This dataset contains measurements of water chemistry taken from experimental incubation of sediment cores collected from the Fox and Duck rivermouths during the 2016 growing season. In addition, some characteristics of the sediment were recorded. This data can be used to generate estimates of nutrient change over time, due to flux of nutrients from the sediments. These flux estimates (or release rates) can be used to estimate total flux from sediments to the surface waters over the course of the 2016 growing season. This dataset is a subset of a larger effort to quantitatively estimate the effect of rivermouths on nutrient loading to Lake Michigan.

Nutrient reduction on the landscape scale often focuses on actions that reduce the movement of nitrogen (N) and phosphorus (P) from agricultural lands into streams and rivers. However, processing of N and P in streams and rivers can be substantial and increasing these in-stream processing rates could result in reductions or transformations of nutrients to less labile or less mobile forms. We hypothesize that buffer conditions could influence the microbial community and sediment characteristics of streams and rivers and thereby influence in-stream N and P processing rates. As a result, we predict that variation in buffer land cover (from agricultural to wetlands to forest) causes differences in processing rates. To test this prediction, we measured inorganic nutrient transformation in the water column and sediment flux of inorganic N and P in streams draining predominantly agricultural landscapes in the Fox River and Duck Creek watersheds (WI, USA) repeatedly during the 2018 growing season.

These data are associated with experiments performed in 2016 and 2017 in the Fox rivermouth (Green Bay, WI; Lake Michigan). Between the De Pere Dam and the Lake Michigan coastline, we performed experiments to measure water column transformation of dissolved organic matter (DOM) and sediment flux of DOM. These experiments consisted of incubations of surface water or intact sediment cores and repeated measures over time of DOM concentration and optical properties. When these experiments were performed, we also measured inorganic nitrogen and phosphorus dynamics. Results and data related to nitrogen and phosphorus have already been published. We also measured ancillary environmental data that would assist in understanding variation in DOM dynamics (e.g., incident solar radiation, water temperature, etc.). Using these data, we then modeled the overall change in DOM that is occurring in the Fox rivermouth.

These data were collected to compare nitrogen and oxygen exchange at the sediment-water interface in two adjacent habitat types common in estuaries. These are submerged aquatic vegetation (SAV) and bare sediment. The data collection involved application of a unique in-site chamber deployment and also included collection of sediment genomic data to examine potential drivers of nitrogen exchange. The associated dataset includes replicate exchange rate estimates for three species of nitrogen and oxygen, as well as genomic similarity data used ot compare habitats.

The data released are associated with an examination of eDNA from round goby fish (Neogobius melanostomus) in a series of field sample collections (lake nearshore and stream transport) and in vitro laboratory experiments. The round goby was used as a model for our source of eDNA in the field collections and mesocosm experiments. The field samples for lake nearshore (water and sediment) were collected from two Lake Michigan shoreline locations (Portage Lakefront, Portage, Indiana and Washington Park, Michigan City, Indiana) to examine the detectability of eDNA, the influence of sediment on eDNA estimates, and eDNA spatial and temporal resolution. The field samples for stream transport (water) were collected from Brown Ditch, a Lake Michigan stream, and were used to model and test eDNA transport. Rates for eDNA shedding and decay in water and sediment were developed using in vitro laboratory experiments and provided a comparison of eDNA behavior (persistence and degradation) and detection in water and sediment.

Data include total nitrogen and organic carbon, total metal, and particle-size analyses of upland (cropland, woodland, gullies, roads) and streambank from the East River basin, Brown County, Wisconsin that was collected in July and August 2022. These data will be used in a sediment-source apportionment tool to attribute the proportional contribution of individual sources to suspended sediment in the basin.

Data include total nitrogen and organic carbon, total metal, and particle-size analyses of upland (cropland, woodland, gullies, roads) and streambank from the East River basin, Brown County, Wisconsin that was collected in July and August 2022. These data will be used in a sediment-source apportionment tool to attribute the proportional contribution of individual sources to suspended sediment in the basin.

Sediment data was collected for analyses of potential environmental impacts from a sea cage barramundi (Lates calcarifer) aquaculture farm.Analyses were conducted on solid wastes for N, P, OC, trace elements (e.g. Zn) and other components included in feeds. Sediment oxygen consumption rates (respiration) were used an indicator of OC input, and ammonium, phosphate, and nitrite + nitrate flux rates (umol/m2/day) as indicators of organic N and P input and breakdown (mineralisation). The N:P molar ratio of fluxes and the Redfield ratio (C:N:Si:P) were calculated.Sediments were also analysed for grain size, OC, TC, TN, TP, Zn, Li, redox and pH. Sediment Grain size (um) categories: fine silt, clay, quartz sand and coarse material (leaves, wood, rocks and shell). Sediment C, N and Total Organic C (TOC) percentages were measured. C:N ratios were calculated for the different sites (cage, north, reference and south). The ratios of Zn:Li and P:Li in sediments were also calculatedThe reference location, a transect through the cages and sites at adjacent mudbanks were sampled for sediment Redox potential (Eh), pH, temperature, and surface dissolved oxygen, temperature and salinity. Leaves from Rhizophora stylosa (the dominant mangrove species) were analysed for 15N along the entire length of Conn Creek and at the reference location.Water column sampling: Transects comprised single water samples taken subsurface at each station throughout Conn Creek. Variables measured were: dissolved nitrogen (ammonium, nitrate and TDN), dissolved phosphorus, particulate nutrients, suspended solids and dissolved silica.Other variables were: tides (spring and neap); seasons (wet/summer and dry/winter); and place in the water column (near surface and near bottom).Chlorophyll a and bacterial abundances were measured and a chl:bacteria ratio calculated (as an indicator of organic pollution).Water column photosynthetic and community respiration rates were estimated at sites near cages and remote from cages. To estimate the area of influence of the farm, the carrying capacity of the environment in the area, and the fate of uneaten feed and other aquaculture wastes.

The Fox River transports elevated loads of nitrogen and phosphorus to Lake Michigan. The increased concentration of N and P causes eutrophication of the lake, creating hypoxic zones and damaging the lake ecosystem.To decrease loading, best management practices (BMPs) have been implemented in the uplands of the basin. Little work has been done, however, to reduce nutrient concentrations in the river. Rivers are capable of removing nutrients through biotic uptake and sediment burial and are able to remove N through denitrification. Identifying and managing these locations of increased nutrient cycling known as “hot spots” may be another mechanism for nutrient mitigation.Our objective was to identify hot spots of N and P cycling in the Fox River basin. We measured rates of specific biogeochemical processes (e.g. ambient and potential denitrification, and sediment phosphorus uptake and release) at sites that had varying mixed land use. We also measured variables that are known to affect nitrogen and phosphorus cycling. Models were created to estimate how land use type and BMP coverage can effect the capacity of the Fox River and its tributaries to retain and cycle N and P.

Data include total nitrogen and organic carbon, total metal, and particle-size analyses of upland (cropland, woodland, gullies, roads) and streambank from the East River basin, Brown County, Wisconsin that was collected in July and August 2022. These data will be used in a sediment-source apportionment tool to attribute the proportional contribution of individual sources to suspended sediment in the basin.