Abstract:Assessing the feeding intensity of fish in large-scale cages is crucial for enhancing feed utilization and reducing farming costs. Traditional feeding methods heavily rely on the experience of aquaculture managers, often leading to overfeeding, which contaminates water quality, or underfeeding, and adversely affects fish health. To accurately determine fish feeding intensity in deep-sea cage farming and achieve precise feeding, focusing on the splashes generated by pompano during feeding, utilizing depth images captured by a binocular camera, a non-invasive feeding intensity analysis method was proposed, involving semantic segmentation and area calculation of the splash. Firstly, to enable the model’s deployment on low-cost edge devices, the YOLO v8n-seg model was improved through the incorporation of StarNet, BiFPN, and a custom-designed SCD-Head shared convolutional detection head, resulting in the lightweight YOLO v8n-SBS model. This modification achieved a 3.2 percentage points increase in accuracy while reducing the number of parameters and floating-point operations by 71% and 36%, respectively. Secondly, to minimize equipment costs, a binocular camera was employed, and PVC boards were used to simulate splash targets on land for experimental convenience. A linear regression model (DI) was proposed to calculate splash area-based on depth information. The results of the DI model on the test set demonstrated an R2 value of 0.977, an RMSE of 0.033 m2, and an MAE of 0.023 m2, indicating robust performance. Ultimately, the two models were combined into YOLO v8n-SBS-DI, which can segment splashes and compute their area, allowing for the assessment of feeding intensity through the trend of splash area changes. Sea trial results showed that the calculated splash area yields an R2 value of 0.914, an RMSE of 0.973 m2, and an MAE of 0.870 m2. These experimental outcomes confirmed that the model exhibited strong robustness and met the demands for splash area calculations in complex environments, thereby providing technical support for determining fish feeding intensity.
