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USING GRADIENTS IN LANDSCAPECHARACTER TO IDENTIFY RESPONSES TO NUTRIENTS AND OTHER STRESSORS IN GREAT LAKES COASTAL ECOSYSTEMS
Citation:
Kelly, J. R., J A. Morrice, P. M. Yurista, A M. Cotter, T. Hollenhorst, AND N. Danz. USING GRADIENTS IN LANDSCAPECHARACTER TO IDENTIFY RESPONSES TO NUTRIENTS AND OTHER STRESSORS IN GREAT LAKES COASTAL ECOSYSTEMS. Presented at EaGLe Meeting (sponsored by STAR), Bodega Bay, CA, December 4-5, 2003.
Description:
Using GIS and coarse-scale, publicly-available data, the GLEI project has defined the landscape character of areas draining to 76d2 shoreline segments - the entire US portion of the Great Lakes basin. Using principal components and clustering analyses to discriminate among the segments, groups of coastal wetland and nearshore sites were chosen to span available gradients in landscape disturbance, emphasizing characteristics that can affect nutrient delivery to adequate ecosystems. More than 100 locations were sampled in 2002 and 2003. Two highlighted results to date: 1) Sampling has confirmed that principal components derived a priori from agriculture-chemical statistics and land cover/use data are each general predictors of in situ nutrient concentrations in shallow coastal receiving ecosystems. EPA research seeks further to define stressor-response curves and establish indicators of threshold responses for aquatic life criteria studies. 2) The signal of landscape character, expressed as nutrient concentrations, diminishes in fidelity as one moves downstream from waters more firmly embedded within the landscape (tributaries and coastal wetlands) to the more open nearshore waters of each Great Lake. Recognizing this, EPA research is exploring whether it is possible to link biological indicators to landscape-derived stressors with high resolution data collected using in situ sensors continuously towed to map plankton in nearshore receiving waters. This abstract does not necessarily reflect EPA policy.