Since 1979, Fisheries and Oceans Canada has conducted near-annual mackerel egg surveys in the southern Gulf of St. Lawrence using a standardized methodology. This survey typically takes place over approximately 10 days in June and aims to quantify mackerel eggs, thereby contributing to the stock assessment of the northern contingent. Sampling is conducted at 66 fixed stations arranged in a predefined grid (see included image for station locations and names). Additional stations—following the same sampling methodology—have also been surveyed off of southwestern Newfoundland, eastern Cape Breton and south of Prince Edward Island, as well as in other regions. The mackerel survey is often coordinated with the Atlantic Zone Monitoring Program (AZMP) for the Quebec region, which takes place around the same time using the same research vessel and similar equipment. While these two surveys are distinct, they are coordinated to complement each other.At each station, a tow using 61 cm bongo nets (333 µm mesh size) is towed following a saw-tooth profile through the upper 50 m of the water column. Tows last approximately 10 minutes at a speed of roughly 2.5 knots. These tows target mackerel eggs and larvae but collect other species and plankton stages. The taxonomic identification and classification of the developmental stages of the samples are then carried out in the laboratory. The number of taxon counted varies between survey years, based on new species encountered and identified. Egg development stages (I–V) are recorded only for mackerel.This dataset includes the records of all ichthyoplankton species sampled during the survey. It includes information for each sampling station, including gear specifications, species identifications, and life history stages. Each unique combination of COLLECTOR_STATION_NAME, COLLECTOR_EVENT_ID, START_DATE, START_LAT and START_LON represents a single sampling event, and all rows sharing this combination correspond to individual samples collected during that event.The dataset covers the period from 1983 to 2024 and is updated annually as new data become available.It is important to note that prior to 2023, nearly all species were systematically counted, with only a few exceptions where presence alone was recorded. However, since 2023, data collection has shifted to presence/absence for all species, except capelin larvae, herring larvae, and mackerel eggs and larvae, which continue to be counted.Note – raw data use with caution – please contact the author if you have any questions.The data processing methods used for the stock assessment are described in detail in the following publication:Lehoux, C., Van Beveren, E., and Plourde, S. 2024. Results of the Mackerel (Scomber scombrus L.) Egg Surveys Conducted in the Southern Gulf of St Lawrence from 1979 to 2022. DFO Can. Sci. Advis. Sec. Res. Doc. 2024/037. v + 47 p.https://www.dfo-mpo.gc.ca/csas-sccs/Publications/ResDocs-DocRech/2024/2024_037-eng.html

SummaryThe Quebec region of the Department of Fisheries and Oceans (DFO) is responsible for the assessment of several fish and invertebrate stocks exploited in the Estuary and the northern Gulf of St. Lawrence. The commercial catches sampling program is one of the sources of information used to complete these assessments. The data collected by this program, at wharf or at sea, offers among other things the advantage of a relatively large spatio-temporal coverage and provides some of the necessary knowledge to assess the demography and the structure of the exploited populations. This program is implemented by specialized DFO staff whose main mandate is to collect biological data on groundfish, pelagic fish and marine invertebrate species that are commercially exploited in the various marine communities.DataThis dataset on the Atlantic mackerel (Scomber scombrus) includes the metadata, sample weight, fish length, the sex and the number of specimens measured. This dataset covers the periods of 1976-1977 and 1984 to present. In order to protect the confidentiality of the sources, some informations (such as those concerning the vessel) have been excluded and others (such as the date of capture) have been simplified. Entries where there was only one vessel in a fishing area for a given year were also excluded. Further information including the fishing areas coordinates can be found by clicking on the «Atlantic and Arctic commercial fisheries» and «Fishing areas» links below.

