Bathymetry of Lake Ontario has been compiled as a component of a NOAA project to rescue Great Lakes lake floor geological and geophysical data and make it more accessible to the public. The project is a cooperative effort between investigators at the NOAA National Geophysical Data Center's Marine Geology & Geophysics Division (NGDC/MGG) and the NOAA Great Lakes Environmental Research Laboratory (GLERL). was compiled utilizing the entire historic sounding data base. The entire historic hydrographic sounding data base from the U.S. and Canada, originally collected for nautical charting purposes, was used to create a complete and accurate representation of Lake Ontario bathymetry. The U.S. data primarily came from the NOS Hydrographic Survey Data. This and other bathymetric sounding data collected by the U.S. National Ocean Service's (NOS) Coast Survey and the U. S. Army Corps of Engineers was employed to construct bathymetric contours at 1 meter intervals from 1-10 meters depth and 2 meter intervals at depths greater than 10 meters. Compilation scales ranged from 1:10,000 to 1:50,000. Bathymetric sounding data collected by the Canadian Hydrographic Service (CHS) were employed to construct bathymetric contours at 1 meter intervals and compilation scales ranging from 1:1,000 to 1:30,000. Digitization of the bathymetric contours, merging of the bathymetric contour data sets, poster construction, and preparation of a CD-ROM, were accomplished at the NGDC. Multibeam bathymetric data collected by the University of New Brunswick's Ocean Mapping Group (UNB-OMG), with support of the Geological Survey of Canada (GSC) and the CHS, were kindly made available in gridded form. In the two areas where multibeam bathymetric data were available, no other bathymetric data were used in the compilations. In some areas all available Canadian and U. S. bathymetric sounding data, collected at different times on different survey expeditions, were used to derive the contours. The U.S. coastline used was primarily the GLERL Medium Resolution Vector Shoreline dataset (Lee, 1998). Where needed for more coverage, the NOS Medium Resolution Vector Shoreline for the Conterminous U.S. (1994) dataset was used. Coastlines from the CHS bathymetric sounding data field sheets were used to complete the Canadian coastline. Images were constructed using the publicly-available software Generic Mapping Tools (GMT).

Bathymetry is the measurement of water depth in lakes. From the 1940s to the 1990s, the Ministry of Natural Resources and Forestry produced bathymetry maps for over 11,000 lakes across Ontario. The data can be used by the general public and GIS specialists for: * climate change modelling * fish monitoring and other ecological applications * hydrologic cycle modelling * recreational fishing maps * watershed-based water budgeting The maps were created using simple methods to determine lake depths. They were meant for resource management purposes only. Little effort was made to identify shoals and other hazards when creating these bathymetric maps. Since this data was collected, many constructed and naturally occurring events could mean that the depth information is now inaccurate, so these maps should not be used for navigational purposes. In many cases, these maps still represent the only authoritative source of bathymetry data for lakes in Ontario. Technical information These maps are being converted to digital GIS line data which can be found in the Bathymetry Line data class. The Bathymetry Index data class identifies if GIS vector lines have been created and the location of mapped lakes. The historic paper maps have been scanned into digital files. We will add new digital files to this dataset if they become available. The digital files have been grouped and packaged by regions into 13 compressed (zipped) files for download. Note: package 99 contains scanned maps where the location shown on the map could not be determined.

