Population size estimation of the pond smelt Hypomesus nipponensis in Lake Kasumigaura and Lake Kitaura, Japan

作者：Sakamoto Daisuke; Nemoto Takashi; Sunoh Noriyuki; Iwasaki Jun; Niwa Shintaro; Arayama Kazunori; Suzuki Naoki^*; Pai Son; Takagi Kaori; Sakuramoto Kazumi

来源：Fisheries Science, 2014, 80(5): 907-914.

DOI：10.1007/s12562-014-0791-1

• Cohort analysis
• DeLury method
• Growth curve
• Hypomesus nipponensis
• Lake Kasumigaura
• Lake Kitaura
• Pond smelt
• Population level index

We estimated the population size of the pond smelt Hypomesus nipponensis at the beginning of the fishing season in Lake Kasumigaura and Lake Kitaura, Japan using two DeLury methods and cohort analysis. A growth curve was estimated on the basis of monthly standard length. The relationship between standard length and weight was utilized for calculating the mean weight on the survey day in a particular month. Total monthly catches in Lake Kasumigaura and Lake Kitaura were calculated using partial monthly pond smelt catch obtained from processing plants located near the lakes between July and December. The total monthly catch was calculated from the total monthly catch weight and the monthly mean weight. The number of boats operating each month, compiled by the Kasumigaura-Kitaura Fisheries Office of Ibaraki Prefecture, was also employed. The estimated initial population sizes were compared with the population level index (PLI) estimated from survey data before the start of the fishing season. No significant differences were detected among the initial population sizes estimated by DeLury method, cohort analysis and PLI. The estimates ranged from 7.4 million to 410 million in Lake Kasumigaura, and from 7.7 million to 44 million in Lake Kitaura.

• 出版日期2014-9