Open Government Portal
Found 10 records similar to Great Lakes Sediment Archive Database (1960-1975)
Monitoring activities have collected bulk suspended sediment samples using continuous flow centrifuges and Phillips Tube samplers in the Lower Athabasca River and tributaries respectively. Further, in the absence of pre-development monitoring for this region, high fidelity dated lake sediment cores were used to assess the natural range in contaminant deposition to this region and to obtain a historical perspective of contaminant loadings. All sediments (suspended river and lake cores) have been analyzed in the laboratory for sediment quality variables as per Appendix B in the Integrated Monitoring Plan (cores were also analyzed for paleo indicators of ecosystem health such as diatoms). In addition, as the Lower Athabasca river bed sediments are known to shift and migrate downstream, bathymetric maps of the bed-channel morphology over time was also completed.
Recent and historical deposition of mercury (Hg) are examined over a broad geographic area from southwestern Northwest Territories to Labrador and from the U.S. Northeast to northern Ellesmere Island using dated sediment cores from 50 lakes (18 in midlatitudes (41-50 degrees North), 14 subarctic (51-64 degrees North) and 18 in the Arctic (65-83 degrees North)). Objectives were to quantify latitudinal and longitudinal trends of anthropogenic mercury deposition in eastern and northern North America, to investigate variations in mercury deposition, to examine relationships with lake area, catchment/lake area ratio and sedimentation rates, and to compare results with model predictions. Distinct increases of mercury over time were observed in 76% of Arctic, 86% of subarctic and 100% of midlatitude cores. Subsurface maxima in mercury depositional fluxes were observed in only 28% of midlatitude lakes and 18% of arctic lakes, indicating little recent reduction of inputs.
Lake sediment cores were collected from several locations in Canada as part of the historic mercury and heavy metal deposition trend, analysis, and research component of the Clean Air Regulatory Agenda/Climate Change and Air Pollutant (CARA/CCAP) and Oil Sands Monitoring (OSM) programs. The reason sediment core analysis is used for research purposes is the bottom of a lake can act as a record of the contaminants and all other materials which have fallen into the lake over time. The lake water acts as both a sorting device and as a preservative since the deposits fall in chronological order and if not subject to dredging are not normally otherwise disturbed by humans. In areas where depositional histories are complex, including changing contributions from local, regional and global sources, multiple dated lake sediment cores are useful tools for examining response of not only aquatic ecosystems, but their surrounding landscapes through time to changing emission/deposition scenarios.
Sediment from Lakes
Polycyclic aromatic hydrocarbons (PAHs), 47 elements including numerous metals, and visible reflectance spectroscopy or VRS-chla have been determined in sediment core samples collected in 2012, 2013 and 2014 from 16 small (surface area 4-97 ha; maximum depth ~1-5 m deep), hydrologically simple lakes located 30 to 120 km from major oil sands development areas. Canadian Council of Ministers of the Environment (CCME) guidelines are available for 13 of the 53 PAHs reported here. Sediment concentrations did not exceed Canadian Council of Ministers of the Environment (CCME) probable effects levels (PELs), which define the level above which biological adverse effects are expected to occur, for PAHs in any lake. Exceedances of the CCME interim sediment quality guidelines (ISQG) for the protection of aquatic life occurred for 4 PAHs (naphthalene, 2-methyl naphthalene phenanthrene, and benzo(a)pyrene) in 8 lakes.
Sediment quality data for 20 lakes across Canada. Parameters include total mercury, methylmercury, sulfate, inorganic and organic carbon, nitrogen, and total recoverable metals. Bottom sediment samples were collected from one to three locations on each lake, following nationally standardized protocols. Sampling period was 2011 to 2016, with some core lakes sampled throughout the period and others sampled one time only.
Provides public access to archived sediment data daily loads, daily concentration, instantaneous concentration for stations of interest using search criteria. The sediment monitoring program discontinued in 1989. Archived sediment data are disseminated both online and offline via MS Access file.
Sediment quality data from the Great Lakes collected to determine baseline status, long term trends and spatial distributions, the effectiveness of management actions, determine compliance with sediment quality objectives and identify emerging issues are included in this dataset.
Stormwater ponds have been widely used to control increased volumes and rates of surface runoff resulting from urbanization. Stormwater ponds have also been designed to provide multiple other benefits; including protection of downstream waters, sediment and habitat (land/aquatic) quality, provision of educational, recreational use as well as aesthetic amenities. Stormwater ponds create unique opportunities for enhancing community benefits, but they also cause ecological concerns with respect to the quality of the newly created habitat. Stormwater ponds receive untreated runoff from urban areas and transportation corridors, and such runoff transports sediment and pollutants from urban sources into the stormwater facilities.
Description of the submarine morphology and characteristics of the sediments (lithology, grain size, mineralogy, and chemistry) of the Saguenay fjord, the lower Estuary and Gulf of St. Lawrence. The layer contains a synthesis of geological and geochemical data collected and interpreted over 10 years and is accompanied by detailed bathymetric and surface sediment maps. Most of this study deals with the geomorphology, surface sediments (lithology, mineralogy, and chemistry), and present depositional conditions, but several studies have also been made of the bedrock geology and the stratigraphy of the unconsolidated sediments. Purpose
These studies are regional and of a reconnaissance nature in the sense that they have been designed to obtain acoustical and sampling data on the morphology and basic properties of the sediments from the whole Gulf.
This data set demonstrates some variation in the data parameters, both in time and with distance along the mainstem Athabasca and two tributaries (Ells and Steepbank Rivers). For the mainstem Athabasca (bulk suspended sediment samples collected via continuous flow centrifugation), these variations are not considered unusual for a dynamic mobile bed river. For the Ells and Steepbank Rivers (bulk suspended sediment samples collected via long-term time-integrated Phillips Tube samplers), however, some spatial and temporal trends were evident. Eight polycyclic aromatic hydrocarbon parameters for the Ells River and thirteen for the Steepbank River showed increasing trends as you move downstream (for periods where samples were collected at multiple sites).