Le Parc Marin Saguenay–Saint-Laurent : processus océanographiques à la base de ce site unique d’alimentation des baleines du Nord-Ouest Atlantique

Les résultats d’un programme de recherche écosystémique, mené dans le Parc Marin Saguenay–Saint-Laurent, sont résumés pour comprendre les processus fondamentaux responsables de l’existence de ce site traditionnel d’alimentation des baleines, découvert par les baleiniers basques il y a 450 ans. Un ensemble de processus pérennes maintient les proies des baleines agrégées à la tête du chenal principal du plateau continental de l’est du Canada. Quel est-il ?Cette région est le site de la plus riche agrégation de krill documentée à ce jour pour le nord-ouest Atlantique. Les mécanismes responsables sont le pompage, la rétention et la concentration du krill adulte provenant du golfe du Saint‑Laurent par l’énergique circulation estuarienne du Saint‑Laurent. Les courants de marée remontant le long des talus des chenaux et des bancs sous-marins interagissent avec le comportement vertical du krill adulte et le concentrent. Ce processus est plus intense à la tête des chenaux où l’« upwelling » d’origine tidale (remontée d’eau profonde due à la marée) est amplifié. Il est rehaussé par endroits par l’« upwelling » côtier dû au vent. La circulation moyenne transporte les riches essaims de krill le long des rebords des bassins. À l’embouchure de l’estuaire, le krill, concentré à la marge de la grande gyre cyclonique (tourbillon anti-horaire) d’Anticosti, est injecté dans l’estuaire maritime du côté nord, lorsque les conditions de circulation sont favorables. L’étroit courant de talus remontant l’estuaire l’emporte alors vers la zone d’agrégation de krill du parc marin. Des poissons pélagiques fourragers, tel le capelan, se concentrent aussi à la tête du chenal et à l’entrée du fjord sous l’action de l’« upwelling », des courants de marée et des fronts, qui aussi concentrent et augmentent la disponibilité de leurs proies. Ils contribuent à nourrir les baleines et les oiseaux marins.Des caractéristiques océanographiques spéciales, rarement réunies ailleurs, se combinent dans le parc marin pour créer ce site d’alimentation des baleines. Les pressions anthropiques et les changements climatiques sont les principales menaces à sa préservation pour les prochains siècles.The results from an ecosystem research program are summarized. It was conducted in the Saguenay–St. Lawrence Marine Park to understand the basic processes responsible for the existence of this traditional whale feeding ground, discovered by the Basques whalers 450 years ago. Persistent processes maintain aggregated whale preys at the head of the main deep-water channel of eastern Canada continental shelf. What are they?This site is the richest krill aggregation yet documented in the northwest Atlantic. The mechanisms responsible are the pumping, retention and concentration of adult krill from the Gulf of St. Lawrence, by the strong estuarine circulation of the St. Lawrence. Tidal currents upwelling along channels and bank slopes combine with adult krill vertical behavior and concentrate it. This process is more intense at the head of the channels where tidal upwelling is amplified. It is locally enhanced by wind-driven coastal upwelling. The mean circulation transports the rich krill patches along the slopes of the basins. At the mouth of the estuary, the concentrated krill at the margin of the large cyclonic Anticosti gyre (counterclockwise) is injected into the lower estuary on the northern side, under favorable circulation conditions. The narrow slope current flowing upstream along the estuary then imports it towards the Marine Park krill aggregation zone. Pelagic forage fish such as capelin also aggregate at the channel head and entrance of the fjord under the action of the tidal upwelling currents and fronts, which also concentrate and enhance the availability of their preys. They contribute to the feeding of whales and sea birds.Special oceanographic features, seldom found elsewhere, combine in the Marine Park to generate this whale feeding ground. Anthropogenic pressures and climate change are the main threats to its preservation for the next centuries

Cross Recurrence Plot Analysis Based Method For TDOA Estimation Of Underwater Acoustic Signals

International audience—In this paper, we propose to use cross recurrence plot analysis (CRPA) to estimate the time-difference of arrival (TDOA) of underwater acoustic signals arriving on an array of hydrophones. Instead of considering the signal as a whole to estimate the TDOA, like classical methods do, we first detected the series of samples that look alike on each pair of hydrophones of the array by using cross-recurrence plot analysis. The TDOA is then estimated by relying only on these common sample series. The TDOA estimator is based on quantification measures specifically designed for CRPA. The proposed method is successfully validated on real data containing frequency-modulated sounds from beluga whales

Shipping noise in whale habitat: Characteristics, sources, budget, and impact on belugas in Saguenay-St. Lawrence Marine Park hub

