DOI: 10.25976/6fgn-0915
title: Great Lakes Water Quality Monitoring and Surveillance Data

description: Water quality and ecosystem health data are collected in the Great Lakes to determine baseline water quality status, long term trends and spatial distributions, the effectiveness of management actions, determine compliance with water quality objectives and identify emerging issues are included in this dataset
description: Ship-based surveys are conducted during spring and summer seasons on the Great Lakes. The number of stations ranges from 50-100 per lake but varies based on program requirements and field constraints.  Primarily using the Canadian Coast Guard Ship (CCGS) LIMNOS, whole water and filtered samples are collected from various depths; surface, multi-depth discrete, and integrated from surface to 2 m above bottom. Cruises are conducted on Lakes Ontario, Erie, Huron, and Superior as well as Lake Huron. Sampling instruments include a multi-bottle array (Rosette) or single bottle samplers (Van Dorn bottle) for discrete depth samples, an integrator for depth-integrated samples, PoPCart for persistent organic pollutants, and ISOMET for trace metals and mercury. 

These water samples are analysed for a broad suite of compounds including nutrients, major ions, physical parameters, trace metals, pesticides and organic contaminants at ECCC’s National Laboratory for Environmental Testing (NLET) in Burlington, ON using methods accredited by the Canadian Association for Laboratory Accreditation (CALA). Additional variables are analysed at other accredited ECCC or external labs. The most recent variable and methods table can be downloaded here: https://open.canada.ca/data/en/dataset/cfdafa0c-a644-47cc-ad54-460304facf2e

Selected methods and recent results published in:
Dove, A., S.M. Backus and K. Sharp King, 2021. Tritium in Laurentian Great Lakes Surface Waters, Journal of Great Lakes Research. https://doi.org/10.1016/j.jglr.2021.06.007
Dove, A. and S.C. Chapra, 2015. Long-term trends of nutrients and trophic response variables for the Great Lakes. Limnology and Oceanography. 60(2): 696-721. http://dx.doi.org/10.1002/lno.10055.
Venier, M., A. Dove, K. Romanak, S. Backus and R. Hites, 2014. Flame Retardants and Legacy Chemicals in Great Lakes Waters. Environmental Science and Technology 48(16): 9563−9572. http://dx.doi.org/10.1021/es501509r
Chapra, S.C., A. Dove and G.J. Warren, 2012. Long-term trends of Great Lakes major ion chemistry, Journal of Great Lakes Research 38: 550-560. doi:10.1016/j.jglr.2012.06.010
Dove, A., B. Hill, P. Klawunn, J. Waltho, S. Backus and R.C. McCrea, 2012. Spatial distribution and trends of total mercury in waters of the Great Lakes and connecting channels using an improved sampling technique, Environmental Pollution 161: 328 - 334, http://dx.doi.org/10.1016/j.envpol.2011.06.004.
Dove, A., 2009. Long-term trends in major ions and nutrients in Lake Ontario, Aquatic Ecosystem Health Management 12(3): 281-295. http://dx.doi.org/10.1080/14634980903136388
description: As part of quality assurance procedures, replicate samples are collected by sequential sampling for each container type. Field blanks are processed by prefilling sampling bottles with ultra-trace clean (MilliQ) water in the laboratory and subjecting them to field handling, travel, and laboratory processes.
Values reported below the detection limit (i.e., trace values) and samples with undetected concentrations (i.e. left censored values) are denoted with a “T” flag and “L” flag respectively.