The historic bathymetry maps were created using simple methods to determine lake depths and were meant for resource management purposes only.Bathymetry is the measurement of water depth in lakes. From the 1940s to the 1990s, the Ministry of Natural Resources and Forestry produced bathymetry maps for over 11,000 lakes across Ontario.The data can be used by the general public and GIS specialists for:climate change modellingfish monitoring and other ecological applicationshydrologic cycle modellingrecreational fishing mapswatershed-based water budgetingThe maps were created using simple methods to determine lake depths. They were meant for resource management purposes only. Little effort was made to identify shoals and other hazards when creating these bathymetric maps.Since this data was collected, many constructed and naturally occurring events could mean that the depth information is now inaccurate, so these maps should not be used for navigational purposes.In many cases, these maps still represent the only authoritative source of bathymetry data for lakes in Ontario.Technical informationThese maps are being converted to digital GIS line data which can be found in the Bathymetry Line data class.The Bathymetry Index data class identifies if GIS vector lines have been created and the location of mapped lakes.The historic paper maps have been scanned into digital files. We will add new digital files to this dataset if they become available.The digital files have been grouped and packaged by regions into 13 compressed (zipped) files for bulk download.Note: package 99 contains scanned maps where the location shown on the map could not be determined.Product PackagesHistoric Bathymetry Maps - Package 1 (ZIP)Historic Bathymetry Maps - Package 2 (ZIP)Historic Bathymetry Maps - Package 3 (ZIP)Historic Bathymetry Maps - Package 4 (ZIP)Historic Bathymetry Maps - Package 5 (ZIP)Historic Bathymetry Maps - Package 6 (ZIP)Historic Bathymetry Maps - Package 7 (ZIP)Historic Bathymetry Maps - Package 8 (ZIP)Historic Bathymetry Maps - Package 9 (ZIP)Historic Bathymetry Maps - Package 10 (ZIP)Historic Bathymetry Maps - Package 11 (ZIP)Historic Bathymetry Maps - Package 12 (ZIP)Historic Bathymetry Maps - Package 13 (ZIP)Historic Bathymetry Maps - Package 99 (ZIP)Additional DocumentationBathymetry User Guide (Word)Bathymetry Package Map (Word)Bathymetry Lookup Values (Excel)StatusCompleted: Production of the data has been completedMaintenance and Update FrequencyNot planned: There are no plans to update the dataContactOntario Ministry of Natural Resources - Geospatial Ontario,geospatial@ontario.ca

The attribute table included in the dataset provides some limited metadata information that is specific to each lake. This includes the:survey yearsurvey methodoriginal map scaleThis dataset should be used for discovery of Bathymetry data. It provides no bathymetric information, but allows users to discover where bathymetry data exists and in what format. To access bathymetry data, see the following products: Bathymetry LineBathymetry PointHistoric Bathymetry MapsAdditional DocumentationBathymetry User Guide (Word)StatusOn going: data is being continually updated Maintenance and Update FrequencyAs needed: data is updated as deemed necessary ContactOntario Ministry of Natural Resources - Geospatial Ontario, geospatial@ontario.ca

Lake depth plays a crucial role in understanding large-scale biogeochemical processes. The thickness of the hypolimnion, influenced by lake depth, is a key factor in oxygen dynamics and carbon processing within lakes. Furthermore, lake depth impacts seasonal ice-off dates and CO2 emissions. Bathymetry shapes lake mixing dynamics, which in turn regulate methane (CH4) emissions and phosphorus release from sediments. Consequently, landscape-scale biogeochemical studies of lake-dominated regions require extensive and accurate bathymetric data. In Canada, more than a million lakes remain without detailed bathymetric data. However, between the 1940s and 1990s, the Ontario Ministry of Natural Resources and Forestry produced bathymetric maps for over 11,000 lakes across Ontario. These maps have been scanned and are publicly accessible via Ontario's Open Data Portal (https://data.ontario.ca/dataset/historic-bathymetry-maps). From these historical maps, maximum depths were manually extracted and compiled into this dataset. In addition to maximum depths, lake geometry has been derived using lake polygons provided by the National Hydro Network (NHN) from Natural Resources Canada https://open.canada.ca/data/en/dataset/a4b190fe-e090-4e6d-881e-b87956c07977). Morphometric metrics such as circularity, shoreline complexity, and relative depth were calculated from these polygons and the bathymetric data. This dataset offers a critical resource for understanding the geomorphological and biogeochemical dynamics of lakes across Ontario, Canada.

This seamless topo-bathymetric DEM is designed to represent true ground and bathymetric elevation across two sections of the GTA along the western shoreline of Lake Ontario ((i) Hamilton in the west to Niagara-on-the-Lake in the east, and (ii) Scarborough in the west to Port Hope in the east). The Lake Ontario Topo-Bathymetric DEM was constructed from two source datasets: the 2002 GTA Ortho vector data (MNRF) and 2001 SHOALS bathymetric LiDAR (USACE JALBTCX). This product is suitable for applications such as: querying elevation values in a given area and as a reference or input dataset.

