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Paradise Archipelago in East of Indonesia |
The archipelago around Sulawesi and Borneo has been described as an ecological 'hot spot'. East of Indonesia Archipelago have much terrain varied, from walls and fringing reef to caverns, big Green Turtles (Chelonia mydas), whitetip, leopard and nurse sharks, schooling barracudas, napoleon wrasses, cuttle fish, spanish mackerel, jacks and batfishes, and ornamentalreef fishes hang out in record densities and diversity.
If the sea has a heart, it lies somewhere in the dynamic mosaic that is
the Indonesian archipelago. In this biological hot zone, there are more
coral and fish species than anywhere else on Earth. The numbers are
staggering: for instance, Indonesia has 83 species of angelfish and
butterflyfish, while the whole of the Caribbean supports just seven of
each.
This diversity is celebrated in The Sulu-Sulawesi Seas, a new
photo-book by German photo-journalist Jürgen Freund. Part of a
conservation initiative by the World Wide Fund for Nature (WWF), the
book focuses on the area around Sulawesi, Borneo and the southern
Philippines - the epicentre of the hot zone. This is a world where
schools of jacks group into seething tornadoes over reef drop-offs,
where tiny porcelain crabs seek refuge among the swaying tentacles of a
host anemone. Stray from the reefs into a mangrove swamp and you are
just as likely to run into a saltwater crocodile, the mightiest of the
reptiles.
This region, referred to often as the 'coral triangle' or the
'East-Indies Triangle', encompasses three nations and an area of
complex oceanography. All the islands have narrow continental shelves
and many are separated from each other by relatively deep waters.
Surface currents flow permanently eastwards along the north coast of
Sulawesi and southwards along the west coast. To the south of the
island there is a strong east-flowing current during the northeast
monsoon, which is reversed during the southeast monsoon.
Conditions are ideal for reef development and there are fringing reefs
along the shores of most of the smaller islands, and some continuous
stretches running for hundreds of miles along the coastline. It doesn't
take an expert to see that this is a special place: if you were to do a
dive on a Sulawesi reef, then jet off to anywhere in, say, the tropical
western Atlantic, the difference would be immediately noticeable. For
years, photographers have said that the reefs of the Caribbean are like
English gardens compared with the marine jungles of Southeast Asia.
For divers, it's down to the ease of finding certain exotic creatures.
The highly cryptic leaf scorpionfish, for instance, can be found all
over the Indo-Pacific, but in most places no one bothers to look over
areas of exposed coral (their preferred habitat) for suspiciously leafy
objects. When you're in the coral triangle, it's always worthwhile
looking around for semi-disguised creatures. And if you're observant
enough to find one leaf scorpionfish, there are usually others nearby.
Local dive operators are only too aware of the region's super-abundance
of marine species. Log on to any website promoting diving in Borneo or
Sulawesi and you will find phrases along the lines of 'located in the
middle of the ocean's centre for biodiversity' or 'slap-bang in the
middle of the ocean's Eden'. It's a strong selling-point, but can be
misleading in terms of understanding the true nature of this magical
place.
So, why are there so many different corals, fish and invertebrates in
this region? Is it, as the websites suggest, some sort of underwater
Eden? This has certainly been a popular theory, that the seas from Java
to New Guinea represent an underwater 'cradle of evolution' from which
all life in the shallow tropical seas originated. According to this
approach, places such as Sulawesi have an abundance of species because
it has been an evolutionary production line since since an early point
in Earth's history. It's an attractive notion and has an appealing
symmetry, not least because of parallel theories about the emergence of
humans from Africa.
Unfortunately, the 'marine Eden' theory has a wealth of evidence
stacked against it. If it is to be believed, all the coral in the world
must have originated in and around Southeast Asia - but fossil research
on Acropora corals shows that they originated around North Africa,
Spain or even other parts of Europe, but not Indonesia. According to Dr
Brian Rosen, a scientific associate in zoology at London's Natural
History Museum, simple fossil data clearly shows that Southeast Asia
was not a long-term cradle of coral development. 'If you look back 40
million years ago, Europe and the Caribbean were the major centres for
coral reef diversity, and research in progress increasingly suggests
that many reef organisms originated there,' Rosen explained.
