基于渔业捕捞产量的监测渔船数量优化

Optimization of the Number of Sampling Fishing Vessels Based on Marine Fisheries Catch

海洋捕捞活动数据是渔业资源评估与管理的基础,监测渔船数量的设置需要兼顾保证数据质量和降低监测成本。本研究基于2017年浙江省海洋捕捞抽样调查数据,采用分层随机采样和计算机模拟再抽样方法,以小黄鱼(Larimi-chthys polyactis)、带鱼(Trichiurus lepturus)、海鳗(Muraenesox cinereus)等9种经济种类的单船月捕捞产量以及所有9种渔获总产量作为渔业生产监测目标,以相对估计误差(REE)、相对偏差(RB)作为评价指标,分析了渔业生产监测船数量对渔业生产监测目标估计精度的影响。研究表明:各物种的单船月捕捞产量以及总产量估计值的REE和RB随着监测渔船数量的增加而下降,当渔船数量少于110时REE值下降幅度较快,当渔船数量多于110时REE值下降幅度减缓并趋于平稳。分析每增加10艘监测渔船时REE的减少量,发现当渔船数量为70时,各研究目标产量估计值的REE减少量均小于5%,此时监测渔船总数量减少了73.28%;当渔船数量为110时,各研究目标产量估计值的REE减少量均小于1%,此时监测渔船渔船点数量减少了58.11%。研究结果表明,在兼顾调查精度与准确度的前提下,可以将监测渔船数从262艘优化至110艘,同时发现对于不同的优化目标,优化结果存在较大差异。本研究的优化过程具有操作性强的特点,可为全国或其他省份开展海洋捕捞抽样调查研究提供参考。

Marine fishery-dependent data is the basis of stock assessment and fishery management.The number of sampling vessels should be optimized so that a balance between data quality and monitoring cost can be achieved.Based on the marine fisheries data in Zhejiang Province in 2017,in this study,we adopted the methods of stratified random sampling and computer simulation resampling.The single-vessel monthly catch production of 9 economic species,including Larimichthys polyactis,Trichiurus lepturus and Muraenesox cinereus etc.,as well as the total catch production of all 9 species,are used as targets for monitoring fishery production,were extracted,and the Relative estimation error(REE)and Relative deviation(RB)were used as the evaluation indexes to analyze the influence of the number of sampling fishing vessels on the estimation accuracy of fishery production monitoring targets.The results showed that the monthly catch of each species and the REE and RB of the estimated total catch decreased while the number of sampling vessels increased.When the number of fishing vessels is less than 110,the decline rate of REE value is higher.When the number of fishing vessels is greater than 110,the decline rate of REE value slowed down and tended to be stable.We found that when the number of fishing vessels is 70,the reduction of REE in the estimated output of each target species is less than 5%,and the total number of sampling vessels is reduced by 73.28%.When the number of fishing vessels was 110,the reduction of REE in the estimated output of each target species was less than 1%,and the number of fishing vessels decreased by 58.11%.When the survey accuracy and correctness were taken into account,the number of sampling vessels can be reduced from 262 to 110.At the same time,in this study,we found a great difference among optimization results of different optimization objectives.The optimization process used in this study is practical,which can provide a reference to the research of marine fishing sampling surveys in other provinces.