PURPOSE:The research survey provides a fisheries-independent source of information about all marine living organisms that are captured by the fishing trawl used to obtain samples in the southern Gulf of St. Lawrence.DESCRIPTION:Tow, catch, length frequency, and biological information for fish caught during the annual September research vessel trawl surveys in the southern Gulf of St. Lawrence (NAFO Division 4T). Abundance indices and spatial distribution patterns of commercial and non-commercial groundfish.The catch data that appear in this dataset SHOULD NOT BE USED FOR ECOLOGICAL ANALYSES INVOLVING CATCH RATES. Important factors such as vessel, fishing gear and diurnal periods must be accounted for to use these data in analyses. Please contact the data custodians if you are interested in using this data for any kind of ecological analyses involving catch rates. PARAMETERS COLLECTED:Abundance estimates (ecological); distribution (ecological); species counts (ecological); gear (fishing); vessel information (fishing); point (spatial)NOTES ON QUALITY CONTROL:Scientific names listed in the survey species list have been mapped to recognized standards - marine taxa have been mapped to the World Register of Marine Species (WoRMS) using their online taxon match tool. All sampling locations were plotted on a map to perform a visual check confirming that the latitude and longitude coordinates were within the described sampling area.In 2003, because of a fire aboard the Alfred Needler, the Wilfred Templeman was used for the survey. However, no comparative fishing experiments have been conducted between the Alfred Needler and the Wilfred Templeman. We are therefore unable to integrate the indices derived for 2003 to the remainder of the survey time-series.SAMPLING METHODS:Sampling Method: Consult the "Protocols for research vessel cruises within the Gulf Region (dermersal fish) (1970-1980)" report, link provided in the citations list.USE LIMITATION:To ensure scientific integrity and appropriate use of the data, we would encourage you to contact the data custodian.

A derivative of DFO’s benthic species survey for the Strategic Program for Ecosystem-based Research and Advice (SPERA) (open data record ID: e736c0f0-b19e-4842-903d-28bfc756d48a), this benthic survey funded through the Canadian Healthy Oceans Network (CHONeII) looks at the presence/absence and abundance of two biogenic habitat-forming species that are listed as vulnerable to disturbance in a subset of 50 drift camera transects in the ‘Head Harbour/West Isles Archipelago/The Passages’ Ecologically and Biologically Significant Area (EBSA) in the Bay of Fundy, New Brunswick, Canada (~113km2). Presence/absence and abundance data of the stalked sea squirt (Boltenia ovifera) and horse mussel (Modiolus modiolus) were derived from the use of high-resolution Nikon D800 36.1 megapixel still images (n=2576, see link to parent record for more descriptive survey information) to be used in species distribution modelling. Image field of view (FOV) was estimated using a 10 cm-wide trigger weight for scale,and standardized across images using the average FOV estimate (0.75 x 0.5 m) across a subset of 200 images. Species counts were then converted to abundance estimates (number of individuals per square-meter) by dividing counts by 0.375m2. Boltenia ovifera was observed at densities reaching 456 ind./m2, while Modiolus modiolus density reached a maximum of 240 ind./m2.Cite this data as: Mireault C.A., Lawton P., Devillers R. and Teed L. Presence/absence and abundance of vulnerable marine ecosystem species Boltenia ovifera and Modiolus modiolus in the lower Bay of Fundy derived from high resolution still imagery. Published September 2023. Coastal Ecosystems Science Division, Fisheries and Oceans Canada, St. Andrews, N.B. https://open.canada.ca/data/en/dataset/152ae3f1-d2b9-43d9-a7b4-d769d9e9fc41

