Research Projects 
Project Title 1. State of Science Review 
Project Coordination and Resources (0.4 FTEs: AED-0.3, MED-0.1) 
Objectives 
To efficiently plan and manage NHEERL research efforts, a necessary first step is to assess the 
current knowledge. The objective of this effort is to fulfill the first Goal under this research 
implementation plan, which is to report on the state of the science and progress in developing 
suspended and bedded sediment criteria. 
Scientific Approach 
NHEERL personnel will summarize and synthesize current knowledge on quantitative stressor- 
response relationships among sedimentation, biota, and habitat, and the efforts to date in 
developing sediment criteria. The overall review will be conducted in concert with other ORD 
Laboratories, as well as OW, USGS, and the Army Corps of Engineers. Subject areas to be 
reviewed will include: 
1. A review of relationships between potential classification variables and suspended and bedded 
sediments. Classification variables will include ecoregional factors (e.g., vegetation, climate, 
geology, and soils); landscape characteristics such as forest fragmentation, water storage and 
hydrogeomorphology; and ecosystem type (streams, rivers, reservoirs, coastal wetlands, estuaries 
and near-shore zones). 
2. A review of the known ecological effects of suspended and bedded sediments. Effects 
categories include effects on different biotic assemblages such as microbes, primary producers, 
invertebrates, and fish; issues of scale (e.g., effects at population, community, and ecosystem 
levels of biological organization); and effects on habitat quality and quantity. Direct effects on 
biota will be contrasted with effects on physical habitat which may result in indirect effects on 
biota. Mechanistic, experimental approaches toward detecting and analyzing effects will be 
compared to large-scale empirical, correlational analyses. 
3. The effects of elevated suspended solids (turbidity) and excessive bedded sediments (i.e., 
increased sedimentation). It is expected that the ecological effects of suspended solids differ 
from those of sedimented solids. The review will encompass both stressor types. Potential 
impacts due to lack of enough suspended and bedded sediment, which can contribute to habitat 
loss, also will be investigated. 
4. Routes and mechanisms of the delivery of sediments to aquatic ecosystems. A critical step 
toward effects prediction and ecosystem protection is to understand the relationships among 
characteristics and processes at the landscape scale and the quantity and quality of sediment 
delivered to aquatic systems, whether that be terrestrial runoff with increased sediment loads or 
hydrologic modifications that result in increases in-inchannel erosion. 
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