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Bibliographie de l'Institut Maurice-Lamontagne

Mammifères marins - Baleines / Balaenoptera physalus / Rorqual commun

CHION, C., P. LAMONTAGNE, S. TURGEON, L. PARROTT, J.-A. LANDRY, D.J. MARCEAU, C.C.A. MARTINS, R. MICHAUD, N. MÉNARD, G. CANTIN, S. DIONNE, 2011. Eliciting cognitive processes underlying patterns of human-wildlife interactions for agent-based modelling. Ecol. Model., 222(14): 2213--2226.

[Résumé disponible seulement en anglais]
Integrating humans in our perception of ecosystems is of critical importance to adequately protect natural resources. This poses the challenge of understanding human decision making in the context of decisions potentially threatening nature’s integrity. We developed a spatially explicit agent-based model that simulates commercial whale-watching vessel movements based on a representation of the captains’ decision making process when observing marine mammals in and around the Saguenay–St. Lawrence Marine Park in Québec, Canada. We focus here on the human part of the global model, the submodel of whale movements having been developed and validated independently (Lamontagne, 2009). The objective of this study is to select and validate a model of whale-watching captains’ decision making using the patternoriented modelling approach (POM): three models of cognitive heuristics (satisficing, tallying and Take The Best) along with a null model (random choice) were tested. These concurrent decision making models were built upon knowledge extracted from data collected during field investigations, including interviews with whale-watching captains and park wardens, onboard and shore-based observations, and analyses of a multi-year dataset of sampled whale-watching excursions. Model selection is performed by statistically comparing simulated and real patterns of boat trajectories (excursion length), spatial hotspots (kernel home range 50 %), and excursion content (species observed, time allocated to different activities). The selection process revealed that the Take The Best heuristic was the best performing model. We used the distribution of the number of whale-watching boats in the vicinity (2000 m) of each vessel as a secondary pattern to validate the ability of each decision making model to reproduce real observations. Given the prevalence of the species attribute in the choice of which whale to observe, the Take The Best heuristic’s ability to deal with non-compensatory information partly explains its overall best performance. Moreover, implementation of communication abilities between modelled captains led to the emergence of persistent observation sites in the park, which is a well-known collective spatiotemporal characteristic of the whale-watching industry; thus validating the fundamental assumption that cooperation is an important mechanism behind the pattern of whale-watching boat dynamics. The relatively good performance of the satisficing and tallying heuristics supports both field evidence and literature on bounded rationality in that humans likely use collections of heuristics (adaptive toolbox) to solve decision problems in different contexts. The POM strategy appears suitable to build up an informative ABM regarding the management of human activities in a natural environment so that further developments will be assessed following the same approach.©2011 Elsevier B.V.

MOUY, X., M. BAHOURA, Y. SIMARD, 2009. Automatic recognition of Fin and Blue Whale calls for real-time monitoring in the St. Lawrence. J. Acoust. Soc. Am., 126(6): 2918-2928.

[Résumé disponible seulement en anglais]
Monitoring blue and fin whales summering in the St. Lawrence Estuary with passive acoustics requires call recognition algorithms that can cope with the heavy shipping noise of the St Lawrence Seaway and with multipath propagation characteristics that generate overlapping copies of the calls. In this paper, the performance of three time-frequency methods aiming at such automatic detection and classification is tested on more than 2000 calls and compared at several levels of signal-to-noise ratio using typical recordings collected in this area. For all methods, image processing techniques are used to reduce the noise in the spectrogram. The first approach consists in matching the spectrogram with binary time-frequency templates of the calls (coincidence of spectrograms). The second approach is based on the extraction of the frequency contours of the calls and their classification using dynamic time warping (DTW) and the vector quantization (VQ) algorithms. The coincidence of spectrograms was the fastest method and performed better for blue whale A and B calls. VQ detected more 20 Hz fin whale calls but with a higher false alarm rate. DTW and VQ outperformed for the more variable blue whale D calls.©2009 Acoustical Society of America

SAVARIA, J.-Y., G. CANTIN, L. BOSSÉ, R. BAILEY, L. PROVENCHER, F. PROUST, 2008. Proceedings from a scientific workshop on marine mammals, their habitats and food resources, held in Mont-Joli (Quebec) from April 3 to 7, 2000, within the context of the St. Lawrence Estuary Marine Protected Area project. Can. Manuscr. Rep. Fish. Aquat. Sci., 2647, 124 p.

