-
Representing important processes in the earth's history, geological processes
of interest (Criterion A).
The Cat Ba archipelago in general, located in the
northeastern part of Vietnam, has a long geological development history of
about 18,000 years, once a part of the Caledonite folded structure marking the
end of the Katszzia deep-sea trough regime. Siluar century. In Quaternary
history, this area was once an island with imprints of the sea left at
different heights, the submerged result of the last ice advancing after the
last glacial (Flandrian advance) formed. Cat Ba archipelago today.
Lan Ha Bay (Cat Ba Archipelago) is the most popular and
largest pattern of tower-shaped karsto (Fengling) and pyramid (Fengcong)
features invaded by the sea and is one of the most important areas in the
world. About karsto fengling and fengcong topography. One of the
characteristics of karsto fengcong topography is large, closed lakes, flooded
fields, some of which only appear at high tide. The cave is also one of the
geological features of the heritage area with three main types of caves: the
ancient underground cave, the ancient karsto cave cave and the frog jaw cave.
It is also an area that fully presents karsto formation processes on a large
scale and illustrates a long period of geological evolution.
The Cat Ba archipelago is also a prominent model of the
tower-shaped karsto terrain that has been eroded by the sea and is one of the
important areas of karsto fengling and fengcong topography with the feature of
karsto fengcong terrain as closed profiles. large as Ang Vem, the fields are
submerged (Ang Tham), some lakes only appear at high tide (Dark and Bright).
This area has 40 caves such as ancient underground caves, ancient karst cave baskets
and cave jaws, fully demonstrating the processes of karsto formation on a large
scale and illustrating a long period of geographic evolution. substance,
geomorphology.
Cat Ba - Lan Ha - Ha Long Island presents a complete
matrix of typical moist tropical karst karst landforms. These include cones,
closed valleys (cockpit form), mountain drainage valleys (poljes), karren,
underground streams, caves with mineral deposits (stalactites), and a range of
features. This is partially submerged by the sea and altered by coastal
processes.
- Represents
the ongoing ecological and biological process with the development of a
homogenous and prominent ecosystem (fauna and flora living on land and in
water, marine and coastal environments) (Pepper Releases B)
Lan Ha Bay contains the
following typical and outstanding ecosystems: (1) cave ecosystems, (2) tidal
ecosystems, (3) coral ecosystems, (4) ecosystems soft bottoms and (5) saltwater
lake ecosystem.
(1)The cave ecosystem consists
of typical flooded caves, a special structure type of karst topography on the
sea. The flooded caves in Cat Ba include partly submerged and completely
flooded caves. Marine species are crowded in these caves. In particular,
sponges and soft corals are commonly found here.
(2)Intertidal ecosystems with
unique inlaid organisms that are rarely found: Including sandy, rocky mudflats
and mudflats. In Lan Ha Bay area, there are about 40 sandy beaches, distributed
concentrated in Southeast of Cat Ba Island; sand beaches are often located on
coral shelves from 1m - 4m high; width of 20m - 200m. Intertidal reefs make up
most of the intertidal area around the islands A mosaic of organisms that
attach to the reef is a structure constructed by seaweed and almost typical of
the tropical clinging ecosystem.
Intertidal organisms are groups of organisms that are
highly adaptable to cyclic and abnormal changes in natural conditions. They are
distributed adjacent to mangroves and tropical forests, creating complex
nutritional links between species. This is considered one of the important
factors contributing to the creation of typical biological and ecological
processes, thereby forming terrestrial species with characteristics adapted to
the marine environment.
(3) The
most developed coral reef ecosystem in the Tonkin Gulf: typical coral reef
ecosystem, typical for the whole areas of Cong Do, Hang Trai, Dau Be, Cat Ba
and Long Chau in terms of morphology. reef structure, distribution area,
composition and structure of reef-forming biomes. Coral reefs remain relatively
intact, which is a concentration of most marine life groups such as silk worms,
molluscs, echinoderms, crustaceans, sea reptiles, coral reefs ... Besides being
a habitat for hunting and breeding, coral reefs are also a safe haven for these
groups of organisms. One of the salient features of Cat Ba - Long Chau coral
reefs is that they are not only distributed in the subtidal zone but also in
tidal areas. This creates diverse biological but ecological relationships of
tidal and subtidal organisms.
