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Center for Earth and Environmental
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2005
Research Program Nutrient and Sediment Stream Budgets of Streams Under the Influence of Agriculture, Urbanization, and In-transition areas in Eagle Creek Watershed, IN The research study determined changes in water quality during low flow and event flow in streams as land use changed from agricultural to urban. Special attention was given to the characterization of the impact of areas currently transitioning from agricultural to residential land-use. Results indicate that the increase in urbanization from less than 3% in the upstream areas to 10% lower in the watersheds led to a decrease in atrazine and total nitrogen in the stream. However, the moderate increase in urban land-use observed in the downstream direction did not strongly impact phosphorus, nitrate or suspended sediments in the watersheds studied. Nutrient Limitation and Phytoplankton Succession in Eagle Creek Reservoir A series of experiments on Eagle Creek Reservoir measured changes in nutrient dynamics in the reservoir. The experiments were designed to determine if a decrease in nitrogen availability was related to an increase in a specific nuisance alga: filamentous blue-green algae capable of fixing atmospheric nitrogen. These blue-green algae are of particular concern as they have the potential of forming taste and odor compounds and surface scums on water. Some have been shown to cause adverse health affects through the production of toxins. Preliminary data show that Eagle Creek Reservoir undergoes changes from nitrogen abundance to nitrogen scarcity. These changes in nitrogen availability occurred with a change in algal communities, resulting in an increase in nuisance algae. Data from this study confirm the findings of the multi-reservoir survey showing the relationship between nitrogen scarcity and nuisance algae occurrence. Findings demonstrate that predicting and preventing nuisance algal blooms in these small reservoir systems will require managing both nitrogen and phosphorus loads. Multi-Reservoir Survey Showing the Relationship between Nitrogen Limitation and Nuisance Algal Bloom Formation The study involved five reservoirs from Indiana and Michigan to determine the relationship between nutrients, nitrogen and phosphorus, and overall reservoir algal growth. Forms of nitrogen (nitrate, nitrite, ammonia, and TKN) and phosphorus (orthoP and TP) as well as chlorophyll a (a photosynthetic pigment found in algae) were measured on each reservoir. Data from two Michigan reservoirs, Ford Lake and Belleville Lake were collected from 1998 – 2000, while data from the three Indiana reservoirs, Eagle Creek, Geist, and Morse Reservoirs, were collected from 2005-2006. While phosphorus is often used as an indicator or predictor of overall reservoir health and potential to support exponential growth of algae, these small reservoirs show that the lack of nitrogen in the presence of abundant phosphorus plays an important role in the formation of nuisance blooms of a specific nuisance alga: the Nostacales or filamentous blue-green algae capable of fixing atmospheric nitrogen. Nostacales blue-green algae are of particular concern as they have the potential of causing taste and odor in drinking water and forming surface scums. Some have been shown to cause adverse health affects through the production of toxins. Study of these small reservoirs showed that the highest algal cell concentrations occurred when phosphorus availability was high and nitrogen availability was low, showing that decreasing nitrogen-to-phosphorus ratios and the dynamics between nitrogen and phosphorus availability are more important in Nostacales bloom formation than nitrogen or phosphorus availability alone. These findings contribute to understanding the drivers of algal bloom formation in these small reservoir systems, informing reservoir and public health managers how to best predict and prevent the occurrence of these potentially harmful blooms. Mapping Blue-Green Algae with Hyperspectral Imagery in Central Indiana Reservoirs CIWRP and the Lake and River Enhancement Program of the Indiana Department of Natural Resources funded a research project to develop an assessment tool to map nuisance blue-green algal blooms in Central Indiana reservoirs that are part of the Indianapolis drinking water system. These nuisance and sometimes harmful algal blooms can result in degradation of lakes and reservoirs due to the production of surface scum, earthy smells from taste and odor causing compounds, recreational use degradation, and possibly human health concerns. Using the optical properties of phytoplankton pigments such as chlorophyll a and phycocyanin, a pigment unique to blue-green algae, CEES researchers were able to develop methods to rapidly map blue-green algae using light reflectance data. Reflectance data collected both by boat-based and airplane-based sensors on Eagle Creek, Geist, and Morse Reservoirs have resulted in maps of blue-green algae distribution in all three reservoirs. This assessment tool is currently being tested as a real-time tool for tracking the distribution of blue-green algae in the reservoirs and allowing researchers and managers to better understand how to manage blooms and more effectively target reservoir sampling and treatment. The research team is led by Dr. Lin Li, Dr. Jeffery Wilson, and Dr. Lenore P. Tedesco and CEES research scientists D. Lani Pascual, Kate Randolph, and Bob E. Hall. This research program remains an important part of the applied work that is the focus of CIWRP programs. Program focus continues to refine applications of algorithms to increase accuracy of predictions as well as allow for the transfer of this work to other lakes and reservoirs both throughout Indiana as well as potentially in Europe and Australia. Watershed-Scale Evaluation of BMP Effectiveness and Acceptability: Eagle Creek Watershed, Indiana Purdue University and IUPUI CEES have teamed up to investigate how well various water resource conservation practices work, how much they cost, and how landowners feel about implementing the practices through a project funded with a $650,000 grant from the USDA’s Cooperative State Research, Education and Extension Service (CSREES). The Conservation Effects Assessment Project (CEAP) is concentrating on the Eagle Creek watershed to evaluate the long and short-term effects of practices such as tillage, nutrient management, pesticide management, conservation buffers and water management. The project is also studying the social and economic factors that affect decisions about water quality management alternatives. CEES and Veolia Water Indianapolis, through the Central Indiana Water Resources Partnership, have collected and managed historical data and ongoing analysis of the Eagle Creek watershed that will be utilized in CEAP. This information will be used to develop models in order to project the watershed’s future and recommend alternative management practices. The analyzed information will be provided to conservation agencies that can then plan and put in place strategies to correct problems. Real data will be used to drive scenario modeling to use in educational programs for policymakers and implementers of best management plans to influence water quality practices in the Eagle Creek watershed. |
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