Cyanobacteria blooms and water quality parameters in two Mecklenburg County Park and Recreation ponds in Charlotte, NC

Abstract

GOYNE, Lauren Mary Louise. Master of Environmental Assessment. Cyanobacteria Blooms and Water Quality Parameters in Two Mecklenburg County Park and Recreation Ponds in Charlotte, NC. As Harmful Algal Blooms (HABs) become an increasing concern in small bodies of water, such as ponds, effective management strategies become more necessary. The most common group of algae to produce HABs in small bodies of water are the photosynthetic bacteria, Cyanobacteria (Blue-Green Algae). Some kinds of Cyanobacteria, such as Microcystis spp., can produce toxins that are harmful to humans and animals. Unfortunately, HABs caused by Cyanobacteria are becoming more frequent. To gain a better understanding of algal community dynamics, a comparison of two urban ponds was conducted in Charlotte, NC in the summer of 2020. Sampling events to collect algae from the water body, algae from a bloom, and water quality data were conducted every two weeks between June 9th and October 20th, producing a total of 10 samples. Pond management routines for both ponds were also documented during the same season. The two ponds exhibited different ecological dynamics, with differences in algal community, bloom status, and water quality parameters. Both ponds experienced a Microcystis spp. bloom at some point in the season, though the intensity of the bloom was greater in Freedom Park Pond. Cyanobacteria density and/or biovolume were significantly correlated with nutrients (total phosphorus and total Kjeldahl nitrogen), conductivity, and temperature. Pond treatments for both ponds during the sampling season did not follow the product-recommended practices. Reducing nutrient inputs and implementing effective pond management strategies could be the most effective way of minimizing or eliminating HABs in urban ponds.