Inter-Annual Variabilities of the Body Weights of Two Cephalopod Species in the Yellow Sea Under Different Environmental Conditions

As fish stocks have been overexploited and catches have decreased over the last few years, the cephalopod catch has increased globally to the point that they are now among the most important marine resources in the world. Climate change and human activities greatly affect the growth and abundance of cephalopods. Understanding how the individual growth of key species varies and how they respond to environmental changes is essential for an effective fishery management. Loliolus beka and Amphioctopus fangsiao are two dominant species in the cephalopod community of Yellow Sea (YS). Both of them are commercially important and have great ecological values. Herein, we compared the body weights ( BW ) of these two species from 2011 to 2018 based on an analysis of biological parameters ( i.e. , mantle length and BW ) from trawl surveys in the YS. Considerable temporal variations in the BW of the two species are apparent. Specifically, the BW of L. beka was the lowest in 2011 and the highest in 2017, and the well growth was noted in 2015–2018. The BW of A. fangsiao was the lowest in 2013 and the highest in 2016, while well growth was observed in 2015–2016. Mixed-effect models indicate that the BW of these species correlates significantly with the sea surface temperature (SST) and Southern Oscillation Index (SOI), suggesting the impact of the regional environment associated with strong ENSO events on BW . In a different response window, growth increases with increased SST and decreases with increased SOI. The consistent patterns of the BW of these cephalopods in response to environmental factors demonstrate they can be employed as indicator species for studying environmental change in the YS. Our results improve the understanding of the responses of cephalopods to environmental changes in the YS, as well as the mechanisms that drive their growth. Such information is critical for the effective management and sustainable development of cephalopod fisheries in this region.