(4) Soft-bottom
ecosystem: the bottom of Lan Ha - Cat Ba bay exists an intricate network of
ancient river beds covered by clear blue sea water reaching a depth of 29m.
This area is home to over 1,000 species of marine flora and fauna and also
contains the main fish and breeding grounds of the Gulf of Tonkin. The seabed
is not continuously distributed but is strongly divided by islands, reefs,
coral reefs. It is this that creates a close link between soft-bottom
organisms, coral reefs, mangroves and tidal areas, sometimes without defining
their specific boundaries. Therefore, the soft bottom is not only a diverse
habitat for species, but also plays an important role in the biological and
ecological relationships between marine ecosystems (tidal areas, mangroves, and
reefs),
as well as
interactions with rainforest ecosystems.
According to the research results of Lan Ha bay benthic
animals, there are 210 such animals in the coral reefs of Lan Bay. There are 4
species belonging to the group of high-valued girls, of which 2 species are
classified as endangered (EN), male snail (Tectus Pyramis) and apricot (Pinna
vexillum), one species. classified as endangered (VU) is a species of
black-pearl oyster (Pinctada margaritifera). The female snail shell (Tectus
niloticus) is now classified as Critically Endangered (CR). The distribution of
benthic species on coral reefs in Lan Ha Bay is uneven, depending on the degree
of protection of the reefs. The better protected coral reefs have a larger
number of these species (Van Boi, Cat Dua 1, Tai Keo and Basket Cung).
(5) Salt Lake Ecosystem: Using Google Earth, author Jaap
Jan Vermeulen, Netherlands has identified 138 marine lakes for Cat Ba. The salt
water lake in Cat Ba area alone has 119 - 138 lakes, accounting for about one
third of the global salt water lake. Ang Vem Lake (28.8 ha) is the largest
lake; The smallest one is Tre Moi (0.7 ha), they are scattered throughout the
study area. Most saline lakes are concentrated in Cat Ba archipelago.
The research results of many authors have determined the
special value of saltwater lakes expressed in scientific and practical values
such as:
- Demonstrate strong evolution of the population, often
creating new species and native species.
- Saltwater lake ecosystem is evidence of the
evolutionary adaptation of organisms to the formation of new species under new
environmental conditions.
- As a unique ecosystem of the sea, but more or less
separated from the surrounding sea, they clearly show the impact of weather and
climate on the environment.
It is the characteristics of the saltwater lake ecosystem
that provide an excellent opportunity to monitor and study the relationship
between the fluctuations of physical and climate factors to the evolution of
the population ecology of species.
- Represents
a natural phenomenon or a place with exceptional beauty (Criterion C)
The captivating beauty of Lan Ha Bay is made up of hundreds
of rocky islands such as Island Guoc, Island But, Island Rua, Island Doi, Island
Hai Co, Island Bu Lau, Island Tai Keo, But Day ... The amazing thing is that
even though it is a small rocky island, the islands on the bay are lush all
year round because they are covered with diverse vegetation. Lan Ha Bay has
many small sandy beaches, quiet, without big waves, which are ideal beaches for
visitors.
The small villages along the coast are connected by
simple village roads and trails. Some villages live in hidden fjords,
especially around the southern shore, floating on the sea. It all reflects the
traditional way of life of fishermen who have existed for centuries. Floating
fishing villages with traditional fishing boats and colorful paintings
significantly add diversity and unique beauty to the landscape, creating a
striking contrast against the backdrop of the steep cliffs. Cliff. This image
was posted on IUCN's specialized research cover "Caves and karst at World
Heritage Sites".
The elements of rock, water, forest, and sky combine to
create a changing natural world with unmatched beauty and attractiveness. The
colorful landscape reflects the gray of mountain rocks, the greenery of the
forest and the transition between deep blue and blue in the hidden lakes to the
hidden canyons and fjords on the sea. A striking feature is the landscape that
changes color every time it starts to rain. Gray limestone immediately turned
black. The reason is that cyanobacteria are waterlogged, creating a landscape
that turns dark tones.
