Thailand a country of 2,614 kilometers of coast line of which 1,660 km. are in the Gulf of Thailand and another 954 km. on the Andaman Sea. With this length, Thailand can take advantages in being able to have best opportunity to use the sea not only in harvesting marine resources but also can easily have excess for ocean communication and transportation systems.

Naga Expedition, 1959-61 operated in the Gulf of Thailand and the South China Sea stated that the Gulf of Thailand is one among the very productive areas of the world. Since 1957, Thailand started to be interested in marine resources when formerly the freshwater resources had been so rich enough to be more than sufficient for in country consumption. Within a few years after that, Thai fishing vessels had been increasing tremendously. After 3 years when bottom trawler had been introduced, the number reached few thousands of vessels. Thai fishermen developed their skill very fast. From their operation within the Thai waters in the Gulf of Thailand, they went out to other areas all over, such as off the coast of Kalimantan, Indonesia, North of Australia, Bangladesh, Sri Lanka, India etc.

Unfortunately for these Thai fishing vessels, when they had been developed, the new law of the sea has been set up. The areas used to be the international water snow became the Exclusive Economic Zone of various countries concerned. The Thai fishermen had to face the consequences even though Thailand did not rectify this new law of the sea. The serious problems Thailand had to face was the flooded of the trawlers coming back to operate within the Thai waters resulted in serious overfishing problem within the Gulf of Thailand. Near shore resources usually depended by the local people also faced depletion because the illegal intrusion of the trawlers into the 3 km. limit for their operations.

When catching were less, many vessels turned into new technique adapted from traditional hand pushed net operating locally along the shore into gigantic pushed net operating by high power boat. From small bamboo pole to be pushed by hand into now metal beams 3 - 4 times longer than the vessel itself. These push net vessels have been operating all over near shore areas. Most of their catch are trash fish which normally composed of juvenile or young adult animals. These push net technology proved to be one of the most destructive techniques in fisheries since it would catch all the immature or smaller size animals. Anyway, these push net vessels are still in operation because still business in production of animal feeds which require trash fish in large amount is still existed. Deterioration of recourses in coastal areas have become very serious.

From about 3,000 kg. of commercial size fish were caught within one hour trawling when the trawler had newly been introduced, now-a-day only very small amount of commercial size and mostly trash fish are caught. Fishermen developed varieties of new techniques in compensation of this reclined of resources. Using light for cattle fish fishery locally called "dy-boat" (from dynamore for light production) is a very popular technique. At night, lights from such boats are now seen all over the Thai waters. The amount of cattle fish caught has been increasing but less fish caught.

Anchovy fishery which used to be only for local consumption has been expanded for international market, particularly for Malaysia, China and Japan. Light had been adapted to use with new technique developed for this anchovy fishery. Very cleverly, they used the behavior differences of various animal to select only anchovy for the catch. The technique is known as "Owon krob" by turning the light on and off for few times before dropping a square net to catch the anchovy. Amazing that this technique could reduced the by-catch to almost nil. More fishing vessels with light in operation appearing in the see.

Another development to collect short-neck clams had also been employed, metal sieve which could dig rather deep into the surface of the bottom had been used. This sieve would destroy the surface community along its path. Due to the high price of the clam, the operations have been expanding all over.

With all these destructive factors, together with the larger number of trawlers, fishery resources in the Gulf of Thailand had known to be of serious over fishing. Laws and regulations show to be ineffective. At present, serious conflict among local villagers, who have to depend on coastal resources for their income as well as daily consumption, against those types of fishing technologies are evidenced. Despite various policies in reducing the fishing vessels, abandon some devastation techniques used, control the area of operation etc., the reinforcement is still for from making those policies effective. Deterioration of resources is still carried on.

Various coastal ecosystems needed to support the richness of coastal resources are also in serious conditions along the Thai coasts. Coral reefs, even Thailand do have the policy and action plan in coral management, still have been deteriorated from anthropogenic factors as well as from natural phenomena. Tourism which has been one of the top programs promoted by the government as one of the aspects to ease the economical crisis on Thailand could also count as one of the factors causing damage to the reefs when not operating properly and it is commonly evidenced. Apply of toxic chemical to collect aquarium fishes could also cause destruction to the reef, illegal operations are still going on. Waste water discharged into the sea from coastal settlements and fishing villages caused destruction to the reef. Many examples can be found concerning the serious damage to the reef by coastal construction as well as destruction directly to the reef for new that channels or dumped of sediment on to the reefs. Coral bleaching, a natural phenomenon, lately occurred in Thailand is another factor causing reefs degradation and community changed.

