1 st Draft: 4 pages Date Printed: 12 July 2018 08:00 A.M. Key words: AMD, marine debris, Mayo Bay, Philippines, solid waste management A Survey of Subtidal Anthropogenic Marine Debris (AMD) in Mayo Bay, Mati City, Davao Oriental, Philippines *Corresponding author: nas.abreo@gmail.com Neil Angelo S. Abreo 1,2,4 *, Edison D. Macusi, 2,3 and Lea A. Jimenez 2 Anthropogenic marine debris (AMD) is considered a global threat to the marine environment. Mortality from ingestion or entanglement in AMD is widely reported from marine animals and has harmful impacts on seagrass and corals. The distribution of AMD plays a vital role in its interaction with marine organisms. However, there is little information on AMD distribution in the Philippines – a country ranked as the third most significant contributor of AMD in the ocean. During the monitoring of dugong (Dugong dugon) feeding trails in Mati City, Davao Oriental, Philippines, AMD was recorded at one of the sites surveyed. Plastic debris was the most dominant in number and weight of total AMD collected. Here we present the first quantification, characterization, and distribution of AMD in a shallow subtidal area in Mati City, Philippines. More studies are needed to assess the impacts of AMD on the marine environment and organisms, particularly within the Philippines. Philippine Journal of Science 147 (4): 599-602, December 2018 ISSN 0031 - 7683 Date Received: 02 Jul 2018 5_MS_18-009 1 Senior High School Department, Malayan Colleges Mindanao, Davao City, Philippines 2 Regional Integrated Coastal Resource Management Center (RIC–XI), Davao Oriental State College of Science and Technology, Mati City, Davao Oriental, Philippines 3 Institute of Agriculture and Life Sciences, Davao Oriental State College of Science and Technology (DOSCST), Guang-Guang, Barangay Dahican, Mati City, Davao Oriental, Philippines 4 Institute of Aquatic and Applied Sciences, Davao del Norte State College, Panabo City, Davao del Norte, Philippines INTRODUCTION The threat of anthropogenic marine debris (AMD) to marine biodiversity is a global problem. Plastic, the most dominant type of AMD, reportedly affects marine organisms at different trophic levels and coastal habitats (Kühn et al. 2015) . The full extent of AMD is still unknown, possibly because of the “cryptic” nature of the problem (Williams et al. 2011). Impacts of AMD may only become evident when data from stranding events and necropsies reveal their presence. Reports on AMD ingestion rely on post- mortem examinations (e.g., Abreo et al. 2016) and not all strandings are examined. Given the ubiquity of plastic usages in society (e.g., food wrappers, plastic bags, and decorations), some eventually ends up in the marine environment and impacts marine organisms (Kühn et al. 2015). Coastal areas are often densely populated by people contributing to the entry of disposable plastics to the marine habitat. In Mati City, the habitat of sea turtles and dugong overlaps with coastal communities. This overlap may lead to interactions between AMD and marine organisms, 599