Feeding ecology is an essential component of an organism’s life, but foraging comes with risks and energetic costs. Species in which populations exhibit more than one feeding strategy, such as sea turtles, are good systems for investigating how feeding ecology impacts life-history traits, reproduction and carried over effects across generations. Here, we investigated how the feeding ecology of loggerhead sea turtles (Caretta caretta) nesting at the Cabo Verde archipelago correlates with reproductive outputs and offspring fitness. We determined the feeding ecology of female turtles before and during the breeding season from stable isotope analysis of carbon and nitrogen, and correlated isotopic ratio with female and hatchling fitness traits. We found that female turtles feeding at higher trophic positions produced larger clutches. We also found that females with less depleted δ13C values, typical of productive foraging areas, had greater fat reserves, were less likely to be infected by leech parasites, and produced heavier offspring. The offspring of infected mothers with less depleted δ13C values performed best in crawling and self-righting trials than those of non-infected mothers with less depleted δ13C values. Overall, our study shows adult female loggerheads that exploit productive areas build capital reserves that impact their reproductive success and offspring fitness. Together, we uphold the suggestion that not all foraging habitats are equal, and can alter the fitness of populations.

Ocean noise varies spatially and temporally and is driven by natural and anthropogenic processes. Increased ambient noise levels can cause signal masking and communication impairment, affecting fitness and recruitment success. However, the effects of increasing ambient noise levels on marine species, such as marine mammals that primarily rely on sound for communication, are not well understood. We investigated the effects of concurrent ambient noise levels on social whistle calls produced by bottlenose dolphins (Tursiops truncatus) in the western North Atlantic. Elevated ambient noise levels were mainly caused by ship noise. Increases in ship noise, both within and below the dolphins' call bandwidth, resulted in higher dolphin whistle frequencies and a reduction in whistle contour complexity, an acoustic feature associated with individual identification. Consequently, the noise-induced simplification of dolphin whistles may reduce the information content in these acoustic signals and decrease effective communication, parent–offspring proximity or group cohesion.