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HAMMILL, M., V. LESAGE, J.-F. GOSSELIN, 2009. Stock assessment of Northern Quebec (Nunavik) Beluga (Delphinapterus leucas). DFO, Canadian Science Advisory Secretariat, Science Advisory Report, 2009/076, 7 p .
HAMMILL, M., V. LESAGE, J.-F. GOSSELIN, 2009. Évaluation du stock de béluga du nord du Québec (Nunavik) (Delphinapterus leucas). MPO, Secrétariat canadien de consultation scientifique, Avis scientifique, 2009/076, 8 p .
LAWSON, J.W., J.-F. GOSSELIN, 2009. Distribution and preliminary abundance estimates for cetaceans seen during Canada's Marine Megafauna Survey : a component of the 2007 TNASS ; Répartition et estimations préliminaires de l'abondance des cétacés vus lors du relevé de la mégafaune marine du Canada : un élément de l'édition 2007 du TNASS. DFO, Canadian Science Advisory Secretariat, Research Document ; MPO, Secrétariat canadien de consultation scientifique, Document de recherche, 2009/031, 34 p .
The Canadian Department of Fisheries and Oceans (DFO) conducted a large-scale aerial survey of marine megafauna in the northwest Atlantic during the summer of 2007. This is the first systematic effort to provide coverage for much of the eastern Canadian seaboard, and the first in more than two decades to survey the continental shelf along the Labrador and Newfoundland coasts for marine mammals, sea turtles, and other species that intermittently reside near the surface. The Canadian survey is a component of the multinational Trans North Atlantic Sightings Survey (TNASS) that extends from the northeastern U.S.A. to the U.K. The Canadian survey included three initiatives that covered different geographic areas: 1) Labrador Shelf and Grand Banks, 2) Gulf of St. Lawrence and 3) Scotian Shelf. Using a deHavilland Twin Otter and two Cessna 337 Skymaster aircraft, and multiple trained observers, we flew transects at altitudes of 183 and 198 m, respectively, to gather data on the distribution and abundance of a variety of marine megafauna at the ocean surface. Using Distance-based analytical techniques, with covariates such as group size, sighting cue, depth, sea state and sea surface temperature (collected in real time from the Twin Otter), we estimated the abundance and distribution of mysticete species such as blue, fin, humpback, and minke whales, as well as large (sperm, pilot and killer whales) and small (white-beaked, common and Atlantic white-sided dolphins, and harbour porpoises) odontocetes, leatherback sea turtles, sunfish, and basking sharks. Here we present the cetacean data, uncorrected for perception and availability biases. The most abundant species was the common dolphin (54,625; 95 % CI: 35,179-81,773), with lower numbers of other small cetaceans (e.g., Atlantic white-sided dolphin: 5,796; 95nbsp;% CI: 2,261-13,088, and harbour porpoise: 4,955; 95nbsp;% CI: 2,254-8,971). Pilot whales were the most abundant medium-sized species (5,612; 95nbsp;% CI: 3,020-10,867), while there were an estimated 2,149 humpback (95nbsp;% CI: 1,347-3,169), and 1,360 fin whales (95nbsp;% CI: 825-2,241). These abundance estimates are negatively biased due to the lack of correction factors for availability and perception biases. Once corrected, the results will be integrated with concurrent data from other international components of the TNASS to produce the first estimate of abundance in the North Atlantic. These data will greatly improve our understanding of marine populations whose summer home ranges extend across international boundaries and improve our ability to provide advice for these species within Canada
MOSNIER, A., V. LESAGE, J.-F. GOSSELIN, S. LEMIEUX LEFEBVRE, M.O. HAMMILL, T. DONIOL-VALCROZE, 2009. Information relevant to the documentation of habitat use by St. Lawrence Beluga (Delphinapterus leucas), and quantification of habitat quality ; Information pertinente à la documentation de l'utilisation de l'habitat par le béluga du St-Laurent (Delphinapterus leucas) et à la quantification de la qualité de l'habitat. DFO, Canadian Science Advisory Secretariat, Research Document ; MPO, Secrétariat canadien de consultation scientifique, Document de recherche, 2009/098, 39 p .
The current population size and distribution range of St. Lawrence beluga are a fraction of those used historically. Their core distribution is centered on the Saguenay River, and is now located between the Battures-aux-Loups-Marins and Rivière-Portneuf / Rimouski in the Estuary, and Baie Ste-Marguerite in the Saguenay River. Concentration areas outside of this sector vary seasonally, as they did in the 1930s, but are now constrained within a zone located between Battures-aux-Loups-Marins and Sept-Îles / Cloridorme (vs west of Quebec City to Natashquan in the 1930s), with only rare observations in the Baie des Chaleurs. St. Lawrence beluga distribution range is small compared to other beluga populations, and even smaller during summer. The timing and extent of seasonal movements of beluga are likely dictated by at least three key drivers: sea ice, predation risks, and food availability. However, little is known about beluga distribution outside of summer. Currently available knowledge indicates that sex- and agesêcific spatial segregation is typical of the species during summer. The Upper Estuary, where females accompanied by calves and juveniles concentrate, is likely an important habitat for calving and juvenile rearing. Reasons for sexual segregation and habitat characteristics that are critical to the survival of females, juveniles and calves in this sector are unclear. The species also consistently aggregates at certain river mouths during summer, which suggest that they are an essential part of beluga habitat. The functions of these areas are unknown. Several smaller areas where beluga occur on a regular basis or where they spend relatively large proportions of their time exist within their seasonal distribution area, some of which have been identified for the summer period. However the current understanding of the functions and key features of these habitats and of habitat use and movements among these areas by beluga does not allow the assessment of their relative importance for the survival of the population. Given that current distribution is small relative to that used historically, a degradation of key habitat features or a reduction in key habitat availability would probably result in negative effects on recovery. In this context, preserving access to and integrity of areas used currently or historically by a large proportion of the population is considered important for the recovery and future range expansion of the population. Species characteristics such as longevity, social organization and learned behaviours may influence seasonal habitat use, and might delay re-colonization of areas used historically.
