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Ng, P.K.L. & K.S. Tan,
2000. The state of marine biodiversity in the South China
Sea. The Raffles Bulletin of Zoology, Supplement No.
8 (The Biodiversity of the South China Sea):
3-7. THE STATE OF MARINE BIODIVERSITY IN THE SOUTH CHINA SEA Peter
K. L. Ng K.
S. Tan
The
South China Sea (SCS) is of particular promise for
biodiversity researchers globally. Covering some three
million square kilometers of sea and including over 200
coral islets, the SCS stretches from the equator near
Singapore to the Tropic of Cancer in the Taiwan Strait.
While most of SCS consists of the Sunda Shelf which is less
than 200 metres in depth, the northern part includes the
South China Sea Basin, which in some areas are more than
5000 metres deep. Indeed, the SCS encompasses a tremendous
diversity of natural ecosystems, ranging from coral reefs,
rocky and sandy shores, mangroves, estuaries and mudflats to
open waters and abyssal habitats, and are home to hundreds
of thousands of species of organisms. Its waters wash the
shores of 12 countries/areas, and the maritime coasts of
Brunei, Cambodia, Indonesia, Malaysia, Philippines,
Singapore, Thailand, and Vietnam (all of which belong to
ASEAN, or the Association of South East Asian Nations),
Peopleís Republic of China, Hong Kong and Taiwan are
all connected via the SCS. Not withstanding political,
economic and social differences, the people in these
countries depend upon the biological resources of the SCS in
no small terms. As
part of ongoing efforts to better understand the rich marine
bioresources in the SCS and bring scientists from all the
SCS countries closer together, several initiatives have been
implemented by the countries in the region (see Djalal,
1999). One of these initiatives (part of the Technical
Working Group on Marine Scientific Research) culminated in a
workshop on SCS biodiversity held in Singapore in May 1997,
and was hosted by the National University of Singapore. This
workshop and subsequent discussions brought together
biodiversity scientists from throughout the SCS region, as
well as international experts from Australia, Europe, Japan
and the United States. The plant and animal diversity of the
SCS, however, is far too diverse to allow a detailed study
of all of them. The workshop therefore focused on several
key groups, viz. algae and nearshore and intertidal vascular
plants, sponges, corals, polychaetes, molluscs, crustaceans,
echinoderms, and of course, fish. Many are key plants and
animals (e.g. as biofoulers, bioindicators) in their
respective ecosystems, but they include species important
for fisheries, aquaculture and other commercial
applications. Scientists
from the countries around the SCS have been conducting
independent marine biodiversity research in their respective
countries for many years, but while national floral and
faunal inventories are available for some countries, there
has been little or no coordinated regional effort to
identify knowledge gaps and provide useful solutions.
Moreover, with the multitude of sampling methods (not all of
which are exhaustive or appropriate), variety of data
gathering and identification tools used (much of which is
obsolete or outdated), there is often extensive
misidentification of key organisms in existing literature.
Further, the use of outdated publications can lead to much
confusion with synonyms and generic placements of species.
This is also made more difficult by the fact that new
species are still being described at a steady rate (Bouchet,
1996). The frequent misidentifications and/or
underestimation of biodiversity have serious consequences
when marine areas need to be studied, assessed and/or
conserved. A fundamental requirement in coming to terms with
our biological heritage is surely the correct identification
of species. For more detailed studies, including those on
conservation and habitat management, to be conducted on the
flora and fauna of the SCS, there is a critical need to
consolidate the regional biodiversity data, arrange for and
train local staff in the precise identification of key
plants and animals, and to make available accurate regional
inventories of these organisms (Stork, 1994). The
present volume attempts to resolve some of the
above-mentioned shortcomings, and it is the result of hard
work put in by participants of this workshop. It contains a
total of 13 checklists treating the vascular plants,
sponges, polychaetes, several molluscan and crustacean
groups, echinoderms and marine fish. The checklists were
compiled and checked by experts in their respective groups,
and include many personal observations made by the authors
themselves. All are accompanied by detailed lists of
pertinent literature. These lists will be useful to
scientists dealing with flora or fauna outside their field
of expertise, while at the same time allowing specialists
and investigators to have a better perspective of the
regional flora and fauna. The checklist of fish is
especially important as it treats a group with substantial
economic and social importance to the people of the SCS. It
is also a remarkable contribution, put together by no less
than 67 ichthyologists (see Randall & Lim, 1999, this
volume). Vascular
plants, including the ferns, are listed by Turner et al.
(1999). A total of 39 species of ferns, eight species of
gymnosperms and a n astonishing 656 species of angiosperms
from more than 120 families are provided in the list. For
each species, brief notes on its size, habitat and
geographical distribution are given. Of particular interest
are listings of habitat-specific plant species. In a
separate bibliography, Turner (1999) has given more than 170
references to recent and/or useful monographs, books and
papers dealing with the plants in and around the SCS region. Compared
to the vascular plants, the marine fauna of the SCS is
poorly known. Except for fish and some groups of
crustaceans, the lists given for the other groups of animals
remain preliminary and incomplete, as pointed out by the
authors themselves. Hooper et al. (1999) have listed more
than 1500 species in 102 families of sponges but estimate
the number of species to be as many as three times higher
than now known, of which only 5% of the SCS sponge fauna is
distributed throughout the Indo-west Pacific! The authors
state that this high endemism, coupled with ecological
specialization and possibly fast speciation rates, suggest
there is still a large number of species yet to be
discovered. These are very significant revelations from one
of the top sponge research teams in the world. Polychaetes
are treated by Paxton & Chou (1999) who have listed 661
species in 54 families. They stress that the number of
species does not show the true situation in the SCS, but
rather reflects the past collecting efforts of biologists. A
similar situation appears to be true for the crustaceans.