The Atlantic Colonial Waterbird Monitoring database captures geo-referenced data collected under the Atlantic Region’s Canadian Wildlife Service (CWS) Colonial Seabird Monitoring program, and data collected under CWS’ waterfowl and protected areas programs. These programs collectively monitor 22 species of colonial waterbirds breeding in the Atlantic Region of the following groups: fulmars, shearwaters, storm-petrels, gannets, gulls, terns, alcids, eiders, herons and cormorants, with the primary outcome to update information on the distribution, status, and trends of waterbirds breeding in all four Atlantic provinces. Surveys are conducted using one of three platforms: aerial, boat, or ground. Aerial surveys provide the most cost-effective way of conducting a comprehensive population census of diurnal species visible from air, namely gulls (Herring, Great Black-backed, Ring-billed, Glaucous), Black-legged Kittiwakes, Northern Gannets, terns (Arctic, Common, Roseate, Caspian), cormorants (Greater, Double-crested), Black Guillemots, and Common Eiders.Aerial surveys are also effective in identifying new colonies and provide additional information on how to most effectively conduct boat and ground surveys. Boat and ground surveys are conducted at smaller geographic scales and are necessary to obtain complementary information on the species composition of colonies and correction factors to finalize gull, tern and eider estimates obtained from the aerial surveys. Ground and/or boat surveys are also necessary to conduct colony counts of cliff-nesting birds (murres and fulmars), crevice nesting birds (razorbills and guillemots) and burrow-nesting birds (puffins, storm-petrels, shearwaters). Raw data are captured using various survey methods, including:1) visual estimates, 2) direct counts of number of individuals or apparently occupied sites and/or photo counts, 3) sub-sampling the colony through plot counts and extrapolating the estimated occupied densities over the occupied area which in turn is estimated using a variety of geographic information system approaches (e.g., Wilhelm et al. 2015). Important outcomes for how data are used include informing marine spatial planning, emergency preparedness, impact assessment of various anthropogenic threats, and COSEWIC status assessment (e.g., COSEWIC 2020). Further, these data are regularly used internally or in collaboration with partners to form the basis of peer-reviewed publications on regional, national, and/or global population trends for target species (e.g., Langlois Lopez et al. 2022, Iles et al. 2025).This dataset represents a subset of data collected from surveys led by CWS spanning from 1910 to 2024 and summarized to present, at a given colony, the year and count of birds from the most recent survey, the year and maximum count of birds within the last 20 years (if available), and the year and maximum count of birds ever recorded. In addition, CWS works closely with a variety of partners (e.g., provincial, other federal departments, academic, not-for profit organizations) to supplement colonial waterbird data collected in the Atlantic Region. To request additional census or survey data, please contact CWS.COSEWIC. 2020. COSEWIC assessment and status report on the Leach’s Storm-Petrel (Atlantic population) Oceanodroma leucorhoa in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. xii + 70 pp. (https://www.canada.ca/en/environment-climate-change/services/species-risk-public-registry.html). Iles, D.T., S.E. Gutowsky, A.M. Calvert, S.I. Wilhelm, J.-F. Rail, A. Hedd, H.L. Major, A.C. Smith, and G.J. Robertson. 2025. Estimating regional trajectories and trends of seabirds from sparse and inconsistent colony counts: case studies from eastern Canada with Leach’s Storm-Petrel and Atlantic Puffin. Avian Conservation and Ecology 20(2):16. https://doi.org/10.5751/ACE-02931-200216Langlois Lopez, S., Bond, A.L., O’Hanlon, N.J., Wilson, J.M., Vitz, A., Mostello, C.S., Hamilton, F., Rail, J.-F., Welch, L., Boettcher, R., Wilhelm, S.I., Anker-Nilssen, T., Daunt, F., and Masden, E. 2022. Global population and conservation status of the Great Black-backed Gull Larus marinus. Bird Conservation International, 1–11. https://doi.org/10.1017/S0959270922000181Wilhelm, S.I., Mailhiot, J., Arany, J., Chardine, J.W., Robertson, G.J., and Ryan, P.C. 2015. Update and trends of three important seabird populations in the western North Atlantic using a geographic information system approach. Marine Ornithology 43: 211-222.

