Effects of construction and operation of Wailuo Offshore Wind Farm in Zhanjiang on nekton

To explore the ecological impact processes of the construction and operation of offshore wind farms on nekton communities, we conducted trawling surveys in the waters of the Wailuo Offshore Wind Farm in Zhanjiang in October 2019 (Construction period) and September 2020 (Operation period), respectively. We systematically evaluated the effects of wind farm construction and operation on nekton using methods including the relative importance index, community diversity indexes, ABC curves, and multivariate statistical analyses, combined with pre-construction background data. The results show that 24 species of nekton were sampled during the construction period, belonging to 23 genera, 19 families, and 11 orders. There are 95 species during the operation period, belonging to 65 genera, 43 families, and 16 orders. The dominant species in construction period (2 species) were fewer than those during operation period (6 species). Arius thalassinus and Mugil cephalus were the common dominant species. The Shannon-wiener diversity (H'), Margalef richness (D), and Pielou evenness (J) indexes were 0.282−3.530, 0.679−3.320, and 0.141−0.975, with mean values of 2.130, 2.040, and 0.674 in construction period, respectively; 2.180−5.920, 2.203−6.460 and 0.483−1.230, with mean values of 3.470, 4.320 and 0.812 in operation period, respectively. ABC curve analysis shows that the nekton communities in this area were moderately disturbed with poor community stability during construction and operation periods. The results indicate that the impact of offshore wind farm construction and operation on nekton follows a temporal response trajectory of "significant disturbance during the construction period, initial adaptation after construction, and gradual recovery during the operation period", and this dynamic provides a scientific basis for the ecological management of integrated wind power-aquaculture model.