Modeling the Hook Depth Distribution of Pelagic Longlining in the Equatorial Area of Indian Ocean  

作　　者：SONG Liming LI Jie GAO Panfeng ZHOU Ji XU Liuxiong 

机构地区：[1]National Engineering Research Centre for Oceanic Fisheries,Shanghai,Ocean University,Shanghai 201306,P.R.China [2]Key Laboratory of Sustainable Exploitation of Oceanic Fisheries Resources of Chinese Ministry of Education,College of Marine Sciences,Shanghai Ocean University,Shanghai 201306,P.R.China [3]College of Marine Sciences,Shanghai Ocean University,Shanghai 201306,P.R.China [4]Lianyunggang Fishery Detachment,Lianyunggang 222004,P.R.China

出　　处：《Journal of Ocean University of China》2012年第4期547-556,共10页中国海洋大学学报（英文版）

基　　金：funded by Ministry of Agriculture of China under Project of Fishery Exploration in High Seasin 2006 (No. Z06-43);the National High Technology Research and Development Program of China (No. 2012AA092302);Specialized research fund for the doctoral program of higher education (No. 20113104110004);Shanghai Municipal Education Commission Innovation Project (No. 12ZZ168)

摘　　要：A survey was conducted in the equatorial area of Indian Ocean for a better understanding of the dynamics of hook depth distribution of pelagic longline fishery. We determined the relationship between hook depth and vertical shear of current coefficieney, wind speed, hook position code, sine of wind angle, sine of angle of attack and weight of messenger weight. We identified the hook depth models by the analysis of covariance with a general linear model. The results showed that the wind effect on the hook depth can be ignored from October to November in the survey area; the surface current effect on the hook depth can be ignored; the equato- rial undercurrent is the key factor for the hook depth in Indian Ocean; and there is a negative correlation between the hook depth and vertical shear of current and angle of attack. It was also found that the deeper the hook was set, the higher hook depth shoaling was. The proposed model improves the accuracy of the prediction of hook depth, which can be used to estimate the vertical distribution of pelagic fish in water column.A survey was conducted in the equatorial area of Indian Ocean for a better understanding of the dynamics of hook depth distribution of pelagic longline fishery.We determined the relationship between hook depth and vertical shear of current coefficiency,wind speed,hook position code,sine of wind angle,sine of angle of attack and weight of messenger weight.We identified the hook depth models by the analysis of covariance with a general linear model.The results showed that the wind effect on the hook depth can be ignored from October to November in the survey area;the surface current effect on the hook depth can be ignored;the equatorial undercurrent is the key factor for the hook depth in Indian Ocean;and there is a negative correlation between the hook depth and vertical shear of current and angle of attack.It was also found that the deeper the hook was set,the higher hook depth shoaling was.The proposed model improves the accuracy of the prediction of hook depth,which can be used to estimate the vertical distribution of pelagic fish in water column.

关 键 词：hook depth LONGLINE temperature-depth-recorder equatorial area the Indian Ocean 

分 类 号：P732.6[天文地球—海洋科学] TN305.3[电子电信—物理电子学]