The Amphipoda is a case in point. Lowry (1999) has listed
272 species from 48 families, but he states that these
small, laterally compressed malacostracans from algal
forests, seagrass meadows and coral reefs in the SCS have
not been studied and remain poorly known. The same
conclusion is echoed by Komai (1999) who list 157 species in
14 families of mud lobsters and anomurans other than hermit
crabs, the latter which is treated by Rahayu (1999) in which
102 species in the families Diogenidae, Paguridae and
Parapaguridae are listed. However, crustaceans of economic
importance are perhaps better known. A tone of quiet
confidence can be detected in the conclusions reached by
Moosa (1999) who lists 116 species of stomatopods in 13
families, and by Jones et al. (1999) who list 316 species in
21 families of thoracic (non-rhizocephalan) barnacles. The
coverage of molluscs in this volume does not do justice to
their important ecological and economic roles they play in
the SCS, but in some ways reflect the extent of
specialization required of workers to grapple with the
taxonomic difficulties inherent in the speciose malacofauna
of the SCS. Amongst the gastropods, 130 species of Muricidae
(Neogastropoda) are listed by Tan (1999) and 193 species of
nudibranchs listed by Sachidhanandam et al. (1999). The
preliminary cephalopod list provided by Norman & Lu
(1999) has 120 species in 31 families, and the authors have
included a useful compilation of erroneous literature
records of cephalopod species found in the SCS. The
echinoderms are a less speciose, but nevertheless important
phylum amongst the marine fauna. Lane et al. (1999) have
listed 982 species in 102 families, of which 12% are thought
to be endemic to SCS. The
list of marine fishes in the SCS is edited by Randall &
Lim (1999, pages) and is a grand compilation of the work of
67 fish taxonomists (including the editors themselves) from
12 countries currently working on various fish families and
groups. Personal preferences and dissent were cast aside to
agree on the contents, which list a total of 3365 species in
263 families. A useful list of key references grouped under
taxonomic orders and/or families is also provided. Although
this marine fish species list is perhaps the most
comprehensive to date for an area this size in the Indo-west
Pacific, the editors are careful to state that the pelagic
and abyssal fish fauna are far from being well documented.
In fact, the SCS is on the whole poorly explored
biologically as reiterated by the contributors of this and
other floral/faunal lists, and there is much to be gained
from a more systematic and co-operative approach. The fish
list can be hailed as an epitome of scientific cooperation
and it is hoped that the same spirit and gusto can be
extended to other aspects of SCS initiatives. Despite
the severely limited repertoire of organisms covered by
these lists, it is clear that the SCS is biologically
diverse. More than 8600 species of plants and animals are
included in the list, but these exclude important, speciose
groups such as the cyanobacteria, eukaryotic algae,
protozoa, cnidarians, platyhelminthes, nematodes, bivalves,
copepods, isopods, major decapod crustaceans (e.g. true
crabs, lobsters and prawns) and tunicates. When these
missing groups are considered the number of species will
certainly increase significantly. This will be in addition
to many new records and new species being discovered every
year in and around the SCS. This will be expected to
continue, given that the region is still relatively
unexplored biologically, and that it is located in the
Indo-West Pacific epicentre of biodiversity. This is not
only true for demersal and abyssal fauna, but also applies
to the smaller organisms living in shallow-water ecosystems,
such as in the mangroves, coral reefs, seagrass meadows and
sandy shores (meiofauna). In addition, once the proper
global systematic revisions are done at the global level,
many species of ìwell knownî animals will
probably turn out to be new to science, unusual or endemic
to the region. Our knowledge of the biology and ecology of
these multitudes of species is obviously unimpressive. These
problems should be considered in the light of modern
economic development in the SCS, where man competes with
other organisms for resources. Destruction of habitats and
pollution are two activities that are expected to escalate
in the next 50 years around the SCS, and the need to
inventorize and find out as much as we can about the
organisms and their interactions with the environment are
more urgent than ever before. There are also major
challenges. Taxonomic impediments are at the forefront of
the biodiversity crisis, and the problems associated with
finding and training a new and competent crop of younger
marine taxonomists are serious. Yet, most of the current
political attention and available international funding,
unfortunately, is still squarely focused on
ìmanagementî rather than systematic research.
It still confounds the authors how an effective management
can be designed when the organisms composing the ecosystem
are still so poorly known, and even less is known of the
ecological interactions. While species checklists themselves
cannot address the above mentioned
problems directly, it is hoped that the friendships and
contacts developed during the workshop will encourage
scientists to take the first joint international step toward
a better understanding of the biological processes in the
SCS. Bouchet,
P., 1996. Inventoring the molluscan biodiversity of the
world: what is our rate of progress? Veliger,
40: 1ñ11.
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