The hidden underworld at Cat Ba Island consists of a
network of little-explored caves and streams. A few are used as tourist
attractions but there are still many caves and rivers still undiscovered with
untouched nature. These are the treasures of nature: hidden landmarks
accumulate evidence of natural environment that has changed over the thousands
of years in the form of sedimentary layers and organic traces marking events.
takes place in the world above.
Visitors to Lan Ha Bay have an amazing feeling with the
mountain towers (Fenling), the ridge (fengcong) seem to float on the surface of
the sea, some attached to the tree-covered hills with cliffs. Adorn mysterious
beauty. The experience of nature here is inspirational but requires effective
concerted effort to sustainably manage its values when many people visit.
- Contain natural habitats for
the conservation of plants and animals, especially endangered species
(Criterion D)
According
to statistics, Cat Ba Archipelago - Long Chau has 3,860 species of plants and
animals on land and in the sea. Of these, 130 species have been identified by
the Government of Vietnam and the world as rare species to be included in the
Red List
for protection. Of which, there are 76 species listed in the IUCN rare list.
Among these are 15 species of terrestrial animals, 1 rare bird species, 70
plant species, 12 reptile species, rare amphibians, 32 species of marine life.
Of the 76 species in Cat Ba that are ranked by the IUCN, there are 01 primate
species and 06 plant species at the critically endangered (CR) level, which are
Vooc Cat Ba Trachypithecus poliocephalus, Dipper Aquilaria crassna, Mun
Diospyros ebony, Taur Vatica diospyroides, Parashorea chinensis, Hopea
chinensis, Hopea chinensis and Dipterocarpus dyeri. There is one endangered
animal species (EN) that is the species of Maniss pentadactyla, 5 species of
plants on the list of endangered species: Red Woodback Afzelia xylocarpa, Green
Lim Erythrophleum fordii, Hybrid Dalbergia oliveri, Dipterocarpus alatus Otter
Oil and Annamocarya sinensis. There are 2 species of mammals, 1 reptile, 9
plant species classified as endangered (VU), 6 mammals, 1 reptile, 5 plant
species classified as near threatened (NT). Marine species on the IUCN list
include 3 species of sea turtles, 1 species of marine mammals and 19 species of
corals. Especially Cat Ba Vooc (Trachypithecus poliocephalus) is endemic to
only a population with 63 individuals distributed only in Cat Ba, nowhere else
in the world appears this species. This species is recommended by IUCN in the
list of species with high risk of extinction, requiring special protection.
This is considered a rare and precious global value and has been honored by
Vietnam as a Symbol of Cat Ba.
Limestone cliffs almost vertical facing the sea, typical
for island-sea interference, are all inhabited by a special group of plants.
Species of succulent or shaggy plants such as Euphorbia antiquorum (Euphorb),
Dracaena cambodiana (Liliac), Cycas sp (Cycad), and Sarcostemma acidum (Apocyn)
leaves for carpets The plants here have the appearance of drought resistant
plants of macaroni. Small patches of grass or bamboo are showing signs of
rehabilitation due to human impact. The vegetation here is a favored habitat
for endemic plant species. The most common and recognizable species is
Primulina (Chirita) drakei (Gesner) that grows in clusters with slightly
grayish leaves and large purple flowers. Endemic species of the same family
include Paraboea halongensis, Primulina gemella, P. hiepii and the lesser known
P. semicontorta. Other endemic species include Alpinia calcicola (Zingib) and
Cycas tropophylla (Cycad). There is a bit of Impatiens halongensis in
Primiteholes, Primulina sp., Most likely an endemic species. Besides, the
cliffs facing the sea belong to the favorite habitat of Cat Ba Vooc
(Trachypithecus p. Poliocephalus).
If you look at the area of Hang Trai Island, Dau Be
Island, Cong Do Island ... on Lan Ha Bay, it is easy to see that the vegetation
here is much bigger and bigger than other areas. of Ha Long Bay. There are many
blooming flowers here that attract many birds.
Management of Cat Ba Bays