THAILAND MARINE NATIONAL PARKS AND DIVE SITES

SIMILAN ISLANDS ARCHIPELAGOS.
Topography:
Consists of numerous islands with high and steep granite mountain, beaches and rocks formation of many shapes. There is no mud at all along the beaches, so the sands are very clean, white and very fine. Some islands do have hills in the area, which are usually quite tall with the highest top of 244 meters above mean sea level, while some islands are of flat area surrounded by sand dunes and coral reefs.
Beach Forest - open forest with scattered plants at approximate height of not over 15 meters such as Terminalia catappa, Barringtonia asiatica, Callophyllum inophyllum. Small perennials and large shrub not exceeding 10 meters in height found are Xylocarpus gaugeticus, Herltiera littoralis, Hibiscus tiliaceus which is a smaller shrub found are Capparis micracautha, Breynia vitris-idaea Fischer, Pandanus odoratissimus. Grounds covering plants common in the area are beans, Vigna sp., Spilanthes sp., Ischaemum barbatum, Lophatherum gracile, Hoya parasittrica, Asplenium nidus.
Scrub Forest - habitat for shrubs which can develop on grounds with soil depth of not exceeding 30 centimeters. A few cacti can be found while more common shrubs found are Cercus spp., Dracaena spp., Memecylon caeruleum, Cleistanhus polyphyllus.
Primary Forest - habitation for perennials at a height of 20 meters or above such as Dipterocarpus costatus, Dipterocarpus boudii, Shores spp., Lower perennials at 15-20 meters in height are palaquium obovatum, Eugenia denaiflora, Wrightia sp., 10-15 meters in height are Hydnocarpus ilicifolius, Semecarpus curtisii, Diospyros wallichii. Bambusa sp., Calamus longisetus, Plam, Amydrium medium and Bauhinia glauca are also found with other creepers and parasites such as betel pepper, bauhinia and orchid. Above the sea surrounding each island lies Beach forest, which steadily becomes Tropical forest further inland. Important tree species include Manilkara sp. Cordia subcordia, and Tournefotia argentia.
Flora and Fauna:
A survey conducted in 1992 revealed that 39 species of birds can be found on the nine islands. Resident species include the Brahminy Kite, and the White-breasted Waterhen, while migratory species include the Pintail Snipe, and Grey Wagtail. Temporary migratory species include the Barn Swallow, Cattle Egret, Watercock, and the Roseate Tern. The most commonly seen species include the Pacific Reef-Egret, Nicobar Pigeon, Pied Imperial Pigeon, White-bellied Sea-Eagle, and the Collared Kingfisher.
The environment of Koh Similian National Park is obviously that of a small island, wherever you go, you are not far from the sea. Natural fresh water reserves are few, and as a result, large mammal species cannot exist. Surveys have revealed that 27 species of small mammals exist within the park, including 16 species of bats namely: black-bearded tomb bat, lesser false vampire bat, intermediate horseshoe bat, lesser bent-winged bat and the hairless bat. 3 species of squirrels can be found including the gray-cheeked flying squirrel. 4 species of rats: yellow Rajah rat, ricefield rat, roof rat and noisy rat can be seen scurrying around as well. Finally, the more unusual but fairly common residents include the bush tailed porcupine, common palm civet, flying lemur and the bottlenose dolphin. 22 species of reptiles and amphibians can be found in the park including the banded krait, reticulated python, white-lipped pit viper, common pit viper, garden blue lizard, hawksbill turtle, leather turtle, bengal monitor lizard, common water monitor lizard, ornate froglet, common asiatic frog, marsh frog, and the common bush frog. Finally, another most interesting species located in the Koh Similan Islands is called the hairy leg mountain land crab. This crab is found in such large numbers you will be sure to see many just by walking around a bit. No matter where you are on the island, seeing this creature will be a reminder you are never far from water
Marine life: Visibility: 20-40m. Depth 3-40m.
Beneath the sea at Koh Similan National Park lies a complex ecosystem commonly called the rainforest of the sea: the coral reef. The major residents of the reef are coral and the closely related sea anemones; of the Phylum Cnidaria, Class Anthozoa, which contains all radically symmetrical invertebrate animals. Corals and sea anemones exist as individual polyps living in either solitary or mostly colonial forms. The polyps of hard corals construct communal limestone homes which are built up into a multitude of shapes and sizes eventually giving rise to a coral reef. Soft corals have soft bodies made of large numbers of identical polyps connected by fleshy tissue (Zooxanthallae). These soft corals contain small algae within their tissues which are able to convert the sun's energy into food. This cooperative relationship is known as symbiosis and also exists in hard corals, clams and other marine organisms. There are several factors that support good environment for the reef i.e. temperature, salinity, light, wave and tide, sedimentation and nutrient. Therefore, healthy coral reef can be found easily in the Andaman Sea comparing to the Gulf of Thailand. In Andaman Sea, coral reefs are able to be classified as deep water and medium water. For the deep water coral reef grow down to 30 m. Of course, in this case water allows enough light for the algae. This reef type is mostly found in Koh Similan Islands and Koh Surin Islands. For the rest area, medium water coral reef grows between 8-15 m beneath the surface. Coral can also be classified to fall into these structural categories: massive, columnar, encrusting, branching, foliceaous, laminar and free-living coral. The hard corals found in Koh Similian Islands National Park are deep water species of mostly staghorn coral types (Acropora echinata) and the smaller cauliflower shaped types (Seriatopora histrix). Many other species of marine life co-exist within the coral reef: Gorgonian sea fans, flower-like soft coral, several species of crabs, spiny painted lobsters, squid, sponges, sea cucumbers and giant clams.

