Eelgrass distributions derived from a towed underwater video survey of the Nisqually River delta, 2017

Metadata Updated: November 12, 2020

This portion of the USGS data release presents eelgrass distributions derived from towed underwater video surveys of the Nisqually River delta, Washington in 2017 (USGS Field Activity Number 2017-614-FA). Eelgrass data were collected from the R/V George Davidson equipped with a towed underwater video system and global navigation satellite system (GNSS) receiver. The underwater video system consisted of a Splashcam standard definition video camera connected to a Sony GV-D1000 video monitor and tape recorder. Positioning of the survey vessel was determined at 1 Hz intervals using a Trimble R7 GNSS receiver and Trimble Zephyr Model 2 antenna. The positioning data from the GNSS were encoded onto the audio track of the digital video recording using Red Hen Systems (RHS) VMS200 hardware. Underwater video data were recorded as the vessel navigated along a series of shore-perpendicular transects at speeds between 1 and 2 knots. The underwater video recording was later reviewed and the presence or absence of eelgrass was determined for each 1-s segment of video tape. These data were used to evaluate the classification of single-beam sonar data acquired during the same time period.

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License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

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Metadata Date July 21, 2020
Metadata Created Date November 12, 2020
Metadata Updated Date November 12, 2020
Reference Date(s) July 21, 2020 (publication)
Frequency Of Update notPlanned

Metadata Source

Harvested from DOI Open Data

Additional Metadata

Resource Type Dataset
Metadata Date July 21, 2020
Metadata Created Date November 12, 2020
Metadata Updated Date November 12, 2020
Reference Date(s) July 21, 2020 (publication)
Responsible Party U.S. Geological Survey, Pacific Coastal and Marine Science Center (Point of Contact)
Contact Email
Access Constraints Use Constraints: USGS-authored or produced data and information are in the public domain from the U.S. Government and are freely redistributable with proper metadata and source attribution. Please recognize and acknowledge the U.S. Geological Survey as the originator(s) of the dataset and in products derived from these data. This information is not intended for navigational purposes., Access Constraints: none
Bbox East Long -122.6841300
Bbox North Lat 47.1185910
Bbox South Lat 47.1044550
Bbox West Long -122.7460220
Coupled Resource
Frequency Of Update notPlanned
Licence 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.
Metadata Language
Metadata Type geospatial
Progress completed
Spatial Data Service Type
Spatial Reference System
Spatial Harvester True
Temporal Extent Begin 2017-02-23
Temporal Extent End 2017-02-23

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