Stable Isotope Analysis of Juvenile White Sharks Inside a Nursery Area Reveals Foraging in Demersal-Inshore Habitats and Trophic Overlap With Sympatric Sharks

Knowledge about top predators’ trophic ecology is crucial for defining their role in ecosystems, understanding habitat preferences, characterizing life stage-specific feeding habits, and evaluating interaction with fisheries. In the northeastern Pacific, white sharks ( Carcharodon carcharias ) occupy coastal habitats during early stages, including Bahía Sebastián Vizcaíno (BSV) Mexico, which a known nursery area. Although BSV presumably provides high prey abundance, of immature poorly understood. Carbon nitrogen bulk stable isotope analyses (SIA) were used to explore relationship stages potential infer dietary overlap sympatric sharks, while SIA amino acids estimate position. Muscle samples from young inshore demersal commonly found stomach contents sampled. Demersal literature-derived ratios pelagic offshore species incorporated into mixing models Bayesian framework contribution shark tissues. Nearshore had highest all (between 35 47%), consistent previous reports based on gut content analysis. The 26 37%) 14 32%) was smaller suggests periodic changes foraging grounds presence maternal-derived isotopic signature. A indicates level local fisheries that target those catch incidentally movement patterns. Isotope two smooth hammerhead Sphyrna zygaena copper Carcharhinus brachyurus , niche space. Immature smallest niche, sharks. Overlap greatest between hammerheads (∼45%), limited (<20%), suggesting less competition. Trophic position estimates similar previously reported species. These results highlight importance heavily targeted by diet support as habitat.