These interior waters may serve as refuges for overwintering populations and act as source regions for seasonal re-establishment of Mnemiopsis population within Narragabsett Bay (Fig. 2). As overwintering refuges, we might expect detectable levels of Mnemiopsis to remain in these inshore regiona latest into the autumn season, before the onset of winter. The persistence of Mnemiopsis longest into the autumn at these locations is consistent with the inshore overwintering refuge hypothesis. The suitability of inshore waters as overwintering refuges is most likely due to their long hydrographic retention periods (Abdelrhman, 2005) that permit some overwintering individuals to persist until the spring when temperature and prey condition become favorable for reproduction (Costello et al., 2006a; Condon and Steinberg, 2008).