In the Great Lakes basin, there are numerous organizations undertaking scientific monitoring and research efforts with the goal of identifying threats and evaluating management strategies that will protect and restore the Great Lakes ecosystem. Coordination among all these stakeholders is a challenge, and having a centralized location where researchers and managers can identify relevant scientific activities and access fundamental information about these activities is crucial for efficient management. The Science in the Great Lakes (SiGL) Mapper was a map-based discovery tool that spatially displayed basin-wide multidisciplinary monitoring and research activities conducted by both USGS and partners from all five Great Lakes. It was designed to help Great Lakes researchers and managers strategically plan, implement, and analyze monitoring and restoration activities by providing easy access to historical and on-going project metadata while allowing them to identify gaps (spatially and topically) that have been underrepresented in previous efforts or need further study. SiGL provided a user-friendly and efficient way to explore Great Lakes projects and data through robust search options while also providing a critical spatial perspective through its interactive mapping interface.

The Great Lakes Initiative Toxicity Data Clearinghouse is a central location for information on criteria, toxicity data, exposure parameters and other supporting documents used in developing water quality standards in the Great Lakes Watershed.

The Great Lakes Initiative Toxicity Data Clearinghouse is a central location for information on criteria, toxicity data, exposure parameters and other supporting documents used in developing water quality standards in the Great Lakes Watershed.

In 2014, the USGS Lake Erie Biological Station participated in the Coordinated Science and Monitoring Initiative (CMSI) program, a program founded by the U.S. Environmental Protection Agency (EPA) and Environment Canada in the 1990s as a means to focus collaborative research attention on one of the five Great Lakes each year (on a rotating schedule) as a means to increase scientific knowledge for Great Lakes restoration. The Lake Erie survey examined the food web across a nearshore to offshore gradient, matching the sampling design the preceding USGS studies of the other four Great Lakes (2010-2013). We sampled all trophic levels in all three lake basins across multiple seasons in order to determine nutrient availability and trophic energy transfers from nearshore to offshore across the lake’s west-east production gradient. In each basin two transects, each consisting of replicate nearshore, mid, and offshore sites were sampled. The lower trophic food web (water nutrients, zooplankton, and benthos) was sampled monthly, and the fish community (via bottom trawl and hydroacoutics) was sampled bi-monthly (May, July, and September). By examining the trophic interactions and energy transfer in all three basins, this data may be of interest to anyone interested in examining some of Lake Erie’s principal environmental and ecological issues such as sedimentation and nutrient loading (western basin), seasonal hypoxia (central basin), and strong nearshore to offshore production gradients (eastern basin).

In 2014, the USGS Lake Erie Biological Station participated in the Coordinated Science and Monitoring Initiative (CMSI) program, a program founded by the U.S. Environmental Protection Agency (EPA) and Environment Canada in the 1990s as a means to focus collaborative research attention on one of the five Great Lakes each year (on a rotating schedule) as a means to increase scientific knowledge for Great Lakes restoration. The Lake Erie survey examined the food web across a nearshore to offshore gradient, matching the sampling design the preceding USGS studies of the other four Great Lakes (2010-2013). We sampled all trophic levels in all three lake basins across multiple seasons in order to determine nutrient availability and trophic energy transfers from nearshore to offshore across the lake’s west-east production gradient. In each basin two transects, each consisting of replicate nearshore, mid, and offshore sites were sampled. The lower trophic food web (water nutrients, zooplankton, and benthos) was sampled monthly, and the fish community (via bottom trawl and hydroacoutics) was sampled bi-monthly (May, July, and September). By examining the trophic interactions and energy transfer in all three basins, this data may be of interest to anyone interested in examining some of Lake Erie’s principal environmental and ecological issues such as sedimentation and nutrient loading (western basin), seasonal hypoxia (central basin), and strong nearshore to offshore production gradients (eastern basin).

As part of the larger Great Lakes Sediment Surveillance Program (GLSSP), the U.S. Geological Survey Mercury Research Laboratory (MRL) partnered with the U.S. Environmental Protection Agency and the University of Minnesota-Duluth to assess contaminant concentrations within surface sediments and sediment cores from the Laurentian Great Lakes. Sediments were assessed for mercury concentrations and mercury stable isotopes to examine spatial trends and sources of mercury within the lakes. In 2021, 30 sites were surveyed in Lake Superior. Mercury concentrations within Lake Superior surface sediment ranged from 1.1 to 161.2 ng/g. Mercury isotopes displayed a range in δ202Hg from -0.12 to -1.74 ‰ with measurable Δ199Hg and Δ200Hg across all Lake Superior sites. In 2022, 32 surface sediment sites were surveyed in Lake Huron. Mercury concentrations within Lake Huron sediment ranged from 0.7-to- 113.7 ng/g across all samples. Mercury isotopes displayed a range in δ202Hg from -0.12 to -1.74 ‰. In 2023, surface sediments were collected at 30 sites across Lake Ontario. Total mercury concentrations in surface sediments ranged from 19 ng/g to 2001.1 ng/g. Three deep sediment cores were collected in each lake. The sediment cores ranged in length from 15 cm to 50 cm. All cores showed a similar pattern for HgT except for cores at H038 and H054. From the top of the core, HgT concentrations increase to a maximum concentration (127.4 - 3035.3 ng/g) that occurs between 5 and 15 cm below the surface and then decreases to concentrations that range from 18.7 ng/g to 40 ng/g. The cores from H038 and H054 show decreasing or no change in HgT concentration in the upper portion of the core and then follow similar trends to the third core (H012) collected in Lake Huron.

