Ecological change over the decades: What have we learned from long-term monitoring and restoration of the Upper Mississippi and Illinois Rivers?

Dr. Kristen Bouska

Research Ecologist, US Geological Survey

Abstract

Long-term monitoring plays a critical role in understanding ecological change over time and space. Within the Upper Mississippi and Illinois Rivers, monitoring of water quality, aquatic vegetation, and fish communities has occurred annually since 1993 through the Upper Mississippi River Restoration program’s Long Term Resource Monitoring element. In this talk, I will highlight a suite of recently documented widespread and regional changes derived from those long-term datasets from six study reaches spanning 900 river miles. Total phosphorus and total suspended solids concentrations have decreased in many study reaches. Water clarity and aquatic vegetation prevalence have increased in upstream study reaches and bigheaded carps have become dominant in downstream study reaches. Through making connections among these and other observed changes (i.e., hydrology, geomorphology, and floodplain vegetation) we strive to develop and communicate a more comprehensive understanding of ecological change across this river system. Further, opportunities to learn from habitat rehabilitation projects offer insights into mechanisms and processes that are difficult to disentangle through long term monitoring. I will share a new collaborative project in which we are building capacity to understand key uncertainties through such targeted research. Advancing our knowledge of ecosystem dynamics, trajectories of change, and impacts of restoration actions can aid in assessing whether different management approaches are likely to be effective in a changing world.  These findings and insights illustrate the value of long-term data in understanding ecological dynamics, which will continue to be crucial in an era of persistent and rapid change.