PURPOSE:Chlorophyll a is a photosynthetic pigment common to aquatic algae, and its measurement can provide an estimate of free-floating algae abundance in an aquatic system. For more than 40 years, the Fisheries and Oceans Canada - Great Lakes Laboratory for Fisheries and Aquatic Sciences (DFO-GLLFAS) office in Sault Ste. Marie Ontario has collected water samples for chlorophyll a spectrophotometric analysis, producing data in the form of mg/m3. The collection of chlorophyll a data was generally conducted to assist in characterizing the aquatic systems level of primary productivity, since that can influence fish abundance. This was a supplementary measure of the quality of fish habitat in these systems for a variety of fish-related projects of relevance to DFO’s mandate. Consistency of data collection was dependent on the duration of each project and funding available. DESCRIPTION:The initial study collected chlorophyll a data from the five lakes in the Turkey Lakes Watershed (TLW – Upper and Lower Batchawana Lakes, Wishart Lake, Little Turkey Lake and Turkey Lake) as well as Quinn Lake which is located outside of the TLW (see Smokorowski et al. 2006) in partnership with Environment and Climate Change Canada (ECCC) and Natural Resources Canada (NRCAN), as part of Canada’s Acid Rain Initiative. The TLW study was established in 1979 to evaluate the impacts of acid rain on terrestrial and aquatic ecosystems. This dataset encompasses chlorophyll a data collected from five lakes in the TLW and Quinn Lake (data also collected by the Canadian Wildlife Service and Environment and Climate Change Canada) from 1983 - 2010 with some gaps of varying duration (Webster et al., 2021). Note that an experimental habitat removal took place in some TLW lakes and Quinn Lake in 1999 and 2000. Specifically, in autumn of 1999, 50% of the coarse woody material was removed from the shorelines of Little Turkey Lake and Quinn Lake, and in autumn of 2000, 50% of the course woody material was removed from Wishart Lake shoreline (details available in Smokorowski et al., 2006). Methods Summary: Sampling was only conducted during the open water season and the frequency and extent of sampling frequency in each waterbody varied and was project- and funding-dependent. There are no chlorophyll a data for the years 1986, 1989 – 1990, 1996 – 1997, 2006-2007 and 2009.Sampling was accomplished by rinsing on site an appropriately-cleaned 1 L, brown-opaque polyethylene bottles at least three times. For hand draw samples, the bottle was immersed sub-surface (less than 0.5 meters) to collect the sample. Composite tube samples were collected using an integrated water sampling tube that collected epilimnion water from the entire water column to a depth of 5 meters. Up to five - 1 L (1000 mL) samples were collected per station and returned to the lab on ice. Each 1 L sample was filtered using glass fiber filters (Whatman GF/C, 42.5 mm) within one day of sampling, and then frozen prior to standard chlorophyll a analysis (American Public Health Association [APHA] 1985). From 1983-1998, Chlorophyll a concentrations (mg/L) was calculated based on APHA 1985; from 1998 to present the calculation was based on APHA (1998). The sample dataset information includes the georeferenced sampling locations, the raw data for chlorophyll a calculations, and the calculated chlorophyll a concentrations using both the APHA (1985) and APHA (1998) methods. This dataset was published in partnership with the Canadian Institute of Ecology and Evolution - Living Data Project, which was funded by a CREATE grant from the Natural Science and Engineering Research Council of Canada. We would like to recognize Caroline Dallstream for her effort in publishing this dataset. SAMPLING METHODS:Methods Summary: Sampling was only conducted during the open water season and the frequency and extent of sampling frequency in each waterbody varied and was project- and funding-dependent. There are no chlorophyll a data for the years 1986, 1989 – 1990, 1996 – 1997, 2006-2007 and 2009. See Sampling was accomplished by rinsing on site an appropriately-cleaned 1 L, brown-opaque polyethylene bottles at least three times. For hand draw samples, the bottle was immersed sub-surface (less than 0.5 meters) to collect the sample. Composite tube samples were collected using an integrated water sampling tube that collected epilimnion water from the entire water column to a depth of 5 meters. Up to five - 1 L (1000 mL) samples were collected per station and returned to the lab on ice. Each 1 L sample was filtered using glass fiber filters (Whatman GF/C, 42.5 mm) within one day of sampling, and then frozen prior to standard chlorophyll a analysis (American Public Health Association [APHA] 1985). From 1983-1998, Chlorophyll a concentrations (mg/L) was calculated based on APHA 1985; from 1998 to present the calculation was based on APHA (1998). The sample dataset information includes the georeferenced sampling locations, the raw data for chlorophyll a calculations, and the calculated chlorophyll a concentrations using both the APHA (1985) and APHA (1998) methods.USE LIMITATION:To ensure scientific integrity and appropriate use of the data, we would encourage you to contact the data custodian.

