The Occurrence of Microplastics in Sediment Cores from Two Mangrove Areas in Southern Thailand

Abstract

Mangroves are areas that connect the land and sea, and are important to the ecosystem. They are important places for food sources and the habitat of aquatic fauna in the tidal areas. However, the existence of plastic debris poses a risk to the aquatic environment. This study aimed to investigate the accumulation of microplastics (MPs) in sediment cores from two mangrove areas. The first mangrove area is in the outer section of the Songkhla lagoon (SK), while the second is in the coastal area of Pattani province (PN). Sediment core sampling was performed from SK = 8 stations and PN = 5 stations. Surface enrichment of MP was observed, especially in sediments of 0–4 cm. MPs were found throughout the depth in both areas, while fewer MPs were found in deeper sediment core layers (p < 0.05) at some stations inside the mangrove zone. Simple linear regression of the observed MPs and distance in the horizontal were found to be significant at SK within the mangrove zone with r2 = 0.79 (p < 0.05). MP fibers were the most commonly found MP type in both areas and were less than 1 mm. Blue and black MPs were the most abundant colors found in both areas. The six polymer types reported in this study comprised polyethylene, rayon, rubber, styrene, Poly (vinyl acetate), and paint. The findings of the present study suggest that long-term monitoring of marine debris along coastlines is necessary to help improve national policies and measures related to marine plastic debris.

Preliminary study on microplastic abundance in mangrove sediment cores at Mae Klong River, upper Gulf of Thailand

“…The microplastics found in this study were mostly in fiber form, as in previous studies in mangrove core sediments in southern Thailand, Hangzhou Bay, China, and Northern Vietnam (Li et al, 2020a;Luu Viet et al, 2021;Pradit et al, 2022). Moreover, many previous studies also suggested that the fiber type is detected as a major shape of microplastics in mangrove environments (biota: (Hastuti et al, 2019;Klangnurak and Chunniyom, 2020), sediments: (Mohamed Nor and Obbard, 2014;Wang et al, 2020;Zuo et al, 2020)).…”

“…Accordingly, the microplastics found in this study can be implied as sourced from households around the study area. Besides the microplastics found in mangrove sediment cores from Pattani and Songkhla, southern Thailand, rubber and paint have been reported (Pradit et al, 2022). Other synthetic particles were also discovered associated with plastic polymers in this study, and the µ-FTIR analysis identified compounds of small particles, tire rubber, pigment, paint, dyes, and flame retardant.…”

“…Mangrove areas have a high sinking potential for sediment load and microplastics because of their plant root systems and lowenergy environments (Mohamed Nor and Obbard, 2014). Moreover, the investigation of undated sediment cores from mangrove areas in southern Thailand showed that microplastics occurred in greater amounts in mangrove areas than that in outside areas because of the trapping potential of mangrove roots (Pradit et al, 2022). In addition, there was a significant amount of microplastics in the shelter of wetlands and the surrounding community area, whereas there was a lower amount in open seafacing areas, the Gulf of Thailand, and the outer community area (Pradit et al, 2022).…”

Occurrence of microplastics in freshwater gastropods from a tropical river U-Taphao, southern Thailand

“…MP particles were identified, counted, and characterized (shape, size, and color) by visual identification under a stereomicroscope (Leica, EZ4W; Switzerland, Europe) with the Leica Application Suite program. We also applied the Hidalgo-Ruz et al (2012) rules mentioned in Pradit et al (2022a) to assist in identifying the MPs most encountered in this study. The rules were as follows: rule 1 = no cellular or organic structures visible, rule 2 = fibers should be equally thick throughout their entire length, and rule 3 = particles should exhibit homogenous color throughout the item.…”

“…Plastic waste in aquatic ecosystems has become a local, regional, and global issue. Several million tons of plastic waste are released into the marine environment through rivers and atmospheric particles ( Chen et al, 2021 ; Pradit et al, 2022a ). Microplastics (MPs) are plastic debris defined as particles less than 5 mm ( NOAA, 2009 ) and are classified as marine waste.…”