Last Update : Monday 22 January, 2001 4:52 AM

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Survey Report Coral Reef Condition Distribution of Giant Clams Distribution of Edible Invertebrates

Survey of Coral Reef Condition in Mu Ko Surin Marine National Park Area

          Mu Ko Surin Marine National Park is located in Amphur Kuraburi, Pang-Nga Province. In the past, it was a protected forest area within the bounds of petroleum concession. It was used to be offered as a settlement area for Vietnamese refugees; however, the Royal Forestry Department saw its beautiful scenery and its abundance of natural resources so Surin archipelago was, instead, offered to be a national park. Later, it was proclaimed the 29th national park of Thailand on July 9, 1981.

          Surin archipelago consists of 5 main islands, which are North Surin Island, South Surin Island, Torinla Island (Ko Raap), Pajumba Island (Ko Mungkorn), and Stork Island (Beacon Island), and 2 exposed pinnacles called Hin Kong and Hin Prae. It has 135 square kilometers in area (84,357 Rai), and 76% of its area is seawater.

          Mu Ko Surin Marine National Park is located 60 kilometers away from the main land. The northern part is closed to Myanmar border, and not far away from the south is Mu Ko Similan Marine National Park.

          According that Surin archipelago is a very large area, especially North Surin Island and South Surin Island, and its geographical nature lies in good monsoon shelter, coral reefs are found almost around the islands. Only in the southwestern area of South Surin Island that contains steep slope geographical nature and lies in monsoon confrontation, corals are found sticking to the rock, not building up into coral platform.

          Coral reefs found in Surin archipelago area are fringing reef type, one of three coral reef types found all over the world. This same type of coral reef can be found in other areas of Thailand. This fringing reef is the coral reef that limestone is accumulated to be the solid coral foundation and becomes a large coral reef. This type of reef can be separated in to 3 areas, which are:

1. Reef Flat is the area that closed to the shore and flat. Corals in this area usually are in poor abundance because the area usually exposes to the air during low tide period. Therefore, it is greatly influenced by change of water temperature and saltiness. Corals found in this area are Branching corals and Submassive corals.
2. Reef Edge is the area between Reef Flat and Reef Slope. This area lies in confrontation of beaching wave. It is the area the most diversity of corals can be found such as, Acropora Branching corals, Tabulate corals, and Massive corals.
3. Reef Slope is the area next to Reef Edge. This area is very steep slope. Corals mostly found in the area are various Branching corals and Massive corals. In this area of Surin archipelago, there are corals covering until the depth of about 60 feet.

          Corals are invertebrates in Phylum Coelenterata, Class Anthozoa, Subclass Zoantharia, and Order Scleractinia. Corals consist of two components: limestone skeleton formation and living tissue called polyp. Each coral contains a lot of polyps; an individual polyp consists of six tentacles or multiple of six. This tentacle’s function is to capture plankton for nutrition. Apart from this, there are unicellular algae, zooxanthellae, living within the tissues of the polyps, and providing nutrients for corals by photosynthesis. This photosynthesis of algae influences limestone skeleton formation to create coral reefs.

          There are approximately 400 species of corals found in Indo-Pacific area. Out of them, approximately 240 species are found in Andaman Sea.

Objectives

1. To study the distribution of coral reefs in Mu Ko Surin Marine National Park area
2. To study forms of corals found in Mu Ko Surin Marine National Park area
3. To evaluate coral reef conditions in Mu Ko Surin Marine National Park area

Survey Method

          Lifeform Transect method was applied by using 3,000-centimeter tape measure, random placing parallel with the coral reefs for five times per each coral reef area, then recording forms of corals, and covering things over the coral reefs.

