分隔网片对桁拖网鱼类渔获的分隔效率  

Separating efficiency of separator panels rigged in beam trawls for fishes

作　　者：张健[1,2,3] 孙满昌[1] 叶旭昌[1,2,3] 彭永章 钱卫国[1,2,3] 

机构地区：[1]上海海洋大学海洋科学学院,上海201306 [2]上海海洋大学,上海201306 [3]上海市高校大洋生物资源开发和利用重点实验室,上海201306 [4]江苏省启东市海洋与渔业局,江苏启东226200

出　　处：《大连水产学院学报》2008年第5期340-347,共8页Journal of Dalian Fisheries University

基　　金：国家科技支撑计划(2006BAD09A05);教育部高等学校博士学科点专项科研基金(20050264004);上海市重点学科建设项目(T1101)

摘　　要：为了实现桁拖网渔具的渔获分离,在吕四渔场进行了两个航次的网片分隔试验。试验中,在不同网囊中安装网目尺寸分别为60、75、90 mm的菱形网目网片,将网囊分为上下两层(上层称为虾囊,下层称为鱼囊),以实现渔获分离。结果显示,随着分隔网片网目尺寸的增大,鱼囊中鱼类(短吻舌鳎Cynoglos-sus abbreviatu、小黄鱼Pseudosciaena polyactis和棘头梅童鱼Collichthys lucida)渔获量占鱼类总渔获重量的比例逐渐下降。利用分隔装置效率分析模型对不同鱼类的渔获体长分布数据进行拟合,结果表明:(1)同一种类鱼接触不同网目尺寸分隔网片的概率没有显著的差异;(2)短吻舌鳎和小黄鱼(包括棘头梅童鱼)接触分隔网片的概率曲线有着明显的区别,表明上述2种鱼在网囊中的行为差异很大;(3)随着分隔网片网目尺寸的增大,分隔网片对鱼类个体的尺寸选择性也逐渐增大,导致分隔效率降低;(4)多囊桁拖网各网囊的鱼类渔获重量不存在显著性差异,各网囊的作业强度相等;(5)分隔网片与相同网目尺寸的网囊网目选择性具有明显的差异,并对产生这一差异的原因进行了探讨。Two fishing trials in Lvsi Fishing Ground were conducted to evaluate separator vices in separation of fishes from shrimps catch caught by beam trawl with several codends panels as separating defishing in offshore of the East China Sea. Inclined separator panels with different mesh sizes （ nominal mesh size 60 mm, 75mm and 90mm） divided the codends into 2 levels （ upper section named after codends for shrimps and lower section named after codends for fishes）. The results showed that the proportions of fishes （small yellow croaker Pseudosciaena polyactis, spinyhead croaker Collichthys lucida and shortnose tongue -sole Cynoglossus abbreviatus） catch weights of codends for fishes decreased with the increase in mesh sizes of the separator panels. A model for separating efficiency assessment was fitted to the size frequency of fishes mentioned above, indicating that： （ 1 ） probability curves of contacting different separator panels were not significantly different for each fish species ; （2） probability curves of contacting the same separator panels were significantly different between fishes, indicating different responding behaviors of spinyhead croaker and small yellow croaker （ including shortnose tongue - sole） in trawl; （3） selectivity for fishes was increased with the increase in mesh sizes, resulting panels; （4） the relative fishing powers （or fishing efficiency） not considered different according to catch weights of different size selectivity of codends and separator panels was found and in the decrease in separating efficiency of separator of different codends rigged in different position were fish species; （5） the significant difference between the reasons for the difference were discussed.

关 键 词：桁拖网 分隔网片 分隔效率 短吻舌鳎 小黄鱼 棘头梅童鱼 

分 类 号：S972.13[农业科学—捕捞与储运]