Determining the distribution characteristics of Japanese and Chinese fishing vessels for neon flying squid using automatic identification system (AIS) data

To sustainably use neon flying squid resources in the high seas, understanding the fishing operation locations and status in the various countries involved is essential. We analyzed automatic identification system (AIS) data installed on the fishing vessels to describe the operational characteristics of Japanese and Chinese neon flying squid fishing vessels in the central North Pacific (in the range of 35°–45° N and 165° E–165° W). From May to July in 2016–2019, fishing vessels of these two countries were in operation with the west side for Chinese and east side for the Japanese vessels in most of the cases. In addition, Japanese vessels were on average located 3° farther north than Chinese vessels. Trend analysis showed that Chinese fishing efforts had gradually increased to the east, recently overlapping the fishing grounds between the two countries in the central North Pacific in study period. Our analysis of ocean environmental data indicated that vessels from both countries mainly operated around 15 °C during May–June each year. In contrast, in July, Chinese vessels operated 2–5℃ higher than Japanese vessels. These differences in distribution and environments in fishing location suggest that the two countries vessels may have exploited different cohorts.