Distribution of C/N/P stoichiometry in suspended particulate matter and surface sediment in a bay under serious anthropogenic influence: Daya Bay, China

Chen

et al. 2021

Preprint

Sediment (SOM) and suspended particulate (SPOM) organic matters are two important organic matters in water. Their occurrence, migration and transformation, and stability have important effects on the environmental behaviors of carbon, nitrogen, phosphorus, and other pollutants in a water environment. The content, composition, fluorescence characteristics, source, and stability of SOM and SPOM in Hulun Lake, a typical lake in cold and arid region of China, were compared by sequential extraction, three-dimensional fluorescence spectroscopy, parallel factor technique, carbon–nitrogen ratio, and stable carbon isotope. SOM and SPOM in north and west were higher than those in east and south. The average content of SPOM (24.70 ± 4.63 g/kg) was slightly higher than that of SOM (23.04 ± 10.27 g/kg), but the difference was not significant. Humin was the dominant component in SOM and SPOM, accounting for 73.7% and 61.2%, respectively. Humus was the main fluorescence component of water-extractable organic matter in SOM and SPOM, accounting for 79.9% and 70.4%, respectively, of the total fluorescence intensity. SOM and SPOM were derived from terrestrial sources with relative contribution rate of about 70%. SPOM was more influenced by autochthonous sources and had significantly lower humification degree and stability than SOM. Effects of climate changes on migration, transformation, stability, and bioavailability of organic matters and endogenous pollutants closely related to organic matters in lakes of cold and arid regions should be paid attention in the future.

Section: Introductionmentioning

confidence: 99%

Differences in the Composition, Source, and Stability of Suspended Particulate Matter and Sediment Organic Matter in Hulun Lake, China

Chen

et al. 2021

Preprint

“…It was indicated that sediment MPs shared similar sources with total organic N and C in the sediments, which was also suggested by a significant Pearson correlation between the contents of total organic N and C and sediment MP abundance (p < 0.05). The C/N ratio is frequently used to identify the proportions of sedimentary organic matter originating from marine autogenic and terrigenous inputs [83]. Generally, the C/N ratio of sediment organic matter from terrestrial sources is equal to or above 20, while that from marine origins typically varies between 5 and 8 [84].…”

Section: Potential Correlation Between Environmental Factors and Micr...mentioning

confidence: 99%

Microplastic Pollution and Its Potential Correlation with Environmental Factors in Daya Bay, South China Sea

Liu

Liao

Deng

et al. 2023

JMSE

Self Cite

Microplastics (MPs) have been given considerable attention due to their risk to aquatic organisms in marine environments. In this study, MPs’ abundance and their potential correlation with environmental factors were investigated from 26 sites in Daya Bay, South China Sea. The results showed that the abundance of MPs was 1.8–13.87 items/L in surface water and 190–823 items/kg (dry weight) in sediment. The most abundant shape of MPs in both water and sediment was fiber, the most abundant particle size was 0.5–1 mm and the most abundant color was transparent. In addition, the most common polymer type of MPs was polyethylene terephthalate (PET), followed by rayon (RY), polypropylene (PP), cellulose (CL) and polyethylene (PE). The abundance of MPs in sediment was significantly correlated with sediment organic N and C (p < 0.05), while that in surface water had no significant correlation with the environmental factors except dissolved oxygen (p > 0.05). A factor analysis showed that MPs in sediment might share similar sources with organic N and C, which were mainly from the autochthonous sedimentation of marine organisms, and MPs might sediment jointly with organic matter. In summary, this study reflects on MP pollution and the potential correlation with environmental factors, providing essential data for governmental agencies to formulate microplastic pollution control policies.

“…Similarly, phytoplankton community stability might be primarily determined by phytoplankton species diversity, which requires evaluation of the relationship between phytoplankton diversity and stability in marine ecosystems. Meanwhile, assessment of ecological stoichiometry (ES) mainly focuses on chemical elements (carbon (C), nitrogen (N), and phosphorous (P)) in components as well as interactions and processes in ecosystems, and it is beneficial for understanding the effect of human activities on the balance and biogeochemical cycling of bio‐elements in oceanographic ecosystems (Babbin et al, 2014 ; Bradshaw et al, 2012 ; Chen et al, 2021 ). Consequently, the number of ES studies has increased rapidly in recent years (Sardans et al, 2021 ).…”

Section: Introductionmentioning

confidence: 99%

Ecological stoichiometry influences phytoplankton alpha and beta diversity rather than the community stability in subtropical bay

Huang²,

Shu

et al. 2022

Ecology and Evolution

Numerous studies have shown that changes in environmental factors can significantly impact and shift the structure of phytoplankton communities in marine ecosystems. However, little is known about the association between the ecological stoichiometry of seawater nutrients and phytoplankton community diversity and stability in subtropical bays. Therefore, we investigated the relationship between the phytoplankton community assemblage and seasonal variation in the Beibu Gulf, South China Sea. In this study, we found that the abundance of Bacillariophyceae in spring was relatively greater than in other seasons, whereas the abundance of Coscinodiscophyceae was relatively low in spring and winter but greatly increased in summer and autumn. Values of the alpha diversity indices gradually increased from spring to winter, revealing that seasonal variations shifted the phytoplankton community structure. The regression lines between the average variation degree and the Shannon index and Bray–Curtis dissimilarity values showed significantly positive correlations, indicating that high diversity was beneficial to maintaining community stability. In addition, the ecological stoichiometry of nutrients exhibited significantly positive associations with Shannon index and Bray–Curtis dissimilarity, demonstrating that ecological stoichiometry can significantly influence the alpha and beta diversity of phytoplankton communities. The C:N:P ratio was not statistically significantly correlated with average variation degree, suggesting that ecological stoichiometry rarely impacted the community stability. Temperature, nitrate, dissolved inorganic phosphorous, and total dissolved phosphorus were the main drivers of the phytoplankton community assemblage. The results of this study provide new perspectives about what influences phytoplankton community structure and the association between ecological stoichiometry, community diversity, and stability in response to environmental changes.