Assessing the Nonstationary Spatial Effects of Environmental Conditions on <scp> <i>Illex argentinus</i> </scp> in the Patagonian Region

ABSTRACT Argentine shortfin squid ( Illex argentinus ) is an important fishery species in the southwest Atlantic Ocean. Its abundance is influenced by the marine environment, exhibiting significant spatial clustering, and it is assumed that there is a spatially stationary relationship between I. argentinus and its environment. However, a growing body of research suggests spatial nonstationarity. To investigate the potential spatial nonstationarity between the distribution of I. argentinus and the complex marine environment in the Patagonian Shelf waters, we developed a multiscale geographically weighted regression (MGWR) model. Based on local regression, this model analyzed the relationships between various environmental factors and the catch per unit effort (CPUE) of I. argentinus . The model results revealed significant spatial heterogeneity between I. argentinus CPUE and key environmental factors, including sea surface height (SSH), water temperature at 50 m depth (T50m), chlorophyll‐ a concentration (Chl‐ a ), and sea surface salinity (SSS). The local regression coefficients of these environmental factors exhibited significant spatial variation, with effects particularly pronounced on the continental slope and in adjacent waters, where both positive and negative influences were observed. Furthermore, compared to the generalized additive model (GAM), the MGWR model provided a better explanation for the local impacts of environmental factors on I. argentinus . This provides evidence that the complex marine dynamic processes in the Patagonian Shelf waters have shaped a spatially heterogeneous marine environment, thereby influencing the distribution and feeding migration of I. argentinus , resulting in spatial nonstationarity between the species and its environment.