KOH BON & KOH TACHAI.
Marine life: Visibility: 20-40m. Depth: 3-40m.
Both are tall, rocky islands, and offer varied and beautiful underwater scenery. At Koh Bon, a steep, rocky point, which plunges to over 40 meters' depth, is often a good place to see Leopard Sharks and large rays. Koh Bon is also a good place to see big pelagic creatures; both Mantas and Whale Sharks are seen here with fair regularity. Koh Tachai, a pair of coral-encrusted pinnacles, which are connected by a long, rocky ridge. Currents, which are extremely rich in nutrients, sweep this site and plankton, resulting in outstanding growths of sea fans, whips corals and other filter feeders. This is also a good area for Leopard Sharks and Stingrays, but probably the most over-whelming attraction is the schooling fish action.

RICHELIEU ROCK.
Marine life: Visibility: 10-20m. Depth: 3-30m.
This is the world's top listed location for sighting Whale Sharks and Mantas. One of Thailand's best dives, this is a wall-dive around the main outcrop, which is surrounded by smaller submerged pinnacles. Around the corals is a wide diversity of marine life: common residents include Schooling Banner fish, Single-spot and Giant Snappers, Scorpion fish, Moray eel, and colorful nudibranch. As this is the only food source in the immediate area, it is excellent for large pelagic. Rainbow runner, great barracuda, travelly, tuna and jack are frequently observed.

SURIN ISLANDS ARCHIPELAGOS.
Topography:
Koh Surin Islands comprise of five main islands, including 2 large islands consisting of the northern Koh Surin Island and southern Koh Surin Island which located very adjacent like the twin island. They are separated by the 200 meters width shallow sea. In the low tide period, you can walk across to the other island or so-called "cutted channel bay". The other three islands are rocky islands with some dwarf trees. Plants that found here are the rainforest plants. They are one source of the big and best fertile shallow coral reef of Thailand.
Vegetations, able to classify the society of plants as follows:
- Primary rainforest covers most area of the national park, both of slopes and ridge of mountain. The important plants found here are Diospyros malabarica Kostel, etc.
- Beach forest could be found in beach areas where you can find many kinds of plant such as Barringtonia, Cerbera odollam, etc.
- Mangrove forest is located in the mud area and the brackish water of Mae Yai bay. This is not the fertile forest but you can find some kinds of plants such as Rhizophora apiculata, Rhizophora mucronata, Xylocarpus granatum, etc., while some dwarf forest or grove plants comprise of Cycas pectinata Griff., Dillenia obovata (Bl.) Hoogl., Erythroxylum cuneatum Kurz, etc.
Flora and Fauna:
- Birds, from survey found totally 91 types of birds including local birds about 57 types and the others are the migrating birds from elsewhere, such as Little Heron, Common Sandpiper, Little Tern, etc.
- Mammal animals could be found here totally 22 types including 12 types of bat such as Island Flying fox, Black-Bearded Tomb Bat, Pig-Tailed Macaque, Common Wild Pig, etc.
- Reptiles have been found 6 types such as Indian or Bengal Monitor, Water Monitor, Skink, Reticulated Python, etc.
Marine life: Visibility: 10-25m. Depth: 3-40m.
Coral, such as Needle coral, etc. Fish, such as Damselfish, Wrasse, Butterfly-fish and Midas blenny; Ecsenius midas etc. Sea Turtles, Sea turtles are a very ancient family of animals and their ancestors date back to when Dinosaurs roamed the earth. Although the Dinosaurs are now extinct, the sea turtles are still surviving although their future existence is in doubt. Many species are endangered with several species near extinction. Their principle threat is the loss of their nesting beaches to development stimulated by increasing tourist pressure. This has reduced the number of turtles worldwide to such an extent that positive action must be taken to secure their existence in the future. The principle action is the preservation of their nesting beaches, and the protection of the eggs from theft once laid. Sea turtle still nests on the Koh Surin Islands, with two species coming ashore to lay their eggs, Hawksbill, and Green turtles. In the early 1990’s we also had a few nest of the rare Olive Ridley turtle. Ko Surin Islands are the best place in Thailand for anyone who want to swim with sea turtles. Most visitors have a few chances to get close to them, mostly hawksbill turtle.