A Comparative Assessment of Mid-Water Trawl and Deep Vision for Investigating Fishery Resources in the Coastal Waters off Jeju Island, Korea

Abstract

Acoustic-trawl surveys use trawl sampling to identify aquatic species. The Deep Vision stereo camera system collects images of fish passing through trawl extensions. We conducted a survey using Deep Vision with a mid-water trawl to identify and measure the lengths of domestic fish species in October 2020 and July 2021 in coastal waters off Jeju Island, Korea. We identified 86.4% of 22 species captured from images and estimated the lengths of 40% of the identified fish. A comparison of species numbers identified by mid-water trawl and Deep Vision revealed that, with the exception of three species with fewer than five individuals, identification was consistent. Our results indicate that the combined use of Deep Vision and mid-water trawl can be an eco-friendly and effective approach of examining the spatial distribution and size of fish species.