A Preliminary Analysis of the Relationship Between the Common Octopus (Octopus vulgaris) Juveniles Abundance and Environmental Parameters off the Moroccan Coast

In the Moroccan ecosystem, Octopus vulgaris population shows high seasonal and interannual variability. Understanding the processes that influence octopus abundance is important in order to manage the fishing grounds and offer advice on the exploitation of this important resource. Fluctuations in the abundance of exploited stocks may be due to a great variety of factors. However, in short-lived animals such as octopuses, in which abundance depends on the strength of the recruitment, it is well known that population abundance is highly influenced by environmental conditions. In this study, the relationship between octopus (Octopus vulgaris) juveniles’ abundance from the research vessel Charif Al Idrissi in the area of the south of the Moroccan coast and oceanographic parameters, such as sea surface temperature (SST), surface chlorophyll (CHL) and salinity (Sa) was investigated. A generalized additive model (GAM) was applied to investigate six years (2016-2021) variability of octopus juveniles in Moroccan waters. It was noticed that the principal area of recruitment was located between Cap Barbas and Cap Blanc in the spring and autumn seasons and between Cap8 and Aarich in autumn. Concerning the environmental parameters, the sea surface temperature (SST) showed a positive impact on juveniles’ abundance. The highest abundance of juveniles was associated with SST at around 21°C.