Comparative study on the survey effectiveness of two mobile platforms in coastal marine bioacoustic surveys

To evaluate the impact of different moving platforms on the accuracy of acoustic surveys for nearshore marine biological resources, this study employed a synchronous acoustic survey method to compare and analyze the application effectiveness of small fishery research vessel and catamaran unmanned surface vehicles in the adjacent waters of the Daya Bay Nuclear Power Plant. Fishing vessel survey results indicate: Mean TS was −69.7 dB, with an average resource density of 8.03 ind·m⁻³. Horizontally, organisms were primarily distributed around 22.56°N, 114.59°E and 22.555°N, 114.64°E. Vertically, the main distribution was within the middle-lower water layers. Unmanned surface vessel survey results indicate: Mean TS was −70.6 dB, with an average resource density of 25.57 ind·m⁻³. Horizontally, organisms were concentrated around 22.56°N, 114.59°E. Vertically, the distribution was also predominantly within the middle-lower water layers. The comparative analysis revealed that while the two platforms exhibited a high consistency in mapping the spatial distribution of biomass in coastal bioacoustic surveys, the catamaran unmanned surface vessel demonstrated superior performance to the small fishing boat platform in assessing biomass abundance and detecting small biological targets.