江苏海域日本鳗鲡苗资源时空分布特征初步研究

摘要

根据2012 ～2016年1～5月在东台、如东、启东和海门4个监测区域的捕获数量和渔获规格,研究了江苏海域日本鳗鲡(Anguilla japonica)苗的时空分布特征.结果表明:2012 ～2016年,江苏海域鳗苗主汛期为2～4月,各区域监测船在主汛期的2～4月捕捞数量占该年总捕捞数量的比例为61.96％～100.00％,平均为88.18％.东台、如东、启东三地鳗苗逐句捕捞量分布形态5年均呈单峰型,而海门除2015年和2016年呈双峰型外,其余3年均为单峰型.单网月捕获数量均值最高的年份为2014年,最高的区域为海门,最高的月份为3月;最低的年份为2013年,最低的区域为如东,最低的月份为1月.白天苗量比夜间苗量高出约30％.江苏海域鳗苗全长平均为56.1 mm,体质量为95.14 mg.为实现江苏海域鳗苗资源可持续利用,建议将捕捞期调整为2～3月,在捕捞价值较低的1月以及处于鱼类繁殖季节的4～5月实施禁捕.%Japanese eel is an important economic fish and important breeding object in the East Asia.However,the seedling of eel farming still depends on artificial fishing.Jiangsu sea area has always been one of the main producing areas of Japanese eel elvers in China,Change of the region's eel resources will profoundly affect the development of the domestic eel industry.However,there is no systematic study on the characteristics and catches of eel flood in Jiangsu Province.Based on the data of special investigation in sea area of Dongtai,Rudong,Qidong and Haimen,studies on capture size and yield in monitoring season of elvers were carried out during 2012-2016.This paper studied the spatiotemporal distribution patterns of the elver in the Jiangsu sea area.It was found that in 2012-2016,the elvers resources of the year were fluctuating as a whole.The peak period of glass eel catch was from February to April.Qidong and Haimen are located in the Yangtze River Estuary area,the peak period of glass eel catch was earlier than Rudong and Dongtai areas.The combined catch in February and April accounted for 61.96％ to 100.00％ of annual yield with an average of 88.18％.The distribution patterns of eel catches in Dongtai,Rudong and Qidong were single peaked in 5 years,while Haimen was bimodal except 2015 and 2016.Monthly yield of Japanese eel per net,the highest was in 2014,the lowest in 2013;the highest area was Haimen,the lowest area was Rudong;the highest mouth was March,the lowest was January.Daytime production was about 30％ higher than the night.There was no significant difference in the total length of eel among different regions.The weight difference between the Haimen area and Dongtai area was much higher than that of Qidong and Rudong areas.Mean values of total length and body weight in Jiangsu sea area were 56.1 mm and 95.14 mg respectively.For the sustainable use of anguillid elver in the Jiangsu sea area,it is suggested that the elver fishing time should be limited from February to March,and to implement the banning in January when the fishing value is low,and April-May when the fish is in breeding season.