Oneida lake has large algal blooms annually during the summer and fall months, that have various social and economic impacts on the surrounding communities. Nutrients inputs, from various sources including groundwater, has been recognized as one of the main factors influencing algal blooms. Previous studies in Sparkling Lake, Wisconsin, suggested that areas of high groundwater influx correspond with high algal biomass and low algal diversity; compared to areas with low ground water influx. Similarly, previous studies at Oneida lake have demonstrated high spatial and temporal variability in groundwater fluxes. Therefore, we aim to investigate the relationship between algae biomass and groundwater fluxes at Oneida Lake.
Six sites near the Cornell Biological Field Station at Shackleton point were selected for the study. Three sites had been identified by earlier research as areas of high ground water seepage and an additional three had been identified as low flow sites. Seepage meters had been previously installed at the sites, and fluctuations in water levels, in ml per m2 hr., were recorded various times a week during the duration of the study. Epipelic algae samples were collected using inverted Petri dishes and sediment cores, weekly during summer for over 4 weeks. Chlorophyll- A was extracted from the samples using standard operating procedure for in vitro determination of chlorophyll A in freshwater phytoplankton by fluorescence and analyzed for concentration using a fluoroprobe.
Results/Conclusions
The sites designated as being high flow sites had an average groundwater seepage rate of 83.98 ml per m2 hr., while the low flow sites had a mean groundwater seepage rate of 10.26 ml per m2, confirming previous research indicating variation in seepage at sites designated to be high and low flow. The Relative Fluorescence Units, RFU, of high flow sites average 736.91 ± 312.5 ug per liter, while the low flow sites average 611.27 ± 111.93 ug per liter. Resulting in the conclusion that given there is no significant relationship between RFU and seepage fluxes. The observed relationships between groundwater seepage and algal biomass does not support our hypothesized expectations. Further research is necessary to understand the resulting discrepancies, and the influence of groundwater dynamic on benthic algal biomass.