## 3 Results
### Template of Environmental Factors for Lyc-A
#### 3.2.2 Marine Hydrological Factors Contributing to the Template for LYC-A  
Considering that the change in SST influences the growth of large yellow croaker, it should be analyzed comprehensively from 2020 to 2023. SST distribution maps (Figure 6) showed variations in temperature across different marine areas. The color variations indicate temperature fronts, which are regions where water bodies of different temperatures meet. These fronts can significantly impact marine ecosystems (Figure 6I,J,O). The SST along the coast of Zhejiang Province is influenced by seasonal changes, with higher temperatures in the summer and lower temperatures in the winter. By examining the SST distribution maps, we can identify the range of water temperatures in the aquaculture areas and pinpoint areas that match the ideal growth conditions for the species being cultured. Referring to Section 3.1, which details the location of the large yellow croaker aquaculture zones, it is evident that north of 30\({}^{\circ}\)N, the SST ranges from 12 to 13 \({}^{\circ}\)C in spring (Figure 6D,J,K,O), 25-26 \({}^{\circ}\)C in summer (Figure 6), 24-25 \({}^{\circ}\)C in autumn (Figure 6M,P), and 11-12 \({}^{\circ}\)C in winter (Figure 6A-C,F-I). South of 30\({}^{\circ}\)N, the SST in the large yellow croaker aquaculture areas varies seasonally as follows: 13-14 \({}^{\circ}\)C in spring (Figure 6D,J,K,O), 25-27 \({}^{\circ}\)C in summer (Figure 6E,L), 25-26 \({}^{\circ}\)C in autumn (Figure 6M,P), and 11-12 \({}^{\circ}\)C in winter (Figure 6A-C,F-I,N). The study of salinity and temperature profiles is essential for comprehensive environmental monitoring in large yellow croaker cage aquaculture areas. It aids in maintaining the health of the cultured species, optimizing production conditions, and ensuring the long-term sustainability of aquaculture operations. In the scope of the current large yellow croaker cage aquaculture along the Zhejiang coast, studies focusing on the upper 20 m of the water column reveal significant temperature change. Seasonal variations in sea temperature are evident within this depth, with distinct patterns emerging. During the summer and autumn months, higher sea surface temperatures are observed due to solar radiation, contrasting with the lower temperatures in winter and spring (Figure 7a). This temperature variation is particularly notable, highlighting the impact of solar heating on the sea surface. Figure 6: Sea surface temperature distribution maps of the study area from 2020 to 2023, derived from Landsat 8 imagery. Subfigure (**A–P**) Lists the parameters in chronological order. The maps utilize a gradient of color intensity to represent temperature levels, with warmer colors indicating higher SST and cooler colors indicating lower SST. An interesting phenomenon identified through temperature profiles is the presence of upwelling in the Zhoushan fishing ground during the summer, specifically within the longitude range of 122\({}^{\circ}\)E to 123\({}^{\circ}\)E (Figure 7b(B)--summer). This upwelling, characterized by a vertical movement of water, can significantly influence the local marine ecosystem and the conditions within aquaculture cages. Salinity profiles also exhibit a pronounced gradient in the nearshore areas north of 30\({}^{\circ}\)N, with this gradient being more accentuated in the summer (Figure 7b). This suggests that freshwater inputs, likely from river runoff, play a substantial role in shaping the marine environment in these regions. When considering potential sites for large yellow croaker cage aquaculture, these findings are pivotal. The seasonal sea temperature patterns, the occurrence of upwelling, and the significant salinity gradients must be factored into the decision-making process. Understanding these environmental dynamics is crucial for optimizing aquaculture practices and ensuring the sustainability of fish aquaculture operations in the area. Other hydrological elements include sea surface temperature and salinity, current velocity, and wind speed.