Raging Ocean and Fragile Island: Loss of Sea Turtle Eggs Leads to the Collapse of Island Reptile Communities

Terrestrial ecosystems often rely on marine subsidies, particularly on low-productivity islands, yet the consequences of losing such inputs are difficult to predict. Using 23 years of survey data from Orchid Island, we examined the effects of an abrupt loss of sea turtle eggs due to climate-driven beach erosion and predator exclusion. Following this loss, predatory snakes shifted their foraging inland, increasing predation pressure on terrestrial reptiles. As a result, most reptile species declined. In contrast, comparable turtle-free regions showed stable lizard populations. These findings demonstrate that removing a single marine subsidy can trigger cascading food-web effects, highlighting the importance of considering indirect interactions and unintended consequences in island conservation management.