Parameter acquisition and model development for the Dynamic Energy Budget (DEB) of oyster Saccostrea mordax

This study constructs a Dynamic Energy Budget (DEB) model to gain a deeper understanding of the growth, reproduction, and energy allocation of oyster Saccostrea mordax in different marine areas, providing theoretical support for the site selection, design, and sustainable management of oyster reefs. Through model construction and validation, the research explores the impact of environmental factors such as water temperature and chlorophyll concentration on oyster growth, offering technical guidance for optimizing oyster farming strategies as well as marine ecosystem protection and restoration. Seven basic parameters required for the DEB model were measured through indoor physiological experiments, while other parameters were obtained from literature and model calibration. The shape coefficient (δ_m) was calculated using the regression method of shell length and soft tissue wet weight. Based on the measured oxygen consumption rates of oysters at different temperature conditions, the Arrhenius temperature (T_A) was calculated. After 45 days of starvation experiments, the energy required to form a unit volume of structural material E_G, the maximum storage energy E_M, and the maximum storage energy E_M, and the energy required to maintain life Ṗ_M were obtained. Feeding experiments determined the maximum feeding rate Ṗ_Am and maximum uptake rate J̇_Xm. Remote sensing technology was used to obtain chlorophyll-a concentration and water temperature from June 2022 to April 2024 at Mischief Reef and Daya Bay. These data were used as forcing functions, and an individual growth model of the biting oyster in Daya Bay was constructed using R software and validated against actual growth data from Mischief Reef. Seven basic parameters required for the DEB model were successfully measured in indoor experiments, with δ_m = 0.270, T_A = 4 900.01 K, E_G = 5 600 J/cm³, E_M = 6 382 J/cm³, Ṗ_M = 26 J/(cm³·d) Ṗ_Am = 244 J/(cm²·d) and J̇_Xm = 325 J/(cm²·d). The model simulation results showed a significant linear relationship between the simulated values of soft tissue dry weight and shell height and the measured values, demonstrating the effectiveness of the DEB model in this experiment. Regarding the growth of the biting oyster, the model indicates that food limitation has a higher impact than water temperature. The constructed DEB model can effectively simulate the individual growth of S. mordax. The temperature and food conditions at Mischief Reef are more suitable for the growth of biting oysters than those at Daya Bay.