Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Skip to content

Bottom Hardness and Surficial Substrate Composition of Fish Spawning Reefs in the St. Clair-Detroit River System from 2012 - 2018

Metadata Updated: October 29, 2023

This data set contains bottom hardness and surficial substrate compositions measured as part of a study evaluating the maturation of fish spawning reef restoration projects in the St. Clair-Detroit River System. Five spawning reef complexes (Middle Channel, Harts Light, Pointe Aux Chenes, Grassy Island, and Belle Isle) constructed with 10-20 cm broken limestone from 2012-2016 were evaluated as part of the study. Sonar surveys began in 2012, following the construction of the Middle Channel Reef complex and expanded to additional projects, as they were completed (Harts Light and Pointe Aux Chenes Reefs in 2014, Grassy Island Reef in 2015, and the Belle Isle Reef complex in 2016). Sonar surveys over the Fighting Island Reefs (constructed in 2008 and expanded in 2013) also began in 2015. Sonar surveys were conducted yearly along multiple transects oriented parallel with flow and spaced 5-10 m apart. A Humminbird 998c SI sonar unit was used during all sonar surveys. Sonar data were processed in the BT+SS edition of DrDepthPC v5.1.8 using the bottom type toolkit to calculate bottom hardness, an index of substrate type, with lower values corresponding to finer substrates. Annual underwater video surveys began in 2015, following the construction of the Harts Light and Pointe Aux Chenes Reefs and expanded to include the Middle Channel and Grassy Island Reefs in 2016 and Belle Isle Reef complex in 2017. Underwater video data also includes surveys of other reefs and sites that were not included in the reef maturation study. Video was recorded at each site along two transects to quantify surficial sediment composition at reef sites and adjacent areas. Sediment classification was based on a modified Wentworth scale, with sediments less than 2 mm classified as fines, sediments 2-100 mm classified as gravel, sediments > 100 mm classified as reef rock (reefs were constructed with 100-200 mm limestone), and dreissenid mussels and shells identified by their distinct shape and coloration. A cutoff of 100 mm was used to segregate gravel and coarse sediment to capture the proportion of reef rock (100-200 mm) present in the video frames.

Access & Use Information

Public: This dataset is intended for public access and use. 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.

Downloads & Resources


Metadata Created Date June 1, 2023
Metadata Updated Date October 29, 2023

Metadata Source

Harvested from DOI EDI

Additional Metadata

Resource Type Dataset
Metadata Created Date June 1, 2023
Metadata Updated Date October 29, 2023
Publisher U.S. Geological Survey
Identifier USGS:5d07fb28e4b0e3d3115bd9cb
Data Last Modified 20200820
Category geospatial
Public Access Level public
Bureau Code 010:12
Metadata Context
Metadata Catalog ID
Schema Version
Catalog Describedby
Harvest Object Id 775de99d-23e7-413f-ae59-97f8a43cbf9f
Harvest Source Id 52bfcc16-6e15-478f-809a-b1bc76f1aeda
Harvest Source Title DOI EDI
Metadata Type geospatial
Old Spatial -83.6334,41.984,-82.3315,43.0287
Publisher Hierarchy White House > U.S. Department of the Interior > U.S. Geological Survey
Source Datajson Identifier True
Source Hash c6c64b2daf770d89ce09df71cb040ab664c43e21aa0e0a65befedf0e7aece390
Source Schema Version 1.1
Spatial {"type": "Polygon", "coordinates": -83.6334, 41.984, -83.6334, 43.0287, -82.3315, 43.0287, -82.3315, 41.984, -83.6334, 41.984}

Didn't find what you're looking for? Suggest a dataset here.