Seagrass beds, another coastal ecosystem which usually has been neglected, is actually a very important ecosystem particularly for the juvenile or young adult organisms to depend upon. Thailand had recognized the importance of the seagrass beds and had been monitoring them all along. The result revealed that the Thai seagrass beds are deteriorating resulted from the direct destruction of the seagrass beds by the push nets, dredging for clam or by coastal construction which change the current patterns and substratum condition.

Mangroves eventhough well recognized for their value but destruction of mangroves have still been very serious, particularly from shrimp farms, settlements, changing land use or direct destructive activity aims towards the mangroves. It is well recognized that mangroves is the major contribution of nutrients to the coastal waters which directly enrich the coastal resources. Thailand had tried in various methods to stop the mangrove destruction but resulted in failure. At present, the Cabinet passed the regulation that all the existing natural mangrove forests have to be put on reserved. All concession given out for marry, had to be terminated when the term end. Any way, there are so many activities cause deterioration to the mangrove which can be found in many areas.

All those three coastal ecosystems actually are interconnected. Coastal waters nourished eggs and planktonic larvae of coastal resources. When they reached juvenile or young adult stage, they need seagrass beds to grow up to adult stage before they either go to the reefs or to the mangrove to stay. If only one of these coastal ecosystems is protected it will not be of good help since they need other ecosystems to complete their life cycle. Destruction to one would have impact on others. Hence, to look after or rehabilitate only one of these systems would not help in maintaining the richness of coastal resources.

Knowing the importance of the coastal ecosystems to their livelihood, local villagers now are helping in protecting and rehabilitating these ecosystems. In many areas, they united together and becoming very strong community structure which could extended further into conservation aspect of other organisms such as dugong, turtle, etc.

Formerly, coastal areas used to be inhabitated of fishing villages because of the easy excess to the resources. At present not only that the former villages have been expanding but more people are migrating to settle in the coastal areas all the time. Therefore, more pressure are on the coastal resources.

Coastal constructions are now becoming a serious problem in causing coastal erosion. In Thailand and in other countries, coastal constructions are expanding rapidly. With population explosion coastal areas have been the primary target for human settlement. Hence, more constructions as well as land reclamation can be found all over. Coastal construction needs real understanding of natural coastal process. Many times that the engineer responsible for the construction does not realized the importance of understanding the factors concerning the coastal process, such construction might not be able to stand the wave action or it could cause serious coastal erosion either there or some where near by. It is not only changing the coast line but it could also cause changing in the structure of the habitat as well which would be devastating to the existing animal community.

Land use pattern on the coastal areas which has been changed could also cause some problem to the coastal ecosystem. Interrupting the natural condition of the tide or the coastal ecosystem could be of drastic change, for example, to stop the coming in and out of the tide in the mangrove for human settlement or any other purposes could end up in the total lost of mangrove as well as to discharge untreated waste water into the sea could cause degradation to the coastal water which could also affected coastal resources.

It is also to be noted that any change on land, even sometimes very far away, such as the dam construction upstream, could cause the reduction of sediment transported into the sea. This could cause serious erosion of the area near the water mouth and the diminished of the delta. Those valuable coastal areas could turn to be of no value it they are eroding away or lots of money would have to be spent to mitigate the problem.

Population expansion on the coastal areas would bring in variety of problems if proper management had not been applied. It is therefore necessary to understand the important of integrated coastal management and to apply it correctly. Sustainable development of the coastal area needs to adjust the population pressure on resources. Either to resettle them somewhere else or take some pressure out of some resources by providing them with other alternatives or job opportunities. Developing countries are now facing with rapid development. Without the real understanding of Integrated Coastal Zone Management, many of the developing activities might cause conflict among each other. Rather than to be able to develop to its full capacity and sustainable, it could result in blocking other projects or causing deteration in such a way that valuable resources would be degrading or even to destruction. Therefore, truly understanding of integrate coastal development is needed urgently in developing countries before it is too late for possible sustainable development.