Bioavailable Nutrients (N and P) and Precipitation Patterns Drive Cyanobacterial Blooms in Missisquoi Bay, Lake Champlain

Abstract

Anthropogenic activities release large amounts of nitrogen (N) and phosphorus (P) nutrients into the environment. Sources of nutrients include surface and sub-surface runoffs from agricultural practices with the application of chemical fertilizers and manure as well as combined sewer overflows (CSOs). Nutrient runoffs contribute to the eutrophication of aquatic ecosystems and enhance the growth of cyanobacteria. Precipitation is an important driving force behind the runoff of nutrients from agricultural fields into surrounding water bodies. To understand the dynamics between nutrient input, precipitation and cyanobacterial growth in Missisquoi Bay, Lake Champlain (Quebec), one location in Pike River (a major tributary into the bay) and four locations in Missisquoi Bay were monitored from April to November in 2017 and 2018. Biweekly water samples were analyzed using chemical methods and high-throughput sequencing of 16S rRNA gene amplicons. High concentrations of N and P were typically measured in April and May. Three major spikes in nutrient concentrations were observed in early and mid-summer as well as early fall, all of which were associated with intense cumulative precipitation events of 40 to 100 mm within 7 days prior to sampling. Despite the high concentrations of nutrients in the spring and early summer, the cyanobacterial blooms appeared in mid to late summer as the water temperature increased. Dolichospermum sp. was the major bloom-forming cyanobacterium during both summers. A second intense bloom event of Microcystis was also observed in the fall (October and November) for both years. Variation in the cyanobacteria population was strongly associated with inorganic and readily available fractions of N and P such as nitrites and nitrates (NOx), ammonia (NH3) and dissolved organic phosphorus (DOP). During blooms, total Kjeldahl nitrogen (TKN) and total particulate phosphorus (TPP) fractions had a substantial influence on total nitrogen (TN) and total phosphorus (TP) concentrations, respectively. The abundance of bacteria involved in the metabolism of nitrogen compared to that of phosphorus revealed the importance of nitrogen on overall microbial dynamics as well as CB formation in the bay. Our findings emphasize the combined influence of precipitation events, temperature and several bioavailable fractions of nitrogen and phosphorus on cyanobacterial bloom episodes.

Perceptions of Freshwater Algal Blooms, Causes and Health among New Brunswick Lakefront Property Owners

“…Nutrients and temperature drive these changes. In the early days, nutrients from farming played the major role but as waterfront property was developed in rural areas, septic tanks became major driver of blooms in inland lakes (Celikkol et al 2021 ; Mrdjen et al 2018 ). Climate change has brought warmer summer temperatures which accelerates bloom growth.…”

Water Quality Modelling for Nitrate Nitrogen Control Using HEC-RAS: Case Study of Nakdong River in South Korea

“…+ and NH 3 are pH-dependent, NH 3 -N exists in the form of NH 4 -N in most aquatic environments [66,67]. We thus replaced the data of NH 4 -N required in HEC-RAS with the available data of NH 3 -N. The DON concentration was calculated by subtracting the sum of NH 3 -N and NO 3 -N from TDN [3,63].…”

“…A severe reduction in water quality can pose a risk to public health by increasing human exposure to contaminated water [2]. Among the major sources of water pollution, nitrate nitrogen (NO 3 -N), one of the nitrogen fractions [3], may cause specific cancers and adversely affect human reproduction when people take it in excess [4][5][6]. In this regard, the maximum contaminant level (MCL) of NO 3 -N has been set to 10 mg L −1 for drinking water by the U.S. Environmental Protection Agency (EPA).…”

Studying the Effect of Mineral Fertilizers on the Development of the Eutrophication Process in the Water Bodies

“…Viktor Kostenko 1 , Maryna Tavrel 1 , Olha Bohomaz 1 , Tetiana Kostenko 2* , Olesia Kostyrka 3 , Oleh Zemlianskyi 3 Cyanobacterial blooming is a widespread phenomenon throughout the world, which is conditioned by the interaction of geographically and ecologically diverse environmental variables. The long evolutionary history of blooming types of cyanobacteria has dictated a high degree of tolerance and adaptability to both short-term (i.e., seasonal, decadal) and long-term (geological) environmental changes.…”

“…They are defined by a number of peculiarities, including cell physiology (gas bubbles in cells allow buoyancy regulation), physiological response (e.g., light and nutrient utilization), cell size, cell structure, and overall morphology. The predominance of cyanobacteria over other species occurs under certain environmental conditions, including optimal light intensity and water temperature, availability of nutrients, and stability in the water column (Celikkol et al, 2021). Anthropogenic activity, in the form of intensive industrial, domestic and agricultural and industrial runoff, leads, primarily, to significant changes in the chemical composition of the aquatic environment as a biotope for hydrobionts.…”