Abstract:Artificial reefs are manmade facilities designed to enhance fish populations, slow down the degradation of natural habitats, and affect the development of Marine biological resources. The corresponding monitoring and assessment of the artificial reefs that have been deployed play an important role in protecting fishery resources. The image data based on sidescan sonar exposes the loss of threedimensional information and image deformation. Using multibeam point clouds for the recognition and extraction of artificial reefs has become a new research direction. In this paper, an improved DGCNN model method has been put forward. A normal vector feature extraction module and a multihead attention mechanism module have been introduced, and the edge convolution features and normal vector features in DGCNN for focused attention have been fused. In this paper, two representative types of fish reefs have been selected for training and testing. The improved method has been compared with PointNet, PointNet++ and DGCNN in terms of results. The experimental results show that the improved DGCNN model outperforms traditional classic methods in the completeness and accuracy of artificial fish reef extraction,and has the advantages of rapid recognition, higher extraction accuracy and higher credibility.