Historical biomass/number estimates and weight/number based indices of Pacific saury from Japanese fishery independent survey up to 2021

The fishery independent survey by Japanese scientific research vessels were conducted in 2021. The historical biomass/number estimates and weight/number based indices were calculated based on the survey results. Estimated total biomass was 845 thousand metric tons, which consisted of 537 thousand and 458 thousand metric tons of age 0 and 1 fish, respectively. The estimated total biomass in 2021 was the lowest among the years except for 2020, in which the biomass estimate was missing. These values are potentially slightly underestimated, since the eastmost and a part of the second eastmost lines were not surveyed due to the unavoidable return induced by an injury of a crew. For equitable comparison, we also estimated the biomass trend only for areas survey in 2021 and trend was generally the same.