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Ce rapport manuscrit fait suite à un atelier scientifique tenu à l'Institut Maurice-Lamontagne en avril 2000, portant sur les mammifères marins fréquentant l'estuaire du Saint-Laurent. Le but de cet atelier était de vérifier la pertinence scientifique de l'établissement d'une zone de protection marine (ZPM) dans l'estuaire du Saint-Laurent visant la protection des mammifères marins, de leurs habitats et de leurs ressources alimentaires. Les problèmes actuels et potentiels pour les mammifères marins, découlant essentiellement des activités humaines se déroulant dans le secteur, ont été débattus par les participants, ce qui leur a permis d'établir un ordre de priorité de ces différents problèmes ainsi que d'évaluer la pertinence des limites proposées de la ZPM. Le dérangement, la contamination et le manque de connaissances ont été ciblés comme étant les problèmes les plus importants. Enfin, les participants ont jugé qu’en raison de l'ampleur des problèmes auxquels font face les mammifères marins, l'établissement de la ZPM est justifié, voire essentiel à la protection de ces animaux et de leurs habitats.

DONIOL-VALCROZE, T., D. BERTEAUX, P. LAROUCHE, R. SEARS, 2008. Influence of thermal fronts on habitat selection by four rorqual whale species in the Gulf of St. Lawrence. Mar. Ecol. Prog. Ser., 335: 207-216.

[Résumé disponible seulement en anglais]
Understanding the factors influencing habitat selection is critical to improving management and conservation plans for large whales. Many studies have linked the distribution of cetaceans to basic environmental features such as underwater topography and sea surface temperature (SST), but the mechanisms underlying these relationships are poorly understood. Dynamic mesoscale processes like thermal fronts are prime candidates to link physiographic factors to whale distribution because they increase biological productivity and aggregate prey. However, previous studies of large whales have found little evidence of such associations, possibly because they were not at the appropriate spatio-temporal scales. We quantified the relationship between SST fronts and the distribution of blue Balaenoptera musculus, finback B. physalus, humpback Megaptera novaeangliae and minke B. acutorostrata whales in the northern Gulf of St. Lawrence. We compared the distribution of 1094 whale sightings collected from boat surveys conducted in 1996 to 2000 to the locations of frontal areas determined from 61 satellite maps. The distributions of whales and thermal fronts were highly correlated (random resampling and Mantel tests of matrix similarity). Spatial distributions differed among species, probably reflecting differences in feeding strategies. Identification of surface fronts from satellite imagery thus effectively complemented field observations of whales. These findings significantly increase our understanding of habitat quality in rorqual whales, and encourage a greater use of dynamic environmental variables in future studies of whale habitat use. ©2007 Inter-Research

SIMARD Y., N. ROY, 2008. Detection and localization of blue and fin whales from large-aperture autonomous hydrophone arrays: a case study from the St.Lawrence estuary. Can. Acoust., 36(1): 104-110.

La faisabilité d’utiliser la technologie de monitorage acoustique passif (PAM) pour suivre la distribution spatio-temporelle des rorquals bleus et communs dans le Parc Marin Saguenay-Saint-Laurent a été explorée à l’aide de réseaux d’hydrophones à maille lâche couvrant de grandes distances. Les réseaux ont été déployés pendant les étés 2003 à 2005 à la tête du chenal laurentien, profond de 300 m. Ils étaient composés de 5 hydrophones autonomes AURAL mouillés à mi-profondeur, près du couloir de son estival. Un petit réseau côtier de faible ouverture complétait le déploiement en 2003. Les ouvertures des réseaux étaient de 20 à 40 km et leurs configurations étaient changées à chaque année. Les vocalisations les plus fréquentes étaient les infrasons identitaires des rorquals bleus et communs. Le bruit de navires transitant dans la Voie Maritime achalandée du Saint-Laurent masquait souvent les vocalisations sur les hydrophones les plus proches, ce qui parfois résultait en un nombre insuffisant de récepteurs pour localiser les baleines à l’aide de méthodes utilisant les différences de temps d’arrivée (TDoA). Les caractéristiques techniques des réseaux et du traitement des données sont présentées avec un exemple de détection et de localisation. Malgré les difficultés inhérentes à cet environnement, la technologie PAM peut y être efficacement implémentée, éventuellement pour des opérations en temps réel.©2008 Association Canadienne d'Acoustique

ROY, N., Y. SIMARD, J. ROUAT, 2008. Performance of three acoustical methods for localizing whales in the Saguenay - St. Lawrence Marine Park. Can. Acoust., 36(1): 160-164.