Chlorophyll-a (mg/m2) time series at the 3 fixed stations and 46 stations, grouped into transects, of the Atlantic Zonal Monitoring Program (AZMP) under the Quebec region responsibility.The mean integrated chlorophyll-a data (0-100 m) of the last ten years are displayed as 2 layers, one for the June survey (2013-2022. 2020 not sampled), another for the autumn survey (2013-2022). A third layer shows the positions of the fixed stations of the program (Anticosti Gyre, Gaspé Current and Rimouski).Each station is linked with a .png file showing the chlorophyll-a time series and with a .csv file containing all the integrated chlorophyll-a data acquired at those stations since the beginning of the program sampling (columns : Station, Latitude, Longitude, Date(UTC), Sounding(m), Depth_min/Profondeur_min(m), Depth_max/Profondeur_max(m), Integrated_chlorophyll-a/Chlorophylle-a_intégrée(mg/m²)).PurposeThe Atlantic Zone Monitoring Program (AZMP) was implemented in 1998 with the aim of increasing the Department of Fisheries and Oceans Canada’s (DFO) capacity to detect, track and predict changes in the state and productivity of the marine environment.The AZMP collects data from a network of stations composed of high-frequency monitoring sites and cross-shelf sections in each following DFO region: Québec, Gulf, Maritimes and Newfoundland. The sampling design provides basic information on the natural variability in physical, chemical, and biological properties of the Northwest Atlantic continental shelf. Cross-shelf sections sampling provides detailed geographic information but is limited in a seasonal coverage while critically placed high-frequency monitoring sites complement the geography-based sampling by providing more detailed information on temporal changes in ecosystem properties.In Quebec region, two surveys (46 stations grouped into transects) are conducted every year, one in June and the other in autumn in the Estuary and Gulf of St. Lawrence. Historically, 3 fixed stations were sampled more frequently. One of these is the Rimouski station that still takes part of the program and is sampled about weekly throughout the summer and occasionally in the winter period.Annual reports (physical, biological and a Zonal Scientific Advice) are available from the Canadian Science Advisory Secretariat (CSAS), (http://www.dfo-mpo.gc.ca/csas-sccs/index-eng.htm).Devine, L., Scarratt, M., Plourde, S., Galbraith, P.S., Michaud, S., and Lehoux, C. 2017. Chemical and Biological Oceanographic Conditions in the Estuary and Gulf of St. Lawrence during 2015. DFO Can. Sci. Advis. Sec. Res. Doc. 2017/034. v + 48 pp.Supplemental InformationWater sampling for chlorophyll-a analysis (Welschmeyer 1994 method) is done from Niskin bottles according to AZMP sampling protocol:Mitchell, M. R., Harrison, G., Pauley, K., Gagné, A., Maillet, G., and Strain, P. 2002. Atlantic Zonal Monitoring Program sampling protocol. Can. Tech. Rep. Hydrogr. Ocean Sci. 223: iv + 23 pp.

Description:Chlorophyll-a concentration (a proxy for phytoplankton biomass) was retrieved from the MODIS instrument on the Aqua satellite, with data distributed by the NASA Ocean Biology Processing Group, and averaged into monthly climatological composites. The data span the years 2003-2020 and this record includes data at 4 km pixel resolution.Methods:MODIS-Aqua Chlorophyll-a (Chl-a) was acquired from the NASA Ocean Biology Processing Group at processing Level-3 (version 2018), 4-km resolution, where Chl-a concentration was calculated using the OC3/OCI method. The months of January and December were excluded from this dataset, as data in the winter months at higher latitudes are missing due to low sun angle preventing acquisition. The monthly geometric mean value at all pixels was calculated for individual years, then the geometric mean and geometric standard deviation factor of chlorophyll-a were calculated by month from these images. These methods of calculating mean and standard deviation were used due to the log-normal distribution of chlorophyll-a. The geometric standard deviation is a unitless factor, where the lower bound is the ratio of the geometric mean and geometric standard deviation, and the upper bound is the multiplication of the two. In addition to the geometric mean and geometric standard deviation factor the number of occurrences of valid data at each pixel over the period of observation were calculated. Pixels with fewer than two occurrences over the entire period of observation were removed from these maps, and set to a NaN value in the tif files. All resulting rasters were cropped to the Canadian Exclusive Economic Zone and assigned to the NAD83 geographic coordinate reference system (EPSG:4269), and have a final pixel resolution of approximately 0.0417 degrees. The monthly geometric mean, monthly geometric standard deviation factor, and number of occurrences for all pixels are provided.Data Sources:NASA Ocean Biology Processing Group. (2017). MODIS-Aqua Level 2 Ocean Color Data Version R2018.0. NASA Ocean Biology Distributed Active Archive Center. https://doi.org/10.5067/AQUA/MODIS/L2/OC/2018Uncertainties:Satellite values have been evaluated against global datasets, and datasets of samples in the Pacific region (see references). However, uncertainties are introduced when averaging together images over time as each pixel has a differing number of observations. Short-lived or spatially limited events may be missed.

