All six marine turtles: Loggerhead (Caretta caretta), Green (Chelonia mydas), Hawksbill (Eretmochelys imbricata), Olive Ridley (Lepidochelys olivacea), Flatback (Natator depressus) and Leatherback (Dermochelys coriacea), are found in the region.

These are classified as endangered or vulnerable in the IUCN Red List of Threatened Animals (Groombridge 1993). Turtles, in particular, are very much like birds because of their faithful nesting behaviour, which makes them vulnerable to hunters and egg collectors.

Dugong dugon and other marine mammals found in the region are also included in the Red List. Many of these species are comparable to migratory birds in their cross country migratory behaviour and wide range. The transboundary habits of these species make research and actions for conservation strategies extremely difficult unless regional and international cooperation can be reached.

Marine ecosystems are by far the least known among the ecosystems in the world, especially in developing countries where research is often not a priority. Information on the marine environment and species in Myanmar and Cambodia are especially scarce. Nevertheless, new species continue to be discovered worldwide. Which marine species of these little-known countries of the region are in a critical state either due to human threats or to naturally restricted range, and how many are only beginning to be explored. What we know are wide under-estimations.

It is also significant to note that the Southeast Asian region, which is considered an area of the highest marine biodiversity, is the most seriously threatened (see also Burke et al. 2002). Like its terrestrial counterpart, the marine biodiversity of the region suffers from high human density and heavy human dependence on natural resources. Poverty and hunger remain to be a main concern in most countries of this region, leading to the exacerbation of pressures on the marine environment. The rapid increases in human population, coastal urbanisation and development, and demand for export and cash economy have contributed to the overexploitation and degradation of the coastal and marine environment and resources. It has been estimated that 11% of the world’s coral reefs have already been degraded and about 16% are no longer fully functional; 14% are in a critical state such that they are likely to collapse within 2-10 years; and another 18% are also threatened and may probably be destroyed in 10-30 years (Wilkinson 2000).

The Philippines, Indonesia and Malaysia derive 60-70% of their animal protein intake from marine fisheries (McManus 2000). With the onset of overfishing coupled with wealth disparity, subsistence and artisanal fishermen are often forced into destructive fishing techniques such as blastfishing and poisons (Pauly et al. 1989). Poisons like cyanide are generally used for catching aquarium fish and highly priced food fish such as groupers and the maori wrasse (Cheilinus undulatus) for live fish exports for restaurants.

Other techniques being used such as muro-ami in the Philippines are also destructive, especially to coral reefs. The recent alternative gear, Pa-aling, is highly efficient in catching fish but also does not seem to be sustainable (Miclat et al. 1991; Abesamis et al. in press). Illegal trawling by commercial fishers, which is of particular concern in Thailand and Malaysia, also causes serious damage to the habitat and overexploitation. Increased siltation and commercial fishing using push net and bottom trawl are believed to have caused the degradation and destruction of seagrass beds in the Andaman Sea (Chansang & Poovachiranon 1992). The loss of seagrass beds has led to the slow disappearance of the dugong, especially in the Gulf of Thailand, where they are not only killed accidentally by fishing gear, but also hunted (Nateekanjanalarp & Sudara 1992). Terrestrial impacts on coastal habitats and biodiversity, often caused by river runoffs carrying pollutants and sediment from deforested hills, and coastal development have been widely documented in the Philippines and the region as a whole (Hodgson & Dixon 1988; Chou 1994). Degradation caused by coal and sand mining, port development, marine traffic and overuse by tourism have been addressed nationwide in Vietnam (Biodiversity Action Plan Planning Team 1994). The conversion of mangrove areas for shrimp ponds and other development projects, not only destroys the mangrove habitats but also causes siltation of the water, which in turn can kill corals and seagrasses.

The countries of the region exhibit a wide range of legal and management frameworks and strategies for MPAs and marine conservation in general. Due to the longer history of terrestrial protected areas than MPAs, the mandate for the planning and management of MPAs in most countries lies upon the Departments of Forestry or Environment, which are traditionally the authority for nature reserves and national parks on land (see Table i.2). Such an arrangement is far from ideal since, in most cases, the legal framework and personnel capacity of these departments are inadequate or inappropriate for marine environmental issues. The governments of the Philippines and Singapore receive a lot of assistance on MPA planning, monitoring and awareness promotion from scientific institutions and non-government organisations. However, jurisdictional problems occur due to unclear mechanisms for coordination among the government agencies. In the Philippines, complicated issues on coordination exist between the Department of Environment and Natural Resources (DENR) and the Bureau of Fisheries and Aquatic Resources (BFAR) under the Department of Agriculture (DA), in addition to the concerns of the local government.

Likewise for Peninsular Malaysia, MPAs are managed by the Fisheries Department, which has the knowledge on fisheries resources management although a change in perspective is now beginning. However, this arrangement is hampered by the fact that the Fisheries Department does not have any jurisdiction over the terrestrial portions of the MPAs, hence negative impacts from terrestrial activities such as deforestation and coastal development within MPAs are often difficult to control. On the other hand, in Sabah of Eastern Malaysia, such problems are less serious as all state-owned land or MPAs are managed by a single authority, the Sabah Parks Wildlife Department. Protected areas outside of the state land are managed by the Wildlife Department.

Due to the different culture, tradition, land and marine tenure systems, management capabilities and the nature of threats imposed upon the marine environment, the strategies for planning and management of MPAs also vary widely from country to country and among sites. Government support is important for the management of MPAs in Malaysia and most parts of Thailand and Indonesia. Community-based management of MPAs and marine resources is very much advocated and practised in the Philippines and some parts of Thailand (e.g. in dugong areas around Trang in the Andaman Sea).

Traditional management practices also occur in the Maluku of eastern Indonesia although, in some areas, financial constraints, inadequate developmental capability and undue government interference have impaired management effectiveness.