Analysis of the fishing seasons characteristics of Ommastrephes bartramii and prediction of the main fishing seasons based on the grey system theory

Abstract:

Ommastrephes bartramiii, a neon flying squid, is an economically important oceanic cephalopod, which is widely distributed in the North Pacific Ocean. In China, it is one of the most important fishing targets of distant-water squid jigging vessels. Because of its short life cycle, the fishing seasons and its main fishing seasons have obvious year difference. Therefore, analyzing the characteristics of the O. bartramii fishing season and predicting the main fishing season are helpful for the rational development and sustainable harvest of O. bartramii. We analyzed fishery data for neon flying squid from China squid jigging fisheries during 2013 to 2017. The daily catch per fishing effort (CPUEday) was used to provide the abundance index and was considered as an indicator for judging the division of main fishing seasons. The quantile method was used to identify the main fishing seasons. And the grey wave forecasting method is also used to establish the grey model group [GM (1,1) model] based on the date series of the actual main fishing seasons. The results showed that the earliest catch of neon flying squid is May 12 with catches lasting until the end of the year. The primary period of the fishing season is from August to November each year. The first main fishing peak occurs in August. The average relative error of the grey wave forecasting GM (1,1) model group is 6.83%, the average relative error of the date series forecast during the main fishing season is 8.19%, and the average relative error of the validation data is 15.82%. It is concluded that this grey model can be used to predict the main fishing season for neon flying squid in the North Pacific Ocean. The findings of this study not only provide technical support for efficient and rational capture of distant-water fishery enterprises, but also provide a useful tool for prediction of the main fishing seasons for marine capture fisheries.