Additional Documentation

Lake Ontario Topo Bathymetric DEM - User Guide (DOCX)

Status

Completed: Production of the data has been completed

Maintenance and Update Frequency

Not planned: there are no plans to update the data

Contact

Ontario Ministry of Natural Resources - Geospatial Ontario, geospatial@ontario.ca

Great Lakes bathymetry has been compiled as a component of a NOAA project to synthesize Great Lakes lake floor geological and geophysical data and make it more accessible to the public. The project is a cooperative effort between investigators at the NOAA National Geophysical Data Center's Marine Geology, Geophysics Division (NGDC/MGG) and the NOAA Great Lakes Environmental Research Laboratory (GLERL) with data development utilizing the entire historic sounding data base. The entire historic hydrographic sounding data base from the U.S. and Canada, originally collected for nautical charting purposes, was used to create a complete and accurate representation of Lake Ontario bathymetry. The U.S. data primarily came from the NOS Hydrographic Survey Data. These and other bathymetric sounding data collected by the U.S. National Ocean Service's (NOS) Coast Survey and the U. S. Army Corps of Engineers was employed to construct bathymetric contours at 1 meter intervals from 1-10 meters depth and 2 meter intervals at depths greater than 10 meters. Compilation map scales ranged from 1:10,000 to 1:50,000. Bathymetric sounding data collected by the Canadian Hydrographic Service (CHS) were employed to construct bathymetric contours at 1 meter intervals and compilation map scales ranging from 1:1,000 to 1:30,000. Digitization of the bathymetric contours and merging of the bathymetric contour data sets was accomplished at the NGDC. Multibeam bathymetric data collected by the University of New Brunswick's Ocean Mapping Group (UNB-OMG), with support of the Geological Survey of Canada (GSC) and the CHS, were kindly made available in gridded form. In the two areas where multibeam bathymetric data were available, no other bathymetric data were used in the compilations. In some areas all available Canadian and U. S. bathymetric sounding data, collected at different times on different survey expeditions, were used to derive the contours. The U.S. coastline used was primarily derived from the GLERL Medium Resolution Vector Shoreline dataset (Lee, 1998). Where move coverage was needed, the NOS Medium Resolution Vector Shoreline for the Conterminous U.S. (1994) dataset was used. Coastlines from the CHS bathymetric sounding data field sheets were used to complete the Canadian coastline. Images were constructed using the publicly-available software Generic Mapping Tools (GMT).

Bathymetry of Lakes Michigan, Erie, Saint Clair, Ontario and Huron has been compiled as a component of a NOAA project to rescue Great Lakes lake floor geological and geophysical data and make it more accessible. Lake Superior bathymetry partially completed. The present contours and grids have been partially derived and completely compiled here at NOAA's National Geophysical Data Center (NGDC) using a variety of sources of data including the NOS Hydrographic data base and the Canadian Hydrographic Service (CHS) smooth sheets. This project is a cooperative effort between investigators at the NGDC, the NOAA Great Lakes Environmental Research Laboratory and the Canadian Hydrographic Service. Bathymetric data used for this project have been collected from the Great Lakes in support of nautical charting for at least 150 years by the US Army Corp. of Engineers (before 1970), the NOAA National Ocean Service (after 1970), and the CHS.

This is a polygon layer that represents the shorelines of Lake Superior, Lake Michigan, Lake Huron, Lake Erie, Lake Ontario, Lake St. Clair, Detroit River, St. Clair River, and the St. Lawrence River and Seaway. The dataset is strictly a cartographic layer intended only for small-scale display (nominally 1:250,000); the data is of unknown origin and source scale.

