Kuala Gula which is located towards of the Matang Mangrove Forest Reserve (MFR) is the single largest tract of mangrove forest in Peninsular Malaysia that covers an area of 40,000 ha. In 1906, Kuala Gula was first protected as a forest reserve and currently is rated as the best-managed mangrove forests on a sustainable source in the world. Kuala Gula and its associated wetlands which are mudflats, mangroves, rivers, and estuaries extend to approximately 12,000 ha. The mangrove that is rich breeding ground for various aquatic life, including shrimps, cockles, and mud crabs have been a vital area for fisheries as a majority of the local community at Kuala Gula is involved in this successful business. There are about 600 families involved in the harvesting of fish, shrimp, and shellfish, cockle farming, aquaculture as well as in the processing of shrimp and fish products (Hua, n.d.). In Malaysia and Thailand, cockle breeding activities become a major aquaculture activity that has been actively developing recently (Yurimoto, Kassim, Fuseya, & Man, 2014).One of the main attractions at Kuala Gula is can experience the cockle-breeding activities done by the cockle breeders or the fishermen. Today many of the fishermen and cockle breeders still rely on conventional methods to bring in their haul. As the boat glides down the river, tourists will see fishermen casting their nets and cockle breeders harvesting their catch. A demonstration will be done by the fishermen with their deft cockle harvesting skills using a steel cage tied to a long mangrove wood pole. The fishermen will fit the pedal to the pole for them to step on, which then thrusts the cage into the water to scoop up the cockles. Then, the fishermen will pull the cage when the bubbling sound generated by the shellfish and also when the weight of the cage is loaded with the bounty of cockles. The cockles then are automatically sorted by size. The small ones will fall out through the gap between the bars on the cage and these are thrown back into the sea to mature further. The species of cockle (Anadara granosa) that present at Kuala Gula is also widely distributed from the Middle East to East Asia. It is a member of the Arcidae family that has red bodily fluid which contains hemoglobin and its habitat is in soft muddy bottoms of tidal flats that formed in estuaries or the interior of bays (Yurimoto, Kassim, Fuseya, & Man, 2014).In 2014, Star Online has reported that most of the cockles that live in estuaries area are facing some threats that declined its population. According to Lim (2014) has stated that some plastic bags have been notable during the harvesting of cockle activities being done. This indicates that the cockles breeding areas have been polluted by the waste materials. The effluent of chemicals that have been used to clean up the ponds for the aquaculture farm and the chemical wastes from the factories were discharged into the water. Factors thought that have caused the waste materials in the breeding area come from the tourists that have thrown away their rubbish into the visit site and from the local community from the residential areas around the estuaries. This is because based on the observation, the estuaries are surrounded by the houses of the local communities and have been a visit site for eco-tourism activities. Furthermore, the boats that navigated the cockle sites also give impact on the growth of the cockles. The runoffs surface and the strong waves from the movement of the boats caused the soft sediment layer in the seabed that cockles depend upon for growth has been washed away. In addition, anthropogenic activities also have to be highlighted as they will contribute to the accumulation of hazardous chemicals in the environment.Next, other factors that may have an influence on the declination of the cockle population such as overcrowding cockles, sediment deterioration, flooding, and sediment disturbance in aquaculture grounds have been identified (Yurimoto, Kassim, Fuseya, & Man, 2014). However, the main identification of the main causative factors that have played an important role in causing the death of the cockles still cannot be identified since these events involve a complicated interplay between the physiological condition of bivalves and environmental factors. So, the cause of death can rarely be explained by a single factor. For example, even when bivalves are exposed to poor environmental conditions, such as hydrogen sulfide or hypoxia, they exhibit some resistance and do not die straight away (Nagasoe, Yurimoto, Suzuki, Maeno, & Kimoto, 2011). Besides, a study has been done has shown that the exposure of the hydrogen sulfide is not directly killed the bivalves but has caused the damage of bivalves’ tissue and its physiology such as incapable to feed normally. However, the bivalves would starve or be gradually weakened as a result of the sulfide-caused damage to their gills although the environment may return to optimal conditions. Consequently, weakened clams would be more vulnerable to disease and death. These impacts of hydrogen sulfide may be related to the mortality of bivalves in the field. Therefore, the authorities have to overcome this problem together if the pollution is detected and the factories in the surrounding areas need to be compounded for their unmonitored discharge. Lastly, the aquaculture activities also have to stop in order for the water to return to its initial state..