Trois algorithmes sont explorés pour la localisation de vocalises de rorqual commun enregistrées par un réseau d'hydrophones à large ouverture déployé dans le Parc Marin du Saguenay-Saint-Laurent. Les méthodes doivent composer avec une vitesse du son variable dans l'espace et le temps, des erreurs dans les mesures des différences de temps d'arrivée (DTA) avec un environnement bruyant, et souvent un nombre limité d'hydrophones ayant capté un événement donné. Le réseau était composé de 5 hydrophones autonomes AURAL avec une ouverture totale d'environ 40 km, couplé avec 2 hydrophones d’un petit réseau côtier. La dérive des horloges des hydrophones autonomes a été évaluée avec un niveau d’incertitude à l'aide de sources aux temps connus ainsi que de la référence temporelle du réseau côtier. Les vocalises ont ensuite été localisées par la méthode à vitesse constante des hyperboles, par celle à vitesse variable des isodiachrones avec simulations de Monte-Carlo, et par un modèle de propagation de rayons. Les simulations de Monte-Carlo produisent des nuages de localisations possibles à partir des incertitudes sur les positions des hydrophones, sur les DTAs et sur les vitesses horizontales effectives du son le long des différentes trajectoires source-hydrophone. Le modèle de propagation des rayons produit une grille fixe de DTAs qui est ensuite consultée pour trouver les positions les plus probables des baleines. Les résultats des différentes méthodes sont comparés et leurs avantages ou limites relatives sont discutés.©2008 Association Canadienne d'Acoustique

SIMARD, Y., N. ROY, C. GERVAISE, 2008. Passive acoustic detection and localization of whales: Effects of shipping noise in Saguenay-St. Lawrence Marine Park. J. Acoust. Soc. Am., 123(6): 4109-4117.

[Résumé disponible seulement en anglais]
The performance of large-aperture hydrophone arrays to detect and localize blue and fin whales' 15-85 Hz signature vocalizations under ocean noise conditions was assessed through simulations from a normal mode propagation model combined to noise statistics from 15960 h 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 30 km for a receiver at the optimal depth. The 30 dB 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.©2008 Acoustical Society of America

DONIOL-VALCROZE, T., D. BERTEAUX, P. LAROUCHE, R. SEARS, 2007. Influence of thermal fronts on habitat selection by four rorqual whale species in the Gulf of St. Lawrence. Mar. Ecol. Prog. Ser., 335: 207-216 .

[Résumé disponible seulement en anglais]
Understanding the factors influencing habitat selection is critical to improving management and conservation plans for large whales. Many studies have linked the distribution of cetaceans to basic environmental features such as underwater topography and sea surface temperature (SST), but the mechanisms underlying these relationships are poorly understood. Dynamic mesoscale processes like thermal fronts are prime candidates to link physiographic factors to whale distribution because they increase biological productivity and aggregate prey. However, previous studies of large whales have found little evidence of such associations, possibly because they were not at the appropriate spatio-temporal scales. We quantified the relationship between SST fronts and the distribution of blue Balaenoptera musculus, finback B. physalus, humpback Megaptera novaeangliae and minke B. acutorostrata whales in the northern Gulf of St. Lawrence. We compared the distribution of 1094 whale sightings collected from boat surveys conducted in 1996 to 2000 to the locations of frontal areas determined from 61 satellite maps. The distributions of whales and thermal fronts were highly correlated (random resampling and Mantel tests of matrix similarity). Spatial distributions differed among species, probably reflecting differences in feeding strategies. Identification of surface fronts from satellite imagery thus effectively complemented field observations of whales. These findings significantly increase our understanding of habitat quality in rorqual whales, and encourage a greater use of dynamic environmental variables in future studies of whale habitat use. ©2007 Inter-Research