All statistical analyses were conducted in R 2.15.1 (R Core Team, 2012). Stations were categorized as being in the inner margins of Narragansett Bay (stations 1–3, 13–16) or in the central or exterior waters of the estuary (stations 5–12), based upon their proximity to refugia surveyed in Costello et al. (Costello et al., 2006a)