Carbon and nitrogen recycling during cyanoHABs in dreissenid-invaded and non-invaded US midwestern lakes and reservoirs

Abstract

Lakes and reservoirs play key roles in global carbon cycling, especially as a carbon sink. Enrichment of nutrients in lakes and reservoirs (eutrophication) and rising global temperatures favors the proliferation of bloom-forming cyanobacteria. Harmful blooms of cyanobacteria (cyanoHABs) alter carbon and nutrient cycling in freshwater ecosystems. Some evidence suggests the introduction or establishment of invasive mussel species (i.e., Dreissena spp.) also favor cyanoHAB formation through selective filter feeding, a process through which they may also impact biogeochemical processes including carbon cycling and sequestration. However, few studies have considered the combined effects of invasive mussels and cyanoHABs on carbon and nitrogen cycling in freshwater ecosystems. Here, we examined microbial community composition and biogeochemical attributes (including carbon and nitrogen stable isotopes) in eutrophic lakes, reservoirs, and rivers in western Ohio, eastern Indiana, and northern Kentucky during the cyanobacterial bloom period of the summer of 2015. Our samples include both sites impacted by invasive mussels and those where invasive mussels have not yet been observed. Based on 16S and 18S rRNA gene sequence analysis, we found that cyanobacterial and algal communities varied across sites and were most closely related to habitat (sediment or water column sample) and site, regardless of the presence of invasive mussels or other environmental factors. However, we did find evidence that invasive mussels may influence both carbon and nitrogen cycling. While the results are based on a single time point sampling, they highlight the interactions of multiple environmental stressors in aquatic ecosystems and the critical need for more temporally intensive studies of carbon and nutrient cycling in bloom-and mussel-impacted waters.

Vertical Divergence Characteristics of Dissolved Inorganic Carbon and Influencing Factors in a Karst Deep-Water Reservoir, Southwest China

“…Reservoirs play an important role in the exchange of matterand energy at the wateratmosphere interface [11], water-rock interface, and water-biological interface [12], as well as incarbon cycling and accumulation in watersheds [13], and they also play an important role in altering the carbon fluxes and pathways in reverie ecosystems [14]. In recent years, research on carbon cycling reservoirs has produced many results, for example, the exploration of computational methods and models for reservoir carbon fluxes [15,16], the assessment of the carbon sink effects of river-reservoir systems [17,18], the study ofthe effects of thermal stratification, biological pumps, and chemical stratification on carbon cycling [14,19,20].…”

“…Reservoirs play an important role in the exchange of matterand energy at the wateratmosphere interface [11], water-rock interface, and water-biological interface [12], as well as incarbon cycling and accumulation in watersheds [13], and they also play an important role in altering the carbon fluxes and pathways in reverie ecosystems [14]. In recent years, research on carbon cycling reservoirs has produced many results, for example, the exploration of computational methods and models for reservoir carbon fluxes [15,16], the assessment of the carbon sink effects of river-reservoir systems [17,18], the study ofthe effects of thermal stratification, biological pumps, and chemical stratification on carbon cycling [14,19,20]. Reservoirs carbon transport models have confirmed that complex biogeochemical changes occur within reservoirs [14,20], including the conversion of inorganic carbon to organic carbon by photosynthesis of aquatic organisms [21], the degradation and mineralization of organic matter to produce inorganic carbon [22], bacteria producing CH 4 under anaerobic or sulphuricconditions [23][24][25], and the degassing of dissolved inorganic carbon (DIC) to produce CO 2 [26,27].…”

“…In recent years, research on carbon cycling reservoirs has produced many results, for example, the exploration of computational methods and models for reservoir carbon fluxes [15,16], the assessment of the carbon sink effects of river-reservoir systems [17,18], the study ofthe effects of thermal stratification, biological pumps, and chemical stratification on carbon cycling [14,19,20]. Reservoirs carbon transport models have confirmed that complex biogeochemical changes occur within reservoirs [14,20], including the conversion of inorganic carbon to organic carbon by photosynthesis of aquatic organisms [21], the degradation and mineralization of organic matter to produce inorganic carbon [22], bacteria producing CH 4 under anaerobic or sulphuricconditions [23][24][25], and the degassing of dissolved inorganic carbon (DIC) to produce CO 2 [26,27]. However, carbon exchange is limited by many factors [18], such as water residence time [28,29], water level [6], thermal stratification [30], chemical stratification [31], and reservoir age [32].…”

Phycocyanin Monitoring in Some Spanish Water Bodies with Sentinel-2 Imagery

“…The ability to fix carbon depends largely on the availability of macronutrients and the changes that can occur in the Redfield Ratio C:N:P (106:16:1) [11]. When phytoplankton consume too much carbon, as occurs during the development of phytoplankton blooms, the C:N ratio changes and can lead to the temporary release and accumulation of carbon-rich dissolved organic matter [12]. The ratio and availability of these nutrients can be altered by the massive artificial input of nutrients, nitrogen and phosphorus into water bodies, resulting in their eutrophication.…”

Spatio-Temporal Variability of Phytoplankton Primary Production in Baltic Lakes Using Sentinel-3 OLCI Data

“…Lakes and reservoirs play a key role in global carbon cycling, either as carbon sinks [1] or sources [2][3][4]. According to Verpoorter et al [5], there are about 117 million lakes larger than 0.002 km 2 , covering 3.7% of the Earth's non-glaciated land surface.…”