Discussion outline.txt

Discussion outline

Occurrence and concentrations of HIB and FIB and implications
HIB
	-magnitude at diff sites and scales
	-evidence for indicator of sewage from this study
	  -relation to human viruses
	    -call out the problems with using viruses along (lack of presense when not in the population)
	-compare to evidence of sewage from previous studies

FIB
	-lack of evidence for sewage indicator in current study
	-lack of evidence for pathogen indicator in previous studies
	-prevalence of use in permits and recreational use: epi studies that indicate increased sickness
	-

Regressions
	-Site groupings and implications
	-Small scale: doesn’t work. Reasons and implications
	-Current sensors vs new sensors. Some incremental improvements may be made, but it isn’t likely that large improvements would be achieved. Correlation among many signals.
	-HIB regressions for sewage presence, loadings of sewage, use in comparing loadings through watershed to compare magnitude of contributions from different areas of the watershed
	-FIB regressions to provide info for the more commonly used indicators. Still useful for general fecal contamination assessment from a composite of many sources. These are more commonly used, much less expensive to monitor
	-Limitations: 
		-These are still surrogates and not actual measures of bacteria. 
		-watershed-dependent: while some watersheds can be included in common regressions, it requires similar background DOM for it to work
		-Doesn't work as well in some watersheds: Could be due to variable DOM sources that confound the signal.
		-Regressions were developed based on composite samples. Discrete sampling would need to be done to explore whether optical signals can provide valuable info in short term variability.
		-detection level: if contamination is low, it may be difficult to develop meaningful regressions due to background interference and ability to detect HIB.

Implications for optical sensor use
	-Current-use sensors may work just fine without development of new sensors
	-All of this hinges on a good translation of lab-measured optical properties to the field.
	


Laura:
Data release:
FIB + Optical + virus for environmental samples
FIB + Optical + virus for QA samples
FIB + Optical for sewage samples