Dynamic Habitat Models Reflect Interannual Movement of Cetaceans Within the California Current Ecosystem

The distribution of wide-ranging cetacean species often cross national or jurisdictional boundaries, which creates challenges for monitoring populations and managing anthropogenic impacts, especially if data are only available a portion the species’ range. Many found off U.S. West Coast known to have continuous distributions into Mexican waters, with highly variable abundance within their This has contributed annual variability in design-based estimates from systematic shipboard surveys Coast, particularly warm temperate such as striped dolphin, Stenella coeruleoalba , increases California during warm-water conditions decreases cool-water conditions. Species models (SDMs) can accurately describe shifts caused by changing environmental conditions, increasingly used marine management. However, until recently, waters Baja peninsula, México, not been modeling ranges that span Coast. In this study, we combined 1992–2018 develop SDMs Pacific ten taxonomically diverse cetaceans. We Generalized Additive Modeling framework based on line-transect dynamic habitat variables Hybrid Coordinate Ocean Model (HYCOM). Models were developed species: long- short-beaked common dolphins ( Delphinus delphis D. d. bairdii ), Risso’s dolphin Grampus griseus white-sided Lagenorhynchus obliquidens bottlenose Tursiops truncatus sperm whale Physeter macrocephalus blue Balaenoptera musculus fin B. physalus humpback Megaptera novaeangliae ). provide first fine-scale (approximately 9 x km grid) average density abundance, including spatially-explicit measures uncertainty, peninsula. Results novel insights ecology region well quantitative spatial assessment mitigation impacts.