As part of the larger Great Lakes Sediment Surveillance Program (GLSSP), the U.S. Geological Survey Mercury Research Laboratory (MRL) partnered with the U.S. Environmental Protection Agency and the University of Minnesota-Duluth to assess contaminant concentrations within surface sediments and sediment cores from the Laurentian Great Lakes. Sediments were assessed for mercury concentrations and mercury stable isotopes to examine spatial trends and sources of mercury within the lakes. In 2021, 30 sites were surveyed in Lake Superior. Mercury concentrations within Lake Superior surface sediment ranged from 1.1 to 161.2 ng/g. Mercury isotopes displayed a range in δ202Hg from -0.12 to -1.74 ‰ with measurable Δ199Hg and Δ200Hg across all Lake Superior sites. In 2022, 32 surface sediment sites were surveyed in Lake Huron. Mercury concentrations within Lake Huron sediment ranged from 0.7-to- 113.7 ng/g across all samples. Mercury isotopes displayed a range in δ202Hg from -0.12 to -1.74 ‰. In 2023, surface sediments were collected at 30 sites across Lake Ontario. Total mercury concentrations in surface sediments ranged from 19 ng/g to 2001.1 ng/g. Three deep sediment cores were collected in each lake. The sediment cores ranged in length from 15 cm to 50 cm. All cores showed a similar pattern for HgT except for cores at H038 and H054. From the top of the core, HgT concentrations increase to a maximum concentration (127.4 - 3035.3 ng/g) that occurs between 5 and 15 cm below the surface and then decreases to concentrations that range from 18.7 ng/g to 40 ng/g. The cores from H038 and H054 show decreasing or no change in HgT concentration in the upper portion of the core and then follow similar trends to the third core (H012) collected in Lake Huron.

This data release provides water chemistry results and quality assurance data for samples collected from Great Lakes tributaries in the states of Minnesota, Wisconsin, Michigan, Indiana, Ohio, and New York. In total, 158 chemicals were analyzed which are primarily pharmaceuticals. Between one and four water samples were collected at 37 sampling locations between November 2017 and July 2018 resulting in a total of 87 environmental, 95 field replicate, and 15 field blank samples. Of the 158 chemicals analyzed, 23 chemicals were detected in at least one regular sample. Detections per site ranged from 0 to 12 chemicals at concentrations of 1.56 to 30900 nanograms per liter. Sample collection and analysis was performed by the U.S. Geological Survey and summarized in the associated journal article (https://doi.org/10.1002/etc.5403). More detailed method descriptions will be published in the future.

This data release provides water chemistry results and quality assurance data for samples collected from Great Lakes tributaries in the states of Minnesota, Wisconsin, Michigan, Indiana, Ohio, and New York. In total, 158 chemicals were analyzed which are primarily pharmaceuticals. Between one and four water samples were collected at 37 sampling locations between November 2017 and July 2018 resulting in a total of 87 environmental, 95 field replicate, and 15 field blank samples. Of the 158 chemicals analyzed, 23 chemicals were detected in at least one regular sample. Detections per site ranged from 0 to 12 chemicals at concentrations of 1.56 to 30900 nanograms per liter. Sample collection and analysis was performed by the U.S. Geological Survey and summarized in the associated journal article (https://doi.org/10.1002/etc.5403). More detailed method descriptions will be published in the future.

The data in this record contains water physical, chemical, and biological vertical observational data from fixed mooring CHRP2 in the central basin of Lake Erie, Great Lakes region during the summer seasons from 2021-06-17 through 2021-09-28. The approximate depth at CHRP2 is 20.0 m. Observations were collected at hourly or sub-hourly time intervals for water temperature and dissolved oxygen and other water quality parameters. The moorings are designed in a U-shape with a spar buoy and a subsurface buoy approximately 300 ft apart. The spar buoy has a surface expression float and holds the upper water column sensors. The subsurface buoy holds the subsurface float and lower water column sensors. The vertical placement of temperature and dissolved oxygen sensors, as well as the spatial location of the mooring, varied from year to year. The total depth of the mooring location is approximated from nautical charts. The data files associated with this accession contain the terms “spar” or “subsurface” to differentiate the two locations for each mooring. The file names end with the time resolution of the data in ISO 8601 format. This mooring location is one of seven CHRP moorings that collected observations during the 2021 summer season. Note, these moorings have been deployed in Lake Erie's central basin during the open water season since 2017. In 2021, the CHRP7 mooring was not deployed.