WOSInternational audienceA continuous car ferry line crossing the Saguenay Fjord mouth and traffic from the local whale-watching fleet introduce high levels of shipping noise in the heart of the Saguenay-St. Lawrence Marine Park. To characterize this noise and examine its potential impact on belugas, a 4-hydrophone array was deployed in the area and continuously recorded for five weeks in May-June 2009. The source levels of the different vessel types showed little dependence on vessel size or speed increase. Their spectral range covered 33 dB. Lowest noise levels occurred at night, when ferry crossing pace was reduced, and daytime noise peaked during whale-watching tour departures and arrivals. Natural ambient noise prevailed 9.4% of the time. Ferry traffic added 30-35 dB to ambient levels above 1 kHz during crossings, which contributed 8 to 14 dB to hourly averages. The whale-watching fleet added up to 5.6 dB during peak hours. Assuming no behavioral or auditory compensation, half of the time, beluga potential communication range was reduced to less than 30% of its expected value under natural noise conditions, and to less than 15% for one quarter of the time, with little dependence on call frequency. The echolocation band for this population of belugas was also affected by the shipping noise

Whistle source levels of free-ranging beluga whales in Saguenay-St. Lawrence marine park

International audienceWild beluga whistle source levels (SLs) are estimated from 52 three-dimensional (3D) localized calls using a 4-hydrophone array. The probability distribution functions of the root-mean-square (rms) SL in the time domain, and the peak, the strongest 3-dB, and 10-dB SLs from the spectrogram, were non-Gaussian. The average rms SL was 143.8 +- 6.7 dB re 1microPa at 1m. SL spectral metrics were, respectively, 145.8 +- 8 dB, 143.2 +-7.1 dB, and 138.5 +-6.9 dB re 1 microPa. 1microPa / Hz at 1m

Arctic underwater noise transients from sea ice deformation: characteristics, annual time series, and forcing in Beaufort Sea

International audienceA 13-month time series of Arctic Ocean noise from the marginal ice zone of Eastern Beaufort Sea is analyzed to detect under-ice acoustic transients isolated from ambient noise with a dedicated algorithm. Noise transients due to ice cracking, fracturing, shearing, and ridging are sorted out into 3 categories: broadband impulses, frequency modulated (FM) tones, and high-frequency broadband noise. Their temporal and acoustic characteristics over the 8-month ice covered period, from November 2005 to mid-June 2006, are presented and their generation mechanisms are discussed. Correlations analyses showed that the occurrence of these ice transients responded to large-scale ice motion and deformation rates forced by meteorological events, often leading to opening of large-scale leads at main discontinuities in the ice cover. Such a sequence, resulting in the opening of a large lead, hundreds by tens km in size, along the margin of landfast ice and multiyear ice plume in Beaufort-Chukchi seas is detailed. These ice transients largely contribute to the soundscape properties of the Arctic Ocean, for both its ambient and total noise components. Some FM tonal transients can be confounded with marine mammal songs, especially when they are repeated, with periods similar to wind generated waves

Passive acoustic detection and localization of whale: effects of shipping noise in Saguenay - St Lawrence marine park

WOSInternational audienceThe performance of large-aperture hydrophone arrays to detect and localize blue and fin whales’ 15–85Hz signature vocalizations under ocean noise conditions was assessed through simulations from a normal mode propagation model combined to noise statistics from 15960h of recordings in Saguenay–St. Lawrence Marine Park. The probability density functions of 2482 summer noise level estimates in the call bands were used to attach a probability of detection/masking to the simulated call levels as a function of whale depth and range for typical environmental conditions. Results indicate that call detection was modulated by the calling depth relative to the sound channel axis and by modal constructive and destructive interferences with range. Masking of loud infrasounds could reach 40% at 30km for a receiver at the optimal depth. The 30dB weaker blue whale D-call were subject to severe masking. Mapping the percentages of detection and localization allowed assessing the performance of a six-hydrophone array under mean- and low-noise conditions. This approach is helpful for optimizing hydrophone configuration in implementing passive acoustic monitoring arrays and building their detection function for whale density assessment, as an alternative to or in combination with the traditional undersampling visual methods

La Marche mondiale des femmes de l’an 2000

Pour réaliser la Marche mondiale des femmes de l’an 2000 (MMF), des femmes provenant des quatre coins du globe se sont regroupées dans un mouvement et ont tenu diverses activités, selon les réalités de leurs pays. L’organisation de la Marche prévoyait de grandes actions communes pour démontrer et développer la solidarité des femmes, obtenir des appuis dans la société civile, dénoncer les oppressions auprès des décideurs et enfin, tenter de faire des gains concrets pour les femmes à partir d’un certain nombre de revendications. Les actrices ont agi à plusieurs niveaux: international, national, provincial et local. Les stratégies utilisées ont été de trois ordres: l’éducation populaire et la mobilisation, le lobbying, et l’organisation en réseaux. La monographie s’arrête aux aspects particulièrement bien réussis de la lutte et aux difficultés rencontrées. Sont également suggérées quelques pistes de renouvellement de l’action, si celle-ci devait être répétée

