This data release links fish survey data from a suite of programs in the Chesapeake Bay watershed as well the benthic macroinvertebrate sites included in the Chesapeake Bay Basin-wide Index of Biotic Integrity (Chessie BIBI) developed by the Interstate Commission on the Potomac River Basin (ICPRB) and available from the Chesapeake Bay Program (https://datahub.chesapeakebay.net/LivingResources). The data set contains site name, survey program, coordinates of sample, and ancillary information such as sample date and site location information where available. It also includes the NHDPlus V2.1 unique identifier, COMID, as well as a confidence classification category for each of these assignments based on a set of pre-determined rules. In total there were 15 confidence categories ranging from high confidence to low confidence. We caution the use of sampling points which were given anything other than "high" confidence in their assignment to a given NHD catchment/flowline to avoid spurious/inappropriate attribution of geospatial data to benthic macroinvertebrate and fish data samples represented herein and refer the potential user to the Confidence Dictionary.csv which describes the criteria for each confidence category.

This data release links benthic macroinvertebrate sites to both the NHDPlus Version 2 and NHDPlus High Resolution Region 02 networks, hereafter referred to as V2 and HR, using the hydrolink methodology. Linked benthic macroinvertebrate sites are those included in the Chesapeake Bay Basin-wide Index of Biotic Integrity (Chessie BIBI) developed by the Interstate Commission on the Potomac River Basin (ICPRB) and available from the Chesapeake Bay Program (https://datahub.chesapeakebay.net/LivingResources). The data set contains a unique sample identifier created by ICPRB, survey program, coordinates of sample, linked V2 COMID and HR Permanent Identifier, and information regarding uncertainty in the attribution. We strongly caution the use of sampling points with attribution uncertainty to avoid spurious attribution of geospatial data to benthic macroinvertebrate samples.

This data release links benthic macroinvertebrate sites to both the NHDPlus Version 2 and NHDPlus High Resolution Region 02 networks, hereafter referred to as V2 and HR, using the hydrolink methodology. Linked benthic macroinvertebrate sites are those included in the Chesapeake Bay Basin-wide Index of Biotic Integrity (Chessie BIBI) developed by the Interstate Commission on the Potomac River Basin (ICPRB) and available from the Chesapeake Bay Program (https://datahub.chesapeakebay.net/LivingResources). The data set contains a unique sample identifier created by ICPRB, survey program, coordinates of sample, linked V2 COMID and HR Permanent Identifier, and information regarding uncertainty in the attribution. We strongly caution the use of sampling points with attribution uncertainty to avoid spurious attribution of geospatial data to benthic macroinvertebrate samples.

This data release links fish survey data from a suite of programs in the Chesapeake Bay watershed to the NHDPlus High Resolution Region 02 networks, hereafter referred to as NHDPlusHR. The data set contains site name, survey program, coordinates of sample, ancillary information such as sample date and site location information where available, and HR Permanent Identifier. It also includes a confidence classification category for each of NHD assignment based on a set of pre-determined rules. In total there were 15 confidence categories ranging from high confidence to low confidence. We caution the use of sampling points which were given anything other than "high" confidence in their assignment to a given NHD catchment/flowline to avoid spurious/inappropriate attribution of geospatial data to fish data samples represented herein and refer the potential user to the Confidence Dictionary.csv which describes the criteria for each confidence category.

This data release links fish survey data from a suite of programs in the Chesapeake Bay watershed to the NHDPlus High Resolution Region 02 networks, hereafter referred to as NHDPlusHR. The data set contains site name, survey program, coordinates of sample, ancillary information such as sample date and site location information where available, and HR Permanent Identifier. It also includes a confidence classification category for each of NHD assignment based on a set of pre-determined rules. In total there were 15 confidence categories ranging from high confidence to low confidence. We caution the use of sampling points which were given anything other than "high" confidence in their assignment to a given NHD catchment/flowline to avoid spurious/inappropriate attribution of geospatial data to fish data samples represented herein and refer the potential user to the Confidence Dictionary.csv which describes the criteria for each confidence category.

This dataset provides analysis results for recent status of and trends in 44 fish and 99 macroinvertebrate assemblages in the Chesapeake Bay watershed. For both biological datasets a multi-metric index, metric of assemblage sensitivity, functional feeding group metric and habitat preference metric was selected for analysis. Sites used to calculate trends required a minimum of 7 years of data. Status was calculated as a three-year average by averaging metric values for the most recent three years of data at each site and trends were calculated using generalized additive models (GAM) in the R package 'mgcv' for the full window of sample years at each site. Detailed data preparation information, analytical methods, and results are presented and discussed in the associated Scientific Investigative Report (https://doi.org/10.3133/sir20255072).