HAMMILL, M., V. LESAGE, J.-F. GOSSELIN, 2009. Stock assessment of northern Quebec (Nunavik) beluga (Delphinapterus leucas). DFO, Canadian Science Advisory Secretariat, Science Advisory Report, 2009/016, 13 p .
HAMMILL, M., V. LESAGE, J.-F. GOSSELIN, 2009. Évaluation du stock de bélugas du nord du Québec (Nunavik) (Delphinapterus leucas). MPO, Secrétariat canadien de consultation scientifique, Avis scientifique, 2009/016, 13 p .
GOSSELIN, J.-F., V. LESAGE, M. HAMMILL, 2009. Index estimates of abundance for beluga in eastern Hudson Bay, James Bay and Ungava Bay in Summer 2008 ; Indices de l'abondance des bélugas dans l'est de la baie d'Hudson, la baie James et la baie d'Ungava à l'été 2008. DFO, Canadian Science Advisory Secretariat, Research Document ; MPO, Secrétariat canadien de consultation scientifique, Document de recherche, 2009/006, 25 p .
The management of beluga whales hunted around Nunavik relies on the estimation of abundance of summering stocks, including the endangered Ungava Bay and eastern Hudson Bay stocks. Systematic aerial line-transect surveys to estimate abundance of beluga whales were conducted in James Bay, eastern Hudson Bay and Ungava Bay from 20 July to 28 August 2008. The flights followed east-west lines with a spacing of 18.5 km in all strata except in the central portion of eastern Hudson Bay, a high coverage area where spacing was reduced by half, i.e. 9.3 km, and the stratum was surveyed twice. A total of 279 beluga clusters was detected between perpendicular distances of 120 m to 2880 m from the track line. The hazard-rate model (AIC = 4145.3) with a lower AIC than the half-normal model (AIC = 4156.9) fitted on the ungrouped perpendicular distance distribution provided an effective strip half width of 839 m (cv = 0.08). Abundance indices were not corrected for availability of diving animals nor for the observer perception. A total of 214 clusters with an average size of 3.99 (cv = 0.31) were detected on 4,279 km of lines in James Bay providing an abundance index of 9,292 (cv = 0.64). A single animal was seen over the 1,246 km surveyed in the low coverage area of eastern Hudson Bay for an abundance index of 13 (cv = 1.02). A group of three animals over 82 km provided an abundance index of 15 (cv =1.03) in the Richmond Gulf (Lac Guillaume-Delisle). There were 2.8 times more beluga whales detected on the first survey of the high coverage area of eastern Hudson Bay than on the second survey of the same area, with 107 clusters of an average size of 2.97 (cv = 0.13) and 45 groups with an average size of 2.49 (cv = 0.30) for the first and second survey, respectively. The abundance indices of 1,797 (cv = 0.27) and 657 (cv = 0.38) for the first and second surveys respectively, provided an average, weighted by effort, of 1,237 (cv = 0.46). No whales were seen in the estuaries of the Nastapoka and Little Whale rivers during coastal surveys. The addition of the low coverage area and Richmond Gulf abundance indices to the weighted average of the two surveys in the high coverage area provided an abundance index for the whole eastern Hudson Bay of 1,265 (cv = 0.45). Beluga whales were not detected in Ungava Bay despite the 4,334 km of offshore survey lines, the coastal surveys done between transect lines and the surveys of the estuaries of the Mucalic, False, George and Koksoak Rivers. Beluga whales were also not detected during the coastal survey of the Hudson Strait from Quaqtaq to Inukjuak conducted on 27 and 28 August. This is the fifth visual systematic survey of James Bay and eastern Hudson Bay. Differences in the surface abundance indices among years and between surveys of the high coverage area of eastern Hudson Bay in 2008, illustrate the challenges to estimate the abundance of small populations with clumped distributions.
HAMMILL, M., M.C.S. KINGSLEY, V. LESAGE, J.-F. GOSSELIN, 2009. Abundance of eastern Hudson Bay belugas;Évaluation de labondance des belugas de lest de la Baie dHudson. DFO, Canadian Science Advisory Secretariat, Research Document ; MPO, Secrétariat canadien de consultation scientifique, Document de recherche, 2009/009, 22 p .
In previous assessments a population model incorporating density-dependence as well as information on total catches has been fitted to estimates of beluga whale abundance obtained from aerial surveys. In this assessment, a simple exponential model, incorporating information on catches was also fitted to aerial survey estimates of abundance using Bayesian methods. During initial runs, both approaches gave similar results with an estimated 1985 population of 3,900 obtained using the old model, compared to an estimated 4, 100 obtained using the new model. In 2008, the estimated population has declined to 3,200 and 3,000 using the old and new models respectively. It is recommended that the model fitted using Bayesian methods be used in future assessments because the current population is much reduced from pristine levels, such that the effects of density dependent factors are expected to be limited, and the Bayesian approach presents a more rigorous approach to dealing with uncertainty concerning the dynamics of this population and is based on the full multivariate posterior distribution of the parameter estimates. Traditionally, eastern Hudson Bay beluga whales have been made up 12 %, 21 % and 13 % of the harvests from the Belcher Islands, Hudson Strait and Ungava Bay respectively. More recent analyses suggest that the proportion of eastern Hudson Bay animals in the spring Hudson Strait harvest is less than the proportion obtained from the fall harvest. Overall, the sample proportion of eastern Hudson Bay animals has declined to 9 %. No changes were made to model assumptions because the seasonal distribution of samples collected for DNA analyses did not reflect the seasonal distribution of harvesting.