Performance of a Deep Neural Network at Detecting North Atlantic Right Whale Upcalls

Passive acoustics provides a powerful tool for monitoring the endangered North Atlantic right whale ($Eubalaena$ $glacialis$), but robust detection algorithms are needed to handle diverse and variable acoustic conditions and differences in recording techniques and equipment. Here, we investigate the potential of deep neural networks for addressing this need. ResNet, an architecture commonly used for image recognition, is trained to recognize the time-frequency representation of the characteristic North Atlantic right whale upcall. The network is trained on several thousand examples recorded at various locations in the Gulf of St.\ Lawrence in 2018 and 2019, using different equipment and deployment techniques. Used as a detection algorithm on fifty 30-minute recordings from the years 2015-2017 containing over one thousand upcalls, the network achieves recalls up to 80%, while maintaining a precision of 90%. Importantly, the performance of the network improves as more variance is introduced into the training dataset, whereas the opposite trend is observed using a conventional linear discriminant analysis approach. Our work demonstrates that deep neural networks can be trained to identify North Atlantic right whale upcalls under diverse and variable conditions with a performance that compares favorably to that of existing algorithms.Comment: 11 pages, 9 figures, 2 tables, submitted to JASA on Dec 22, 2019, as part of a special issue on The Effects of Noise on Aquatic Life; resubmitted on Feb 29, 2020, upon minor revisions and improved SNR estimate

Molecular characterization and phylogenetic analysis of small ruminant lentiviruses isolated from Canadian sheep and goats

<p>Abstract</p> <p>Background</p> <p>Small Ruminant Lentiviruses (SRLV) are widespread in Canadian sheep and goats and represent an important health issue in these animals. There is however no data about the genetic diversity of Caprine Arthritis Encephalitis Virus (CAEV) or <it>Maedi Visna </it>Virus (MVV) in this country.</p> <p>Findings</p> <p>We performed a molecular and phylogenetic analysis of sheep and goat lentiviruses from a small geographic area in Canada using long sequences from the <it>gag </it>region of 30 infected sheep and 36 infected goats originating from 14 different flocks. Pairwise DNA distance and phylogenetic analyses revealed that all SRLV sequences obtained from sheep clustered tightly with prototypical <it>Maedi visna </it>sequences from America. Similarly, all SRLV strains obtained from goats clustered tightly with prototypical US CAEV-Cork strain.</p> <p>Conclusions</p> <p>The data reported in this study suggests that Canadian and US SRLV strains share common origins. In addition, the molecular data failed to bring to light any evidence of past cross species transmission between sheep and goats, which is consistent with the type of farming practiced in this part of the country where single species flocks predominate and where opportunities of cross species transmissions are proportionately low.</p

Variations in the NBN/NBS1 gene and the risk of breast cancer in non-BRCA1/2 French Canadian families with high risk of breast cancer

<p>Abstract</p> <p>Background</p> <p>The Nijmegen Breakage Syndrome is a chromosomal instability disorder characterized by microcephaly, growth retardation, immunodeficiency, and increased frequency of cancers. Familial studies on relatives of these patients indicated that they also appear to be at increased risk of cancer.</p> <p>Methods</p> <p>In a candidate gene study aiming at identifying genetic determinants of breast cancer susceptibility, we undertook the full sequencing of the <it>NBN </it>gene in our cohort of 97 high-risk non-<it>BRCA1 </it>and -<it>BRCA2 </it>breast cancer families, along with 74 healthy unrelated controls, also from the French Canadian population. <it>In silico </it>programs (ESEfinder, NNSplice, Splice Site Finder and MatInspector) were used to assess the putative impact of the variants identified. The effect of the promoter variant was further studied by luciferase gene reporter assay in MCF-7, HEK293, HeLa and LNCaP cell lines.</p> <p>Results</p> <p>Twenty-four variants were identified in our case series and their frequency was further evaluated in healthy controls. The potentially deleterious p.Ile171Val variant was observed in one case only. The p.Arg215Trp variant, suggested to impair NBN binding to histone γ-H2AX, was observed in one breast cancer case and one healthy control. A promoter variant c.-242-110delAGTA displayed a significant variation in frequency between both sample sets. Luciferase reporter gene assay of the promoter construct bearing this variant did not suggest a variation of expression in the MCF-7 breast cancer cell line, but indicated a reduction of luciferase expression in both the HEK293 and LNCaP cell lines.</p> <p>Conclusion</p> <p>Our analysis of <it>NBN </it>sequence variations indicated that potential <it>NBN </it>alterations are present, albeit at a low frequency, in our cohort of high-risk breast cancer cases. Further analyses will be needed to fully ascertain the exact impact of those variants on breast cancer susceptibility, in particular for variants located in <it>NBN </it>promoter region.</p