Data provided from the Virginia Department of Environmental Quality (DEQ) including simulated values of 72 hydrologic metrics, or indicators of hydrologic alteration (IHA), 37 fish metrics, and 64 benthic invertebrate metrics were reviewed to assess significant flow-ecology relations that may be developed. Hydrologic alteration was represented by simulation of streamflow record for a pre-water-withdrawal condition (baseline) without dams or developed land, compared to the simulated recent-flow condition (2008) including withdrawals, dams and altered landscape to calculate a percent-alteration of flow. Biological samples used represent a median condition of the biological community from 1972 to 2010. This study reviewed more than 7,272 linear regression models that relate altered flow conditions to biological sample metrics in Virginia. Decreasing flow conditions were the focus of this evaluation because of their relevance to the water-supply permitting process. The data tables highlight relations which may be significant and useful in future study and were further explored in the companion report; and relations that do not meet basic assumptions for valid linear regressions which were noted and omitted from the companion report. The three regions in Virginia defined by major drainage and physiographic boundaries as the Ohio River Drainages, Atlantic non-Coastal Plain, and Atlantic Coastal Plain were evaluated as well as a statewide grouping for fish and benthic data. This extensive dataset provided the opportunity for hypothesis testing and prioritization of flow-ecology relations that have the potential to explain the effect(s) hydrologic alteration has on biological metrics in Virginia.

Data provided from the Virginia Department of Environmental Quality (DEQ) including simulated values of 72 hydrologic metrics, or indicators of hydrologic alteration (IHA), 37 fish metrics, and 64 benthic invertebrate metrics were reviewed to assess significant flow-ecology relations that may be developed. Hydrologic alteration was represented by simulation of streamflow record for a pre-water-withdrawal condition (baseline) without dams or developed land, compared to the simulated recent-flow condition (2008) including withdrawals, dams and altered landscape to calculate a percent-alteration of flow. Biological samples used represent a median condition of the biological community from 1972 to 2010. This study reviewed more than 7,272 linear regression models that relate altered flow conditions to biological sample metrics in Virginia. Decreasing flow conditions were the focus of this evaluation because of their relevance to the water-supply permitting process. The data tables highlight relations which may be significant and useful in future study and were further explored in the companion report; and relations that do not meet basic assumptions for valid linear regressions which were noted and omitted from the companion report. The three regions in Virginia defined by major drainage and physiographic boundaries as the Ohio River Drainages, Atlantic non-Coastal Plain, and Atlantic Coastal Plain were evaluated as well as a statewide grouping for fish and benthic data. This extensive dataset provided the opportunity for hypothesis testing and prioritization of flow-ecology relations that have the potential to explain the effect(s) hydrologic alteration has on biological metrics in Virginia.

This data release links habitat assessment sites to both the NHDPlus Version 2 and NHDPlus High Resolution Region 02 networks using the hydrolink methodology. Linked habitat sites are those compiled by the Interstate Commission on the Potomac River Basin (ICPRB) during creation of the Chesapeake Bay Basin-wide Index of Biotic Integrity (Chessie BIBI) for benthic macroinvertebrates (https://datahub.chesapeakebay.net/LivingResources). The data set contains a unique sample identifier created by ICPRB, survey program, coordinates of sample, linked V2 COMID and HR Permanent Identifier, and information regarding uncertainty in the attribution. We strongly caution the use of sampling points with attribution uncertainty to avoid spurious attribution of geospatial data to benthic macroinvertebrate samples.

This data release links habitat assessment sites to both the NHDPlus Version 2 and NHDPlus High Resolution Region 02 networks using the hydrolink methodology. Linked habitat sites are those compiled by the Interstate Commission on the Potomac River Basin (ICPRB) during creation of the Chesapeake Bay Basin-wide Index of Biotic Integrity (Chessie BIBI) for benthic macroinvertebrates (https://datahub.chesapeakebay.net/LivingResources). The data set contains a unique sample identifier created by ICPRB, survey program, coordinates of sample, linked V2 COMID and HR Permanent Identifier, and information regarding uncertainty in the attribution. We strongly caution the use of sampling points with attribution uncertainty to avoid spurious attribution of geospatial data to benthic macroinvertebrate samples.