Species characterization by environmental DNA (eDNA) is a method that allows the use of DNA released into the environment by organisms from various sources (secretions, faeces, gametes, tissues, etc.). It is a complementary tool to standard sampling methods for the identification of biodiversity. This project provides a list of invertebrates species whose DNA has been detected in water samples collected at 2018 using the marker COI.The surveys were carried out in the summer of 2018 from August 11 to 14, between Forestville and Godbout (Haute-Côte-Nord). Sampling was carried out between 9-52 meters depth in 40 stations with one sample par station. Two liters of water were filtered through a 1.2 µm fiberglass filter. DNA extractions were performed with the DNeasy Blood and Tissue extraction kit (Qiagen). Negative field, extraction and PCR controls were added at the different stages of the protocol. Libraries at the COI locus were prepared by Genome Quebec and sequenced on an Illumina MiSeq PE250 system. The bioinformatics analysis of the sequences obtained was carried out using an in-house analysis pipeline as reported in Bourret et al. 2022. A first step made it possible to obtain a molecular operational taxonomic unit table (MOTU) using the cutadapt software for the removal of the adapters and the DADA2 R package for the filtration, fusion, chimera removal and data compilation. The MOTUs table was subsequently corrected by taking into account the negative controls, where the number of observations in the latter was removed from the linked samples. Singleton MOTUs have also been removed. Finally, the taxonomic assignments were carried out on the MOTUs using the IDTAXA classifier (present in the DECIPHIER R package) using a training set trained on the COI reference bank for Golf St-Laurent (GSL-rl v1.0, https://github.com/GenomicsMLI-DFO/MLI_GSL-rl) and a threshold of 40. Detections with an “Unreliable due to gaps” category were reported at the genus level only.The file provided includes generic activity information, including site, station name, date, marker type, assignment types used for taxa identification, and a list of taxa or species. The list of taxa has been verified by a biodiversity expert from the Maurice-Lamontagne Institute.This project was funded by Fisheries and Oceans Canada's Coastal Environmental Baseline Data Program under the Oceans Protection Plan. This initiative aims to acquire baseline environmental data that contributes to the characterization of significant coastal areas and supports evidence-based assessments and management decisions to preserve marine ecosystems.Data are also available on SLGO platform : https://doi.org/10.26071/ogsl-cd4c205b-f63b

Nekton assemblages in Zostera marina beds and adjacent bare soft-sediments were sampled on the south and eastern shore of Nova Scotia. Sampling gear used were visual snorkel transects and a benthic beam trawl. Fish were identified and size either measured (trawl) or estimated in situ (snorkel transects). Surveys were conducted in mid-July to August in summer of 2013 and 2014 across multiple sampling sites. Multiple replicate transects were conducted at each site. Raw abundances from observations were transformed into young of year (YOY) equivalent abundance, and then into density of each species calibrated to account for the sampling equipment and day/night differences.Cite this data as: Wong, M. C. Data of: Fish and large decapods in eelgrass (Zostera marina) beds on the Atlantic coast of Nova Scotia, Canada. Published: April 2020. Coastal Ecosystems Science Division, Fisheries and Oceans Canada, Dartmouth, N.S. https://open.canada.ca/data/en/dataset/dbc56f11-4a97-45e7-99f4-71966b51630c

Funded under DFO's Marine Conservation Targets Program, this optical imagery benthic survey documents the occurrence and estimated percent cover of the invasive colonial tunicate, Didemnum vexillum in seven drift-camera transects in the 'Head Harbour/West Isles Archipelago/The Passages' Ecologically and Biologically Significant Area (ESBA, ~113km2) in the western Bay of Fundy, New Brunswick, Canada. Occurrence data was derived from the use of high-resolution still images (n=386) taken periodically throughout each transect, and simultaneous continuous high-definition video. Video was divided into 20-second segments (here, we report the start and end location of each segment within a transect) and when D. vexillum was present in a video segment, frequency of occurrence was classified as common (continuous coverage/patches throughout the video segment), occasional (individual colonies of various sizes encountered >5 times throughout the video segment), or rare (small, isolated colonies encountered ≤5 times throughout the video segment). A video segment was deemed unusable and removed from the dataset if there was too much turbidity, or if the camera position was too high off-bottom to reliably image the seafloor. For still images, when D. vexillum was observed in an image, colony percent cover was categorized as >50%, 26-50%, 6-25%, or ≤5% of the images field of view (FOV). Distance travelled and distance between still images (m) was calculated using ArcGIS tools. FOV was estimated by measuring the length and width of a subset of still images and video frame grabs in ImageJ2, using 10-cm lasers for scale. FOV was standardized for each reported altitude, and area sampled (m2) along a continuous video segment was estimated by multiplying the average FOV by the distance travelled in that segment. D. vexillum was found in 44% of the area sampled at depths from 34 to 118m, deeper than previous reports globally of ~80m.Cite this data as: Teed LL, Goodwin C, Lawton P, Lacoursière-Roussel A, Dinning KM (2024) Multiple perspectives on the emergence of the invasive colonial tunicate Didemnum vexillum Kott, 2002 in the western Bay of Fundy, Atlantic Canada. BioInvasions Records 13(3): 713–738, https://doi.org/10.3391/bir.2024.13.3.12

