Malaysia's marine environment is rich and diverse, encompassing ecosystems such as coral reefs, mangroves, seagrass beds, and coastal waters. These ecosystems support vital fisheries and aquaculture industries, which are essential for local communities and contribute significantly to the national economy. However, human activities have led to the release of pollutants into these waters, posing a threat to the health and sustainability of these natural resources. Booster biocides contribute to the pollution found in Malaysian waters, primarily due to their use in shipping activities, agro-industries, and domestic applications. These substances are known to cause adverse effects on marine ecosystems and non-target organism, including the inhibition of photosynthesis in marine plants and the potential to accumulate in marine organisms. This book discussed the levels of booster biocides of Irgarol 1051, diuron, 3,4-dichloroaniline (3,4-DCA), and chlorothalonil found in blood cockle, Tegillarca granosa, and sediment from cockle cultivation areas in Peninsular Malaysia. The accumulation of these chemicals in T. granosa tissues and sediment highlights their potential as biomonitors in the marine environment.