Spatial and seasonal shifts in bloom‐forming cyanobacteria in Lake Chaohu: Patterns and driving factors

Abstract

The patterns of spatial and temporal shifts in bloom-forming cyanobacteria and the driving factors for these patterns were determined by analyzing the distribution of these cyanobacteria in Lake Chaohu using data from satellite images and field samples collected during 2012 and 2013. The cyanobacterial blooms primarily occupied the western region of Lake Chaohu, and the direction and speed of the prevailing wind determined the spatial distribution of these blooms. The cyanobacteria in Lake Chaohu were dominated by species of Microcystis and Anabaena. Microcystis reached its peak in June, and Anabaena had peaks in May and November, with an overall biomass that was higher than that of Microcystis. Microcystis generally occupied the western region of the lake in summer, whereas Anabaena dominated in other regions and seasons. Temperature may be responsible for these seasonal shifts. However, total phosphorus (TP), pH, temperature, turbidity and nitrate/nitrite nitrogen determined the coexistence of the two genera in different regions in summer. TP was correlated with Microcystis dominance, and pH and light availability were correlated with Anabaena dominance. Our results contribute to the understanding of shifts in bloom-forming cyanobacteria and are important for the control of cyanobacterial blooms.

Opportunities and Limits of Using Meteorological Reanalysis Data for Simulating Seasonal to Sub-Daily Water Temperature Dynamics in a Large Shallow Lake

“…Overestimations in wind speed would rather weaken instead of intensifying stratification in the model. Although wind directions in the reanalysis data differed from measured directions, they were similar to what has been denoted as the main wind direction in Chaohu by others [54,60,62]. Huang et al [60] denote an eastern wind as the main wind direction between 2011 and 2013, which is comparable to the reanalysis from 2015 ( Figure 2).…”

“…Its area covers 780 km 2 with a maximum length of 54.5 km from east to west and a maximum width of 21.0 km from south to north. Its average depth is approximately 3 m, and its maximum depth is 6 m [54]. Lake Chaohu is a major water body in the province of Anhui: the water of Lake Chaohu provides drinking water to approximately 250,000 people [55].…”

Spatial and Temporal Dynamics of Potentially Toxic Cyanobacteria in the Riverine Region of a Temperate Estuarine System Altered by Weirs

“…Despite their high adaptability, cyanobacterial abundance and diversity are still influenced by Water 2017, 9, 819 2 of 14 certain environmental conditions such as light intensity [5], temperature [6,7], turbidity [6,8], grazer populations [9], and nitrogen and phosphorus availability, as well as their ecophysiological characteristics (e.g., growth rate) [9]. These factors are crucial in understanding bloom formation, although eutrophication is generally a major cause of cyanobacterial blooms [6,10,11]. Blooms impact ecosystems by depleting oxygen and light supply in the water, but more importantly, certain species of cyanophytes produce toxins that can be transferred to higher trophic levels.…”

“…Their widespread adaptability is credited to their proficient internal characteristics, such as sheath pigments that absorb UV light for radical scavenging [2], buoyancy regulation for advantageous access to light and atmospheric CO 2 [3], and their capacity to undergo spontaneous pre-selective mutations [4]. Despite their high adaptability, cyanobacterial abundance and diversity are still influenced by Water 2017, 9, 819 2 of 14 certain environmental conditions such as light intensity [5], temperature [6,7], turbidity [6,8], grazer populations [9], and nitrogen and phosphorus availability, as well as their ecophysiological characteristics (e.g., growth rate) [9]. These factors are crucial in understanding bloom formation, although eutrophication is generally a major cause of cyanobacterial blooms [6,10,11].…”

Red Algae Bloom Detection in Occhito Lake Combining MERIS and MODIS Data

“…In lacustrine environments much attention has been paid to the monitoring of cyanobacteria blooms [14,15] because of their potential harmfulness.…”