Grey seal distribution and abundance in the Estuary and the Gulf of St. Lawrence, including Saguenay River
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Data were collected during aerial surveys carried out at low tides in June and August 1994-1997, 2000 and 2001. June and August are respectively pupping and moulting seasons, when the haulout sites are intensively used by seals. Features in this layer show the Grey seal distribution and mean abundance for all aerial surveys (tables 4 and 6, figures 4 and 6 from Robillard et al. 2005). In the estuary, areas of high abundance have more than 25 individuals, areas of medium abundance have between 5 and 25 individuals and areas of low abundance have fewer than 5 individuals. In the Gulf, areas of high abundance have more than 70 individuals and areas of medium to low abundance have fewer than 70 individuals. Data are valid only during summer because Grey seals in the Estuary and northern Gulf migrate to the southern Gulf of St. Lawrence in the fall. These seals will spend the winter on Sable Island, on the ice shelf in the Northumberland Strait or on neighboring islands. During the summer, in the Estuary and the Gulf of St. Lawrence, its distribution is not uniform between the different concentration areas identified, but it is similar between June and August. However, there are some areas where Grey seals are more abundant in August than in June. Abundance classes are arbitrary but fit with the published results of haul-out sites utilization from Robillard et al. (2005). Data shown are a picture of the situation in 2005 because it is the most recent mapping available for this species. Data sources and references: Lavigueur, L., Hammill, M.O., and Asselin, S. 1993. Distribution et biologie des phoques et autres mammifères marins dans la région du parc marin du Saguenay. Rapp. manus. can. sci. halieut. aquat. 2220: vi + 40. Lesage, V., and Hammill, M.O. 2001. The status of the grey seal, Halichoerus grypus, in the Northwest Atlantic. Can. Field-Nat. 115(4): 653-662. Robillard, A., V. Lesage, and M.O. Hammill. 2005. Distribution and abundance of harbour seals (Phoca vitulina concolor) and grey seals (Halichoerus grypus) in the Estuary and Gulf of St. Lawrence, 1994–2001. Can. Tech. Rep. Fish. Aquat. Sci. 2613: 152 pp.
Counts of harbour seals (Phoca vitulina) and grey seals (Halichoerus grypus) from an aerial survey of the coast of the Newfoundland Shelf and Sandwich Bay, Labrador during the summer of 2021
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Harbour seals reside throughout the year around Newfoundland and Labrador (NL). The first systematic survey for harbour seals occurred along the NL Shelf during July and August 2021 to obtain counts of hauled out individuals and assess distribution. Grey seals are seasonal residents in NL, mainly present in the summer and autumn months. Grey seals were also recorded during the survey as these two species can share haul-out locations. Surveys were flown along the coastline with a Bell 429 helicopter with photographs taken of hauled out seals. This data includes the counts of hauled out harbour, grey and unknown seals seen during the survey. Adjusted counts are also provided, which assign the unknown seals to species based on the number of positively identified harbour and grey seals from each survey day. The realized survey coverage (survey tracks) is also included. Cite this data as: Hamilton, C.D., Goulet, P.J., Stenson, G.B., and Lang, S.L.C. 2024. Data of: Counts of harbour seals (Phoca vitulina) and grey seals (Halichoerus grypus) from an aerial survey of the coast of the Newfoundland Shelf and Sandwich Bay, Labrador during the summer of 2021 This data can be found in: Hamilton, C.D., Goulet, P.J., Stenson, G. B., and Lang, S.L.C. 2023. Counts and spatial distribution of harbour seals (Phoca vitulina) and grey seals (Halichoerus grypus) from an aerial survey of the coast of the Newfoundland Shelf and Sandwich Bay, Labrador during the summer of 2021. Can. Tech. Rep. Fish. Aquat. Sci. 3566: v + 39 p. https://publications.gc.ca/site/eng/9.927831/publication.html DFO. 20XX. Stock assessment of Atlantic harbour seals (Phoca vitulina vitulina) in Canada for 2019-2021. DFO Can. Sci. Advis Sec. Sci. Advis. Rep. 2023/XXX. Lang, S.L.C., St-Pierre, A.P., Hamilton, C.D., Mosnier, A., Lidgard, D.C., Goulet, P., den Heyer, C.E., Bordeleau, X., Irani, A.I., and Hammill, M.O. 20XX. Population status assessment and Potential Biological Removal (PBR) for the Atlantic harbour seal (Phoca vitulina vitulina) in Canadian waters. DFO Can. Sci. Advis. Sec. Res. Doc. 2024
Distribution of foraging effort of Antarctic fur seals in relation to oceanographic features around Heard and Kerguelen Islands
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Metadata record for data from ASAC Project 1251 See the link below for public details on this project. ---- Public Summary from Project ---- The aim of this study is to develop spatial GIS models of fur seal foraging density over the Kerguelen Plateau that will enable a rapid assessment method for identifying areas of high conservation value for Marine Protected Area planning and management. These models will be based on data on fur seal foraging densities in the HIMI region, and oceanographic data on bathymetry, sea-surface temperature and ocean colour (primary productivity). From the abstract of the referenced paper: We investigated the spatial and temporal distribution of foraging effort by lactating Antarctic fur seals Arctocephalus gazella at Heard Island using satellite telemetry and time-depth recorders. Two principal diving types were identified: 'deep' dives averaging 48.6 m, and 'shallow' dives averaging 8.6 m. Discriminant function analyses were used to assign dives based on their depth and duration. Generalised linear mixed-effects models of night dives (greater than 80% of all dives) indicated both spatial and temporal effects on the distribution of deep and shallow dives. Deep dives were more common in the deeper shelf waters of the Kerguelen Plateau, and these dives predominantly occurred after sunset and before sunrise. In contrast, shallow dives were more common in slope waters on the southeastern margin of the Kerguelen Plateau in the hours either side of local midnight. We suggest that these 2 distinct diving