In all cross-shore gradient-dependent mortality models the mortality function M was determined either by the cross-shore location of the particle (ADG), or by the cross-shore location of the particle and scaled solar insolation (ADGI). The cross-shore dependence of M was similar to the horizontal diffusion function used in all models (Eq. (1)): equation(8) ADG model:M=m1+m0-m121-tanhy-y0yscale equation(9) ADGI model:M=I(t)Imaxm1+m0-m121-tanhy-y0yscalewhere
m0 is surfzone mortality, m1 is offshore mortality, y0 is the offshore edge of the surfzone, and yscale determines the cross-shore scale of the surfzone/offshore transition. Values for y0 and yscale BGJ398 mouse were 50 m and 5 m, respectively, the same values used to parameterize diffusivity (Eq. (1)). Note that in the ADG and ADGI models, mortality is not an intrinsic property of a given particle (as in the ADS and ADSI models). Instead, particles move through stationary cross-shore mortality gradients and take on different mortality rates based on their cross-shore location within those gradients. selleck chemical All presumptive Enterococcus isolates were found to come from one of nine different groups. Five of
these groups were common fecal (E. faecalis, E. faecium, E. hirae) and plant-associated (E. casseliflavus, E. mundtii) Enterococcus species, and one group contained rare Enterococcus biotypes (“other” Enterococcus). Three additional non-enterococcal groups were also isolated. These organisms grow and produce enterococcus-like reactions on mEI agar (blue halo) but are not Enterococcus. These organisms tuclazepam were Streptococcus bovis, found in ruminant guts, Aerococcus viridans, and a group of unidentified non-enterococcal organisms collectively called the “not Enterococcus” group. During HB06, E. casseliflavus (∼32%) was the dominant Enterococcus species observed, while E. faecalis (∼22%) and E. faecium (∼15%) were also common ( SI Fig. 2). The dominance of E. casseliflavus during HB06 is notable, as E. casseliflavus is a plant- rather than fecal-associated species. Its dominance in the surfzone at Huntington Beach, and other nearby beaches ( Ferguson
et al., 2005 and Moore et al., 2008), suggests that the use of total Enterococcus counts without subsequent species identification may lead to spurious identification of surfzone fecal pollution. Statistically significant differences were observed in the Enterococcus species composition onshore vs. offshore (Chi-square p-value < 0.01). Onshore, E. casseliflavus, E. faecalis and E. faecium all occurred at high percentages (>17% each), while offshore, concentrations of E. faecium were only ∼8%, reducing it from a major (onshore) to a minor (offshore) constituent. Furthermore, the percentage of E. mundtii was much higher offshore than onshore (14% vs. 7%), and E. hirae, A. viridans, rare Enterococcus biotypes, and non-enterococcal organisms were more prevalent offshore ( Fig.