Study on species/size separation mechanism of bottom trawl for reducing bycatch
| Project/Area Number |
17K07916
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Multi-year Fund |
|---|
| Section | 一般 |
|---|
| Research Field |
Aquatic bioproduction science
|
|---|
| Research Institution | Kagoshima University |
|---|
Principal Investigator |
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
安樂 和彦 鹿児島大学, 農水産獣医学域水産学系, 教授 (50274840)
|
|---|
| Project Period (FY) |
2017-04-01 – 2020-03-31
|
| Project Status |
Completed (Fiscal Year 2019)
|
| Budget Amount *help |
¥4,680,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥1,080,000)
Fiscal Year 2019: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2018: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
Fiscal Year 2017: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000)
|
|---|
| Keywords | 底曳網 / 漁具選択性 / 分離漁獲 / 水中環境照度 / 混獲削減 / シャッタースピード / 高感度デジタルカメラ / 暗所視照度 / 水中撮影 / コッドエンド / 対漁具行動特性 / 混獲回避 / ヒラツメガニ / 底びき網 / 網目選択性 / 網目展開 / 水中カメラ観察 / 分離漁獲装置 / 接触確率 / 水産学 / 資源保全 / 網内流速 / 環境調和型農林水産 |
|---|
| Outline of Final Research Achievements |
Reaction behaviour and entry pathway of target and non-target species to bottom trwal were investigated to contribute to improvement of bycatch reduction technology. A simple device for opening conend meshes of trawl was tested onboard in order to improve mesh selectivity of codend.
We also constructed a relational expression which allowed selection of appropriate shutter speed (exposure time) of camera based on sensitivity (ISO) of the camera and enviornmental herradiance in water. Shutter speed selection by camera at different ISO sensitivity settings were able to explained by the scotopic luminous flux. We suggest that simple and portable luminous measuring device aids successful photography underwater.Simple and portable luminous measuring device aids successful photography underwater. Our result also suggests that 10-20lx in scotopic luminous flux is about a threshold to record images under non-illuminated condition when use high sensitivity camera (ISO51200).
|
| Academic Significance and Societal Importance of the Research Achievements |
東シナ海の底曳網で多獲されるヒラツメガニの網口付近における行動特性（入網経路）について基礎的な情報を得ることができた。
カメラの設定感度(ISO)と水中環境照度データに基づき、適宜のシャッタースピードを選択可能にする関係式を構築した。簡便な光センサーを用いた計測ロガーを使用し、本研究と同様の分析を行い、各種関係式を求めておくことは、貴重な洋上での試験時間を利用して行う水中撮影をより高い成功率で実施するために有益な方法と考えらる。
|
Report
(4 results)
Research Products
(1 results)
