ISSN 1063-0740, Russian Journal of Marine Biology, 2006, Vol. 32, No. 5, pp. 269–275. © Pleiades Publishing, Inc., 2006.
Original Russian Text © Yu.Ya. Latypov, 2006, published in Biologiya Morya.
The productivity of the coastal waters of Vietnam
(the abundance of ﬁsh, shrimp, lobsters, mollusks, and
algae) is largely determined by the status of coral reefs.
Like humid tropical forests, coral reefs are a very pro-
ductive natural ecosystem, which is important for peo-
ple in various aspects. Coral reefs form a habitat that
creates a remarkable variety of the ecological niches for
numerous organisms. They provide a barrier to the
destructive energy of waves, thereby protecting the
coastline from erosion. The coral reef is, in essence, a
“living barrier,” its base perishing and being renewed
. Erosion of coral reefs leads to the formation of
sand that replenishes its resources on the shores. This is
particularly important for the coast of Vietnam with
sandy shores, which are being continuously destroyed.
Coral reefs are involved in many areas of human activ-
ity. Among them are various kinds of recreation (snor-
keling and scuba diving, ﬁshing, glass-bottom boat
tours, etc.) that are directly dependent on the state of
coral reefs. Hence, governmental and scientiﬁc institu-
tions in many countries consider coral reefs to be an
extremely important component of their national econ-
The major threat to coral reefs in the near future is
the increase of human activity on local and regional
scales. This danger may prove to be much more serious
than the expected global warming in the distant future.
The city of Nha Trang and its vicinity located on the
shores of Nha Trang Bay are intensely developing. Res-
idential and communications construction, establish-
ment of new hotels and underwater swimming centers,
intensiﬁed mariculture operations, and increased pres-
sure of tourism have led to enhanced terrigenous runoff
in Nha Trang Bay [5, 26]. The infrastructure of the
municipal sewage and waste disposal plants and protec-
tive measures do not satisfy modern requirements dic-
tated by economic growth.
Deposition of terrigenous material is the major rea-
son for pollution and damage to coral reefs. Inputs of
terrigenous material are increasing due to the destruc-
tion of vegetation cover (agriculture and forest cutting),
mining and building operations, wastewater discharge,
and application of fertilizers. This leads to a reduction
in the light arriving at corals, their being buried under
sediment, and abrasion of the polyp tissue through fric-
tion. Eutrophic waters affect the metabolism in zooxan-
thellae and augment the development of phytoplankton,
leading to reduced light levels and to the development
of benthic ﬁlter-feeding organisms. Under these cir-
cumstances, corals can become inferior to macroalgae
and invertebrates in competition for nutrients [4, 10].
The deterioration of coral reefs is producing con-
cern on the part of Vietnamese scientists and their gov-
ernment. Efforts have been concentrated on the study of
the reasons for reef ecosystem variations and on the
elaboration of a management strategy for conservation
and restoration of coral communities. The present pub-
lication is based on data from many years of observa-
tions on the status of selected coral reefs in Nha Trang
Bay. We aim to attract the attention and funding
urgently required for immediate conservation measures
on the reefs of Vietnam, which are an organic part of the
Indo–West Paciﬁc tropical center of coral diversity and
origin [3, 9, 14, 25].
Changes in the Composition and Structure of Coral Communities
of Mju and Moon Islands, Nha Trang Bay, South China Sea
Yu. Ya. Latypov
Institute of Marine Biology, Far East Division, Russian Academy of Sciences, 690041 Vladivostok, Russia
Received February 16, 2006
—In October 2003 and January 2005, comparative observations were made on the reefs of Mju and
Moon islands near the city and port of Nha Trang, which we ﬁrst investigated in 1981. Appreciable changes due
to anthropogenic impact have occurred on the reefs that are the nearest to the city. There was a reduction in
substrate cover by reef-building corals, a substitution of dominant scleractinian species, and a decrease in the
numbers and diversity of common species of corallobionts. The index of species diversity for scleractinians also
decreased. The seaweeds
spread into all zones of the reefs. Changes in coral com-
munities on more distant and protected reefs were not so marked.
reefs, communities, corals, change, anthropogenic impact.