GOSSELIN, J.-F., 2008. Programme de levés géophysiques dans louest de T.- N.-L. de Nwest Energy Inc. : examen de la section sur les relevés relatifs aux pêches commerciales du rapport dévaluation environnementale. Réponse des sciences (Secrétariat canadien de consultation scientifique), 2008/006, 4 p .
CAMPANA, S.E., J. GIBSON, J.C. BRAZNER, L. MARKS, W. JOWCE, J.-F. GOSSELIN, R.D. KENNEY, P.A. SHELTON, M.R. SIMPSON, J.W. LAWSON, 2008. Status of basking sharks in Atlantic Canada ; État du requin-pèlerin de lAtlantique canadien. DFO, Canadian Science Advisory Secretariat, Research Document ; MPO, Secrétariat canadien de consultation scientifique, Document de recherche, 2008/004, 67 p .
The life history characteristics of basking sharks are inadequately known, and key parameters such as growth rate, natural mortality and fecundity are assumed rather than measured. However, there is little doubt that the species is relatively unproductive and incapable of sustaining even modest mortality rates. Basking shark distribution appears to be restricted to temperatures between 6 and 16 °C, which implies that observations of basking sharks north of Newfoundland and in cold waters elsewhere are likely to be misidentifications of Greenland sharks. There is no directed fishery for basking sharks in Canadian waters. Observed bycatch in foreign fisheries peaked in the 1980s and early 1990s at about 150 mt per year, but has averaged only a few mt annually (i.e., a few individual fish) since 2000. Basking sharks are caught incidentally in domestic fisheries, with most observed bycatches having occurred in groundfish and redfish trawl fisheries. When scaled to total landings, total estimated bycatch has averaged 164 mt annually (corresponding to 164 basking sharks) since 1986. It is possible that bycatch is somewhat larger than estimated, since there has been little in the way of observer coverage of inshore fishing gear such as gill nets and cod traps. None of the existing fish surveys provide an abundance index for basking sharks. An annual index derived from surveys for right whales in the Bay of Fundy indicated a sharp increase in abundance in the 1990s, followed by an equally abrupt decline to 2000. The apparent change in abundance was likely due to changes in distribution due to oceanographic factors, rather than mortality. Estimates of absolute basking shark abundance from aerial surveys of whales in the Bay of Fundy, the Scotian Shelf, Gulf of St. Lawrence and Newfoundland waters suggest numbers of 4,200, 5367 and 558 respectively, for a total of 10,125 in the summer of 2007. These estimates are uncertain due to the number of assumptions that were invoked, but particularly that associated with the proportion of time at the surface. A life table analysis indicated that the intrinsic rate of basking shark population growth (r) in an unfished population is 0.040, which is near the maximum sustainable bycatch mortality. With Fcrit= 0.043, and the annual mean number of discards being 164, and assuming 100 % mortality of discards, this would suggest that the average population size which could support the estimated number of discards Ncrit would be about 4,800. The best available estimate of population size for 2007 is above Ncrit . The Monte Carlo simulation model results indicate a median value of r of 0.032, of Fcrit of 0.035 and of Ncrit of about 5900 sharks, the latter value still being less than the 2007 population size estimate. The results of this population model, which are consistent with the results of the life table analysis, suggest a 23 % probability (about a 1-in-5 chance) that the population is decreasing, although the uncertainty associated with the model inputs is large. This result is more or less consistent with SPUE indices in U.S. waters that show no evidence of a decline since 1979. Given the life history characteristics of the basking shark, high discard mortality associated with bycatch could lead to population collapse. Therefore it is important that basking shark bycatch continue to be monitored and kept to a minimum. Measures to improve species identification accuracy in the observer program, record the numbers of individuals and sex in the bycatch, and to reduce discard mortality would be useful.
GOSSELIN, J.-F., 2007. Tekoil & Gas Corporation Port au Port seismic program screening - review of the EA report. Science response (Canadian Science Advisory Secretariat), 2007/011, 3 p .
HAMMILL, M.O., J.F. GOSSELIN, G.B. STENSON, 2007. Abundance of Northwest Atlantic grey seals in Canadian waters. Pages 99-115 in T. Haug, M. Hammill & D. Olafsdottir (ed.). Grey seals in the North Atlantic and the Baltic. North Atlantic Marine Mammal Commission (NAMMCO Sci. Pub., 6) .
Northwest Atlantic grey seals form a single stock, but for management purposes are often considered as 2 groups. The largest group whelps on Sable Island, 290 km east of Halifax, Nova Scotia. The second group referred to as non-Sable Island or Gulf animals whelps primarily on the pack ice in the southern Gulf of St. Lawrence, with other smaller groups pupping on small islands in the southern Gulf and along the eastern shore of Nova Scotia. Estimates of pup production in this latter group have been determined using mark-recapture and aerial survey techniques. The most recent visual aerial surveys flown during January-February 1996, 1997 and 2000 in the southern Gulf of St Lawrence and along the Eastern Shore resulted in pup production estimates of 11,100 (SE = 1,300), 7,300 (SE = 800) and 6,100 (SE = 900) in 1996, 1997 and 2000 respectively after correcting for births and including counts of pups on small islands. Incorporating information on pup production, reproduction rates and removals into a population model indicates that the Gulf component increased from 15,500 (95 % CI = 14,600-16,300) animals in 1970 to 62,700 (95 % CI = 49,800-67,800) animals by 1996 and then declined to 22,300 (95 % CI = 17,200-28,300) animals in 2000. On Sable Island the population has increased from 4,800 (95 % CI = 4,700-4,900) animals in 1970 to 212,500 (95 % CI = 159,600-276,200) in 2000. The total Northwest Atlantic grey seal population is estimated to number around 234,800 animals in 2000.©2007 North Atlantic Marine Mammal Commission
LESAGE, V., J.-F. GOSSELIN, M. HAMMILL, M.C.S. KINGSLEY, J. LAWSON, 2007. Ecologically and biologically significant areas (EBSAs) in the Estuary and Gulf St. Lawrence : a marine mammal perspective ; Zones d'importance écologique et biologique (ZIEB) pour l'estuaire et le golfe du Saint-Laurent : une perspective des mammifères marins. DFO, Canadian Science Advisory Secretariat, Research Document ; MPO, Secrétariat canadien de consultation scientifique, Document de recherche, 2007/046, 92 p .
