@article{7,
  keywords = {Chlorophyll a, Field Fluorometry, Inland Waters, Instrument Buoys, Phycocyanin Fluorescence, Remote Sensing},
  author = {A.M. Chegoonian and K. Zolfaghari and P.R. Leavitt and H.M. Baulch and C.R. Duguay},
  title = {Improvement of field fluorometry estimates of chlorophyll-a concentration in a cyanobacteria-rich eutrophic lake},
  abstract = {<p>Instrumented buoys are used to monitor water quality, yet there remains a need to evaluate whether in-vivo fluorometric measures of chlorophyll a (Chl-a) produces accurate estimates of phytoplankton abundance. Here six years (2014-2019) of in vitro measurements of Chl-a by spectrophotometry were compared with coeval estimates from buoy-based fluorescence measurements in eutrophic Buffalo Pound Lake, Saskatchewan, Canada. Analysis revealed that fluorometric and in vitro estimates of Chl-a differed both in terms of absolute concentration and patterns of relative change through time. Three models were developed to improve agreement between metrics of Chl-a concentration, including two based on Chl-a and phycocyanin (PC) fluorescence and one based on multiple linear regressions with measured environmental conditions. All models were examined in terms of two performance metrics; accuracy (lowest error) and reliability (\% fit within confidence intervals). The model that is based on PC fluorescence was most accurate (error = 35\%), whereas that using environmental factors was most reliable (89\% within 3σ of mean). Models were also evaluated on their ability to produce spatial maps of Chl-a using remotely-sensed imagery. Here newly-developed models significantly improved system performance with a 30\% decrease in Chl-a errors and a two-fold increase in the range of reconstructed Chl-a values. Superiority of the PC model likely reflected high cyanobacterial abundance, as well as the excitation-emission wavelength configuration of fluorometers. Our findings suggest that a PC fluorometer, used alone or in combination with environmental measurements, performs better than a single-excitation-band Chl-a fluorometer in estimating Chl-a content in highly eutrophic waters.</p>
},
  year = {2022},
  journal = {Limnology and Oceanography: Methods},
  pages = {1-17},
  month = {02/2022},
  url = {https://doi.org/10.1002/lom3.10480},
}