Lake Ontario Bathymetric ContoursImportant Note: This item is in mature support as of March 2025 and will be retired in July 2025.This feature layer, utilizing data from the National Oceanic and Atmospheric Administration (NOAA), displays the bathymetric contouring of Lake Ontario. Bathymetric contouring shows the depths of landforms below sea level. The bathymetric depths are often shown on maps with contour lines. A contour line represents a corresponding imaginary line on the bottom of a water body that has the same elevation or depth along its entire length.Per NOAA, "NOAA was engaged in a program to compile Great Lakes bathymetric data and make them readily available to the public, especially to the communities concerned with Great Lakes science, pollution, coastal erosion, response to climate changes, threats to lake ecosystems, and health of the fishing industry. This program was managed by NCEI and relied on the cooperation of NOAA/Great Lakes Environmental Research Laboratory, NOAA/National Ocean Service, the Canadian Hydrographic Service, other agencies, and academic laboratories."Note: The purpose of this data is for scientific research, commercial exploration, fishing, and policy & decision-making. These data are NOT intended to be used for navigation. Nautical charts produced and certified by NOAA should be used for navigational purposes. For more information on NOAA"s nautical charts go to: NOAA's Office of Coast Survey.Lake Ontario Bathymetric ContoursData currency: This cached Esri service is checked monthly for updates from its federal source (Lake Ontario)Data modification: NoneFor more information: Lake Ontario Bathymetry Poster Released by NOAAFor feedback, please contact: ArcGIScomNationalMaps@esri.comNational Oceanic and Atmospheric AdministrationPer NOAA, its mission is "To understand and predict changes in climate, weather, ocean, and coasts, to share that knowledge and information with others, and to conserve and manage coastal and marine ecosystems and resources."

In 2008, the U.S. Geological Survey (USGS), Woods Hole Coastal and Marine Science Center (WHCMSC), in cooperation with the U.S. Army Corps of Engineers conducted a geophysical and sampling survey of the riverbed of the Upper St. Clair River between Port Huron, MI, and Sarnia, Ontario, Canada. The objectives were to define the Quaternary geologic framework of the St. Clair River to evaluate the relationship between morphologic change of the riverbed and underlying stratigraphy. This report presents the geophysical and sample data collected from the St. Clair River, May 29-June 6, 2008 as part of the International Upper Great Lakes Study, a 5-year project funded by the International Joint Commission of the United States and Canada to examine whether physical changes in the St. Clair River are affecting water levels within the upper Great Lakes, to assess regulation plans for outflows from Lake Superior, and to examine the potential effect of climate change on the Great Lakes water levels ( http://www.iugls.org). This document makes available the data that were used in a separate report, U.S. Geological Survey Open-File Report 2009-1137, which detailed the interpretations of the Quaternary geologic framework of the region. This report includes a description of the suite of high-resolution acoustic and sediment-sampling systems that were used to map the morphology, surficial sediment distribution, and underlying geology of the Upper St. Clair River during USGS field activity 2008-016-FA . Video and photographs of the riverbed were also collected and are included in this data release. Future analyses will be focused on substrate erosion and its effects on river-channel morphology and geometry. Ultimately, the International Upper Great Lakes Study will attempt to determine where physical changes in the St. Clair River affect water flow and, subsequently, water levels in the Upper Great Lakes.

Coastal wetlands are valued for their diversity of wildlife, habitats, and functions. The Canadian Wildlife Service (CWS) conducted vegetation and elevation surveys between 2009 and 2019, and bathymetric and light attenuation surveys between 2018 and 2019 in coastal wetlands across the Canadian shore of Lake Ontario, Lake Erie, Lake Huron, Lake Superior, and the head of the St. Lawrence River. These datasets were used, in part, to predict the spatial and temporal response of coastal wetland vegetation to climate change as part of the Great Lakes Protection Initiative (GLPI). The goals of this project were to provide insight into climate change impacts by assessing the vulnerability of Great Lakes coastal wetlands, identify adaptive measures to increase the resilience of coastal wetlands, assess wetland vegetation response to physical variables (e.g., Great Lakes water levels), and inform the adaptive management of water-level regulation on Lake Ontario.

