Polygon shapefile showing the coverage area of the acoustic mapping at Sandy Hook, NJ between July 2015 and August 2015. The side scan sonar survey was done simultaneously with the bathymetry swath survey and used an EdgeTech Model 4125 Towfish bow-mounted from Lookdown at 400 and 900 kHz. The 4125 Towfish utilizes EdgeTech’s Full Spectrum CHIRP technology to produce higher resolution images than a non-CHIRP system. EdgeTech Discovery Software was used to acquire the side scan sonar data using the JSF format at a resolution of about 2.3 cm. All JSF files collected using EdgeTech’s Discover Software were processed using John Gann’s Chesapeake Technology SonarWiz5. Dimensions of contacts should be considered accurate to +/- 30% of the measured dimensions. This system also records the direct arrival intensity data.

The side scan sonar survey was done simultaneously with the bathymetry swath survey and used an EdgeTech Model 4125 Towfish bow-mounted from Lookdown at 400 and 900 kHz. The 4125 Towfish utilizes EdgeTech’s Full Spectrum CHIRP technology to produce higher resolution images than a non-CHIRP system. EdgeTech Discovery Software was used to acquire the side scan sonar data using the JSF format at a resolution of about 2.3 cm. All JSF files collected using EdgeTech’s Discover Software were processed using John Gann’s Chesapeake Technology SonarWiz5. Dimensions of contacts should be considered accurate to +/- 30% of the measured dimensions. This system also records the direct arrival intensity data.

This dataset shows the extent of sidescan sonar data collected during acoustic surveys completed within and adjacent to the boundaries of Cape Cod National Seashore (CACO) from 2014-2015. Full coverage sidescan and partial coverage bathymetry data were collected using an Edgetech 6205 Phase-Measuring Sidescan Sonar. In total, 668 hectares were mapped at primarily 20 – 40 meter line spacing and 50 meter swath range to allow overlap of lines.

This dataset presents the raw and processed sidescan mosaic for surveys completed along the 58‐km long Assateague barrier island stretching from the Ocean City inlet in Maryland, down past Chincoteague Island in northern Virginia. The data was collected June 20th-25th, 2014 and May 12th - 21th, 2015. Full coverage side-scan sonar and partial coverage bathymetry data were collected using an EdgeTech 6205 Multiphase Echosounder. In total, 73 square kilometers were mapped at primarily at 100m line spacing and 80 m swath range per channel (to allow overlap between lines).

Tide Data for Acoustical Surveys at CACO. The side scan sonar survey was done simultaneously with the bathymetry swath survey and used an EdgeTech Model 4125 Towfish bow-mounted from Lookdown at 400 and 900 kHz. The 4125 Towfish utilizes EdgeTech’s Full Spectrum CHIRP technology to produce higher resolution images than a non-CHIRP system. EdgeTech Discovery Software was used to acquire the side scan sonar data using the JSF format at a resolution of about 2.3 cm. All JSF files collected using EdgeTech’s Discover Software were processed using John Gann’s Chesapeake Technology SonarWiz5. Dimensions of contacts should be considered accurate to +/- 30% of the measured dimensions. This system also records the direct arrival intensity data.

Collection of benthic infauna and epifauna used a 0.04 m2 Ted Young Modified Van Veen grab. Three replicate benthic samples were collected at 23 sites to total 69 samples in Year 1. The samples were immediately sieved over a 0.5 mm mesh screen. The residue remaining on the screen was fixed in 3.7% formaldehyde solution in seawater, buffered with sodium borate and containing Rose Bengal to stain organisms. A fourth grab was collected for sediment analysis. Sediment for grain size analysis was wet-sieved through a 63μm-mesh sieve in distilled water with dispersant to disaggregate and separate the silt and clay fraction from the sand-sized fraction. Silt and clay mass was determined by drying a known volume of the water-particle mixture passing through the sieve. The sand fraction was dried and then sieved into the following size fractions: <63 µm (silt), 63-125 µm (very fine sand), 125-250 µm (fine sand), 250-500 µm (medium sand), 500-1000 µm (coarse sand), >1000 µm (very coarse sand). Each fraction was weighed. The mass of the <4φ fraction was further analyzed using a Spectrex model PC-2000 laser particle counter (Spectrex Corporation, Redwood City, CA) Counts of particles were obtained corresponding to these additional size categories: 5φ (4-8 µm very fine silt), and 6φ (16-31 µm, medium silt), 7φ (8-16 µm, fine silt), 8 φ ( 4-8 µm, very fine silt), and 9 φ (2-4 µm, clay). Particle counts were converted to mass by multiplying the fractional volume percent in each size category by the total mass of the <4φ fraction determined during wet sieving.

