The freshwater aquatic ecosystem team now has recommendations for revisions to your cooperative’s freshwater aquatic indicators. These changes are now open for comment until October 22nd. You can either comment at the bottom of this post or email me directly (

Here are the proposed changes to the freshwater aquatic indicators:

Number of low impervious surface catchments

Impervious cover provides an indicator of water quality and freshwater instream flow that captures land cover patterns throughout the catchment, is easy to monitor and model, and is widely used and understood by diverse partners

Proposed change: In additional to current the 10% threshold, add a 5% threshold for species that are impacted at lower levels of impervious surface. The 5% threshold is supported in the literature for both Piedmont fish [ Cyprinella trichroistia (tricolor shiner), Percina palmaris (bronze darter), Etheostoma etowahae (Etowah darter)] and Estuarine species [ Callinectes sapidus (blue crab), Morone americana (white perch), M. saxatilis (striped bass), and Leiostomus xanthurus (spot)]

Percent of natural habitat near rivers, streams, and lakes

Habitat near rivers, streams, and lakes is strongly linked to water quality and instream flow, is easy to monitor and model, and is widely used and understood by diverse partners. These buffers provide a “frontline defense” for aquatic systems

Proposed change: Also include lakes which are part of the Freshwater Aquatic ecosystem

Index of Biotic Integrity Richness of fish of conservation concern

Fish of conservation concern provides an indicator of cumulative impacts to the freshwater aquatic ecosystem and are regularly monitored throughout the LCC

Proposed change: State level monitoring of existing insect based IBIs were not sufficiently comparable to use across state lines and EPA region assessments (while consistent across states) didn’t have sufficient sample density in the region. This new indicator, also a type of IBI, is comparable across state lines and is relatively well monitored. Native species that have either NatureServe GRanks less than G5 (Stable) or with ranges that were completely contained within the South Atlantic LCC boundaries (Endemic) are considered species of conservation concern. This also includes diadromous fish.  

* Note on viewing the data: If you want to see which fish species are in each HUC for the Richness indicator, there’s a layer with that info in the “Additional data layers” folder. That info isn’t in the layer in the main folder because all those layers have already been converted to the 200m pixels that’ll be used in Conservation Blueprint 2.0.

View all the data layers

Indicators to be used to calculate freshwater aquatic integrity: