Microplastic Contamination in Blood Cockles and Mussels in Bandon Bay, Suratthani Province, Thailand

Abstract

Widespread microplastic contamination has been of growing concern worldwide and poses a growing threat to the marine environment, particularly the impact on the food chain. This study quantified the presence of microplastics in two bivalves of commercial interest at the Pak Kadae Estuary, Bandon Bay, Surat Thani province, Thailand: green mussel Perna viridis (L.) and cockles Tegillarca granosa (L.). Data collection was carried out over two seasons: dry season (April - May 2019) and wet season (June - August 2019). Microplastics were extracted using a 10 % potassium hydroxide (KOH) digestion method and then identified under a microscope. Results confirmed the presence of microplastics in both cockles and green mussels, during the dry season, with mean concentrations of 0.30±0.07 and 1.26±0.10 items/individual, respectively. During the wet season, the mean microplastic concentrations were 0.20±0.07 and 0.56±0.15 items/individual in the cockles and green mussels, respectively. There was a greater concentration of microplastics found in green mussels compared to cockles (P < 0.05) with no seasonal variation being observed. Five different shapes of microplastics, including fiber, fragment, pellet, rod, and film, were detected in the soft tissues of the bivalves. Fibers were the most common shape in green mussels (49 - 69 %) during both seasons. Cockles, in contrast, predominantly contained the pellet shape in the dry season (49 %) and fiber in the wet season (59 %). In addition, the microplastic concentrations were positively correlated to shell heights of the bivalves (P < 0.01). The number of microplastics recorded in the two commercially exploited species demonstrated the need for controlling plastic pollution in coastal ecosystems.
 HIGHLIGHTS
 
 Green mussels showed higher contamination with microplastics than blood cockles
 An average (Mean±SD) of 0.28±0.05 to 2.14±0.36 items/individual in cockles and 0.65±0.13 to 3.43±0.21 items /individual in mussels were obtained
 Microplastic fibers were the dominant shape found in shellfish
 Blue microplastics was the most frequently found in green mussels whereas the black color dominated in cockles
 
 GRAPHICAL ABSTRACT

Microplastic contamination in the Chanthaburi estuarine ecosystem, Eastern part of Thailand

“…Based on the results, fiber shapes were found to be more predominant in the marine bioindicators and it is very common to observe in the sediments. This study is correspondent to the studies of Yan et al (2021) and Ruairuen et al (2022), who reported that filamentous MPs were the most frequent shape and the highest amount in white shrimps and cockles. The colour of MPs in this study showed various shades like black, red, blue and green, which is consistent with previous studies on microplastic pollution (Chinfak et al, 2021;Jiwarungrueangkul et al, 2021).…”

“…The MP particles found in the samples of cockles, white shrimps and sediments were predominantly black colour (Table 2). Ruairuen et al (2022) 6.The MPs contamination in the marine ecosystem also might cause foodborne illness from digestive system to body tissues due to MP particles were transferred from the environment to the aquatic food webs (Bhutto et al, 2023). Plastic waste causes abundant type of marine pollution in the Gulf of Thailand due to disposal of municipal plastic waste (MPW) in 23 coastal provinces, and 50 % are disposed without appropriated management (Kamsook et al, 2023).…”

Catch assemblages in the small-scale trap fishery with relation to hydrographic features of a tropical bay in the Gulf of Thailand

“…Due to the bay's characteristics, it is home of at least 340 fishes and other aquatic animals; mollusks and crustaceans are particularly abundant, and support many SSF activities [14,17]. Moreover, Bandon Bay also supports intensive sea farming, especially of bivalve species such as blood cockle, green mussel and oysters [18]. A recent report on SSF revealed 2,890 registered fishers, and their estimated combined catch was about 450 tonnes in 2022 from almost 30 fishing gear types that target various types of aquatic animals [19].…”

Analysis of the influence of polystyrene microplastics and their derivatives on the DNA of human colon epithelial cells HT29 with the comet assay

“…Most of the literature data presented up to date suggest that MPs take up to several thousand years to degrade further. 5 Our present level of knowledge about 'nonbiodegradable, durable PS' in face of facts about how MPs are created and changing. 6 There are still new publications about the tissue and organs where MPs were found and especially the toxicity of MPs in a mammal where presented here research ful l lacks.…”

“…2,19 Factors such as UV radiation, the presence of salt ions and wave movement in the marine environment, as well as contact and exposure time, contribute to the increasing fragmentation of plastics and an increased risk to human health. 5 Moreover, so far no one has been able to estimate how these compounds adsorbed by MPs are released in our digestive tract and which changes in our body they undergo. It has been proven that other plastic derivatives, such as bisphenols, can only become dangerous in our digestive tract.…”