeria chalumnae. Envir. Biol. Fishes 32, 313-339.
9. Stobbs R.E. and Bruton M.N. (1991). The fishery of the Comoros, with comments on its possible impact on
coelacanth survival. Envir. Biol.
Fishes 32, 341-359.
10. Bruton M.N., C[ab]ral A.J.P. and Fricke H.W. (1992). First capture of a coelacanth,
Latimeria chalumnae
(Pisces, Latimeriidae), off
Mozambique. S. Afr. J. Sci. 88, 225-227.
11. Heemstra P.C., Freeman A.L.J., Wong H.Y., Hensley D.A. and Resandratana H.D. (1996). First authentic
capture of a coelacanth, Latimeria chalumnae (Pisces: Latimeriidae), off Madagascar. S. Afr. J. Sci. 92, 150-151.
12. Holder M.T., Erdmann M.V., Wilcox T.P., Caldwell R.L. and Hillis D.M. (1999). Two living species of
coelacanths? Proc. Nat. Acad. Sci. 96,
12616-12620.
13. Ramsay P.J. (1996). Quaternary marine geology of the Sodwana Bay continental shelf, northern
KwaZulu-Natal. Council Geosci. Geol. Survey
S. Afr Bull. 117, 1-85
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