@article{oai:oacis.repo.nii.ac.jp:00002450,
 author = {田中, 栄次},
 issue = {6},
 journal = {日本水産学会誌, Nippon Suisan Gakkaishi},
 month = {Nov},
 note = {年齢構成をもつが再生産曲線を用いない資源動態モデルを用いた推定方法を開発しニギス太平洋系群の資源量を推定した。
データは1980-2018年の漁獲量と資源量指数，1970-2009年の漁獲係数の平均の推定値，生物特性値である。推定値の誤差評価はBootstrap法で行った。
Base caseの推定結果では親魚量は965 (SE: 161)-3,069 (515）トンで，20年程度の周期的変動があること，また漁獲係数は徐々に減少し続けていることが示された。推定方法の特色や改良などについて議論した。, An age-structured model of stock dynamics without stock and recruitment model was applied to data of the Pacific stock of deep-sea smelt in order to estimate stock sizes from 1980 to 2018. The data sets used for estima tions were series of catch over the years, that of abundance index with variance estimate, an estimate of the average fishing coefficient over 1970-2009 and some biological parameters. The age-structure consists of only two cohorts because the lifespan of the smelt is three years. 
Using the given fishing coefficient and age-composition in the first year of data and the abundance index, the annual stock size by age in subsequent years is computed by those values, biological parameters and deterministic equations in the model. Unknown parameters are estimated using the estimate of the average fishing coefficient, and the parametric bootstrap method is used to estimate the variance of parameter estimates. 
The estimation results show that point estimates of spawning stock biomass ranged from 965 (SE: 161) tonnes to 3,069 (SE: 515) tonnes, the biomass fluctuated in a cycle of about 20 years and those of fishing coefficient gradually decreased in proportion to effective fishing effort. The features of the estima tion method and modification of the estimations in the future are discussed.},
 pages = {608--616},
 title = {ニギス太平洋系群の資源評価},
 volume = {87},
 year = {2021}
}