The importance of some areas of the Estuary and Gulf of St. Lawrence for the aggregation for marine mammals is a long-recognized phenomenon. In this report, results from three aerial surveys and two satellite-telemetry studies are analysed and combined with results from the existing literature to identify known areas of concentration of marine mammals. The quality of areas of marine mammal concentration and associated functions are assessed against criteria developed to identify Ecologically and Biologically Significant Areas (EBSAs). Based on these criteria, there would be eleven areas of ecological and biological significance for marine mammals: 1) Pointe-des-Monts to Sept-Îles, 2) West of Anticosti, 3) Jacques-Cartier Strait, 4) Strait of Belle-Isle/Mecatina Plateau, 5) Western shelf of Newfoundland, 6) Entrance of St Georges Bay, Newfoundland, 7) Cape Breton Trough, 8) Offshore Gaspé, including the channel of Baie des Chaleurs, 9) North margin of the Laurentian Channel to the south of Anticosti, 10) the St. Lawrence Estuary, and finally, 11) the Shelf of southern Gulf, which would find its importance mainly during the ice-covered period.
HAMMILL, M.O., L.N. MEASURES, J.-F. GOSSELIN, V. LESAGE, 2007. Lack of recovery in St. Lawrence Estuary beluga ; Absence de rétablissement du béluga de l'estuaire du Saint-Laurent. DFO, Canadian Science Advisory Secretariat, Research Document ; MPO, Secrétariat canadien de consultation scientifique, Document de recherche, 2007/026, 19 p .
Estimates of pristine population size and changes in abundance of St. Lawrence Estuary beluga were examined over the period 1866-2006. Overhunting led to a decline in abundance from pristine estimates of 7,800 (SE=600) in 1866, to approximately 1,000 animals in 1985. In spite of almost 30 years of protection from hunting, the St. Lawrence Estuary beluga shows no signs of recovery with a current population of approximately 1,100 (SE=300, 95 % CI=500-1,800, rounded to the nearest 100) animals. A carcass monitoring and necropsy program detects on average 15 carcasses per year, which likely represents a fraction of the total number of deaths in this population. The age structure of adult animal carcasses suggests that adult mortality rates (6.5 %/yr) are similar to what would be expected in a hunted Arctic beluga population (7.0 %/yr) (Burns and Seaman 1985). Estimates of reproductive rates are uncertain, and juvenile animals are underrepresented in the stranding record. Among all animals regardless of age class where cause of death could be determined, parasitic and bacterial infections accounted for 38 % of mortality, followed by cancer (15 %), problems during birth (7 %), and trauma (5 %), while various other factors accounted for 7 %. A paucity of diet information limits attempts to model trophic interactions and habitat requirements. Emigration does not appear to be an important factor, but the loss of only 1-2 animals per year has longer term cumulative impacts that are not beneficial to a small population
GOSSELIN, J.-F., M.O. HAMMILL, V. LESAGE, 2007. Comparison of photographic and visual abundance indices of belugas in the St. Lawrence Estuary in 2003 and 2005 ; Comparaison des indices d'abondance photographique et visuels des bélugas de l'estuaire du Saint-Laurent en 2003 et 2005. DFO, Canadian Science Advisory Secretariat, Research Document ; MPO, Secrétariat canadien de consultation scientifique, Document de recherche, 2007/025, 27 p .
Beluga abundance in the St. Lawrence estuary and Saguenay River was estimated using photographic and visual aerial surveys from the middle of August to early September in 2003 and 2005. Transects covered an area of 5377 km22 in the estuary which corresponds to the main summer concentration of animals. A total of 311 belugas were counted on 1108 photographs taken on 2 September 2003. This count was increased to 312 animals after taking into account that 0.2 % of the area photographed was masked by glare from the sun. This count was also multiplied by an expansion factor of 2.021, to account for the 49.5 % photo coverage of the estuary. Two animals observed in the Saguenay River were added to the final estimate resulting in a surface abundance index of 632 (SE = 116) beluga for the photographic survey in 2003. Systematic visual line transect surveys were completed along every second line of the photographic survey design in order for the whole area to be covered in a single day. Five visual surveys were flown at an altitude of 305 m in 2003, and another 14 surveys completed in 2005, alternated between altitudes of 305 m and 457 m. Distance analyses were done on the truncated distribution of perpendicular distances from the transect line to account for the areas of lower detectability of animals under (re. left truncation) and away (re. right truncation) from the plane. The perpendicular distance distribution was lefttruncated at 99 m and right-truncated at 1569 m in 2003. Left and right truncations were 155 m and 2172 m respectively for the 305 m altitude, and 213 m and 2355 m respectively at the 457 m altitude in 2005. The combined abundance index of 934 (SE = 105) belugas from the visual line transect surveys in 2003 was 48 % higher than the index from the photographic survey. In 2005, the combined abundance index of 675 (SE = 101) for the lower altitude (305 m) was not significantly different (F = 1.79, p = 0.21) than the combined index of 531 (SE = 62) at the higher altitude (457 m). The altitude did not have a significant effect on effective strip half width, estimated cluster size nor encounter rate. Belugas were more frequent and generally more abundant in the Saguenay River in 2005 than in 2003. Animals were detected in the fjord on 13 of the 14 surveys completed with an average of 39 individuals in 2005, compared to 3 out of 6 surveys with an average of 6 individuals in 2003. Although abundance indices from the visual and photographic methods were not significantly different, additional comparisons should be completed to ensure calibration of these two techniques.
