The Department of Fisheries established a survey of demersal juvenile Atlantic cod (*Gadus morhua*) in the nearshore (<10 m deep) in 1959. This survey aimed to characterize the distribution and abundance of juvenile Atlantic cod and was based upon Norway's Flodevigen sampling program which has been conducted continuously since 1919. A 25 m seine was used to sample juvenile Atlantic cod nursery locations on the Avalon Peninsula and Northeast coast of the island of Newfoundland in September and October. The survey continued until 1964 and became known as the Fleming survey, after original initiator Alistair Fleming. The survey was reinstated by Memorial University of Newfoundland from 1992 to 1997. Multiple tows were conducted at a subset of the original 55 Fleming sites located in St. Mary's Bay, Trepassey Bay, the Southern Shore, Conception Bay, Trinity Bay, Bonavista Bay, Gander Bay, New World Island, Fortune Harbour, Badger Bay, Halls Bay and Green Bay.This data set includes several different subsets, some of which span both Fleming Survey periods (1959-1964 and 1992-1997):I. JuvCodCatch60s90s:Catches of juvenile Atlantic cod (1959-1964, 1992-1997) from the first two consecutive tows at each site. This is a summary based on JuvCodLengths90s and FlemingSurveyData60s;II. JuvCodLength90s:Lengths of all individual juvenile Atlantic cod caught for each site (1992-1997);III. SiteEnvData60s90s:Station data for Fleming data 1992-1997;IV. FlemingSurveyData60s:Fleming survey data from 1959-1964 (note there are three record types pertaining to: station data "type 1"; general species catch data including juvenile Atlantic cod grouped by age class ("1+", "Zeroes", and "Total") "type 2; and juvenile Atlantic cod (species 223) listed in length bins "type 3"; andV. FlemingBycatch60s92to96:Bycatch data from 1959-1964 & 1992-1996 from first two tows at each site. This is a summary based partly on the FlemingSurveyData60s set.

Fisheries and Oceans Canada (DFO), in partnership with other government organizations, indigenous groups, and community stakeholders, monitor the migratory return of Atlantic salmon to rivers each season. In Newfoundland and Labrador, there are 15 management areas, known as Salmon Fishing Areas (SFAs), with over 400 rivers containing populations of spawning salmon. Each year, salmon populations are enumerated at monitoring facilities (counting fences or fishways) on several rivers throughout the province. Monitoring begins in April or May for the downstream smolt run and in June or July for the upstream adult run and varies in timing by year and river. Not all rivers are monitored annually and years with incomplete data are often attributable to environmental factors that delay or stop monitoring during a season (e.g. fence washout due to elevated water levels). Days with zero counts can be attributable to no fish and/or closures to the monitoring facility. While monitoring facilities are used primarily to count Atlantic salmon, other freshwater fish may also be enumerated if encountered. The counts from these monitoring facilities, in addition to angling information and other monitoring activities, provide information for estimating returns for the annual stock assessment, which is an important part of conservation and management of Atlantic salmon populations in Newfoundland and Labrador. This data contains information for Atlantic salmon only.

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

In place since fall 1994, the sentinel fisheries program is the result of a collaboration between Fisheries and Oceans Canada (DFO) and Quebec and Newfoundland commercial fishermen's associations. Under this program, contracts are awarded by tender to fishermen’s associations to carry out fishing activities according to scientific protocols developed by DFO. The main objective of this survey is to collect data that will be used to calculate abundance indices for the northern Gulf of St. Lawrence Atlantic cod stock.Description of fixed gears surveyThe fixed gear sentinel fisheries of the northern Gulf of St. Lawrence are conducted in the sub-division 3Pn and the divisions 4R, 4S of the Northwest Atlantic Fisheries Organization (NAFO) using fixed gillnets or longlines (other fishing gears were also used at the start of the program). Fishing activities with nets must have a mesh size of 5 ½ inches (140mm) and are limited to a maximum of 6 to 20 nets depending on the region and capture and the target immersion time is between 19 to 24 hours. Longline fishing activities, for its part, must be carried out with traditional J #16 or C #12 hooks. The maximum number of hooks varies from 500 to 1000, depending on the catch, and the target immersion time is 4 to 6 hours. Data are collected by observers at sea or by technicians.DataFor each fishing activity, the total catch is sorted and weighed by species. For each species other than Atlantic cod, the number of individuals caught is noted. Atlantic cod are then measured at the fork (cm). Other biological data such as weight (total, gonad, liver and stomach), age, sex and maturity can then be collected on a subsample of cod.The biological data are divided into 4 files: a “Metadata” file containing set information, a “Catches” file containing catches per set for fish taxa, a “Carbio” file containing biological and morphometric measurements per individual, a “Freql” file containing the length frequency of fish.The data collected as part of this program is available below. It is important to note, however, that 1) only traits deemed successful have been retained; 2) historical data may contain inaccuracies; 3) the most recent survey is not available for validation purposes.

