Sequence data retrieved from RNA sequences for primer design. This dataset is associated with the following publication: Lu, J., B. Zhu, I. Stuewing, N. Xu, and S. Duan. Nitrogen–phosphorus-associated metabolic activities during the development of a cyanobacterial bloom revealed by metatranscriptomics. Scientific Reports. Nature Publishing Group, London, UK, 9: 2480, (2019).

The data contained in the worksheet provides the quantity data of Cyanobacterial 16S sequences, qPCR and water quality parameters. This dataset is associated with the following publication: Li, H., T. Miller, J. Lu, and R. Goel. Nitrogen fixation contribution to nitrogen cycling during cyanobacterial blooms in Utah Lake. CHEMOSPHERE. Elsevier Science Ltd, New York, NY, USA, 302: 134784, (2022).

Lake Superior is historically a nutrient poor lake that does not typically support significant cyanobacterial blooms. However, the lake has been experiencing an increase in blooms in the western portion of the basin recently. The largest blooms documented have occurred after recent major flooding events, indicating that nutrients transported to the lake during these events may be a source for the blooms. This study looks into the combination of streambed sediment-derived nutrient data during base flow conditions and suspended and settled sediment-derived nutrient data from storm events to provide information about nutrient transformation and storage in the river networks of the Bois Brule River and Siskiwit River watersheds, both tributaries of western Lake Superior.

Lake Superior is historically a nutrient poor lake that does not typically support significant cyanobacterial blooms. However, the lake has been experiencing an increase in blooms in the western portion of the basin recently. The largest blooms documented have occurred after recent major flooding events, indicating that nutrients transported to the lake during these events may be a source for the blooms. This study looks into the combination of streambed sediment-derived nutrient data during base flow conditions and suspended and settled sediment-derived nutrient data from storm events to provide information about nutrient transformation and storage in the river networks of the Bois Brule River and Siskiwit River watersheds, both tributaries of western Lake Superior.

Metals are used in primary producer metabolic pathways, such as photosynthesis and the acquisition of macronutrients nitrogen (N) and phosphorus (P), yet we often do not know their potential as limiting nutrients in freshwaters. In the Great Lakes, metals have sometimes been identified as limiting the acquisition of macronutrients, mostly in off-shore waters that are relatively isolated from tributary inputs and sediment interactions. We hypothesized that another area where metals might be important was within harmful algal blooms (HABs). Harmful algal blooms are more likely to occur where N and P loads are elevated due to human activities, but short-term growth assays still often find summer bloom communities are N or P limited due to high biotic demand. This high biotic is associated with rapid nutrient recycling which may increase demand for trace metals beyond the available supply. A relatively common cyanotoxin (microcystin) has also been hypothesized to have a role in trace metal management, so trace metal demand may also influence the toxicity of bloom communities. Here, we used nutrient diffusing substrates to measure the magnitude of macronutrient and trace metal effects on growth and toxicity of biofilms suspended in 10 nearshore sites in Lake Michigan and Lake Erie (5 with and 5 without perennial HABs). We measured microcystin, chlorophyll a, ash free dry mass and community composition on the experimental biofilms.

Metals are used in primary producer metabolic pathways, such as photosynthesis and the acquisition of macronutrients nitrogen (N) and phosphorus (P), yet we often do not know their potential as limiting nutrients in freshwaters. In the Great Lakes, metals have sometimes been identified as limiting the acquisition of macronutrients, mostly in off-shore waters that are relatively isolated from tributary inputs and sediment interactions. We hypothesized that another area where metals might be important was within harmful algal blooms (HABs). Harmful algal blooms are more likely to occur where N and P loads are elevated due to human activities, but short-term growth assays still often find summer bloom communities are N or P limited due to high biotic demand. This high biotic is associated with rapid nutrient recycling which may increase demand for trace metals beyond the available supply. A relatively common cyanotoxin (microcystin) has also been hypothesized to have a role in trace metal management, so trace metal demand may also influence the toxicity of bloom communities. Here, we used nutrient diffusing substrates to measure the magnitude of macronutrient and trace metal effects on growth and toxicity of biofilms suspended in 10 nearshore sites in Lake Michigan and Lake Erie (5 with and 5 without perennial HABs). We measured microcystin, chlorophyll a, ash free dry mass and community composition on the experimental biofilms.

Number of gene copies associated with phosphate accumulation using qPCR and relative abundance of bacterial groups. This dataset is associated with the following publication: Camejo, P., J. Santodomingo, K. McMahon, and D. Noguera. Genome-enabled insights into the ecophysiology of the comammox bacterium Ca. Nitrospira nitrosa. ENVIRONMENTAL SCIENCE & TECHNOLOGY. American Chemical Society, Washington, DC, USA, 2(5): 1-16, (2017). NOTE: This dataset has been removed from public access due to revocation. Please refer inquiries regarding this dataset to the listed contact person.

This dataset includes field measurements of biological nitrogen fixation (BNF) in all major N-fixing niches across natural terrestrial biomes globally. The dataset comprises 32 variables including site location, biome type, N-fixing niche, sampling year, quantification method, BNF rate (in kgN/(ha*y)), the percentage of nitrogen derived from the atmosphere, N-fixer or N-fixing substrate abundance, BNF rate per unit of N-fixer abundance, and species identity.

Data were collected to determine the abundance of nitrogen-fixing microorganisms in Cladophora algae growing on rocks, breakwall structures, or submerged dreissenid mussel beds around southern Lake Michigan. Cladophora samples (N=33) were collected between June and September 2015 from three urban areas: (a) Jeorse Park, East Chicago, Indiana, (b) Calumet Beach, Chicago, Illinois, and (c) North Beach, Racine, Wisconsin, and a National Park site, Portage Lakefront, Indiana Dunes National Park, Indiana. Corresponding lake water samples (N=33) were collected approximately 15-20 feet away from submerged algal mats. Genomic DNA was extracted from water and processed algal samples. The abundance of nitrogen-fixing microorganisms in water and algal samples was determined by a SYBR-Green quantitative polymerase chain reaction (qPCR) assay by targeting the nifH gene. The coordinate file includes information regarding sampling locations and their corresponding latitudes and longitudes. The data files include DNA quality and yield from water and algal samples, and abundance of nitrogen-fixing microorganisms in water and algal samples as determined by the SYBR-Green qPCR assay.