Sexual reproduction is critical to the resilience of seagrass beds impacted by habitat degradation or environmental changes, as robust seed banks allow new shoots to establish each year. Reproductive strategies of seagrass beds range on a continuum from strictly annual to perennial, driven by local environmental conditions. We examined the reproductive dynamics of Zostera marina beds at six sites on the Atlantic coast of Canada to characterize how life history strategies are shaped by the surrounding environment. Sites were categorized as wave protected and wave exposed, where protected sites were warm, shallow, with little water movement and muddy sediments, and exposed sites were either shallow or deep, with cooler water and sandy sediments. While mixed life history strategies were evident at all sites, protected eelgrass beds exhibited both the highest and lowest sexual reproductive effort relative to exposed beds. These beds regularly experienced thermal stress, with higher temperature range and extended warm water events relative to exposed beds. The development of reproductive shoots were similar across sites with comparable Growing Degree-days at the beginning and end of anthesis, but the First Flowering Date was earlier at the protected warmer sites relative to exposed sites. With different reproductive shoot density among sites, seed production, seed retention, and seedling recruitment also varied strongly. Only one site, located in a warm, shallow and protected lagoon, contained a mixed life history population with a high reproductive effort (33.7%), strong seed bank, and high seedling establishment. However, a primarily perennial population with the lowest reproductive effort (0.5%) was identified at the warmest site, suggesting that conditions here could not support high sexual reproduction. Robustness of seed banks was strongly linked to reproductive shoot density, although the role of seed retention, germination and seedling survival require further investigation. Our study provides insights into one key aspect of seagrass resilience, and suggests that resilience assessments should include reproductive shoot density to inform their management and conservation.Cite this data: Vercaemer B. and Wong M. Reproductive ecology of Zostera marina L. (eelgrass) across varying environmental conditions. Published: May 2022. Coastal Ecosystems Science Division, Fisheries and Oceans Canada, Dartmouth, N.S. https://open.canada.ca/data/en/dataset/56cfea6f-aeca-47ed-94ab-c519d9e63c91

This project was completed by the Groundfish Section in the Newfoundland and Labrador Science Branch of Fisheries and Oceans Canada (DFO). From 2018 to 2020, 14 year-round, acoustic receivers were deployed in Placentia Bay as a part of the Coastal Environmental Baseline Program to form 4 gates: Bar Haven (2 receivers), Centre Channel (1 receiver), Eastern Channel (6 receivers), and Western Channel (5 receivers). Additionally, 162 transmitters were deployed in Atlantic cod in the 3Ps region (2019-2022). Over the deployment period these receivers recorded a total of 2 094 024 detections from 63 unique transmitters including 45 Cod tagged through the Groundfish acoustic telemetry program. Most cod detected were tagged in Placentia Bay (43 fish) and many were detected at multiple receivers or multiple years (37 fish). Passive data collection for this project may extend up to 2030. This record contains the locations of the acoustic receivers in Placentia Bay, NL.