In previous posts, I described the poor status of longfin smelt in the Bay-Delta estuary.  In my last longfin post in April, I recommended a higher prescribed June Delta outflow, but none occurred.  June outflow was a bare minimum daily 7000 cfs.  As it turns out, it may not have done much good because there were simply too few spawners available this year (Figure 1).  The Fall Midwater Trawl Index (Recruits) was at a record low as in 2015.  The spawner indices for 2017 and 2018 will be less than 0.6, which is so low that few if any recruits will be produced.

Figure 1. Longfin Recruits (Fall Midwater Trawl Index) vs Spawners (Index from two years prior) in Log10 scale. The relationship is very strong and highly statistically significant. Taking into account Delta outflow in winter-spring makes the relationship even stronger. Recruits per spawner are dramatically lower in drier, low-outflow years (red years). The low recruitment in 2015 and 2016 does not bode well for future recruits in 2017 and 2018: it is likely that the values will be closer to 0/0.