The Effects of Fish-Shrimp Separator on Catches in Taiwanese Shrimp Drag Net

臺灣近海蝦拖網裝設魚蝦分離器對漁獲物之影響

陳俊德(Chun-Te Chen) ； 林佑信(Yu-Shin Lin) ； 林佳宏(Gaai-Hong Lin) ； 林山章(Shan-Chang Lin)

《臺灣水產學會刊》 27卷2期 (2000/06) Pp. 77-88

https://doi.org/10.29822/JFST.200006.0002

摘要

The purpose of this study is to improve our understanding of the effects of in-waterchlorophyll a,total pigment and total suspended matter(TSM)on the optical properties ofcoastal water and oceanic water around Taiwan.An underwater spectroradiometer isused to measure the vertical profile of the downwelling and the upwelling irradiance in thevisible 400nm to 700nm wavelengths in the coastal and offshore waters around Taiwan.The results show that the relationship of total pigment against chlorophyll a and TSMshows a exponential function.The relationship of optic depth against chlorophyll a,totalpigment and TSM shows inverse exponential function.Shapes of spectral distributioncurve in pure Kuroshio region and coastal waters are obviously different.Some inflectionpoints in spectral distribution curve appear at wavelength bands of 412,443,490,520,550,555 and 670nm.Using irradiance ratio of E(subscript u)(O(superscript -),λ(subscript 1))/E(subscript u)(O(superscript -),λ(subscript 2)),some better bio-opticalalgorithms are obtained.For chlorophyll a algorithm,E(subscript u)(490)/E(subscript u)(510)(r^(2)＞0.983)andE(subscript u)(490)/E(subscript u)(555)(r^(2)＞0.943)are good.For total pigment algorithm,E(subscript u)(490)/E(subscript u)(510)(r^(2)＞0.983),E(subscript u)(412)/E(subscript u)(555)(r^(2)＞0.957)and E(subscript u)(490)/E(subscript u)(555)(r^(2)＞0.947)are suitable.ForTSM algorithm,E(subscript u)(412)/E(subscript u)(490)(r^(2)＞0.929),E(subscript u)(412)/E(subscript u)(510)(r^(2)＞0.915),E(subscript u)(412)/E(subscript u)(555)(r^(2)＞0.886),E(subscript u)(490)/E(subscript u)(510)(r^(2)＞0.875)E(subscript u)(490)/E(subscript u)(555)(r^(2)＞0.820)are suitable for thisstudy.

關鍵字

逃脫率 ； 選擇性 ； 攻角 ； 魚蝦分離器 ； 臺灣近海蝦拖網

並列摘要

The purpose of this study is to improve our understanding of the effects of in-waterchlorophyll a,total pigment and total suspended matter(TSM)on the optical properties ofcoastal water and oceanic water around Taiwan.An underwater spectroradiometer isused to measure the vertical profile of the downwelling and the upwelling irradiance in thevisible 400nm to 700nm wavelengths in the coastal and offshore waters around Taiwan.The results show that the relationship of total pigment against chlorophyll a and TSMshows a exponential function.The relationship of optic depth against chlorophyll a,totalpigment and TSM shows inverse exponential function.Shapes of spectral distributioncurve in pure Kuroshio region and coastal waters are obviously different.Some inflectionpoints in spectral distribution curve appear at wavelength bands of 412,443,490,520,550,555 and 670nm.Using irradiance ratio of E(subscript u)(O(superscript -),λ(subscript 1))/E(subscript u)(O(superscript -),λ(subscript 2)),some better bio-opticalalgorithms are obtained.For chlorophyll a algorithm,E(subscript u)(490)/E(subscript u)(510)(r^(2)＞0.983)andE(subscript u)(490)/E(subscript u)(555)(r^(2)＞0.943)are good.For total pigment algorithm,E(subscript u)(490)/E(subscript u)(510)(r^(2)＞0.983),E(subscript u)(412)/E(subscript u)(555)(r^(2)＞0.957)and E(subscript u)(490)/E(subscript u)(555)(r^(2)＞0.947)are suitable.ForTSM algorithm,E(subscript u)(412)/E(subscript u)(490)(r^(2)＞0.929),E(subscript u)(412)/E(subscript u)(510)(r^(2)＞0.915),E(subscript u)(412)/E(subscript u)(555)(r^(2)＞0.886),E(subscript u)(490)/E(subscript u)(510)(r^(2)＞0.875)E(subscript u)(490)/E(subscript u)(555)(r^(2)＞0.820)are suitable for thisstudy.

並列關鍵字

Escape Ratio ； Selectivity ； Attack Angle ； Fish-Shrimp Separator ； Taiwanese Shrimp Dragnet