Abstract
The article “An Ecological Function Approach to Managing Harmful Cyanobacteria in Three Oregon Lakes: Beyond Water Quality Advisories and Total Maximum Daily Loads (TMDLs), Water 11:1125” by Hall et al. critiques the current approach used by the state of Oregon with regard to managing cyanobacterial blooms and offers the proper functioning condition (PVC) as a superior method of managing cyanobacterial blooms in lakes derived from nonpoint sources of pollution. They evaluated three lakes in Oregon as examples of how this approach could be applied to support water quality improvement. Two of the three lakes, Lemolo and Diamond, experienced cyanobacterial blooms, not as a function of nonpoint source loadings from the watershed, but rather because of internal nutrient cycling associated with high fish biomass. The third lake, Tenmile Lakes, in additional to having a greatly altered fish community, also experiences cyanobacterial blooms (CyanoHABs) issues because of timber harvest on steep slopes, loss of wetlands, altered watershed hydrology and nutrient input from septic systems. The authors’ attempts to use satellite images and PVC methodology on the stream networks is incomplete with respect to Tenmile Lakes and is totally misdirected regarding Lemolo and Diamond Lakes. Although I don’t support the current system employed by the state of Oregon to manage lakes experiencing CyanoHABs issues, the proposed approach offered by staff with the U.S. Environmental Protection Agency will yield little water quality benefit for the lakes in question.
Highlights
The manuscript by Hall et al Water 2019, 11, 1125 [1] offers a critique and extension of Oregon’s total maximum daily load (TMDL) process for managing harmful cyanobacterial blooms (CyanoHABs) by focusing on ecosystem function instead of using response indicators of CyanoHABs.The authors offer an approach they term the Proper Functioning Condition (PFC), which appears to encourage restoring ecologically functioning stream and riparian wetland systems
They noted that “proper ecological hydrological, and geomorphic functioning of lake and river catchments is important and including this in the total catchment management activities to protect water quality and reduce CyanoHabs is essential.”. They concluded that the ecological function of lakes could be restored through application of best management practices (BMPs), TMDLs, CyanoHAB advisories and PFCs
I re-examine the three lakes they chose as examples and show that two of the three lakes are responding to internal cycling of nutrients associated with elevated fish biomass and the third lake (Tenmile Lakes) is affected by several major
Summary
The manuscript by Hall et al Water 2019, 11, 1125 [1] offers a critique and extension of Oregon’s total maximum daily load (TMDL) process for managing harmful cyanobacterial blooms (CyanoHABs) by focusing on ecosystem function instead of using response indicators of CyanoHABs. The authors offer an approach they term the Proper Functioning Condition (PFC), which appears to encourage restoring ecologically functioning stream and riparian wetland systems They noted that “proper ecological hydrological, and geomorphic functioning of lake and river catchments is important and including this in the total catchment management activities to protect water quality and reduce CyanoHabs is essential.”. They concluded that the ecological function of lakes could be restored through application of best management practices (BMPs), TMDLs, CyanoHAB advisories and PFCs. The inherent assumption in this approach seems to be that the three example lakes that they evaluate are affected to a large degree by watershed activities.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
