Effects of aquaponic system on fish locomotion by image-based YOLO v4 deep learning algorithm

Abstract

• Explored the comparison of water quality between aquaponic system and recirculating aquaculture system. • Proposed a method for detecting fish locomotion based on deep learning. • Explore the influence of aquaponic system on fish locomotion and biological characteristics. • Provide a reference for the balance of aquaponic system to achieve maximum benefits. Fish locomotion analysis can provide important information for aquaculture managers to make effective production decision. However, the existing aquaponic system work mainly focuses on the transformation of nitrogen elements and are limited because their complex inspection procedures, it is rarely reported to explore effects of aquaponic system on fish locomotion. Using automated methods to explore the effect of aquaponic system on fish locomotion is a challenging task. To address this research gap, we examined and compared fish locomotion in aquaculture with different systems, i.e., aquaponic system and recirculating aquaculture system based on computer vision. The statistical results of fish locomotion in the two systems showed that the fish locomotion in aquaponic systems is significantly higher than that in recirculating aquaculture system, primarily due to the certain purification effect of plants and microorganisms on water quality. In addition, under the same conditions in the aquaculture system aquaponic system had stronger nitrogen absorption capacity than recirculating aquaculture system, the average multiple of the water quality parameter concentration of nitrate nitrogen, total nitrogen and total phosphorus in RAS are 1.79, 1.58, 1.81 times that of APS, from the stability of the experimental system to the end of the experiment.. The error of our proposed method of calculating fish locomotion is less than 5%. Overall, this is the first automated intensive monitoring method that examined the role aquaponic system played in fish locomotion, which could assess fish health based on the locomotion to further fine tune the planting density of aquaponics to achieve the maximum benefit.