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Values of Biological Diversity
Hạ Long Bay has a very complicated
structure with its meandering coastline and many river
mouths. Rich and diversified sources of food for many
species of plants and animals are also found here. In
particular, the bay, partitioned by thousands of large
and small islands, creates areas of water with an
average and stable sea level. Meanwhile, the climate in
Hạ Long Bay is also very stable, with an average
temperature of between 19 and 25ºC, and an average heat
radiation rate of 17 kcal/ sq. cm/ month. It sees an
average rainfall of 2,000 to 2,200 mm/ year. These
favourable conditions have seen the development of many
varied ecosystems.
Results of scientific research show that Hạ Long Bay
features ecosystems of a tropical ocean region, such as:
salt water-flooded forests, coral reefs and tropical
rain forests.
In the sea surrounding Hạ Long, coral grows in many
places, but is densely concentrated on the eastern and
southern sides, far from the mainland. According to
research conducted by scientists from the Oceanographic
Institute, Hạ Long Bay is home to 163 species of coral,
from 44 lines of descent and 12 families. Coral reefs
are distributed everywhere, generally at a depth of 4 to
6m. The coverage rate of coral reef is 30% on average,
but there are areas where it attains 70 to 80%, such as
at Cống Ðỏ and Bọ Hung. The coral forests of Hạ Long Bay
are a wonderful sight, with many extraordinary shapes
and diversified colours. When the tide flows, the coral
moves with the water, pumping as rhythmically as a
heartbeat. At the same time, the reefs are residence to
a great number of species: fish (107 varieties), water
plants, algae and transitory animals and plants.
The salt water-flooded forests also offer especially
interesting scenery along the coastline of Hạ Long Bay.
These forests are chiefly concentrated in the zones of
Tuần Châu, Cửa Lục and Ba Chẽ. Many species of salt
water-flooded plants, the most diversified collection in
North Vietnam, are found here. Also living in these
flooded forests are a great many species of animals:
migrating birds (37 species), sea-bottom animals (81
species) and fish (90 species belonging to 55 families).
In particular, bottom-feeders account for 61% of the
total species in the whole tidal region, with many
species being of great economic value: arcae, meretrixes
and all kinds of crustaceans.
The tropical rain forest ecosystem also features a rich
quantity of species: đinh, hương, sến, táu trees. This
is the residence of various rare and precious creatures:
deer, weasels, squirrels and in particular, white-tabby
and red-haired monkeys.
At the same time, there is a system of small caves along
the sea, which are the living and development places for
many animals and plants: seaweed, water plants, algae,
fish and shrimp. Deeper into the water, there are also
many species of shrimp, fish (almost 1,000 species),
abalone and other sea-specialities; harvested every year
to the tune of several thousand tons.
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