Jenny L Hanson Jayme M Strange Stephanie R Sattler Erin E Hoy Teresa J Newton 20250227 raster digital data www.sciencebase.gov US Geological Survey Upper Midwest Environmental Sciences Center https://doi.org/10.5066/P9EUMCSF This dataset is a digital image mosaic of sidescan for six sites where known rock structures exist in the St. Croix River. Sidescan sonar emits conical or fan-shaped beam down across a wide angle perpendicular to the path of the sensor through the water. The intensity of the acoustic reflections from the riverbed is recorded in a series of cross-track slices and when stitched together in a mosaic, form an image of the riverbed giving the user a view of the material and texture of the riverbed. Sidescan mosaics are being used in this project mainly as ancillary information to help view the rock structures and will also be used for investigating the use of hydroacoustic technologies for quantifying habitat for imperiled mussels Spectaclecase (Margaritifera monodonta) and Salamander (Simpsonaias ambigua) typically associated with rock structures (e.g., wing dams, revetment) in rivers. Sidescan can be recorded simultaneous with the multibeam data; and were collected using a Norbit integrated wide band multibeam system compact (iWBMSc) sonar unit for five of the sites. A recreational grade Humminbird Helix was used to collect sidescan of the one site too shallow for multibeam. All hydroacoustic data were collected in early May of 2021, and the image mosaics are provided in GeoTiff format. Data were collected to quantify water depth, flow, and rock configuration (e.g., spatial arrangement, size, shape) associated with habitat (e.g., bedrock, rock outcrops, etc.) occupied by imperiled mussels Spectaclecase (Margaritifera monodonta) and Salamander (Simpsonaias ambigua). Combining these types of information with measures of slope, roughness, and backscatter may provide more information to qualitatively and quantitatively describe these rock habitats. Information on habitat associations can be used by managers to identify and characterize existing occupied habitats, identify potential reintroduction areas, and implement restoration programs. Some multibeam sonar systems record sidescan data, which are processed into sidescan image mosaics, which can assist in identifying riverbed types and morphology. Sidescan is the intensity of the intensity of the acoustic reflection and is a commonly used tool to detect debris items and other obstructions. The resulting image is made up of light and dark areas, where hard objects of the bottom send a strong echo displaying lighter color values and soft bottoms like mud send a weaker echo displaying dark color values. The sidescan mosaics are intended to be used to quantitatively and qualitatively describe rock structure among the different rock sites and determine whether associations exist among the rock habitats and mussels. 20210503 20210511 20210512 ground condition Complete None planned St. Croix River -92.76360 -92.68450 45.37120 45.21640 USGS Thesaurus benthic ecosystems endangered species USGS-EMA-LOW-SB SMC: Freshwater mussels acoustic doppler current profiling bathymetry measurement sea-floor acoustic reflectivity sidescan sonar image mosaics Coastal and Marine Ecological Classification Standard Rock Outcrop Rock Substrate Alexandria Digital Library Feature Type Thesaurus rivers USGS Metadata Identifier USGS:635a5b96d34ebe442504705c Common geographic areas Minnesota Wisconsin St. Croix River None Margaritifera monodonta Simpsonaias ambigua Kingdom Animalia animals Subkingdom Bilateria Infrakingdom Protostomia Superphylum Lophozoa Phylum Mollusca molluscs mollusks Class Bivalvia bivalves clams Subclass Palaeoheterodonta Order Unionoida Superfamily Unionoidea Family Margaritiferidae Genus Margaritifera Species Margaritifera monodonta spectaclecase TSN: 983846 Family Unionidae Subfamily Unioninae Tribe Alasmidontini Genus Simpsonaias Species Simpsonaias ambigua salamander mussel TSN: 80145 None. Please see 'Distribution Info' for details. None. Users are advised to read the dataset's metadata thoroughly to understand appropriate use and data limitations. Jenny L Hanson U.S. Geological Survey, MIDCONTINENT REGION Biologist mailing address

