The occurrence of pollutants in organisms and water of inland mariculture systems Shrimp aquaculture is a procession of Microplastics accumulation

Abstract

Microplastics (MPs) pollution in the ocean was widely concerned, but the current study on MPs pollution in the mariculture system is relatively lacking. This study researched the MPs pollution characteristics in water and shrimp at different stages of the pond and industrial aquaculture. The study shows that in the same aquaculture stage, MPs abundance in shrimp and water in pond aquaculture mode is higher than that in industrial aquaculture mode. The MPs pollution characteristics in shrimp and water show significant consistency. The hazard index of MPs in pond water and industrial models are 122 (Level Ⅲ) and 540 (Level Ⅲ), respectively, indicating that industrial aquaculture models may suffer from more severe MPs stress. The aquaculture period and mode significantly affected the MPs abundance of water and shrimp, but there was no interaction between the aquaculture period and mode. MPs abundance in shrimp show a significant relationship with the length of crustacean and weight. This study further enhanced the understanding of MPs pollution of water and organisms in different aquaculture modes at different stages, and warned MPs is widely spread in mariculture systems.

Graphical abstract

Introduction

Plastic has become one of the most crucial materials currently used by human beings due to its advantages such as low cost and lightweight (Andrady and Neal, 2009). More than 390 million tons of plastic were produced in 2021 globally (Plastics Europe, 2022). Unfortunately, plastic contamination of the marine environment is a well-known environmental problem due to poor management. Plastic with less than 5 mm particle size is defined as microplastic (MPs, Thompson et al., 2004). MPs initiate industrial production, and large-scale polymer crushing under the action of physical, chemical, and biological processes (Thompson et al., 2004; Ryan et al., 2009). MPs in marine biotic (Dawson et al., 2018; Wang et al., 2021; Zhang et al., 2022; Tang et al., 2022) and abiotic mediums (Feng et al., 2020a; Huang et al., 2021; Song et al., 2023a) were widely reported in recent years, MPs are even argued as a stratigraphic signal of the Anthropocene due to accumulation (Long et al., 2022). Owing to various mechanisms, MPs can accumulate in the skin, digestive tract, gill, gonad, and even in the liver and lymph (Collard et al., 2018; Feng et al., 2019; Feng et al., 2020b; Song et al., 2022). The traditional study suggested that MPs may lead to harm from the molecular to the individual level (Yuan et al., 2020). With the transmission of the food chain, MPs pollution has raised concerns about human health and ecological risk (Bank et al., 2020; Seeley et al., 2020; Vethaak and Legler, 2021).

The pollution characteristics of MPs in biological media in aquaculture areas and systems due to more intensive human activity were gradually explored (Lin et al., 2022). Traditional studies considered MPs contamination to be more serious in cultured individuals than in wild individuals (Mathalon and Hill, 2014). Nevertheless, the study suggested that the characteristics of MPs pollution in mussel caging are akin to those in native individuals (Kazour and Amara, 2020). An average of 0.62 items/g and 2.93 items/individual MPs were found in cultured oysters (Teng et al., 2019). Wu et al. found widespread MPs contamination in cultured commercial aquatic species, with individuals accumulating 0.95 to 2.1 MPs (2020). The differences in MPs pollution characteristics between aquaculture and wildlife are also uncovered. The fiber was distributed in the gut for cultured cuttlefish while the digestive gland was the predominant location for wild-caught (Oliveira et al., 2020). Differences in MPs contamination features between cultured and wild fugu were also found (Song et al., 2022). Additionally, the characteristics of MPs pollution in freshwater aquaculture systems are gradually being revealed (Wu et al., 2022; Xiong et al., 2022). Yet, there have been few reports related to the characteristics of MPs pollution in land-based mariculture systems so far.