STENSON, G.B., M.O. HAMMILL, J. LAWSON, J.-F. GOSSELIN, 2006. 2005 pup production of hooded seals (Cystophora cristata), in the Northwest Atlantic ; Production de nouveaux-nés chez les phoques à capuchon, Cystophora cristata, dans l'Atlantique nord-ouest en 2005. DFO, Canadian Science Advisory Secretariat, Research Document ; MPO, Secrétariat canadien de consultation scientifique, Document de recherche, 2006/067 .
Photographic and visual aerial surveys to determine current pup production of Northwest Atlantic hooded seals (Cystophora cristata) were conducted off Newfoundland, in the Gulf of St. Lawrence in March 2004, and off Newfoundland, in the Gulf and in Davis Strait during 2005. Surveys in the Gulf and Front were corrected for the temporal distribution of births and the mis-identification of pups by readers. In 2004, pup production at the Front was estimated to be 123,862 (SE = 18,640, CV = 0.150). Pup production in the Gulf was estimated to be 1,388 (SE = 298, CV = 0.216) although this is considered to be negatively biased. In 2005, pup production at the Front was estimated to be 107,013 (SE = 7,558, CV = 0.071) while 6,620 (SE = 1,700, CV = 0.258) pups were estimated to have been born in the Gulf. Pup production in the Davis Strait whelping concentration was estimated to be 3,346 (SE = 2,237, CV = 0.668). Combing these areas resulted in an estimated pup production in the three northwest Atlantic whelping areas of 116,900 (SE = 7,918, CV = 6.8 %). Comparison with previous estimates suggests that pup production may have increased since the mid 1980s. However, understanding if abundance has changed is hampered by our lack of understanding of the relationship among whelping areas.
HAMMILL, M.O., J.-F. GOSSELIN, 2005. Pup production of non-Sable Island grey seals, in 2004 ; Production de jeunes phoques gris en dehors de l'Ile de Sable en 2004. DFO, Canadian Science Advisory Secretariat, Research Document ; MPO, Secrétariat canadien de consultation scientifique, Document de recherche, 2005/033, 20 p .
Northwest Atlantic grey seals form a single stock, but are often considered as two groups for management purposes, the Sable Island and Gulf of St Lawrence herds, named for the location of the main pupping locales. In 2004, visual strip transect surveys were flown over the whelping patches on the ice in the Gulf of St. Lawrence and counts were completed at islands in the Gulf and along the Nova Scotia Eastern Shore. Pup production estimate for visual strip transect surveys, after correcting for timing of births, was 10,145 (SE=1,930) from surveys flown on 21, 22 and 23 January. Surveys flown on 30 and 31 January and 2 February produced an estimate, corrected for timing of births of 13,819 (SE=1,565). Another 3,204 (SE=76.8) births were estimated on the islands, after correcting for timing of births. Total Gulf and Nova Scotia Eastern Shore pup production in 2004 is estimated at 15,900 (SE=1,200) animals.
HAMMILL, M.O., V. LESAGE, J.-F. GOSSELIN, 2005. Abundance of Eastern Hudson Bay belugas ; Évaluation de labondance des bélugas de lest de la Baie dHudson. DFO, Canadian Science Advisory Secretariat, Research Document ; MPO, Secrétariat canadien de consultation scientifique, Document de recherche, 2005/010, 19 p .
A population model was used to follow changes in the eastern Hudson Bay (EHB) beluga population since 1985. The model incorporating harvest information was fitted to aerial survey data by adjusting initial population size and estimates of the number of animals struck, but not reported. The number of belugas in eastern Hudson Bay has declined from approximately 4,200 (SE=300) animals in 1985 to 3,100 (SE=800) in 2004. In order to achieve this fit, 1.67 animals are estimated to be lost for every animal reported in the harvest. Overall harvest rates have declined under the current management plan. The rate of decline in this population has also likely slowed. To halt the decline, a reported harvest rates must be reduced to 61 animals (replacement yield)
YUNKER, G.B., M.O. HAMMILL, J.-F. GOSSELIN, D.M. DION, J.F. SCHREER, 2005. Foetal growth in north-west Atlantic grey seals (Halichoerus grypus). J. Zool., 265(4): 411-419 .
The timing of implantation, duration of gestation and energetic costs associated with ftal development were examined in the north-west Atlantic grey seal Halichoerus grypus. Implantation occurs between 5 and 8 May. Active gestation lasts for 259-272 days and the duration of suspended development is 78-91 days. The duration of active gestation was slightly shorter among north-east Atlantic grey seals (238-255 days), while suspended development was longer (95-112 days). The rate of ftal growth increased in August, 3 months after attachment, until mid December when it began to slow once again, c. 1 month before parturition. During August, the placenta to ftus mass ratio was about 0.3, but declined to around 0.07 near birth. Ftal energy density increased rapidly reaching asymptotic levels of 22.6 kJ g-1 (dryweight) 3-4 months after implantation. Energy density of the placenta changed only slightly throughout gestation increasing from c. 21.7 to 23 kJ g-1 (dry weight) by the autumn. Energy costs associated with foetal growth are c. 648 MJ.©2005 The Zoological Society of London
STENSON, G.B., M.O. HAMMILL, J. LAWSON, J.-F. GOSSELIN, T. HAUG, 2005. 2004 pup production of harp seals, Pagophilus groenlandicus, in the Northwest Atlantic ; Production de nouveau nés du phoque du Groenland (Pagophilus groenlandicus) dans l'Atlantique Nord Ouest en 2004. DFO, Canadian Science Advisory Secretariat, Research Document ; MPO, Secrétariat canadien de consultation scientifique, Document de recherche, 2005/037, 34 p .
