This map is one in a series illustrating the condition of habitat at the river reach level.  Map credit:  Downstream Strategies.

In May 2011, SARP entered into an agreement with the Ohio Basin Fish Habitat Partnership and Downstream Strategies, LLC to complete a fish habitat assessment for the Tennessee/Cumberland/Ohio River Basins.  The goal of this project, which is being undertaken by SARP's Science & Data (S&D) Committee, is to use available fish and landscape data to predict where the best habitat and fish populations are and to provide data for use by SARP partners.  This data can then be used by SARP and others to develop prioritization tools for restoration efforts and to implement measures to protect fish habitat at a regional scale.

Using a modeling process developed by Downstream Strategies, this project will help users to better predict and understand what drives certain fish responses at the regional scale.  This information can then be used to define priority areas for habitat protection and restoration.  A GIS decision support tool will enable users to explore the data and assess the impacts that on-the-ground restoration efforts could potentially have at a particular site, as well as downstream locations.  This could serve as a valuable tool for use by SARP and others when assessing aspects of the conservation value of projects submitted for funding consideration through its SARP/NFHAP/USFWS and SARP/NOAA Aquatic Habitat Improvement Restoration Programs.  The extensive scope of this data collection and assessment effort, the value of the Decision Support Tool, and the fact that this model approach can be replicated in other basins in the southeast, are key factors that differentiate it from other similar studies.

The S&D Committee working group is exploring several different models that would be meaningful to biologists and aquatic resource managers.  To date, six (out of seven) models focused on smaller rivers and streams are in the works.  They are investigating response variables for fish and mussels and have completed the following: Small Streams Signature Fish Index (Streams Index), Modified Index of Centers of Diversity (MICD), Percent Potential Native Species, Smallmouth Bass Presence/Absence, Percent Individuals (Fish) as Intolerant to Human Disturbance (Habitat & Water Quality), and Percent Potential Rheophilic Benthic Fish Species. Mussel studies are ongoing.

Thus far, the group has preliminary results for four of the six different fish responses of interest and has draft results for two response variables.  Downstream Strategies uses a sophisticated statistical approach called Boosted Regression Trees (BRT) to predict and map the response variables across the study area.  BRTs weight the most important predictor variables relative to the response variables, and create function plots to establish thresholds for when the fish community could

be adversely effected.  The four preliminary models are at this stage in the modeling process.  Using the function plots and relative weights from the predictor variables, Downstream Strategies can calculate an Anthropogenic Stress Index and a Natural Habitat Quality Index for each catchment in the study area.  This has been completed for the other two draft models.  Experts in the river basins are reviewing these results before the GIS developers create the Decision Support Tool, the final version of which is anticipated to be completed by January 2012.

To learn more about the TN/Cumberland/Ohio Aquatic Habitat Assessment, click here.