Description:Chlorophyll-a concentration (a proxy for phytoplankton biomass) was retrieved from the MODIS instrument on the Aqua satellite, with data distributed by the NASA Ocean Biology Processing Group, and averaged into monthly climatological composites. The data span the years 2003-2020 and this record includes data at 1 km pixel resolution.Methods:MODIS-Aqua Chlorophyll-a (Chl-a) was acquired from the NASA Ocean Biology Processing Group at processing Level-2 (version 2018), 1-km resolution, where Chl-a concentration was calculated using the OC3/OCI method. The months of January and December were excluded from this dataset, as data in the winter months at higher latitudes are missing due to low sun angle preventing acquisition. The pixels were aligned on a regular grid using the SeaDAS program, after which the monthly geometric mean value at all pixels was calculated for individual years. Finally, the geometric mean and geometric standard deviation factor of chlorophyll-a were calculated by month from these images. These methods of calculating mean and standard deviation were used due to the log-normal distribution of chlorophyll-a. The geometric standard deviation is a unitless factor, where the lower bound is the ratio of the geometric mean and geometric standard deviation, and the upper bound is the multiplication of the two. In addition to these variables, the number of occurrences of valid data at each pixel over the period of observation were calculated. Pixels with fewer than two occurrences over the entire period of observation were removed from these maps, and set to a NaN value in the tif files. A few small gaps between pixels (near the edges of individual images) were filled using the median value of surrounding pixels, provided there were greater than 4 values. Finally, all rasters were cropped to the Canadian Exclusive Economic Zone and assigned to the NAD83 geographic coordinate reference system (EPSG:4269), and have a final pixel resolution of approximately 0.01 degrees. The monthly geometric mean, monthly geometric standard deviation factor, and number of occurrences for all pixels are provided.Data Sources:NASA Ocean Biology Processing Group. (2017). MODIS-Aqua Level 2 Ocean Color Data Version R2018.0. NASA Ocean Biology Distributed Active Archive Center. https://doi.org/10.5067/AQUA/MODIS/L2/OC/2018Uncertainties:Satellite values have been evaluated against global datasets, and datasets of samples in the Pacific region (see references). However, uncertainties are introduced when averaging together images over time as each pixel has a differing number of observations. Short-lived or spatially limited events may be missed.

This dataset accompanies the open access article "Improving satellite chlorophyll-a retrieval in the turbid waters of the Bay of Fundy, Canada" published in Estuaries and Coasts (https://doi.org/10.1007/s12237-024-01334-x). A full methods description is provided in the article. Briefly, we processed daily satellite data from the MODerate-resolution Imaging Spectroradiometer (MODIS) on the Aqua satellite from 2003 to 2021 at 300 m resolution to understand and quantify spatial and temporal trends in chlorophyll-a concentration (chl-a, a measure of phytoplankton biomass), and suspended particulate matter concentration (SPM) in the Bay of Fundy surface waters. This dataset provides the median yearly and seasonal climatology of chl-a (mg m-3 ) and SPM (g m-3) from 2003 to 2021 as geotiff layers. Here winter is defined as January to March, spring as April to June, summer as July to September, and fall as October to December. Chl-a was calculated with the OCX-SPMCor algorithm and SPM was calculated with the Nechad et al 2010 algorithm.Cite this data as: Wilson, K., Hilborn, A., Clay, S., Devred, E. Data ofSatellite derived surface chlorophyll-a and suspended particulate matter in the Bay of Fundy from 2003 to 2021. Published February 2024. Ocean Ecosystem Science Division, Fisheries and Oceans Canada, Dartmouth, N.S. https://open.canada.ca/data/en/dataset/272f5cf1-52bb-416b-b92a-8bc9384fc24d

