Citation:

Riato, L., S. Leibowitz, AND M. Weber. The use of multiscale stressors in biological condition assessments: a framework to advance the assessment and management of streams. SCIENCE OF THE TOTAL ENVIRONMENT. Elsevier BV, AMSTERDAM, Netherlands, , 139699, (2020). https://doi.org/10.1016/j.scitotenv.2020.139699

Impact/Purpose:

Incorporating information on landscape condition (or integrity) across multiple spatial scales and over large spatial extents (e.g., across regions) in biological assessments may allow for a more integrated measure of stream biological condition and better management of these resources. However, streams are often assessed and managed at an individual scale (e.g., an individual watershed or stream site) without a larger regional multiscale context. ORISE post-doctoral associate Luisa Riato, and Scott Leibowitz and Marc Weber of EPA-PESD, developed a conceptual framework that relates stream condition to multiscale integrity data at three different spatial scales: watershed, catchment and stream-reach scale, in order to inform managers of the spatial scale at which management efforts will most likely succeed. The paper provides different examples of the framework’s use to demonstrate the flexibility of its application and relevance to management. The examples are from macroinvertebrate, diatom and fish Biological Condition Gradient (BCG) assessments: Central Appalachia (Virginia/West Virginia), New Jersey, and Connecticut; and from two macroinvertebrate multimetric index (MMI) assessments: Puget Sound Region (Washington state/King county) and New Jersey. Landscape integrity indicators were comprised of U.S. EPA’s nationally available Index of Watershed Integrity (IWI) and Index of Catchment Integrity (ICI), a Connecticut watershed integrity indicator based on flow condition, and Central Appalachia instream measures of conductivity, an important regional stressor used to represent the stream-reach integrity indicator. Scatterplots and a landscape integrity map were used to relate samples of stream condition classes to watershed, catchment and stream-reach scale integrity. Identifying the quadrant in the scatterplot or catchment in the landscape integrity map in which a good or poor condition sample is located may allow for distinct management actions – for example, samples from sites that have high integrity (e.g., high IWI/ICI values) would be good candidates for protection or restoration, whereas sites that have low watershed (low IWI) and but high catchment integrity (high ICI) could require considerable management effort responding to upstream (watershed-scale) stressors. This framework and approach could provide a powerful tool for prioritizing, targeting, and communicating state and regional management actions, and informing the spatial extent at which management is applied.

Description:

Incorporating information on landscape condition (or integrity) across multiple spatial scales and over large spatial extents (e.g., across regions) in biological assessments may allow for a more integrated measure of stream biological condition and better management of these resources. However, streams are often assessed and managed at an individual scale without a larger regional multiscale context. In this paper, our goals were: (1) To develop a conceptual framework that could combine stream biological condition to landscape integrity (or, conversely, stressor) data at three different spatial scales: watershed, catchment and stream-reach scale, in order to inform the spatial scale at which management efforts will most likely succeed. Measures of landscape integrity and stressors are negatively related, i.e., we assume integrity on a 0-1 scale is equal or equivalent to stressors on a 1-0 scale. (2) To develop the framework in such a way that allows operational flexibility, whereby different indicators can be used to represent biological condition, and landscape integrity (or stressors) at various scales. (3) To provide different examples of the framework’s use to demonstrate the flexibility of its application and relevance to management. The examples include stream biological assessments from different regions and states across the U.S. for different biological groups (fish, macroinvertebrates and diatoms) using a variety of assessment tools (e.g., the Biological Condition Gradient (BCG), and an Index of Biotic Integrity (IBI)). Landscape integrity indicators were comprised of U.S. EPA’s nationally available Index of Watershed Integrity (IWI) and Index of Catchment Integrity (ICI), a state-derived watershed integrity indicator based on flow condition, and instream measures of conductivity, an important regional stressor used to represent the reach-scale integrity indicator. Scatterplots and a landscape integrity map were used to relate samples of stream condition classes (e.g., BCG levels of biological condition from (1) undisturbed to (6) highly disturbed; or IBI good, fair, poor) to three different spatial scales of landscape integrity, i.e., watershed, catchment and stream-reach scale integrity. Identifying the quadrant in the scatterplot or catchment in the landscape integrity map in which a good or poor condition sample is located may allow for distinct management actions – for example, samples from sites in good condition that have high integrity (e.g., high IWI/ICI values) would be good candidates for protection, whereas sites in poor condition that have high watershed integrity (high IWI) but lower catchment integrity (low ICI) might be suitable for restoration. This framework and approach could provide a powerful tool for prioritizing, targeting, and communicating management actions, and informing the spatial extent at which management is applied.

URLs/Downloads:

Record Details: