, 2004, Grant et al., 2001 and Rippy et al., in press). Details of the HB06 FIB experiment are reported in Rippy et al. (in press). Briefly, FIB concentrations at Huntington Beach (which runs approximately north–south) were measured for 5 h on October
16th, 2006, at eight stations. Four of these stations spanned a 1000 m alongshore transect from the Santa Ana River, north. The remaining four stations were on a 300 m cross-shore transect starting at the northernmost alongshore station and terminating at an offshore mooring (Rippy 3-MA molecular weight et al., in press, their Fig. 1). Water samples (100 ml) were collected at all stations, every 20 min, from 0650 to 1150 PDT. All samples were analyzed for Escherichia coli (IDEXX www.selleckchem.com/products/ldk378.html Colilert)
and Enterococcus (USEPA method 1600) concentrations by Orange County Sanitation District personnel. Acoustic Doppler Velocimeters (ADV’s) mounted on fixed tripod frames were used to measure currents along the shoreward-most 150 m of the cross-shore transect (Rippy et al., in press, their Fig. 1). These data were used to force alongshore currents in the 2D FIB models discussed below. Enterococcus species identification was performed to detect spatial patterns that could indicate the presence of multiple Enterococcus sources (potentially exhibiting differing mortality rates) in the nearshore. Species were identified at the Orange County Public Health Laboratory using presumptive Enterococcus colonies grown up from water samples on mEI agar plates. Three presumptive Enterococcus colonies were examined per plate when colony counts allowed, corresponding to three colonies per water sample. Initial colony
identification was performed using a Microscan Walk-Away 96 system containing Microscan Pos Combo Type 12 panels (Dade Bhering Inc., West Sacramento, CA). The type 12 panel contains 27 dried biochemical tests for the identification Methane monooxygenase of gram-positive bacteria. The software database for this system contains 42 gram-positive cocci, including seven species of Enterococcus. Additional biochemical tests were also used for identification purposes including carbohydrate fermentation in brain heart infusion broth with 1% sucrose (35 °C), a motility test using motility medium with Triphenyl Tetrazolium Chloride (30 °C), and a pigment production assay using Trypticase soy agar with 5% sheep’s blood (35 °C). Final identification was determined utilizing published standard biochemical identification charts ( Moore et al., 2008). Due to the retentive nature of the surfzone (Reniers et al., 2009), special attention was paid to cross-shore variability of Enterococcus species distributions. All identified Enterococcus isolates were classified based on their collection location as either “onshore” (SAR, TM, FHM, and F1) or “offshore” (stations ⩾ 50 m seaward of the surfzone: F5 and F7). Species composition onshore vs. offshore was compared using a Pearson chi-squared test.