Grantee Research Project Results

2003 Progress Report: Developing Relations Among Human Activities, Stressors, and Stream Ecosystem Responses and Linkage in Integrated Regional, Multi-Stressor Models

EPA Grant Number: R830884
Title: Developing Relations Among Human Activities, Stressors, and Stream Ecosystem Responses and Linkage in Integrated Regional, Multi-Stressor Models
Investigators: Stevenson, R. Jan , Wiley, Michael J. , Seelbach, Paul W. , Pijanowski, Bryan , Hyndman, David
Institution: Michigan State University , University of Michigan , Purdue University
Current Institution: Michigan State University , Purdue University , University of Michigan
EPA Project Officer: Aja, Hayley
Project Period: May 1, 2003 through April 30, 2006 (Extended to January 31, 2008)
Project Period Covered by this Report: May 1, 2003 through April 30, 2004
Project Amount: $748,527
RFA: Developing Regional-Scale Stressor-Response Models for Use in Environmental Decision-making (2002) RFA Text |  Recipients Lists
Research Category: Aquatic Ecosystems , Ecological Indicators/Assessment/Restoration

Objective:

The objectives of this research project are to: (1) relate human activities to multiple common stressors; and (2) relate those stressors to the natural fisheries capital and to the ecological integrity of stream ecosystems. Nutrients, sediments, dissolved oxygen (DO), temperature, and hydrology are common ecological factors in streams affected by humans, and each has a profound effect on valued ecological attributes (VEAs). Few models explain relations among human activities, these stressors, and VEAs with sufficient precision for total maximum daily loads and stream management. The lack of precision in models may be because of complications with refining individual stressor-response relationships and distinguishing responses because of multiple stressors.

Progress Summary:

We have started a preliminary review of an existing database of land use, water chemistry, algae, invertebrates, and fish from about 200 Michigan and Kentucky streams to determine relations among anthropogenic stressors and valued attributes. This database is the result of three past and two ongoing large-scale surveys of streams in the upper Great Lakes region. As a result of ongoing projects, we expect the results of approximately 1,000 streams will be compiled for the region by the conclusion of this research project.

We found that low DO is not likely to be a significant stressor of fish and ecological integrity in a high percentage of streams in the Upper Great Lakes region; however, this relationship probably varies among ecoregions and with stream hydrogeomorphology. Low DO and great responses of biota are rare in regions with deep glacial tills and poorly developed soils where intense agriculture is uncommon, but hydrologic mixing is high and potential for algal blooms is low. Low DO stress, however, most likely is located in low-gradient channelized streams and where agricultural activity is great. Confined animal feed operations present an important problem that may have limited spatial extent, but is intense where the operations occur.

We are developing and testing ideas for refining stressor-response relationships by identifying probable sources of error in relationships and methods for reducing that error. Many stressor-response relationships may be nonlinear and exhibit thresholds. Resolving nonlinearity is important for making management choices and a good example of a problem requiring reduction in error variance to develop more precise predictive models. We have been refining the relationship between phosphorus (P) and growth of the nuisance algae, Cladophora. The measurement of total phosphorus (TP) multiple times over the period of Cladophora growth and the measurement of Cladophora over a larger area of stream increase the precision of estimates of the dependent and independent variables and in the Cladophora-P relationship. We suspected potential for further refining this relationship by accounting for error in using TP as a measure of P availability to algae. Algae take up P in dissolved ionic form (PO 4 -3), but this form rapidly is taken up by algae in streams and is correlated poorly to algal biomass. Diatoms, another kind of algae, respond to P availability in water and can be used as an indicator of P enrichment. When we used this biological indicator of P availability, we observed a nonlinear, sigmoid, and precise relationship between Cladophora cover and our P indicator. When translated, that relationship indicated that Cladophora usually was not able to accumulate in streams where TP concentration was less than 15 mg P/L and that Cladophora cover of stream bottoms usually was high above 30-40 mg TP/L. Thus, biological indicators of nutrient enrichment may be more accurate and precise than a one-time measurement of nutrient concentrations. This observation may hold for many stressors that vary temporally or spatially and that respond to biological influence.

We also have been refining measurement methods and categorizing other issues that may reduce precision in stressor-response relationships. A study of nitrification potential of streams with different levels of agricultural activity was conducted to refine methods and get preliminary results on relations between human activities and nitrification potential in streams. Little relation between oxygen (O) regulation by nitrogen (N)-based O demand and agricultural activity was observed in the range of conditions that we studied. Higher N-based O demand was found more in sediments than in the water columns of streams. Ammonia transformation methods of measuring N-based O demand were the most precise among the many methods that could be used to measure this parameter. We also found that spatial variation in nitrification throughout the stream reach is great and must be considered for sampling strategies to precisely assess conditions in the stream. Contingencies, indirect effects, time lags, interactive effects, and spurious relations are categories of problems that we expect during the refinement of stressor-response relationships for which we are planning solutions.

The linkage of stressor-response relationships in a regional-scale, multi-stressor model will help evaluate our ecological understanding of streams and will help predict the results of different management strategies. Updated and new models relating human activities, stressors, and responses will be integrated into our ecological modeling system (EMS), which includes a land transformation model. Our EMS integrates outputs of many models, many of which model the same parameter, but with different algorithms. We have started relating our EMS to a suite of U.S. Environmental Protection Agency-supported models (e.g., BASINS, QUAL2E, and AQUATOX) and using those models to select our choices of stressor-response relationships that will be studied more intensively.

Future Activities:

We will supplement ongoing surveys of algae, invertebrates, fish, water chemistry, and land use in the Great Lakes region with intensive surveys of O depletion. O depletion and temperature in streams will be assessed in 40 streams with diurnal sampling by survey teams and automated metering. In addition, a more extended survey of early morning and late afternoon DO and temperature will be conducted in additional streams to characterize DO conditions in a broader range of stream conditions. Second, we will intensively study stream conditions in a region of Michigan with numerous confined animal feeding operations, especially intense applications of manure waste to fields. The location and loading of waste on fields is known. Ecological surveys will be conducted on streams in this region, which mostly are low-gradient streams that are highly susceptible to interactive effects of low-current velocity, channelization, high temperature, and low DO.

Journal Articles:

No journal articles submitted with this report: View all 1 publications for this project

Supplemental Keywords:

water, watersheds, groundwater, ecological effects, dose response, indicators, ecosystem, regionalization, scaling, aquatic, ecology, hydrology, modeling, Michigan, MI, EPA Region 5, valued ecological attributes, VEAs, total maximum daily loads, dissolved oxygen, DO, Great Lakes region, phosphorus, P, Cladophora, ecological modeling system, EMS,, RFA, Ecosystem Protection/Environmental Exposure & Risk, Scientific Discipline, Air, Water, Economic, Social, & Behavioral Science Research Program, Economics & Decision Making, Ecological Risk Assessment, Atmosphere, Watersheds, decision-making, Regional/Scaling, Monitoring/Modeling, Air Pollution Effects, climate change, Water & Watershed, Environmental Monitoring, ecological variation, ecosystem assessment, adaptive implementation modeling, multi-stressor model, valued ecological attributes, water quality, watershed assessment, risk assessment, aquatic ecosystem, ecological models, environmental decision making, water monitoring, individual based models, Bayesian classifiers, ecosystem stress, environmental stress, assessment endpoint mechanistic research, decision analysis, ecology assessment models, stress response, fish models, decision support tool, effects of multiple stresses, decision making, environmental risk assessment, watershed, regional scale impacts, ecosystem modeling

Progress and Final Reports:

Original Abstract

2004 Progress Report

2005 Progress Report

2006 Progress Report

Final