Catch per unit effort (CPUE) standardization of Argentine shortfin squid (Illex argentinus) in the Southwest Atlantic Ocean using a habitat-based model

ABSTRACT

The Argentine shortfin squid (Illex argentinus) in the Southwest Atlantic Ocean is an economically important cephalopod. Catch per unit effort (CPUE) of species, a critical proxy for fish abundance, affected by many factors, including environmental variables. Given the importance and less considering of multiple environmental factors in the CPUE standardization for I. argentinus, this study provided an accurate standardized CPUE based on the habitat-based model incorporating the effect of environmental variables including sea surface temperature (SST), sea surface height (SSH), and chlorophyll a concentration (Chl-a). The results showed that the trends of yearly and monthly nominal CPUE were consistent with the standardized CPUE. As the highly concentrated fishing operations, the effective fishing effort was always lower than nominal fishing effort, subsequently, the standardized CPUE was found to be higher than nominal CPUE. Among the environmental factors, SSH and Chl-a are the primary environmental variables when standardizing I. argentinus CPUE revealed by habitat-based model. The precision of CPUE standardization could be improved by our methods. The findings will help to grasp the dynamics in the abundance and provide a basic information for the I. argentines stock assessment in the Southwest Atlantic Ocean.

Acknowledgements

This study is supported by the Young Orient Scholars Programme of Shanghai (QD2017038), the National Key R&D Program of China (2019YFD0901404), the Shanghai Special Research Fund for Training College’s Young Teachers (No. ZZSHOU18025), and the Doctoral Scientific Research Starting Foundation of Shanghai Ocean University. The authors would like to thank the Chinese Squid-jigging Technology Group of Shanghai Ocean University for providing the fishery data, and the NOAA Ocean Watch and the IRI/LDEO Climate Data Library for providing the environmental data.

Disclosure statement

No potential conflict of interest was reported by the authors.