China contributes over 60% of aquaculture production (FAO, 2016), more than 77% of production is from aquaculture sources, and land-based aquaculture occupies a crucial position (China Fishery Statistical Yearbook, 2020). It was reported that Penaeus vannamei is the most widely cultured crustacean species (Zhao et al., 2017). P. vannamei aquaculture has been a crucial economic aquaculture activity due to high market requirement, harvest, and attractive nutritional value, which accounts for nearly 80% of China's cultured shrimps (China Fishery Statistical Yearbook, 2020; Shao et al., 2020). Although there has been a considerable amount of study on cultured shrimps, there is limited knowledge about the MPs pollution in P. vannamei. A study has reported that the abundance of MPs in cultured P. vannamei can reach 18.5 ± 1.2 items/individual (Valencia-Castañeda et al., 2022). The latest study shows that an average 5.5 ± 0.5 MPs were detected in the organs of P. vannamei (Páez Osuna et al., 2023). In addition, there has been some studies on the toxic effects of MPs on P. vannamei (Seta et al., 2023; Yu et al., 2023), but there has been no study on the characteristics of MPs pollution in different aquaculture systems and periods. This study aims to uncover MPs in P. vannamei and the water within land-based mariculture, to explore the similarities and differences in MPs contamination across different aquaculture modes, and to provide baseline data for food safety testing and pollution control.

Section snippets

Sampling and preparation

The culture period of P. vannamei in the study area is typically 3–4 months. To standardize the "stage" expression, we will refer to the water in the source as the early stage. In the medium stage, the sampling is 2 months after the shrimp larvae enter the pond. And in the later stage, the sampling occurs prior to shrimp harvest. During the year 2019, water samples were collected in pond aquaculture mode and industrial aquaculture mode at a depth of 30 cm from each sampling point (Fig. 1).

MPs abundance in different aquaculture modes

The abundance of MPs of water in different aquaculture modes is shown in Fig. 2. In total, 87, 553, and 753 MPs were detected in the early water (150 L), medium water (150 L), and later water (120 L) of pond aquaculture, respectively. Overall, 25, 147, and 309 MPs were detected in early water (72 L), medium water (90 L), and the later water (150 L) of the industrial aquaculture. The concentration of MPs is the lowest during the early stages of water cultivation in both pond and industrial....

MPs abundance of shrimp aquaculture

In this study, MPs abundance in the water continued to increase in the two aquaculture modes, which indicates that the aquaculture of P. vannamei is a process of MPs accumulation. The MPs abundance in the water of pond aquaculture mode increased from source to later stage, significantly. While the MPs abundance in the water of later stage of industrial aquaculture was also higher than source stage, but did not reach a significant level. MPs accumulate in pond aquaculture due to the practice of......

Conclusion

Land-based mariculture is a crucial seafood resource, MPs pollution impacts aquatic production and is a potential threat to human health. This study found that MPs polluted water and shrimp by studying various aquacultural systems: 0.57 ± 0.11–6.47 ± 0.30 items/L for water and 8.40 ± 6.22–18.27 ± 3.55 items/individual for shrimp. MPs pollution features were different for distinct aquaculture modes, more serious MPs contamination existed in water and shrimps in pond aquaculture than in....

CRediT authorship contribution statement

Kexin Song: Methodology, Software, Writing - original draft, Visualization. Siqi Xie: Formal analysis, Methodology. Changwen Li: Visualization, Investigation. Jincheng He: Investigation. Wei Jin: Investigation. Rui Wang: Investigation. Wei Huang: Methodology. Pingjing Li: Supervision, Funding acquisition. Zhihua Feng: Resources, Writing - review & editing, Supervision, Funding acquisition....

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper....

Acknowledgement

This work was supported by: The Natural Science Foundation of the Jiangsu Higher Education Institutions of China (22KJA170001), Jiangsu Province Industry University Research Cooperation Project (BY2020428), 2022 Lianyungang Phase VI "521 Project" Scientific Research Project (LYG06521202265), Hainan Provincial Natural Science Foundation of China (422RC745) and the Priority Academic Program Development of Jiangsu Higher Education Institutions....