Although the shift in biodiversity patterns is theoretically sound, there is a lack of empirical evidence to support it. So far, shifts in biodiversity patterns for coastal lagoons have been restricted to single lagoons and water column assemblages . The benthic system has gained little attention. Typically, the benthic systems of open lagoons are composed of a number of estuarine resident and many temporary marine species . The species composition in intermittent lagoons may be variable according to the current connectivity state. After blocking events (depending on rainfall regime and time of closure), they might become more homogeneous and dominated by freshwater species, typical of coastal lakes [9, 20,21,22]. These isolated observations suggest that the benthic system may not respond gradually after a blocking/opening event (dot-dashed line, Fig 1B), but may respond abruptly showing two alternative stable states (dashed line, Fig 1B).