So, between about five and seven million years ago, Europe's
reef-building coral died out and the Caribbean's managed to stagger
along, but by then Southeast Asia had become the hot zone. Rosen
maintains that this was not due to any single cataclysmic event, but a
long-term series of events which had made it the most attractive option
for marine life.
'When environmental conditions change, organisms will go extinct if
they cannot cope with the new conditions, stay where they are if they
can cope, or if the change is not too drastic or too quick, they will
gradually migrate into other regions where conditions are more suitable
for them.' Put simply, if life has time to get out, it will do so while
the getting out's good.
Most of the conditions and habitats that are found in present-day
Indonesia also occur in the Caribbean - so why are there such
differences in biodiversity? Dr Rosen - whose study of the issue
amounts to a life's work - points out that if the environments are so
similar today, then there must be long-term historical issues behind
the development of the East Indies triangle.
So, let's look to history. It has been estimated that biodiversity may
have accumulated in this region at the same time that extinctions were
occurring in other parts of the world during the Pleistocene period
(the time in our Earth's history from approximately 1.8 million years
ago until about 10,000 year ago). The region is a labyrinth of
volcanoes and deep basins that survived the Ice Ages, possibly
providing a refuge for numerous species.
At the same time, the massive fluctuations in sea level may have
isolated pockets of reef diversity, allowing evolution to follow
different paths. When the species were reunited as sea levels rose,
they had changed in many subtle - and not so subtle - ways, further
adding to their diversity. The tortuous geography of the area has
helped to create what Dr Rosen describes as a 'dynamic mosaic' which
acts with variations in sea level to create a sort of 'diversity pump'.
Today, the triangle straddles an area in which two great oceans - the
Pacific and the Indian - meet. That species from the two oceans come
together and mix here is beyond contention. It is simply another of
many factors that promoted diversity in the coral triangle. Ask any
diver who has seen the currents ripping through Nusa Tenggara, the
islands south of Sulawesi which include the famous Komodo Marine Park.
It is here that the Pacific flows into the Indian Ocean, a vast
movement of water impeded only by a few volcanic islands, around which
some of the fastest currents on Earth occur.
Diverse as they may be, the reefs of the coral triangle face an
uncertain future. Some 82 per cent of them are estimated to be
threatened by human activities in the recent Reefs at Risk report.
Human populations are over-using the resources in many areas, while
rapid industrialisation and the continuing destruction of the forests
on land are causing massive amounts of sediment and pollution to
accumulate on reefs. The other major factor is global warming, widely
believed to be underlying cause of coral bleaching.
Marine biologist Dr Alexander Mustard is another prominent diver and
underwater photographer who has fallen in love with the coral triangle.
He maintains that the preservation of Indonesia's marine environment is
crucial not just for the region, but for the entire world. 'Anyone who
has dived extensively in Indonesia will have seen the impact of
dynamite fishing,' he said. 'If you're underwater and an explosion
takes place within a few miles, you will literally feel the impact,
despite the fact that dynamite fishing has been illegal in Indonesia
since 1985.
'Even with the increasing population, there is more than enough protein
in the sea to provide for human needs. But instead of harvesting it in
a sustainable manner, they are destroying the very environment that
supports the life. It's like being an orange farmer and, instead of
picking oranges, you chop down the whole tree.'
Yet Jürgen Freund, whose pictures illustrate this article, feels there
is still hope for the coral triangle. 'Some fishing communities now
actively protect their fishing grounds and coral reefs, and others have
mangrove reforestation programs,' he said. 'Once given a chance, the
sea can replenish itself. In the Sulawesi Sea northwest of Manado,
fishermen can pull a ton of tuna from the sea in two hours, using only
simple bamboo fishing rods and small hooks. They could easily take
more, but they have a simple philosophy - why take so much when we can
keep some fish in the sea for tomorrow?'
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