Location: Water Quality and Ecology ResearchTitle: Water quality of four major lakes in Mississippi, USA: Impacts on human and aquatic ecosystem health Author
Submitted to: Water Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/7/2015
Publication Date: 9/29/2015
Publication URL: http://handle.nal.usda.gov/10113/62075
Citation: Dash, P., Ikenga, J., Silwal, S., Pinckney, J., Arslan, Z., Lizotte Jr, R.E. 2015. Water quality of four major lakes in Mississippi, USA: Impacts on human and aquatic ecosystem health. Water Research. 7:4999-5030. doi: 10.3390/w7094999. Interpretive Summary: Harmful algal blooms, pathogenic bacteria, and toxic metals are three hazards to water quality. High water quality is critical for water bodies designated for human recreational use or consumption. Water quality in four Mississippi lakes, Sardis, Enid, Grenada, and Ross Barnett Reservoir, was studied to assess these three hazards during the summer of 2012-2014. Results indicated that harmful algal blooms (measured as cyanobacteria and the cyanotoxin, microcystin-LR), while present in every lake, did not exceed World Health Organization advisory limits. Pathogenic bacteria such as total coliforms and enterococii exceeded guideline values on several occasions and heavy metals arsenic, cadmium, chromium, and lead were found in all lake waters, with arsenic exceeding the guideline values at two sites in Ross Barnett Reservoir. Additional water quality measurements of suspended sediments and nutrients indicated eutrophic conditions in all lakes. This information can be used to help improve water quality management of water bodies designated for human use that are also influenced by agriculture and are of interest to regulatory agencies as well as farming stakeholders.
Technical Abstract: Harmful algal blooms (HABs), harmful microorganisms (pathogens) and toxic metals represent three major agents of water quality deterioration. Better water quality is of utmost importance to water bodies that provide recreational opportunities, even better quality is expected in the water bodies that serve as drinking water resources. Three northern Mississippi lakes (Sardis, Enid, and Grenada) and a central Mississippi lake, Ross Barnett Reservoir, were considered for this study. All these lakes are heavily used for recreational purposes, whereas Ross Barnett Reservoir serves as the primary water supply for the City of Jackson, the capital city of Mississippi. The purpose of this study was to examine the water quality of these lakes using field and satellite data, and evaluate potential human and aquatic health impacts. Eleven sampling trips were undertaken at these lakes during the summer of 2012, 2013, and 2014 to collect water samples and to measure several water quality parameters in situ at twelve discrete sites in each of the lakes. A time-series of satellite data were processed and true color images were generated to examine past occurrence of algal blooms in the lakes. The time-series of images indicated that algal blooms have been a recurring phenomenon in all these lakes. Suspended particulate matter exceeded the advisory limits set by World Health Organization (WHO) in all lakes. Cyanobacteria, the algal group that predominantly occur in freshwater and form toxic blooms, was always present in these lakes and was most abundant in many instances. The most toxic cyanotoxin, microcystin-LR was found in all lakes. Although the microcystin levels did not exceed WHO guidelines, potential bioaccumulation may pose serious risk to the aquatic ecosystem and human health. Nutrient measurements indicated all lakes to be eutrophic. Among bacterial populations, total coliforms and enterococii exceeded guideline values on several occasions. Arsenic, cadmium, chromium, and lead was found in all lake waters, with arsenic exceeding the guideline values at two sites in Ross Barnett Reservoir. While it is apparent from this study, that these lakes face many water quality issues, more field data will be required to document potential trends and to devise management strategies. Use of remote sensing technology is suggested to monitor some of the water quality parameters such as suspended particulate matter, algal blooms, and especially the cyanobacterial blooms.