Carbon pathways and trophic attributes are conserved in carnivorous reef fishes across a major human disturbance gradient.

Habitat degradation and overexploitation are key drivers of biodiversity loss globally. Negative, human-driven changes in habitat quality, species abundance, and community composition are well-documented across systems. While it is understood that human stressors destabilize consumer-resource interactions, how energy pathways and food webs may reorganize in hyperdiverse tropical systems in response to human disturbance remains poorly understood due to their complexity and past methodological limitations. Leveraging recent advances in molecular isotope techniques, we performed an ecosystem-scale natural experiment to evaluate how human disturbance reorganizes carbon pathways and trophic structure in a hyperdiverse tropical system, Kiritimati Island, the world's largest atoll. We specifically employed novel integrations of bulk tissue and amino acid-specific stable isotope analyses applied to six nominally generalist fish species sampled across Kiritimati's well-documented human disturbance gradient. Sampled fish species comprised 48% of carnivorous reef fish biomass. Essential amino acid stable carbon isotope (δ