Preliminary Study of Distribution and Quantity of Plastic-debris on Beaches Along the Coast at Phuket Province

The beach sediment samples from Kalim, Tri Trang, and Patong Beaches, Phuket Province, southern of Thailand were collected for preliminary investigation on coastal debris. A total of 9 samples were taken from a 1 x 1 m quadrat at the depth of 5 cm, parallel with the shore during the period of maximum low tides in November, 2018. Microplastics (particles size < 5 mm) were extracted using sodium chloride (1.15 g mL-1) and their characteristics- including abundance (items m-2), weight (g), density (itemsm-2), color and shape- were determined using a stereo microscope. The results showed that microplastic debris varied in abundance from 1 to 35 items m-2 at the three selected beaches, depending on sampling location. In comparison, abundance of macroplastic (> 2.5 cm) and mesoplastic debris (5 mm to 2.5 cm) varied from 1 item m-2 quadrat (Kalim Beach) to 38 items (Patong Beach), 9 items (Tri Trang Beach) and 68 items (Patong Beach) m-2. Blue fibers were predominant among microplastic debris found at Kalim Beach; these are likely to have originated from pieces of rope, safeguard lines and fishing materials. In contrast, microplastic debris found in Patong and Tri Trang Beaches were predominantly green in color. The results of this study provide an overview of the sources of microplastics in coastal environments, which provides a basis for developing long term plastic management plans for these highly popular beaches in Phuket Province.