Holistic Impact Evaluation of Human Activities on the Coastal Fish Biodiversity in the Chinese Coastal Environment

Abstract

Ecological qualities and resources in coasts are threatened by various human activities, such as pollution and fishery. Impact evaluation of environmental stressors over a wide coastal stretch has been limited due to lack of efficient and standardizable biodiversity monitoring and assessment tools. Integrating environmental DNA (eDNA) and ecological traits, a holistic approach was developed to assess the impact of pollution and aquaculture on fish biodiversity in Chinese coastal areas. Taking the Yalujiang Estuary (YLJK) from the Yellow Sea and the Nan’ao Island Area (NAO) from the South China Sea as cases, the performance of the eDNA biomonitoring workflow was validated. First, the eDNA results of 22 sampling sites reached more than 85% of the asymptotes of species or ASVs in each area. A total of 115 fish species in both areas were detected and NAO was 1.8 times richer than YLJK using eDNA and the fish eDNA composition was consistent with the historical data. eDNA recovered distinct variations of fish sequence, taxonomic and functional diversity, and the corresponding trends following the offshore distance between the two areas. Fish sequence diversity was decreased primarily by estuarine pollution factors (chemical oxygen demand and zinc) in the YLJK. Compared with no breeding areas, lower fish sequence diversity was in breeding areas in the NAO. By integrating ecological traits, the eDNA approach offers promising opportunities for future fish biodiversity monitoring and assessment in national and global coastal environments.

Better or worse food: Nutrition value of the prey fishes and the potential health implications for Indo-Pacific humpback dolphins

“…In addition, as an effective management tool for fishery resources (Kitada, 2018), the artificial enhancement and release of nutrientrich fish species, such as the spiny head croaker and Osbeck's grenadier anchovy (Coilia mystus), would be helpful in restoring the dietary quantity and quality of humpback dolphins. Furthermore, novel high throughput technologies, such as targeted metabolomics, environmental DNA barcoding and genomic sequencing, should be used to assess the prey fish population and their nutritional quality as well as their habitat ecosystem (Valenzuela-Quinonez, 2016;Zhong et al, 2022).…”

Phytoplankton and Microzooplankton Community Structure and Assembly Mechanisms in Northwestern Pacific Ocean Estuaries with Environmental Heterogeneity and Geographic Segregation

“…Despite the successful application of eDNA metabarcoding technology in the present study, it still has some shortfalls. The lack of a thorough barcode data set to base the eDNA analysis is the biggest obstacle for application the eDNA metabarcoding technology ( 30 ), which could lead to false negative and a few wrong taxonomic results ( 31 ). In addition, further comparison between the results from classical analysis with the use of microscopes could benefit to evaluate the accuracy of eDNA metabarcoding for microplankton ( 28 ).…”

Fishing eDNA in One of the World’s Largest Rivers: A Case Study of Cross-Sectional and Depth Profile Sampling in the Yangtze

“…Genomic DNA was extracted from the water samples using a DNeasy Blood & Tissue Kit (Qiagen) following the standard manufacturer's procedures, which were modified accordingly for the water samples. 43 DNA quantities were checked by a Qubit 2.0 fluorometer (Thermo Fischer Scientific) using Invitrogen Qubit 1X dsDNA HS Assay Kits. We pooled the four subsamples of the same sampling point into one eDNA sample and stored them at −20 °C until the subsequent analysis.…”