Impact of sea ice and wind field on the suitability of conventional krill fishing operation in the Bransfield Strait, Antarctica

Global warming has attracted more and more attention. As the key factors of climate change, Antarctic sea ice and wind field significantly affect the safety and economic efficiency of fishing vessels. Krill fishery is an important part of China's pelagic fishery. China generally uses traditional fishing vessels for krill fishing, which is more vulnerable to the external environment than continuous pumping fishing vessels. The changing environment has a more and more significant impact on Antarctica. However, there has been no regional study on sea ice and wind field in Bransfield Strait. According to the adaptability of krill fishing, based on the sea ice concentration data of the National Snow and Ice Data Center of the United States and the wind field data of the European Centre for Medium-Range Weather Forecasts (ECMWF) from 1989 to 2020, this study obtained the distribution and variation trend of sea ice concentration and wind in the Bransfield Strait, Antarctica within the Subarea 48.1 of the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) under climate change. The results show that under the background of global warming, the sea ice and wind speed in Bransfield Strait in Subarea 48.1 showed a decreasing trend, compared with CCAMLR Subarea 48.2, 48.3, and 48.4, Subarea 48.1 was more suitable for krill fishing. According to the distribution of fishing vessels’ operating positions, the fishing operation area was mainly concentrated in central basin (CB) area and eastern basin (EB), and the sea ice concentration was 0.15-0.2 and in areas with large wind force (wind force level reached level 6 and above) for 50-70 days. For the characteristics of sea ice and wind field from 1989 to 2020, the suitable operation days under the influence of sea ice in Bransfield Strait (the days with sea ice density <0.2) increased; the wind direction in this area was mainly to the west, and the number of days with large wind force was less, and the trend was mainly increasing. Due to the low Beaufort scale in the study area, the suitable operation days of traditional fishing boats in the study area were greatly affected by sea ice. Therefore, combined with the changes of sea ice and wind in the Strait in the past 32 years and their impact on traditional fishing operation, our study showed that the suitable operation days of traditional fishing vessels will increase in the future, but the variation in krill resources derived from the change of sea ice and wind needs to be considered in the future study.