## 3 Application of Emerging Technologies in Seeding Selection for Large Yellow Croaker
### Environmental Control and Optimization Technologies  
Environmental factors are crucial for the selection of high-quality seed for large yellow croaker, influencing their growth, health, and breeding efficiency (Table 3). Large yellow croaker seed farming is typically divided into two stages: the early fry stage, which primarily uses factory-based farming methods, and the later juvenile fish stage, which transitions to offshore cage farming. The environmental requirements differ significantly between these stages. In the early fry stage, factory-based farming, environmental factors such as water quality, stocking density, and light intensity significantly impact the survival rate and growth rate of the seed. Key water quality indicators, such as temperature, dissolved oxygen, pH, ammonia nitrogen concentration, and salinity, directly affect the fish's immune function and metabolic activities [81; 82; 83]. A stable water environment helps alleviate stress responses and enhance disease resistance [23; 84]. Controlling stocking density is also crucial; appropriate density reduces competition and stress, while overcrowding can lead to water quality deterioration and pathogen spread [85]. Additionally, light intensity and photoperiod influence feeding behavior and endocrine regulation. Suitable lighting can enhance the seed's immunity and promote growth [86]. In recent years, intelligent environmental control technologies have been gradually applied to the early stages of large yellow croaker farming. [PERSON] et al. [87] developed a smart aquaculture monitoring system based on NB-IoT technology, enabling real-time collection of water quality parameters and remote management, providing technical support for precise environmental control. [PERSON] et al. [88] utilized computer vision technology to achieve real-time monitoring of the growth process of the large yellow croaker, which can guide critical operations such as scientific feeding, density regulation, and growth assessment. [PERSON] et al. [89] researched the LED lighting design for aquaculture workshops based on the visual physiological structure of aquatic animals and their light sensitivity, proposing lighting design principles and cost-reduction recommendations. In the later juvenile fish stage, the farming model mainly shifts to offshore cage farming, with farming sites typically located in nearshore areas with relatively calm waters. Daily management requires regular cage operations based on the fish's growth status, as well as continuous monitoring of key environmental factors such as water temperature, salinity, water flow, and transparency. The feeding, schooling behavior, and disease occurrence of the fish are also observed in real time to ensure timely intervention. In 2016, Zhejiang Ocean University established a 100,000 m\({}^{3}\) coastal farming facility based on the \"suspended large cage engineering technology\" on the southern side of Taohua Island in Zhoushan, significantly improving the management of overwintering, automatic feeding, and efficient harvesting, and promoting the large-scale and standardized development of farming models [90]. Regarding site selection research, ZHANG et al. [91] constructed a site selection evaluation model for deep-water cage farming based on the Analytic Hierarchy Process (AHP). They found that water quality was the most critical natural factor, infrastructure was the most important social factor, and marine functional zoning was the main limiting factor, providing a theoretical basis for scientific site selection. In summary, the intelligent control of environmental factors provides strong support for improving the efficiency and health of seed farming. Current environmental monitoring and control systems cover various aspects, including water quality regulation, temperature control management, and growth status monitoring. However, these technologies still face challenges in their promotion, such as high equipment costs, insufficient system stability, and high technical barriers for operators.