In 2008, the U.S. Geological Survey (USGS), Woods Hole Coastal and Marine Science Center (WHCMSC), in cooperation with the U.S. Army Corps of Engineers conducted a geophysical and sampling survey of the riverbed of the Upper St. Clair River between Port Huron, MI, and Sarnia, Ontario, Canada. The objectives were to define the Quaternary geologic framework of the St. Clair River to evaluate the relationship between morphologic change of the riverbed and underlying stratigraphy. This report presents the geophysical and sample data collected from the St. Clair River, May 29-June 6, 2008 as part of the International Upper Great Lakes Study, a 5-year project funded by the International Joint Commission of the United States and Canada to examine whether physical changes in the St. Clair River are affecting water levels within the upper Great Lakes, to assess regulation plans for outflows from Lake Superior, and to examine the potential effect of climate change on the Great Lakes water levels ( http://www.iugls.org). This document makes available the data that were used in a separate report, U.S. Geological Survey Open-File Report 2009-1137, which detailed the interpretations of the Quaternary geologic framework of the region. This report includes a description of the suite of high-resolution acoustic and sediment-sampling systems that were used to map the morphology, surficial sediment distribution, and underlying geology of the Upper St. Clair River during USGS field activity 2008-016-FA . Video and photographs of the riverbed were also collected and are included in this data release. Future analyses will be focused on substrate erosion and its effects on river-channel morphology and geometry. Ultimately, the International Upper Great Lakes Study will attempt to determine where physical changes in the St. Clair River affect water flow and, subsequently, water levels in the Upper Great Lakes.

In 2008, the U.S. Geological Survey (USGS), Woods Hole Coastal and Marine Science Center (WHCMSC), in cooperation with the U.S. Army Corps of Engineers conducted a geophysical and sampling survey of the riverbed of the Upper St. Clair River between Port Huron, MI, and Sarnia, Ontario, Canada. The objectives were to define the Quaternary geologic framework of the St. Clair River to evaluate the relationship between morphologic change of the riverbed and underlying stratigraphy. This report presents the geophysical and sample data collected from the St. Clair River, May 29-June 6, 2008 as part of the International Upper Great Lakes Study, a 5-year project funded by the International Joint Commission of the United States and Canada to examine whether physical changes in the St. Clair River are affecting water levels within the upper Great Lakes, to assess regulation plans for outflows from Lake Superior, and to examine the potential effect of climate change on the Great Lakes water levels ( http://www.iugls.org). This document makes available the data that were used in a separate report, U.S. Geological Survey Open-File Report 2009-1137, which detailed the interpretations of the Quaternary geologic framework of the region. This report includes a description of the suite of high-resolution acoustic and sediment-sampling systems that were used to map the morphology, surficial sediment distribution, and underlying geology of the Upper St. Clair River during USGS field activity 2008-016-FA . Video and photographs of the riverbed were also collected and are included in this data release. Future analyses will be focused on substrate erosion and its effects on river-channel morphology and geometry. Ultimately, the International Upper Great Lakes Study will attempt to determine where physical changes in the St. Clair River affect water flow and, subsequently, water levels in the Upper Great Lakes.

To better understand the status of Lake Trout and Brook Trout populations across the Algonquin Provincial Park landscape 192 index netting surveys were conducted on 161 lakes utilizing standardized multimesh benthic gillnets between the years 2009 and 2022. Index netting was conducted using a depth-stratified randomized site survey design and employed multi-pass sampling on a majority of the lakes to provide the opportunity for occupancy analysis. Two primary netting methods were employed; Summer Profundal Index Netting (SPIN) for Lake Trout populations sampled between 2009-2012; and a modified Ontario Broadscale Monitoring (BsM) method we refer to as Short Duration Point Sampling (SDPS). The SDPS method uses the large mesh BsM nets (NA1) deployed for a one-hour duration within the same depth strata used in the BsM program with a sampling intensity in each stratum proportional to the surface area. The overall sampling intensity (nets/lake) is greater than that employed in the BsM program as we are interested in lake-specific analyses. This data dryad provides general information on each lake sampled including lake characteristics, lake volumes, netting site locations, and spring water chemistry.
Methods This dataset was collected by field crews based on the Harkness Laboratory of Fisheries Research between the years 2009 - 2022. Field activities included spring water chemistry sampling, digital bathymetry surveys, and fisheries index netting. Sample collection for spring water chemistry was conducted shortly after ice out and analyses were conducted by the Ministry of Environment, Conservation, and Parks, Dorset Lab. Digital bathymetry data were collected in the spring on each lake using GPS depth sounders. Lake volume in 1m depth increments was calculated using ArcGIS from the resulting bathymetry rasters. Index netting was conducted using a depth-stratified randomized site survey design and employed multi-pass sampling on a majority of the lakes to provide the opportunity for occupancy analysis. Two primary netting methods were employed; Summer Profundal Index Netting (SPIN) for Lake Trout populations sampled between 2009-2012; and a modified Ontario Broadscale Monitoring (BsM) method we refer to as Short Duration Point Sampling (SDPS). The SDPS method uses the large mesh BsM nets (NA1) deployed for a one-hour duration within the same depth strata used in the BsM program with a sampling intensity in each stratum proportional to the surface area. The overall sampling intensity (nets/lake) is greater than that employed in the BsM program as we are interested in lake-specific analyses. Many of the lakes surveyed using the SPDS method were conducted using multipass sampling where each site was sampled a minimum of three times over the course of the survey.