In 2009, Fisheries and Oceans Canada published the Policy on Managing the Impacts of Fishing on Sensitive Benthic Areas. To support the implementation of this policy, a Canadian Science Advisory Secretariat (CSAS) process was initiated to: assess the distribution of fishing effort in Canada’s Atlantic and Eastern Arctic waters from 2005-2014, evaluate the overlap between fishing effort and Significant Benthic Areas (SiBAs), and identify areas of potential conservation concern. Although Research Document 2018/15 (Koen-Alonso et al. 2018), detailing this work, has not been updated since publication, the methodology outlined within it is still used to generate updated fishing effort layers as new data becomes available. This record illustrates cumulative fishing effort in Canada’s Atlantic and Eastern Arctic waters from 2005-2023, and is based on commercial logbook and vessel monitoring system (VMS) data. Fishing effort has been standardized into percentiles, whereby the top 20th percentile of intensity (cell values ≥20) represent cells containing the most intense fishing activities.

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.

In place since fall 1994, the sentinel fisheries program is the result of a collaboration between Fisheries and Oceans Canada (DFO) and Quebec and Newfoundland commercial fishermen's associations. Under this program, contracts are awarded by tender to fishermen’s associations to carry out fishing activities according to scientific protocols developed by DFO. The main objective of this survey is to collect data that will be used to calculate abundance indices for various fish stocks, including cod, Greenland halibut, Atlantic halibut and rockfish.Description of mobile surveyThe mobile gear sentinel fisheries of the northern Gulf of St. Lawrence are conducted in the sub-division 3Pn and the divisions 4R, 4S and the northern part of the division 4T of the Northwest Atlantic Fisheries Organization (NAFO). This program follows a stratified random survey plan according to depth strata, NAFO divisions and the type of substrate at the bottom. A standard tow is 30 minutes long and made at a speed of 2.5 knots. The fishing gear is a 300 Star Balloon trawl mounted on a Rock Hopper footgear. The trawl mesh size is 145 mm with a liner of 40 mm in the codend. Unless conditions at sea compromise safety during fishing activity, a retaining cable must be used to standardize the horizontal opening between vessels and the various depths fished. Data are collected by observers at sea or by technicians.The data contained in this program are divided into 4 different projects.-The summer series, carried out during the month of July-The fall series, which covers the period from 1995 to 2002-The winter series, to study the mixing between the different stocks-The CRP (Cod reproductive potential) series, which targets the reproductive potential.DataFor each trait, the total catch is sorted and weighed for each species. The number of individuals caught for each unmeasured fish species is noted. Biological data such as length, weight (sampled, per individual, gonad, liver and stomach), age, sex and maturity migth then be collected on a subsample of many species such as Atlantic halibut, Greenland halibut, lumpfish and Atlantic cod, using a variety of protocols. The biological data are divided into 4 files: a “Metadata” file containing set information, a “Catches” file containing catches per set for fish taxa, a “Carbio” file containing biological and morphometric measurements per individual, a “Freql” file containing the length frequency of fish.The data collected as part of this program is available below. It is important to note, however, that 1) only traits deemed successful have been retained; 2) historical data may contain inaccuracies; 3) the most recent survey is not available for validation purposes.

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.

Fisheries and Oceans Canada (DFO) statistical unit areas (also referred to as unit areas) are smaller portions of the Northwest Atlantic Fisheries Organization (NAFO) Subareas, Divisions, and Subdivisions defined in the Convention on Cooperation in the Northwest Atlantic Fisheries (2020). The spatial representation of boundaries defined by NAFO has recently been updated to address inconsistencies and errors in earlier versions, which is available here: https://open.canada.ca/data/dataset/59af1c96-fc8f-4fa0-b398-d65e953eadaa#comment-41855. Unit areas are used by DFO for a variety of purposes including, but not limited to stock assessments, privacy screening of fisheries maps, and statistical analyses.Unit areas were originally defined throughout the 1940s and 1950s. Subsequently, several revisions and alternate versions were created by DFO in various regions leading to inconsistencies in spatial extent and naming conventions. These changes have not been formally documented. The datasets often have topological errors such as gaps and overlaps, especially along diagonals and coastlines. In addition, inconsistencies have arisen from conflicting interpretations of the NAFO divisions, where not all land points are defined by coordinates. Therefore, DFO, with input from the Canadian Hydrographic Service (CHS), has created an updated version of the DFO unit areas file to address inconsistencies and errors among previous versions. The recently updated NAFO divisions were used as the basis for an updated DFO unit areas file.This version of the DFO unit areas must not be used for legal purposes. Legal descriptions of fishing area boundaries can be found in the Atlantic Fisheries Regulations, Maritime Provinces Fishery Regulations, and DFO License Conditions.

Atlantic herring. Concentration, breeding areas and larval retention areas of Atlantic Herring in the St. Lawrence Estuary.Data extracted from the Fish Habitat Management Information System (FHAMIS).Concentration areas, spawning sites and breeding areas of Atlantic herring according to a literature review of documents produced between 1977 and 1998.