Data Analysis

          Forms of Corals: separated by their characteristic formation as follows:

Dead Coral (DC)
Sand (S)
Coral Submassive (CS)
Coral Massive (CM)
Coral Branching (CB)
Coral Tabulate (CT)
Coral Foliose (CF)

          Quality of Coral Reefs: identified by ratio of living corals to dead corals as follows:

Very Good Abundance	ratio of living corals to dead corals is more than or equal 3:1
Good Abundance	ratio of living corals to dead corals is equal 2:1
Moderate Abundance	ratio of living corals to dead corals is in between 1:1
Poor Abundance	ratio of living corals to dead corals is less than 1:2
Very Poor Abundance	ratio of living corals to dead corals is less than 1:3

Place & Time

          The survey was conducted in Mu Ko Surin Marine National Park area by dividing into 6 areas covering coral reefs of North Surin Island, South Surin Island, and Torinla Island. From December 1999 to April 2000

Results

          From the survey results, in Surin Archipelago area, found coral reef conditions of very good abundance in 2 areas of Ko Torinla and Ao Jaak. The moderate abundance was found in an area of Ao Saai Daeng, poor abundance in an area of Ao Mai Ngam, and very poor abundance in 2 areas of Ao Suthep and Ao Tao.

          Ao Jaak was located in distant area. It was difficult for tourists to visit the area; therefore, the coral reef in this area was in very good abundance. The ratio of living corals to dead corals was 3:1. Forms of corals mostly found were Coral Branching at 21.27%, and Coral Foliose at 27.80%. Coral reef in this area did not extend in one continuous platform, but widely separated by sand floor.

          Ao Mai Ngam contained poor abundance of coral reefs since there were explosions of fish in the past. Although many years passed, nearly all corals had not yet recovered. The ratio of living corals to dead corals was 1:2. Forms of corals mainly found were Coral Branching and Coal Submassive.

          Ao Suthep was in very poor abundance of coral reef condition. The ratio of living corals to dead corals was 1:10. The form of corals found in Ao Suthep was Coral Massive at 5.67%. Cause of deterioration was probably by natural phenomenon like El ninõ and so on, which could not be clearly indicated. It had to be studied in detail. However, if consider the coral reefs in Reef Slope area, it was found that most coral reefs were in good conditions. Therefore, study in detail had to be done if serious management of this area was required.

          Ao Tao contained poor abundance of coral reefs. The ratio of living corals to dead corals was 1:3. Form of corals mainly found was Coral Massive at 12.27%. It might be caused by waves, including visitors’ ships entering in this area. There was a survey of Mu Ko Surin National Park by Simon and his team, reporting that at the spot that tourist vessel, Andaman Princess, stopped over in Ao Tao area, broken corals were found extraordinary. It should be studied in detail in order to collect data for suitable management.

          Ao Saai Daeng was in moderate abundance of coral reef condition. The ratio of living corals to dead corals was 1:1. Form of corals mainly found was Coral Branching at 32.47%

          Ko Torinla was in very good abundance of coral reef condition. The ratio of living corals to dead corals was 3:1. Form of corals mainly found was Coral Branching at 60.20%. In this area, coral reef was formed in one large platform without sand floor in between.

Coral Reef Problems in Mu Ko Surin Marine National Park Area

1. Tourists, especially snorkel groups, lacking of knowledge and cautions of snorkel, put their feet on corals which caused corals to break down. However, there was a study of UNESCO project by Dr. Surapol Sudara and his team reporting that, at present, tourists’ grasping or stepping on corals had decreased, compared to the study data of Chanwichai (1994). It was because of the information in exhibition center; however, more improvement of this education media should be done.
2. Sea Gypsies often stepped on corals during low tide in order to catch fishes hiding around corals.
3. Scrap of net from trawler flowed by water covered corals and made them die.
4. El nino phenomenon and change of water quality made corals die, and be covered by algae. This phenomenon happened in 1999 and caused corals die in vast area, especially in Ao Suthep area.

Picture : Coral Reef Abundance in Mu Ko Surin Marine National Park Comparison between this time study and the national park officers’ study (Remarks: Star symbols represent the national park officers’ data)

Remarks

          There was another simultaneously study project by Simon and his team of Mu Ko Surin Marine National Park. This data was gathered, to study coral reef conditions, on the individual line of 100 meters in length, but divided the depth of the survey area into 3 levels of 1, 5, and 10 meters. The abundance of coral reefs was classified into 5 levels: very good, good, moderate, poor, and very poor. Whereas, the other data was done by using 30-meter-long line, placing 5 times at random, and calculating the average. Therefore, the results of these two projects might be partly different.

          If there will be any studies in the future, this project’s method of survey is mainly recommended. So that, it can be compared to the data in the past, and other studies in other areas in Thailand, according to the agreement in coral reefs conference of BRT Project (Burapha University, 1997).

 

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