The Great Lakes Sediment Database (also known as the National Water Research Institute (NWRI) Sediment Archive) is an archive of data on the sediments of the Great Lakes, their connecting channels, and the St. Lawrence River which was collected by NWRI and in cooperation with other agencies between 1960 and 1975. It is housed in Environment and Climate Change Canada's Canada Centre for Inland Waters in Burlington, Ontario. The data has been subdivided into two groups according to location and purpose: 1.Great Lakes Basin Sediment Data: physical and geochemical data for sediment samples and cores collected lakewide in lakes Ontario, Erie, St. Clair, Huron (including Georgian Bay), Michigan and Superior between 1960 and 1975 by R.L. Thomas, A.L.W. Kemp and C.F.M. Lewis of NWRI. The data includes descriptions of sediment and core properties, grain-size statistics and sediment geochemistry; 2. Nearshore Sediments Data: physical data for samples and cores, bathymetry, and sediment thickness collected in the Canadian nearshore zone of lakes Ontario, Erie, St. Clair, Huron and Georgian Bay between 1960 and 1975. The data includes descriptions of sediment and core properties, grain-size statistics, sediment patterns and x-radiographs of sediment cores. Underwater photographs are also available for Lake Huron and Georgian Bay. The database was prepared to preserve historic and current sediment data and make it available for research, remediation, lake and shoreline management, habitat studies and engineering projects. Because the basin and nearshore surveys were the first systematic and detailed surveys of both zones, their data should also be useful for studies of trends in physical properties, sediment transport, and contamination or trophic levels. The sediment-sample archive serves the same purpose by making historic samples available for analysis of changes in composition or geotechnical properties. Supplemental Information The database was produced by Dr. Norm Rukavina, formerly of NWRI, as an archive of his own sediment data and that of some of his colleagues and associates. Marilyn Dunnett was responsible for the editing of the data and its quality control, and Chris Prokopec for the organization of the database, its metadata description, and the preparation of ArcView maps. Supporting Projects: Great Lakes Action Plan (GLAP)

In 2008, the U.S. Geological Survey (USGS), Woods Hole Coastal and Marine Science Center (WHCMSC), in cooperation with the U.S. Army Corps of Engineers conducted a geophysical and sampling survey of the riverbed of the Upper St. Clair River between Port Huron, MI, and Sarnia, Ontario, Canada. The objectives were to define the Quaternary geologic framework of the St. Clair River to evaluate the relationship between morphologic change of the riverbed and underlying stratigraphy. This report presents the geophysical and sample data collected from the St. Clair River, May 29-June 6, 2008 as part of the International Upper Great Lakes Study, a 5-year project funded by the International Joint Commission of the United States and Canada to examine whether physical changes in the St. Clair River are affecting water levels within the upper Great Lakes, to assess regulation plans for outflows from Lake Superior, and to examine the potential effect of climate change on the Great Lakes water levels ( http://www.iugls.org). This document makes available the data that were used in a separate report, U.S. Geological Survey Open-File Report 2009-1137, which detailed the interpretations of the Quaternary geologic framework of the region. This report includes a description of the suite of high-resolution acoustic and sediment-sampling systems that were used to map the morphology, surficial sediment distribution, and underlying geology of the Upper St. Clair River during USGS field activity 2008-016-FA . Video and photographs of the riverbed were also collected and are included in this data release. Future analyses will be focused on substrate erosion and its effects on river-channel morphology and geometry. Ultimately, the International Upper Great Lakes Study will attempt to determine where physical changes in the St. Clair River affect water flow and, subsequently, water levels in the Upper Great Lakes.