Collection of benthic infauna and epifauna used a 0.04 m2 Ted Young Modified Van Veen grab. Three replicate benthic samples were collected at 23 sites to total 69 samples in Year 1. The samples were immediately sieved over a 0.5 mm mesh screen. The residue remaining on the screen was fixed in 3.7% formaldehyde solution in seawater, buffered with sodium borate and containing Rose Bengal to stain organisms. A fourth grab was collected for sediment analysis. Sediment for grain size analysis was wet-sieved through a 63μm-mesh sieve in distilled water with dispersant to disaggregate and separate the silt and clay fraction from the sand-sized fraction. Silt and clay mass was determined by drying a known volume of the water-particle mixture passing through the sieve. The sand fraction was dried and then sieved into the following size fractions: <63 µm (silt), 63-125 µm (very fine sand), 125-250 µm (fine sand), 250-500 µm (medium sand), 500-1000 µm (coarse sand), >1000 µm (very coarse sand). Each fraction was weighed. The mass of the <4φ fraction was further analyzed using a Spectrex model PC-2000 laser particle counter (Spectrex Corporation, Redwood City, CA) Counts of particles were obtained corresponding to these additional size categories: 5φ (4-8 µm very fine silt), and 6φ (16-31 µm, medium silt), 7φ (8-16 µm, fine silt), 8 φ ( 4-8 µm, very fine silt), and 9 φ (2-4 µm, clay). Particle counts were converted to mass by multiplying the fractional volume percent in each size category by the total mass of the <4φ fraction determined during wet sieving.

Collection of benthic infauna and epifauna used a 0.04 m2 Ted Young Modified Van Veen grab. Three replicate benthic samples were collected at 23 sites to total 69 samples in Year 1. The samples were immediately sieved over a 0.5 mm mesh screen. The residue remaining on the screen was fixed in 3.7% formaldehyde solution in seawater, buffered with sodium borate and containing Rose Bengal to stain organisms. A fourth grab was collected for sediment analysis. Sediment for grain size analysis was wet-sieved through a 63μm-mesh sieve in distilled water with dispersant to disaggregate and separate the silt and clay fraction from the sand-sized fraction. Silt and clay mass was determined by drying a known volume of the water-particle mixture passing through the sieve. The sand fraction was dried and then sieved into the following size fractions: <63 µm (silt), 63-125 µm (very fine sand), 125-250 µm (fine sand), 250-500 µm (medium sand), 500-1000 µm (coarse sand), >1000 µm (very coarse sand). Each fraction was weighed. The mass of the <4φ fraction was further analyzed using a Spectrex model PC-2000 laser particle counter (Spectrex Corporation, Redwood City, CA) Counts of particles were obtained corresponding to these additional size categories: 5φ (4-8 µm very fine silt), and 6φ (16-31 µm, medium silt), 7φ (8-16 µm, fine silt), 8 φ ( 4-8 µm, very fine silt), and 9 φ (2-4 µm, clay). Particle counts were converted to mass by multiplying the fractional volume percent in each size category by the total mass of the <4φ fraction determined during wet sieving.

This dataset presents the processed sidescan mosaic for Fire Island National Seashore. The acoustic sonar survey was conducted using a EdgeTech 6205, a Multi-Phase Echo sounder system. This combined bathymetry and dual-frequency sidescan sonar system is optimized for shallow water surveying. The sonar system was bow-mounted to a 28-ft pontoon survey vessel customized for shallow water surveying, including having a draft of less than one foot. Data was collected using GeoDas software developed by Ocean Imaging Consultants (OIC) and monitored topside in real-time to ensure quality of data and full-coverage sidescan was being achieved. The data were collected in association with an Applanix POS MV system to assure positional accuracy and to correct for vessel motion (pitch, roll, heave). The survey was designed to acquire full-coverage sidescan data and partial coverage bathymetry data. As such, the survey was composed of parallel track lines with line spacing of 35 to 50 m and a sonar swath range of 50 m (25 m per side) to ensure overlap with adjacent lines. The raw sidescan and bathymetry records were processed using OIC CleanSweep software (Version 3.8.0, Build #263). All of the acoustic data were examined manually to confirm quality and accuracy. For sidescan, processing followed standard techniques of bottom-tracking the data and then applying angle-varying gains (AVG) and look-up tables (LUT) as necessary to correct for water column returns, arrival angle, and contrast to produce color-balanced sidescan sonar images. The native images are displayed as an inverse gold color scale, with pixel values ranging from zero (dark gold) to 255 (white). The lighter pixels indicate hard acoustic returns and represent the presence of hard surficial sediments (e.g. coarse sand, cobbles, and boulders), whereas darker pixels represent the presence of soft sediments, which tend to absorb sound to a greater degree. The horizontal coordinate system was set to UTM Zone 18N and sidescan data was processed to 25cm pixel resolution.

1m depth contours, derived from Sandy Hook bayside bathymetry, 1m resolution raster. The side scan sonar survey was done simultaneously with the bathymetry swath survey and used an EdgeTech Model 4125 Towfish bow-mounted from Lookdown at 400 and 900 kHz. The 4125 Towfish utilizes EdgeTech’s Full Spectrum CHIRP technology to produce higher resolution images than a non-CHIRP system. EdgeTech Discovery Software was used to acquire the side scan sonar data using the JSF format at a resolution of about 2.3 cm. All JSF files collected using EdgeTech’s Discover Software were processed using John Gann’s Chesapeake Technology SonarWiz5. Dimensions of contacts should be considered accurate to +/- 30% of the measured dimensions. This system also records the direct arrival intensity data.