Frequent detection of a human fecal indicator in the urban ocean: environmental drivers and covariation with enterococci.

Fecal pollution of surface waters presents a global human health threat. New molecular indicators of fecal pollution have been developed to address shortcomings of traditional culturable fecal indicators. However, there is still little information on their fate and transport in the environment. The present study uses spatially and temporally extensive data on traditional (culturable enterococci, cENT) and molecular (qPCR-enterococci, qENT and human-associated marker, HF183/BacR287) indicator concentrations in marine water surrounding highly-urbanized San Francisco, California, USA to investigate environmental and anthropogenic processes that impact fecal pollution. We constructed multivariable regression models for fecal indicator bacteria at 14 sampling stations. The human marker was detected more frequently in our study than in many other published studies, with detection frequency at some stations as high as 97%. The odds of cENT, qENT, and HF183/BacR287 exceeding health-relevant thresholds were statistically elevated immediately following discharges of partially treated combined sewage, and cENT levels dissipated after approximately 1 day. However, combined sewer discharges were not important predictors of indicator levels typically measured in weekly monitoring samples. Instead, precipitation and solar insolation were important predictors of cENT in weekly samples, while precipitation and water temperature were important predictors of HF183/BacR287 and qENT. The importance of precipitation highlights the significance of untreated storm water as a source of fecal pollution to the urban ocean, even for a city served by a combined sewage system. Sunlight and water temperature likely control persistence of the indicators via photoinactivation and dark decay processes, respectively.

Three new species of western California springsnails previously confused with Pyrgulopsis stearnsiana (Caenogastropoda, Hydrobiidae).

We describe three new, allopatric species of springsnails (genus Pyrgulopsis) from western California (Pyrgulopsis lindae, Pyrgulopsis ojaiensis, Pyrgulopsis torrida) that were previously identified as Pyrgulopsis stearnsiana. The new species are differentiated from Pyrgulopsis stearnsiana and each other both by mtCOI sequences (3.9-9.9%) and details of penial morphology. We also provide a phylogeny with increased sampling which confirms a previous finding that Pyrgulopsis stearnsiana sensu stricto is paraphyletic relative to two other California species (Pyrgulopsis diablensis, Pyrgulopsis giulianii). Our molecular and morphological evidence suggests that Pyrgulopsis stearnsiana paraphyly is an artifact of conservative taxonomy, however additional studies utilizing rapidly evolving genetic markers will be needed to confidently tease apart the cryptic diversity in this widely ranging springsnail. The new species described herein are narrowly distributed and vulnerable to anthropogenic stressors. The single known population of Pyrgulopsis torrida may have become extirpated between 2000 and 2015.