WEKO3
アイテム
玉縄の漁獲機構
https://fra.repo.nii.ac.jp/records/2008243
https://fra.repo.nii.ac.jp/records/2008243378ce33f-a785-40f1-878f-8664130aa281
| Item type | 紀要論文 / Departmental Bulletin Paper(1) | |||||
|---|---|---|---|---|---|---|
| 公開日 | 2024-06-20 | |||||
| タイトル | ||||||
| タイトル | 玉縄の漁獲機構 | |||||
| 言語 | ja | |||||
| タイトル | ||||||
| タイトル | Mechanism of Bottom Longline to Catch Groundfish | |||||
| 言語 | en | |||||
| 言語 | ||||||
| 言語 | jpn | |||||
| 資源タイプ | ||||||
| 資源タイプ識別子 | http://purl.org/coar/resource_type/c_6501 | |||||
| 資源タイプ | departmental bulletin paper | |||||
| アクセス権 | ||||||
| アクセス権 | metadata only access | |||||
| アクセス権URI | http://purl.org/coar/access_right/c_14cb | |||||
| その他（別言語等）のタイトル | ||||||
| その他のタイトル | はえ内での漁獲分布と釣針占有における魚種間競合の可能性 | |||||
| 言語 | ja | |||||
| その他（別言語等）のタイトル | ||||||
| その他のタイトル | Consideration on Interspecific Competition among Groundfishes Observed in Baited Hook Occupation | |||||
| 言語 | en | |||||
| 著者 |
前田, 弘
× 前田, 弘× 北島, 忠弘× 廣瀬, 誠× 内田, 和良× 浜口, 正人× 俵, 悟 |
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| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | The bottom longline with by-lines (Tama-nawa in Japanese), which is a hybrid of vertical longline and bottom longline, was employed to collect the original data analysed in the present report. The data obtained using this gear are a suitable material to examine the fine vertical distribution of groundfishes just above the sea bed, because several hundreds of baited hooks are distributed at very narrow vertical intervals within the layer of a few meters covering the sea bed, though, horizontally they are distributed at wider intervals. Because of the vertical and horizontal distribution of baited hooks, consideration on interspecific competition observed on the data obtained using this gear makes it possible to find some clues to understand the mechanism of bottom longline to catch groundfish. This study was carried out analysing the records of the hooks on the 44 strings (3192 by-lines, each with 10 baited hooks) employed during the period from September to December 1979 along the outer edge of the continental shelf in the East China Sea. Concerning the fine vertical distribution of groundfish and the interspecific competition in baited hook occupation, the following facts were found out: 1. The hooked density of most of the species caught showed significantly positive quadratic regression on the order of hooks counted from the mainline side. 2. Comparison of the fine vertical distribution of fish on the by-lines exclusively occupied by one species to those occupied by any species, revealed that the presence of other species of the similar vertical distribution pattern did not modify the fine vertical distribution of the respective groundfish species. 3. Comparison of the observed number of by-lines catching a species (N0) to the expected number under the supposition that all the hooked individuals of this species were distributed independently of one another (N1) or to that under the supposition that hooked density showed difference in fine vertical distribution (N2), revealed that N0 < N1 and N0 < N2. i.e. each of the species inclined to be hooked by the same by-lines. 4. Examination of the 2 × 2 contingency table showing the numbers of 1) by- lines catching both of the species A and B, 2) those catching only the species A, 3) those catching only the species B and 4) those not catching any of the species A and B, revealed that the respective species were distributed independently of one another. 5. The fine vertical distribution of catch suggested that the possibility of in- terspecific competition observed in baited hook occupation should be highest at the downmost hook. And in that place, even if there is only one species caught, it is probable that some of the hooks were competed by two species. The expected number of hooks of the above-mentioned conditions was estimated making use of the catch-hook order regression equation under the supposition that both of the species were distributed independently of one another. And it was found out that the number of the downmost hooks occupied by two species was negligible in most of the strings, only attaining the level of a few percent when one or both of the species hooked were very dense. This fact suggested that, according to baited hook occupation, the hooked density and its fine vertical distribution should be very rarely modified by the presence of competitors. Basing on these findings it may be concluded that the by-line type bottom long- line is one of the most effective gears to estimate the relative abundance of ground- fishes. And also it may be concluded that this gear is very suitable to investigate the fine vertical distribution in the layer very close to sea bed of very rough to- pography, unable to be exploited by trawl or bottom longline. | |||||
| 言語 | en | |||||
| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | 1979年9月より12月まで,東シナ海大陸斜面において行われた 44回の 玉縄操業の各釣針による 漁獲記録(延枝縄数3192本,釣針各10本付)を分析し,海底付近における底魚類の微細垂直分布と釣針占有における魚種問競合の可能性について次の知見を得た.1. 玉縄による漁獲物中,各主要魚種の漁獲密度は幹縄側より数えた釣針番号に対し有意な正の2次回帰を示す.2. 或る魚種だけが漁獲された枝縄における漁獲の微細垂直分布と全枝縄における漁獲のそれとの比較により,同じような微細垂直分布を示す他魚種の存在はそれぞれの魚種の微細垂直分布にほとんど影響をおよばさないことがわかった.3. 或る魚種が1尾でもかかった枝縄数(N0)を各個体が相互に独立に分布したときに,その魚種がかかる枝縄数の期待値(N1)または漁獲密度の微細垂直変化を示すことを加味した期待値(N2)と比較することにより,N0は N1または N2 より少ない,すなわち同一魚種は同じ枝縄にかかる傾向を示すことがわかった.4. 魚種Aと魚種Bがかかるかどうかによる2×2分割表の検定により,それぞれの魚種は相互に独立に分布することがわかった.5. 各魚種の漁獲微細垂直分布によれば,釣針占有における魚種間競合が起こる可能性は最下端の釣針において最も高い.しかし漁獲密度の微細垂直分布を示す式より最下端の釣針に2魚種が競合する可能性のある枝縄数を求めると,1方または両方の魚種の漁獲密度が高い時,このような釣針の数は2%に達するが,ほとんどの場合このような釣針の数は無視できる程度である.このように各魚種の漁獲密度とその微細垂直分布は他魚種の影響をほとんど受けないので,玉縄はトロールや底延縄で調査できないような荒い海底における底魚類の相対密度とその微細垂直分布を知るのに最も有効な漁法の一つであると考えられる. | |||||
| 言語 | ja | |||||
| bibliographic_information |
ja : 西海区水産研究所研究報告 en : Bulletin of the Seikai Regional Fisheries Research Laboratory 巻 57, p. 59-81, ページ数 23, 発行日 1982-03 |
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| 出版者 | ||||||
| 出版者 | 西海区水産研究所 | |||||
| 言語 | ja | |||||
| 出版者 | ||||||
| 出版者 | Seikai Regional Fisheries Research Laboratory | |||||
| 言語 | en | |||||
| item_10002_source_id_9 | ||||||
| 収録物識別子タイプ | PISSN | |||||
| 収録物識別子 | 0582-415X | |||||
| item_10002_source_id_11 | ||||||
| 収録物識別子タイプ | NCID | |||||
| 収録物識別子 | AN00393385 | |||||
| 情報源 | ||||||
| 識別子タイプ | Local | |||||
| 関連識別子 | snf_k_57_59 | |||||
| 関連サイト | ||||||
| 識別子タイプ | URI | |||||
| 関連識別子 | https://agriknowledge.affrc.go.jp/RN/2010261866 | |||||
| 言語 | ja | |||||
| 関連名称 | 日本農学文献記事索引(agriknowledge) | |||||
