A deep learning approach for object detection of rockfish in challenging underwater environments

• Published in: Frontiers in Marine Science Vol. 10
• Main Authors: Liu, Mingxin, Jiang, Wencheng, Hou, Mingxin, Qi, Zihua, Li, Ruixin, Zhang, Chun
• Format: Journal Article
• Language: English
• Published: Lausanne Frontiers Research Foundation 01-12-2023; Frontiers Media S.A
• Subjects: Accuracy; Algorithms; Aquatic environment; attention mechanism; biological population protection; Deep learning; Ecosystem conservation; Endangered populations; Fish; Fish detection; Image enhancement; Localization; Marine ecosystems; marine environment; Marine fish; Marine fisheries; Marine fishes; Neural networks; object detection; Overfishing; Population decline; Protected species; Underwater; underwater image enhancement algorithm; YOLOv7
• ISSN: 2296-7745; 2296-7745
• DOI: 10.3389/fmars.2023.1242041

Introduction
Preserving the marine ecological environment and safeguarding marine species is a global priority. However, human overfishing has led to a drastic decline in fish species with longer growth cycles, disrupting the equilibrium of the marine ecosystem. To address this issue, researchers are turning to deep learning techniques and state-of-the-art underwater devices, such as underwater robots, to explore the aquatic environment and monitor the activities of endangered populations. This approach has emerged as a focal point of recent research in protecting the marine ecological environment. This study employs a deep learning-based object detection algorithm to identify fish species in complex underwater environments.
Methods
The algorithm is built upon the You Only Look Once version 7(YOLOv7) algorithm, with the addition of the attention mechanism Convolutional Block Attention Module (CBAM) in the network’s backbone. CBAM enhances the feature maps through the fusion of spatial attention and channel attention, ultimately improving the robustness and accuracy of the model’s inference by replacing the original loss function CIoU with SCYLLAIntersection over Union(SIoU). In this paper, the rockfish pictures in the dataset Label Fishes in the Wild published by the National Marine Fisheries Service are selected, and the underwater image enhancement model (UWCNN) is introduced to process the pictures.
Result
The experimental results show that the mean average precision (mAP) value of the improved model on the test set is 94.4%, which is 3.5% higher than the original YOLOv7 model, and the precision and recall rate are 99.1% and 99%, respectively. The detection performance of the algorithm in the field of complex underwater environment is improved.
Discussion
The underwater fish detection scheme proposed in this study holds significant practical value and significance in promoting the conservation of marine ecosystems and the protection of fish species.