2026-03-13T11:18:59Z https://fra.repo.nii.ac.jp/oai

oai:fra.repo.nii.ac.jp:02002226 2025-12-16T08:11:05Z 12:14:1716951513399

トロール調査による魚類の豊度推定値の精度について Precision on the fish stock abundance estimates based on trawl survey 永井, 達樹 ナガイ, タツキ Nagai, Tatsuki The mean catch per tow based on trawl survey is used as an index of fish stock abaundance. The author examined the variability of catch per tow (CPT) and effectiveness of stratification based on the three trawl survey data. The results were summarized as follows : any allocations except that of Neyman was not so effective compared to simple random sampling (SRS); the coefficient of variation (C.V.) of CPT ranged from 1.0 for walleye pollock to about 3.5 for horse mackerel and shortfinned squid; from the simulation made for the latter two species with variable CPT's, a sample size of 100-200 tows seems adequate to calculate mean CPT's in linear scale which are used as abundance indices for usually occurring species; taking it into account that the number of tows (n) are generally limited within the range of 100-200 due to man-power and etc., the precision of abundance estimates (D=C.V./ √n) mostly depends on C.V. under SRS; in case of C.V. being equivalent to 1, the 95% confidence intervals of 100 (200) tows, i.e.,±20% (±14%) of the abundance estimate, are fairly usable for management purpose. departmental bulletin paper 遠洋水産研究所 Far Seas Fisheries Research Laboratry 1989-03 遠洋水産研究所研究報告 26 13 20 Bulletin, Far Seas Fisheries Research Laboratry AN00025949 0386-7285 https://fra.repo.nii.ac.jp/records/2002226 jpn enyo_k_26-13 日本農学文献記事索引 （AgriKnowledge） https://agriknowledge.affrc.go.jp/RN/2010430363 metadata only access