2630 Fanta Reed Road

La Crosse WI 54603 US 608-781-6372 608-783-6066 jhanson@usgs.gov State Wildlife Grant, Minnesota Department of Natural Resources; Wisconsin Department of Natural Resources; USGS Ecosystems Mission Area; US Fish and Wildlife Service Windows 10 Enterprise; HYPACK 2021, Inertial Explorer 8.90; AML Oceanographic SeaCast 4.40; Quality Positioning Systems FMGT 7.9.5; GeoCue LP360 2020.1.80.0; ArcGIS Desktop 10.8.1; SonarTRX 2020 No formal attribute accuracy tests were conducted. A review was conducted to ensure that noise and or equipment anomalies were kept to a minimum. No formal logical accuracy tests were conducted. Data set is considered complete for the information presented, as described in the abstract. Users are advised to read the rest of the metadata record carefully for additional details. A formal accuracy assessment of the horizontal positional information in the data set has not been conducted. A formal accuracy assessment of the vertical positional information in the data set has not been conducted or is not applicable. Bathymetric and sidescan data were collected for select rock structures (wing dams and outcrops) using a NORBIT iWBMSc (Integrated Wideband Multibeam System - Compact) echosounder sonar unit and a NovAtel Marine-SPAN (synchronized position attitude navigation) Inertial Navigation System (INS). The iWBMSc/NovAtel solution is a tightly coupled integration of Global Navigation Satellite Systems (GNSS) and Inertial Measurement Unit data (IMU). The INS calculates positioning, orientation, and velocity of the multibeam echosounder (MBES), and provides measures of heave, pitch, roll, and heading of the vessel to accurately position the data received by the MBES. The MBES system was operated at a frequency of 700 kilohertz and a swath width range of 140 degrees. The swath can be rotated within the Norbit graphical user interface (GUI) to either side of nadir, enabling data to be captured along sloping or vertical features up to a depth just below the water surface. Bathymetric data were collected in transects longitudinal to flow. Several sound velocity profiles were collected throughout the surveys (at least one per site) using the Sound Velocity Profiler unit and the SeaCast software. Sidescan was collected for the site on May 3, 2021 using a recreational grade fish finder - a Humminbird Helix. Side imaging was collected at 812-kHz for high-resolution viewing. 20210511 Raw sonar HSX data files were imported into the HYPACK 2021 Targeting and Mosaicking program. Each raw sidescan file was visually examined using the Scan View Mode to remove positional spikes, and applied a "smoothing" process to the track lines. The Mosaic Mode was used to export sidescan data to a mosaic and exported individual transect lines as .TIFF images. The images were exported to a 0.03m resolution. 20210610 The exported mosaics and/or transect lines were imported into ArcGIS for additional assessment. If the mosaic needed no further modification, it was clipped to a study area boundary (SAB) shapefile that was manually delineated around the sonar data. If further editing was required, the individual exported transect images were clipped and mosaicked using the ArcMap, Arc Toolbox, Data Management Tools, Raster tools. 20210630 In the case of the Osceola site, the mosaic had to be georeferenced to the processed data (DEM and hillshade) because the processed GPS positional file is not applied to the raw sidescan data. The mosaic was georeferenced and rectified by adding several control points using ArcToolbox Georeference tool. A text file is provided with the control points for the Osceola mosaic. The five multibeam collected sidesan mosaics, required their projections to be defined to UTM North American Datum (NAD) 1983 Zone 15 North using the ArcToolbox Projections and Transformations, Define Projection tool. 20210707 SonarTRX was used to process the sonar data collected from the Humminbird Helix unit. The individual sonar channels were viewed in horizontal or vertical waterfall mode. Slant range correction and beam angle corrections were applied. The software was used to geo-referenced raster image-tiles, track lines and coverage area polygons from sidescan sonar recordings. The image-tiles were merged into larger geo-referenced "master-images". 20210709 The master images were imported into ArcGIS. The sonar image was clipped to a manually derived shapefile outlining the sonar extent. The mosaic was projected to 20210712 All sonar image mosaics were reviewed for noise and/or anomalies to meet quality control/quality assurance standards. UTM North American Datum (NAD) 1983 Zone 15 North. 20211103 Raster Grid Cell 572500 204882 1 Universal Transverse Mercator 15 0.9996 -93.0 0.0 500000.0 0.0 row and column 0.0300 0.03 meters North_American_Datum_1983 GRS 1980 6378137.0 298.2572221010042 Franconia_SS.tif Raster geospatial data file in 16-bit unsigned integer format, where the NoData value is 256. The data should be viewed with the colormap file (0-255 values). Producer Defined Value Unique numeric values contained in each raster cell, where higher values are lighter in color and represent greater acoustic intensity reflected from the riverbed (and vice versa for dark/lower values). Producer Defined 0.0 255.0 n/a LoghouseB_SS.tif Raster geospatial data file in 16-bit unsigned integer format, where the NoData value is 256. The data should be viewed with the colormap file (0-255 values). Producer Defined Value Unique numeric values contained in each raster cell, where higher values are lighter in color and represent greater acoustic intensity reflected from the riverbed (and vice versa for dark/lower values). Producer Defined 0.0 255.0 n/a LoghouseC_SS.tif Raster geospatial data file in 16-bit unsigned integer format, where the NoData value is 256. The data should be viewed with the colormap file (0-255 values). Producer Defined Value Unique numeric values contained in each raster cell, where higher values are lighter in color and represent greater acoustic intensity reflected from the riverbed (and vice versa for dark/lower values). Producer Defined 0.0 255.0 n/a Osceola_SS.tif Raster geospatial data file in 16-bit unsigned integer format, where the NoData value is 256. The data should be viewed with the colormap file (0-255 values). Producer Defined Value Unique numeric values contained in each raster cell, where higher values are lighter in color and represent greater acoustic intensity reflected from the riverbed (and vice versa for dark/lower values). Producer Defined 0.0 255.0 n/a PineIsland_SS.tif Raster geospatial data file in 16-bit unsigned integer format, where the NoData value is 256. The data should be viewed with the colormap file (0-255 values). Producer Defined Value Unique numeric values contained in each raster cell, where higher values are lighter in color and represent greater acoustic intensity reflected from the riverbed (and vice versa for dark/lower values). Producer Defined 0.0 255.0 n/a Boom_SS_HB.tif 4 band raster geospatial data file of 32-bit format to display either RGB Composite or a Stretched color ramp. Producer Defined Value Unique numeric values contained in each raster cell, where higher values are lighter in color and represent greater acoustic intensity reflected from the riverbed (and vice versa for dark/lower values). Producer Defined 0.0 255.0 The entity and attribute information provided here describes the tabular data associated with the data set. Please review the detailed descriptions that are provided (the individual attribute descriptions) for information on the values that appear as fields/table entries of the data set. The entity and attribute information were generated by the individual and/or agency identified as the originator of the data set. Please review the rest of the metadata record for additional details and information. GS ScienceBase U.S. Geological Survey mailing address

Denver Federal Center, Building 810, Mail Stop 302

Denver CO 80225 United States 1-888-275-8747 sciencebase@usgs.gov Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Digital Data https://doi.org/10.5066/P9EUMCSF None 20250227 Jenny L Hanson U.S. Geological Survey, MIDCONTINENT REGION Biologist mailing address

2630 Fanta Reed Road

La Crosse WI 54603 US 608-781-6372 608-783-6066 jhanson@usgs.gov FGDC Biological Data Profile of the Content Standard for Digital Geospatial Metadata FGDC-STD-001.1-1999