Photographic and visual aerial surveys to determine current pup production of northwest Atlantic harp seals were conducted off Newfoundland and Labrador (the "Front"), and in the Gulf of St. Lawrence during March 2004. Surveys of four whelping concentrations were conducted between 5 and 18 March resulting in estimated pup production of 640,800 (SE=46,900, CV=7.3 %) at the Front, 89,600 (SE=22,500, CV=25.4 %) in the northern Gulf, and 261,000 (SE=25,700, CV=9.8 %) in the southern Gulf (Magdalen Island), for a total of 991,400 (SE=58,200, CV=5.9 %). Surveys were corrected for the temporal distribution of births and the mis-identification of pups by readers. Comparison with previous estimates indicates that pup production has not changed since 1999, likely due to the increased hunting of young animals which began in the mid 1990s.
GOSSELIN, J.-F., 2005. Abundance indices of belugas in James Bay and eastern Hudson Bay in summer 2004 ; Indices d'abondance des bélugas dans la baie James et l'est de la baie d'Hudson à l'été 2004. DFO, Canadian Science Advisory Secretariat, Research Document ; MPO, Secrétariat canadien de consultation scientifique, Document de recherche, 2005/011, 24 p .
Belugas harvested around Nunavik (Northern Quebec) come from different summer stocks, including the endangered Ungava Bay and eastern Hudson Bay stocks. Systematic aerial linetransect surveys were conducted in James Bay and eastern Hudson Bay from 7 August to 1 September 2004. From perpendicular truncation distances of 100 m to 1400 m from the trackline, 250 and 104 groups of belugas were detected over 5288 km and 7987 km of lines flown in James Bay and eastern Hudson Bay respectively. The hazard-rate model was used to estimate effective strip widths of 817 m (CV = 8.9 %) in James Bay and 622 m (CV = 11.2 %) in eastern Hudson Bay. The weighted average of the expected cluster size at maximum detection from observations with perpendicular distances and the average of clusters with no perpendicular measurement was used to provide the expected cluster size of 1.8 (CV = 18.0 %) in James Bay. An average cluster size of 2.1 (CV = 12.0 %) was used to estimate density and abundance in eastern Hudson Bay. Five belugas detected in the Moose River were added to the estimated number of animals at the surface in the systematic survey to provide an abundance index of 3998 (95 % CI: 2379 - 6721) in James Bay. Five belugas in the Nastapoka estuary considered to have been missed during the systematic survey were added to estimated number at the surface in the offshore area to provide an index of 2045 (95 % CI: 1052 - 3982) in eastern Hudson Bay. The 2004 abundance index in eastern Hudson Bay is 44 % higher than in 2001, corresponding to a 12 % annual increase, which is much higher that normally accepted for beluga populations. The variation between survey estimates illustrates the difficulty of estimating the abundance of small clumped populations. As well, environmental conditions (ice extent and Beaufort conditions) might have influenced the number of belugas in eastern Hudson Bay, and changes in survey protocol (reduction of altitude, delays, different observer teams) might have affected the sampling efficiency between years. Combined with evidence of whale movement between regions, the population estimation of the 2004 survey and its large uncertainty should be considered with caution when used for management purposes
GOSSELIN, J.-F., J. LAWSON, 2004. Distribution and abundance indices of marine mammals in the Gully and two adjacent canyons of the Scotian Shelf before and during nearby hydrocarbon seismic exploration programmes in April and July 2003 ; Distribution et indices d'abondance des mammifères marins dans le Goulet et deux canyons adjacents du plateau néo-écossais avant et pendant des programmes d'exploration sismiques voisins en avril et juillet 2003. DFO, Canadian Science Advisory Secretariat, Research Document ; MPO, Secrétariat canadien de consultation scientifique, Document de recherche, 2004/133, 28 p .
The Sable Island Gully is a submarine canyon on the eastern Scotian Shelf that provides habitat to a wide diversity of species including the endangered northern bottlenose whale (Hyperoodon ampullatus). Seismic surveys for hydrocarbons were conducted in waters adjacent to the Gully in the spring and summer of 2003. An effort to evaluate marine mammal species composition, distribution, and abundance within the Gully prior to, and during these seismic surveys was coordinated by the Centre for Offshore Oil and Gas Environmental Research (COOGER). Vessel-based line transect surveys were conducted in the Gully over areas of 1565 km 2 and 2218 km 2 before and during seismic operations and over an area of 1851 km 2 covering two adjacent marine canyons (Shortland and Haldimand Canyons) only before seismic activities. Visual detections were accomplished by a team of two observers and a recorder from a location 7 m above the sea aboard a research vessel, 37 m in length, following a saw-tooth transect design at 18.5 km/h. In the Gully, 148 km were surveyed on 30 April prior to seismic data acquisition, and a total of 395 km were surveyed on 8, 10 and 11 July while seismic operations were underway. In the Shortland and Haldimand Canyons, 175 km of lines were surveyed on 1 May. Seven species of marine mammals in 45 groups (84 individuals) were identified in both areas in spring, with northern bottlenose whale being the most abundant of detected species with three groups (13 individuals) in the Gully and one group (5 individuals) in Shortland Canyon. In July, 11 species in 207 groups (563 individuals) were identified in the Gully, where northern bottlenose whales (8 groups, 35 individuals) were outnumbered by common dolphins (Delphinus delphis), pilot whales (Globicephala sp.) and grey seals (Halichoerus grypus). Four species of large whales were identified during the surveys, with fin (Balaenoptera physalus) and sperm whales (Physeter macrocephalus) detected in both spring and summer, and blue (Balaenoptera musculus) and humpback whales (Megaptera novaeangliae) detected only in summer. Estimated abundance, not corrected for animals missed on the track-line (i.e. g(0)=1), of northern bottlenose whales in the Gully were 44 (95 % CI: 19-105) in April and 63 (95 % CI: 20-230) in July. Fin, humpback, sperm and blue whales, combined into a large whale category for the Gully, were estimated to number 89 (95 % CI: 31-254) in April and 114 (95 % CI: 61-214) in July. Abundance in the Gully of common, Atlantic white-sided (Lagenorhynchus acutus), bottlenose dolphins (Tursiops truncatus), and harbour porpoises (Phocoena phocoena), combined as one group, was estimated at 121 (95 % CI: 21-686) in April and 1763 (95 % CI: 849-3659) in July. Changes in composition, distribution and abundance of marine mammal species between the spring and the summer surveys most likely represent seasonal variation rather than an effect of seismic activity. Since we had to use a uniform model for density estimation of northern bottlenose whales, and did not correct for sighting availability and detection on the track-line for any species, the densities and abundances presented here are likely underestimated.