types reflect the targeting of channichthyid (deep dives) and myctophid (shallow dives ) fish, and are indicative of spatial and temporal differences in the availability of these 2 important prey groups. We also identified 3 distinct behavioural dive groups (based on multidimensional scaling of 19 diving and foraging trip parameters) that also differed in their spatial distribution and in their relative importance of deep and shallow dives. The present study provides some of the first evidence that diving strategies are not only influenced by where foraging takes place, but also when. The fields in the campaign_41_tracks.csv file are: campaign_id (the campaign identifier: aadc_campaign_41) animal_id (the identifier of the individual animal) scientific_name (scientific name: Arctocephalus gazella) ptt_id (the identifier of the PTT device on the animal. Note that individual PTT devices were deployed multiple times on different animals) deployment_location (the location of deployment: Spit Bay, Heard Island)) deployment_longitude (longitude of deployment location) deployment_latitude (latitude of deployment location) observation_date (the date of observation, in ISO8601 format yyyy-mm-ddTHH:MM:SSZ. This information is also separated into the year, month, day, etc components) observation_date_year (the year of the observation date) observation_date_month (the month of the observation date) observation_date_day (the day of the observation date) observation_date_hour (the hour of the observation date) observation_date_minute (the minute of the observation date) observation_date_second (the second of the observation date) observation_date_time_zone (the time zone of the observation date) latitude (the latitude of the observed position, in decimal degrees) longitude (the longitude of the observed position, in decimal degrees) location_class (the Argos location class of the observed position: one of (in increasing order of accuracy) B,A,0,1,2,3) trip (the trip number of the animal) at_sea (whether the observed position occurred at sea) complete (whether the complete trip was recorded) The fields in the campaign_41_supplementary.csv file are: animal_id (the identifier of the individual animal) behavioural_dive_group (1 = deep; 2 = shallow-active; 3 = shallow) departure_date (date of departure of the animal on the trip) departure_mass (mass of the animal on departure, in kg) standard_length (standard length of the
Monk Seal Ecosystem Model Data: A Comparison of Ecosystem Structure and Energy Flows of Monk Seal Populations from Laysan Island and French Frigate Shoals in the Northwestern Hawaiian Islands
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To understand various ecosystem dynamics that could explain observed changes and differences in monk seal biomass at French Frigate Shoals (FFS) and Laysan (LAY), Ecopath with Ecosim (EwE) version 6.4.4 modeling software was used to conduct two types of simulations, sensitivity (to understand the system) and hindcast (to evaluate drivers of monk seal population dynamics). EwE models for LAY and FFS were developed and model output was compared between the 2 models. The model output data included in the data sets represent the most important conclusions as reported in the publication from this study. These are (1) the mean of the last 5 years of each perturbation for sensitivity assessment; and (2) hindcast simulations. The first data set was used to understand the main drivers of the trophic structure and energy flow in the ecosystems. Four perturbation scenarios were simulated for a time span of 40 years (2010 through 2049): (a) baseline (compare static structural ecosystem composition between FFS and LAY), (b) altered predator abundance (30% decrease in biomass of main predators in the ecosystem), (c) altered monk seal prey abundance (30% decrease in biomass of main monk seal prey groups, with and without bottomfish to test how much bottomfish accounts for changes, and (d) altered primary productivity (change productivity annually by 10% for both phytoplankton and benthic algae through an annual forcing factor of 0.9 and 1.1 on both groups). The hindcast simulations were performed to evaluate the importance of historical stressors to monk seal population dynamics by selecting the best-fit model for the monk seal biomass time series (1998-2015). Stressors included were (a) fishing with time series based on commercial fishery data, (b) environment with time series of the monthly PDO index as a multiplier for primary productivity, (c) additional mortality simulated with a constant removal of monk seals of varied intensities, and (4) combinations of these 3 stressors (2a and 2c being the most important with regard to the observed trend in monk seal population). Time series observation data of monk seal biomass and benthic bottomfish biomass, as well as catch time series of bank sharks (only for FFS), benthic and demersal bottomfish, bank jacks, and macroheterotrophs (lobsters) were loaded into Ecosim for model fitting. Refer to Weijerman et al (2017) for complete details.
Harbor seal breeding and feeding areas in the Saguenay Fjord, the Estuary and Gulf of St. Lawrence
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Layer that includes the known information on harbor seal breeding and feeding areas in the Saguenay Fjord, the Estuary and Gulf of St. Lawrence according to a literature review of documents produced between 1968 and 2001. Additional Information Harbor seal breeding and feeding areas were produced according to a literature review of the following documents: Andersen, A. et M. Gagnon. 1980. Les ressources halieutiques de l'estuaire du Saint-Laurent. Rapp. can. ind. sci. halieut. aquat., 119: iv + 56 p. Communications personnelles par Fournier, C. 1999. Communications personnelles par Gosselin, J-F-. 1996. Communications personnelles par Gosselin. J.-F. 2001. Communications personnelles par Lavigueur, L. 1996. Dignard, N., R. Lalumière, A. Reed et M. Julien. 1991. Les habitats côtiers du nord-est de la Baie James. Publication hors-série no. 70. Environnement Canada, Service canadien de la faune. 30 p. + carte. Enquête auprès des pêcheurs et agents du MEF et du MPO. 1995. Mansfield, A. W. 1968. Seals and walruses. In: Beals, C.S., ed. Science, History and Hudson Bay. Vol. 1. Ottawa: Queen’s Printer. 501 p.