This record contains satellite-sensed chlorophyll-a concentration images of the Canadian Beaufort Sea at 1.1 km resolution. The dataset consists of 276 images, aggregated into two-week composites by calculating the mean value at each pixel, comprising years 1998 through 2020.The dataset spans two ocean colour sensors, MODIS-Aqua and SeaWiFS. The Arctic Ocean Empirical algorithm was used to calculate chlorophyll-a concentration, after images were corrected for atmospheric effects using the NIR-SWIR switching algorithm, and Remote Sensing Reflectance (Rrs) were produced. A linear transform in log-10 space was applied to the chlorophyll-a concentration measured by SeaWiFS to improve its correlation with chlorophyll-a concentration measured by MODIS-Aqua.The months of October through February were excluded from these datasets as the sun angle in winter is too low (e.g., polar night) for reliable data to be acquired, and the region is mostly covered in sea ice. For further details, see Galley et al., 2022.

This dataset includes water chemistry data collected from five of the six lakes as part of the Northwestern Ontario Size Series project in 1987 and 1990 including species of nitrogen and phosphorus, carbon, chlorophyll a, conductivity, soluble reactive silica, chloride, sulphate, conductivity, sodium, potassium, magnesium, calcium, pH, alkalinity and organic acids

This data set includes information on sampling locations, water chemistry and chlorophyll collected at 18 locations in the Great Lakes-St. Lawrence River and 4 locations in Lake Simcoe.

Description:Chlorophyll-a concentration (a proxy for phytoplankton biomass) was retrieved from the MODIS instrument on the Aqua satellite, with data distributed by the NASA Ocean Biology Processing Group, and averaged into monthly climatological composites. The data span the years 2003-2020; records were created for both 1 km and 4 km pixel resolutions to be consistent with other satellite products.Methods:MODIS-Aqua Chlorophyll-a (Chl-a) was acquired from the NASA Ocean Biology Processing Group where Chl-a concentration was calculated using the OC3/OCI method. The months of January and December were excluded from these datasets, as data in the winter months at higher latitudes are missing due to low sun angle preventing acquisition. The monthly geometric mean value at all pixels was calculated for individual years, then the geometric mean and geometric standard deviation factor of chlorophyll-a were calculated by month from these images. These methods of calculating mean and standard deviation were used due to the log-normal distribution of chlorophyll-a. The geometric standard deviation is a unitless factor, where the lower bound is the ratio of the geometric mean and geometric standard deviation, and the upper bound is the multiplication of the two. In addition to the geometric mean and geometric standard deviation factor the number of occurrences of valid data at each pixel over the period of observation were calculated. Pixels with fewer than two occurrences over the entire period of observation were removed from these maps and set to a NaN value in the tif files. All resulting rasters were cropped to the Canadian Exclusive Economic Zone, assigned to the NAD83 geographic coordinate reference system (EPSG:4269), and have final pixel resolutions of approximately 0.01 degrees and 0.0417 degrees. The monthly geometric mean, monthly geometric standard deviation factor, and number of occurrences for all pixels are provided.Data Sources:NASA Ocean Biology Processing Group. (2017). MODIS-Aqua Level 2 Ocean Color Data Version R2018.0. NASA Ocean Biology Distributed Active Archive Center. https://doi.org/10.5067/AQUA/MODIS/L2/OC/2018Uncertainties:Satellite values have been evaluated against global datasets, and datasets of samples in the Pacific region (see references). However, uncertainties are introduced when averaging together images over time as each pixel has a differing number of observations. Short-lived or spatially limited events may be missed.

A chlorophyll fluorescence time series was collected at various locations around the coast of Vancouver Island, British Columbia, Canada for monitoring phytoplankton concentrations. A Wetlabs ECO fluorometer was deployed every few months on a schedule depending on season and sensor availability. The instrument hung by a chain attached to the side of the buoy, or dock, depending on location, and measured chlorophyll using the fluorescence emission at 695nm. The instrument also measured turbidity by detecting the scattered light at 700nm. The units had internal batteries and data storage and were programmed to make a group of 5 measurements every 30 minutes. A copper wiper covered the sampling window between groups of measurements to reduce fouling. Times are in UTC unless otherwise stated.