Systematic aerial line-transect surveys of beluga whales, Delphinapterus leucas, were conducted in James Bay, eastern Hudson Bay, and Ungava Bay from 14 August to 3 September 2001. An estimated 7901 (SE = 1744) and 1155 (SE = 507) belugas were present at the surface in the offshore areas of James Bay and Hudson Bay, respectively. An additional 39 animals were observed in estuaries during the coastal survey, resulting in an index estimate of 1194 (SE = 507) in eastern Hudson Bay. No belugas were observed in Ungava Bay. Observations from systematic surveys conducted in 1993 and 2001 were analyzed using both line-transect and strip-transect methods to allow comparisons with the strip-transect survey conducted in 1985. A population model incorporating harvest information and fitted to the aerial survey data indicates that the number of belugas in eastern Hudson Bay has declined by almost half because of high harvest levels. Subsistence harvest levels must be reduced significantly if this population is to recover.©2004 The Arctic Institute of North America
STENSON, G.B., L.P. RIVEST, M.O. HAMMILL, J.-F. GOSSELIN, B. SJARE, 2003. Estimating Pup Production of Harp Seals, Phoca groenlandica, in the Northwest Atlantic. Mar. Mamm. Sci., 19: 141-160 .
GOSSELIN, J.-F., V. LESAGE, M.O. HAMMILL, H. BOURDAGES, 2002. Abundance indices of beluga in James Bay, eastern Hudson Bay and Ungava Bay in summer 2001 ; Indices d'abondance de bélugas dans la baie James, l'est de la baie d'Hudson et la baie d'Ungava durant l'été 2001. DFO, Canadian Science Advisory Secretariat, Research Document ; MPO, Secrétariat canadien de consultation scientifique, Document de recherche, 2002/042, 28 p .
Aerial systematic line transect surveys of beluga whales, Delphinapterus leucas, were conducted in James Bay, eastern Hudson Bay and Ungava Bay from 14 August to 3 September 2001. Coastal surveys were conducted on 28 August in Eastern Hudson Bay, on 4 September in Ungava Bay and on 5 September in Hudson Strait and along the northeastern Hudson Bay coast. An effective strip width of 638 m was estimated from the 717 beluga observed on east-west lines in James Bay (557 beluga) and eastern Hudson Bay(160 beluga). An estimated 7,901 (SE = 1,744) and 1,155 (SE = 507) beluga were present at the surface in the offshore areas of James Bay and Hudson Bay respectively. An additional 39 animals were observed in estuaries during the coastal survey resulting in an index estimate of 1,194 (SE = 507) in eastern Hudson Bay. No beluga were observed in Ungava Bay. Three beluga were observed along the coast near Salluit. Observations from the 1993 and 2001 systematic surveys were analysed using both line transect and strip transect methods to allow comparisons with the strip transect survey conducted in 1985. From 1985 to 2001, the number of beluga summering in James Bay increased fourfold, while numbers in eastern Hudson Bay have declined by almost half.
GOSSELIN, J.-F., L. MEASURES, 2002. La population de bélugas de l'estuaire. Saint-Laurent Vision 2000 (Suivi de l'état du Saint-Laurent, 15) 6 p. .
GOSSELIN, J.-F., L. MEASURES, 2002. Beluga whale population of the estuary. St. Lawrence Vision 2000 (Monitoring the state of the St. Laurence River, 15) 6 p. .
GOSSELIN, J.-F., V. LESAGE, A. ROBILLARD, 2001. Population index estimate for the beluga of the St. Lawrence River Estuary in 2000. DFO, Canadian Science Advisory Secretariat, Research Document ; MPO, Secrétariat canadien de consultation scientifique, Document de recherche, 2001/049, 21 p .
Abundance of beluga in the St. Lawrence estuary was estimated from an aerial survey flown on 28 August 2000. Two fixed-wing aircrafts equipped with 9"x9" format mapping cameras flew 52 strip transects across the Estuary between Baie St-Paul and Rimouski for a total survey coverage of 49.3%. A visual survey to count beluga in the Saguenay River was flown at the same time. In the estuary, 453 (SE = 54) beluga were estimated to be at the surface between Kamouraska and Les Escoumins after correction for sun glare, and 6 beluga were counted downstream of Baie Ste-Marguerite in the Saguenay River. A 15 % correction factor was applied to the estimated number of beluga at the surface in the estuary to account for beluga missed because they were underwater. Adding the Saguenay River count to the corrected estimate resulted in an index count of 527 (SE = 62). This corrected index used in trend analysis along with 5 equivalent survey indices obtained between 1988 and 1997, revealed no significant changes in abundance of beluga in the St. Lawrence estuary since 1988.
