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Clay tiles and tracer particles were deployed in Mill Creek in Cleveland, OH to investigate how biofilm and streambed materials respond to high flow events. Ten cross-sectional transects were established evenly across a 100-meter reach where cinderblocks with 16 unglazed clay tiles were buried in the streambed near the deepest part of the channel to promote biofilm growth. Particles of sizes corresponding to the 50th, 75th, and 90th percentile of the substrate size classes at each transect were painted and numbered for use as tracer particles. Samples from the tiles were collected after each high-flow event and measured their biomass using chlorophyll a (chla) and ash-free dry mass (AFDM). Movement of tracer particles (yes/no) was recorded to estimate how much of the streambed moved. 

Water quality sensors were placed in 3 urban streams in Cleveland, OH and 4 urban streams in Denver, CO to estimate stream metabolism and assess response to high flow events. MiniDOT (dissolved oxygen and temperature) and Onset (specific conductance) sensors were placed mid-channel near USGS gages. Light was measured as global horizontal irradiance (GHI) and supplied by SolCast. Data collection was part of the NSF STORMS project (PI Jefferson, co-PIs Costello, Bhaskar, Turner). Specific conductance, dissolved oxygen, and light were measured every 10 minutes. Sensors were removed during winter months to avoid damage. Datasets were cleaned to remove values when sensors were out of water, buried, and removed for maintenance/calibration. 

ABSTRACT Dinitrogen (N₂) fixation provides bioavailable nitrogen to the biosphere. However, in some habitats (e.g., sediments), the metabolic pathways of organisms carrying out N₂fixation are unclear. We present metabolic models representing various chemotrophic N₂fixers, which simulate potential pathways of electron transport and energy flow, resulting in predictions of whole-cell stoichiometries. By balancing mass, electrons, and energy for metabolic half-reactions, we quantify the electron usage for nine N₂fixers. Our results demonstrate that all modeled organisms fix sufficient N₂for growth. Aerobic organisms allocate more electrons to N₂fixation and growth, yielding more biomass and fixing more N₂, while methanogens using acetate and organisms using sulfate allocate fewer electrons. This work can be applied to investigate the depth distribution of N₂fixers based on nutrient availability, complementing field measurements of biogeochemical processes and microbial communities.IMPORTANCEN₂fixation is an important process in the global N cycle. Researchers have developed models for heterotrophic and photoautotrophic N₂fixers, but there is a lack of modeling studies on chemoautotrophic N₂fixers. Here, we built nine biochemical models for different chemoautotrophic N₂fixers by combining different types of half-chemical reactions. We include three sulfide oxidizers using different electron acceptors (O₂, NO₃⁻, and Fe³⁺), contributing to the sulfur, nitrogen, and iron cycles in the sediment. We have two methanogens using different substrates (H₂and acetate) and four methanotrophs using different electron acceptors (O₂, NO₃⁻, Fe³⁺, and SO₄²⁻). By modeling these methane producers and users in the sediment and their N₂-fixing metabolic pathways, our work can provide insight for future carbon cycle studies. This study outlines various metabolic pathways that can facilitate N₂fixation, with implications for where in the environment they might occur. 

This dataset contains turbidity data and storm event characters of three urban watersheds in Cuyahoga County, Ohio. Turbidity data were collected at a frequency of 10 minutes using in-situ Cyclop-7 turbidimeters designed by Turner Designs and integrated with a Cyclops-7 logger by Precision Measurement Engineering, Inc. Data were collected for three years from September 2018 to 2021. Turbidity data is harmonized with instantaneous discharge data from USGS stream gages. Event characteristics contains runoff, precipitation and antecedent characteristics. The data support the findings of the study titled "Urbanization and Suspended Sediment Transport Dynamics: A Comparative Study of Watersheds with Varying Degree of Urbanization using Concentration-Discharge Hysteresis". 

To address how phytoplankton in the Great Lakes respond to macro- and micronutrients, we conducted a bottle incubation enrichment experiment using water collected from blooming (Maumee Bay and Fox River) and non-blooming sites (Detroit River and Ford River) in Lakes Erie and Michigan, respectively, during late summer. Surface water from these locations was collected and taken to Kent State University either via overnight shipping (Lake Michigan sites) or driven directly after collection (Lake Erie sites). Chlorophyll a (an index of overall biomass), community composition and toxicity were all measured as responses to treatments of labile inorganic nitrogen (N), phosphorus (P) and a mixture of micronutrients (chemical symbols: Fe, Mn, Mo, Ni, Zn). 

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. 

Rivers and streams contribute to global carbon cycling by decomposing immense quantities of terrestrial plant matter. However, decomposition rates are highly variable, and large-scale patterns and drivers of this process remain poorly understood. Using a cellulose-based assay to reflect the primary constituent of plant detritus, we generated a predictive model (81% variance explained) for cellulose-decomposition rates across 514 globally distributed streams. A large number of variables were important for predicting decomposition, highlighting the complexity of this process at the global scale. Predicted cellulose-decomposition rates, when combined with genus-level litter-quality attributes, explain published leaf-litter-decomposition rates with impressive accuracy (70% variance explained). Our global map provides estimates of rates across vast understudied areas of Earth, and reveals rapid decomposition across continental-scale areas dominated by human activities. v1.0 first data release includes all code for models, analyses, and figures. v1.1 addition of code for a new supplemental figure (Figure S1) v1.2 includes new color schemes for all figures, and new title