(General comments) The emerging conceptual model of oxygen depletion in the DWSC is that Mud, Salt and the San Joaquin River upstream of Hwy 165 provide the algal seed that grows down the San Joaquin River resulting in the load of oxygen requiring substances that decay in the DWSC. As such, understanding algal dynamics in the upper basin is critical. Thank-you for working without a contract in these important watersheds.

The key issue in the upper basins is where the algae originate, how they grow down the web of channels and sloughs that characterize the area and what might limit algal biomass in each before they enter the San Joaquin River. To my knowledge there is no oxygen depletion problem in any of these sub basins and so there is no need to conduct BOD tests. Presumably, most of the ammonia, TOC, DOC etc produced up here degrades before arrival in the DWSC, at least the stepwise forward multiple regressions at Mossdale suggest that. Therefore, further efforts to conduct BOD tests and relate them to oxygen requiring substance in the upper basin is not needed. However, a sustained effort to understand algal dynamics with the ultimate goal of understanding why so much algal load is exported during the summer and what could be done to reduce it is critical. Future research efforts should be directed there.