Nutrient Cycling in Aquatic Ecosystems
Nutrients lost from agricultural areas in watersheds of the Great Lakes cause harmful algal blooms and hypoxia in some areas of the Great Lakes. Substantial efforts are being made in these watersheds to reduce the amount of nutrients entering the streams and rivers; however, additional work is needed to further reduce nutrient loads to meet international water quality standards. Limited research has been done to understand how nutrients are transformed, processed, and potentially removed in the river systems. This information is important to managers because the retention of nutrients in these river systems may be lowering the amount of nutrients entering the Great Lakes.
The objectives of this research project are to characterize rates of sediment nitrogen removal and phosphorus retention in agricultural watersheds of the Great Lakes and to assess how land use and agricultural land management actions affect these rates. Two high priority watersheds are being studied for this project: the Maumee River Basin which empties into Lake Erie and the Fox River Basin which drains into Lake Michigan.
IPDS Publications associated with this project:
Phosphorus sources, forms, and abundance as a function of streamflow and field conditions in a Maumee River tributary, 2016-2019
Riparian forest cover modulates phosphorus storage and nitrogen cycling in agricultural stream sediments
Land use effects on sediment nutrient processes in a heavily modified watershed using structural equation models
Complex response of sediment phosphorus to land use and management within a river network
Denitrification in the river network of a mixed land use watershed: Unpacking the complexities
Beyond the edge: Linking agricultural landscapes, stream networks, and best management practices
- Overview
Nutrient Cycling in Aquatic Ecosystems
Nutrients lost from agricultural areas in watersheds of the Great Lakes cause harmful algal blooms and hypoxia in some areas of the Great Lakes. Substantial efforts are being made in these watersheds to reduce the amount of nutrients entering the streams and rivers; however, additional work is needed to further reduce nutrient loads to meet international water quality standards. Limited research has been done to understand how nutrients are transformed, processed, and potentially removed in the river systems. This information is important to managers because the retention of nutrients in these river systems may be lowering the amount of nutrients entering the Great Lakes.
USGS scientist recording site information about a tributary of the Fox River near Green Bay, Wisconsin The objectives of this research project are to characterize rates of sediment nitrogen removal and phosphorus retention in agricultural watersheds of the Great Lakes and to assess how land use and agricultural land management actions affect these rates. Two high priority watersheds are being studied for this project: the Maumee River Basin which empties into Lake Erie and the Fox River Basin which drains into Lake Michigan.
USGS scientist measuring sediment pH in a sample taken from a tributary of the Maumee River in Ohio USGS scientist collecting a water sample in a tributary of the Fox River near Portage, Wisconsin - Publications
IPDS Publications associated with this project:
Phosphorus sources, forms, and abundance as a function of streamflow and field conditions in a Maumee River tributary, 2016-2019
Total phosphorus (TP), dissolved P (DP), and suspended sediment (SS) were sampled in Black Creek, Indiana, monthly during base flow and for 100 storm events during water years 2016–2019, enabling analysis of how each of these varied as a function of streamflow and field conditions at nested edge-of-field sites. Particulate P was normalized for SS (PSS = [TP − DP]/SS). Streamflow events were differRiparian forest cover modulates phosphorus storage and nitrogen cycling in agricultural stream sediments
Watershed land cover affects in-stream water quality and sediment nutrient dynamics. The presence of natural land cover in the riparian zone can reduce the negative effects of agricultural land use on water quality; however, literature evaluating the effects of natural riparian land cover on stream sediment nutrient dynamics is scarce. The objective of this study was to assess if stream sediment pLand use effects on sediment nutrient processes in a heavily modified watershed using structural equation models
Contemporary land use can affect sediment nutrient processes in rivers draining heavily modified watersheds; however, studies linking land use to sediment nutrient processes in large river networks are limited. In this study, we developed and evaluated structural equation models (SE models) for denitrification and phosphorus retention capacity to determine direct and indirect linkages between currComplex response of sediment phosphorus to land use and management within a river network
Rivers affected by anthropogenic nutrient inputs can retain some of the phosphorus (P) load through sediment retention and burial. Determining the influence of land use and management on sediment P concentrations and P retention in fluvial ecosystems is challenging because of different stressors operating at multiple spatial and temporal scales. In this study, we sought to determine how land use aDenitrification in the river network of a mixed land use watershed: Unpacking the complexities
River networks have the potential to permanently remove nitrogen through denitrification. Few studies have measured denitrification rates within an entire river network or assessed how land use affect rates at larger spatial scales. We sampled 108 sites throughout the network of the Fox River watershed, Wisconsin, to determine if land use influence sediment denitrification rates, and to identify zBeyond the edge: Linking agricultural landscapes, stream networks, and best management practices
Despite much research and investment into understanding and managing nutrients across agricultural landscapes, nutrient runoff to freshwater ecosystems is still a major concern. We argue there is currently a disconnect between the management of watershed surfaces (agricultural landscape) and river networks (riverine landscape). These landscapes are commonly managed separately, but there is limited