Biodiversity and spatial heterogeneity of fish communities in response to geo-environmental disturbances

Abstract

Coastal ecosystems are intricately connected to human life. However, increasing human activities have exerted significant pressure on coastal fish communities. Understanding the relationship between fish communities and geo-environmental disturbances is essential for the scientific development of fish conservation and environmental restoration strategies. Despite this importance, our understanding of this relationship remains limited. To address this gap, we established 40 sampling points along the coast of Guangdong in the autumn of 2020 to enhance our understanding of how geo-environmental disturbances have affected the spatial pattern of fish communities. The fish communities along the coast of Guangdong were broadly categorized into three distinct regions (A, B, and C), which were primarily affected by geo-environmental factors including longitude, latitude, depth, and environmental disturbances such as bottom trawling. Notably, biodiversity indicators such as Shannon, Delta+, and FDiv varied significantly in different regions. They were negatively correlated with both longitude and latitude, but positively correlated with water depth and environmental disturbances (W). Furthermore, FDiv served as a critical link between the spatial heterogeneity of fish communities and the geo-environmental disturbances. The spatial average variation degree (SAVD) was positively correlated with biodiversity, but exhibited an opposite pattern with fish community stability. Fish species that significantly contributing to the spatial heterogeneity and stability of fish communities should be prioritized for protection. The results of this study provided valuable insights for developing effective fish conservation strategies within the coastal ecosystem.