To address the safety risks posed by the blockage of water intakes by cold-source organisms in coastal nuclear power plants and to tackle the challenges of insufficient spatial and temporal coverage and short warning times in existing monitoring methods， this study explored the feasibility of utilizing commercial Echosounders mounted on fishing boats to construct a mobile monitoring network. A simulation study was conducted to assess the resource quantity of shrimp in the waters outside the water intake of Yangjiang Nuclear Power Plant. Based on the shrimp resource quantity data intercepted by the water intake net and Gaussian random field theory， a simulation was performed to construct a shrimp biomass distribution field with real spatial heterogeneity. The resource monitoring efficiency of traditional acoustic survey assessment methods for fishery resources and random acoustic sampling by fishing boats with different numbers of routes was compared. The results showed that monitoring frequency is a key factor determining estimation accuracy. Under high-frequency monitoring conditions， the absolute error of shrimp biomass estimation by the fishing boat network can approach the level of low-frequency traditional systematic surveys （ε=4）. The increase in the number of fishing boat routes is limited by the spatial overlap between trajectories， and the improvement in accuracy follows a law of diminishing marginal returns. The optimal number of fishing boat routes during the shrimp outbreak period （January） is eight， beyond which the improvement in survey accuracy slows down. This study provides a scientific basis for the construction of a monitoring system that combines "precise monitoring at fixed stations along the embankment of nuclear power plant water intakes" with "wide-area early warning by mobile fishing boat networks in external waters"， thereby enhancing the early warning capability for cold-source organisms in nuclear power plants.