HAMMILL, M., J.-F. GOSSELIN, 2000. Les secrets de Salmo : déclin de l'abondance du saumon, les phoques sont-ils à blâmer?. Saumons illimités, Automne : 13-15 .
STENSON, G.B., M.O. HAMMILL, J.F. GOSSELIN, B. SJARE, 2000. 1999 Pup production of harp seals, Phoca groenlandica, in the Northwest Atlantic. DFO, Canadian Stock Assessment Secretariat, Research Document ; MPO, Secrétariat canadien de consultation scientifique, Document de recherche, 2000/080, 35 p .
To determine current pup production of Northwest Atlantic harp seals, aerial surveys of the whelping (pupping) concentrations off southern Labrador and/or eastern Newfoundland ("Front") and in the northern and southern Gulf of St. Lawrence ("Gulf") were conducted during March 1999. A total of 5 concentrations were located, two at the Front, one in the northern Gulf and two closely spaced groups in the southern Gulf (which later joined into one). The northern concentrations were located near traditional areas while the southern Gulf group formed up on suitable ice in the traditional areas but drifted southward towards Prince Edward Island where they coalesced prior to the survey. Photographic surveys were conducted on all concentrations between 14 and 24 March while a visual survey was made of the southern Gulf concentrations on 14 March. Photographic counts were corrected for misidentified pups by comparing multiple readings of photographs made by two or more readers. Survey estimates were also corrected for pups absent from the ice at the time of the survey using the occurrence of distinct age-related developmental stages. Multiple estimates were available for two of the whelping concentrations. Pup production was estimated to be 739,100 (SE=96,300) at the Front, 82,600 (SE=22,500) in the northern Gulf and 176,200 (SE=25,400) in the southern Gulf (Magdalen Island) for a total of 997,900 (SE=102,100).
GOSSELIN, J.-F., L.N. MEASURES, 1997. Redescription of Filaroides (Parafilaroides) gymnurus (Railliet, 1899) (Nematoda : Metastrongyloidea), with comments on other species in pinnipeds. Can. J. Zool., 75(3): 359-370 .
The species Filaroides (parafilaroides) gymnurus (Railliet, 1989) Anderson, 1978 is redescribed, based on examination of mature fifth-stage specimens from wild infected ringed seals (Phoca hispida), harp seals (Phoca groenlandica), harbour seals (Phoca vitulina), and grey seals (Halichoerus grypus) collected in eastern and arctic Canadian waters. Mature specimens of Filaroides (Parafilaroides) hispidus Kennedy, 1986 from ringed seals and grey seals were also examined. Comparison of these worms with museum specimens and the literature led to a review of species in the subgenus Parafilaroides (Dougherty, 1946) Anderson, 1978. Filaroides (Parafilaroides) gymnurus (Railliet, 1899) Anderson, 1978, F. (P.) decorus (Dougherty and Herman, 1947) Anderson, 1978, F. (P.) hydrurgae (Mawson, 1953) Kennedy, 1986 and F. (P.) hispidus Kennedy, 1986 are recognized as valid species. Filaroides (Parafilaroides) arcticus (Delyamure and Alekseev, 1966) Kennedy, 1986 and F. (P.) krascheninnikovi (Yarakhno and Skrjabin, 1971) Kennedy, 1986 are synonymized with F. (P.) gymnurus (Railliet, 1899) Anderson, 1978. Filaroides (Parafilaroides) caspicus (Kurochkin and Zablotsky, 1958) Kennedy, 1986 is considered a species inquirenda©1997 National Research Council Canada
MEASURES, L.N., J.-F. GOSSELIN, E. BERGERON, 1997. Heartworm, Acanthocheilonema spirocauda (Leidy, 1858), infections in Canadian phocid seals. Can. J. Fish. Aquat. Sci., 54: 842-846 .
Heartworm, Acanthocheilonema spirocauda, was observed in four of six species of seals (19 seals of 701) examined from the Atlantic coast of Canada including the Canadian Arctic. Fourteen of 221 ringed seals (Phoca hispida), 2 of 18 harbour seals (Phoca vitulina), 2 of 186 harp seals (Phoca groenlandica) (new host record), and the only hooded seal examined (Cystophora cristata) were infected with A. spirocauda. Intensity of infection ranged from 1 to 31. Infected seals were age 0 to 14, but 8 of the 14 infected ringed seals were age 0. All worms were found in the right ventricle except in three cases. In one ringed seal and one harp seal, worms were found in the pulmonary artery, and in another ringed seal, worms were found deep within the lungs. No infections were found in grey seals (Halichoerus grypus) (N=271) or bearded seals (Erignathus barbatus) (N=4). Heartworm is primarily a parasite of young seals. Its apparent absence in grey seals examined to date suggests either that a much larger sample of young seals from a broad geographic area is needed or that grey seals are refractory to infection or do not survive infections.
HAMMILL, M.O., J.F. GOSSELIN, 1995. Grey seal (Halichoerus grypus) from the Northwest Atlantic : female reproductive rates, age at first birth, and age of maturity in males. Can. J. Fish. Aquat. Sci., 52: 2757-2761 .
GOSSELIN, J.-F., F. BOILY, 1994. Unusual southern occurence of a juvenile bearded seal, Erignathus barbatus, in the St. Lawrence Estuary, Canada. Mar. Mamm. Sci., 10: 480-483 .
MEASURES, L.N., J.-F. GOSSELIN, 1994. Helminth parasites of ringed seal, Phoca hispida, from northern Quebec, Canada. J. Helminthol. Soc. Wash., 61: 240-244 .
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