In 2007, several atoll islands in the Federated States of Micronesia (FSM) were inexplicably flooded by sea water.

To describe the impact of an acute-onset sea-level-rise disaster in 2 coral atoll populations.

Households of Lukunoch and Oneop islands, FSM were assessed for demographics, asset damage, food availability, and water quantity and quality. Every fourth household on Lukunoch, (n = 40), was randomly selected and surveyed. All Oneop households were surveyed (n = 72). Prevalence data were analyzed.

A total of 112 total households were surveyed representing 974 inhabitants. On Lukunoch, roughly half of all households surveyed reported at a partial loss of their primary dietary staple and source of calories (taro and breadfruit). Six (15%) of 40 Lukunoch households surveyed (95% CI, 6%–30%) reported a complete loss of taro and four (10%) of the 40 households (95% Cl. 3%-24%) reported a complete loss of breadfruit. On Oneop, nearly all households reported at least a partial loss of these same food staples. Twenty four (31%) of all 76 Oneop households reported a complete loss of taro and another 24 (31%) households reported a complete loss of breadfruit. One third of all households surveyed reported a complete loss. On Lukunoch 11(28%) of 40 households, (95% Cl. 15%–43%) reported damage from well salination, but none were damaged to the point of a complete loss. Forty-nine (64%) of 76 Oneop households reported salination and five (6%) reported complete loss of their well.

These findings suggest that FSM populations experienced disastrous losses due to a sea level rise event damaging crop productivity and freshwater sources.