Summer and Fall Movements of Narwhals (Monodon monoceros) from Northeastern Baffin Island towards Northern Davis Strait

Ten narwhals (Monodon monoceros) were instrumented with satellite-linked radio transmitters in Tremblay Sound in August 1997 (N = 5) and August 1998 (N = 5). All whales stayed in the waters around Bylot Island until the end of September. On the basis of these animals and others tagged previously (total N = 24), it is believed that the Bylot Island summering population has limited or no contact with other summering populations in Canada or Greenland. Four whales were monitored during their southward movement along the east coast of Baffin Island. Three of them travelled close to the shore, visiting several fjords and bays, during September and October. The fourth whale started the southward migration at the same time as the other three, but it returned to the area east of Pond Inlet and made two trips northeast of Bylot Island. It headed south on 21 October 1998. South of Royal Society Fiord, it travelled offshore along the continental slope (1000 to 1500 m), probably because of ice formation in inshore areas. This narwhal and another male tagged in 1997 moved east toward the northern parts of the Davis Strait, reaching an area midway between Canada and Greenland in early November. Their winter movements were monitored until 30 January. The same wintering area in northern Davis Strait was previously documented for two male narwhals tracked from Melville Bay, NW Greenland, in 1993 and 1994. The whales showed a preference for deep areas, including deep fjords and the continental slope, where depths ranged between 500 and 1500 m. Even deeper areas, where maximum daily dives exceeded 1000 m, were also visited occasionally.On a équipé 10 narvals (Monodon monoceros) d'émetteurs radioélectriques en liaison avec un satellite dans le détroit de Tremblay en août 1997 (N = 5) et en août 1998 (N = 5). Toutes les baleines sont restées dans les eaux entourant l'île Bylot jusqu'à fin septembre. En considérant ces animaux et d'autres équipés précédemment (N total = 24), on pense que la population estivale de l'île Bylot n'a que peu, sinon pas de contact avec d'autres populations estivales du Canada ou du Groenland. Quatre baleines ont fait l'objet d'un suivi au cours de leur déplacement vers le sud le long de la côte est de l'île de Baffin. Durant les mois de septembre et d'octobre, trois d'entre elles longeaient la côte de près, effectuant des pauses dans divers fjords et baies. La quatrième a commencé sa migration vers le sud en même temps que les trois autres, mais elle est retournée dans la zone à l'est de Pond Inlet et s'est rendue par deux fois au nord-est de l'île Bylot. Elle a mis le cap vers le sud le 21 octobre 1998. Au sud du fjord Royal Society, elle s'est dirigée vers le large et a longé la pente continentale (à environ 1000 à 1500 m du rivage), probablement en raison de la formation de glace dans la zone côtière. Ce narval ainsi qu'un autre mâle équipé en 1997 se déplaçaient en direction de l'est vers la partie nord du détroit de Davis, atteignant début novembre une zone située à mi-chemin entre le Canada et le Groenland. En hiver, leurs déplacements ont été suivis jusqu'au 30 janvier. La même zone d'hivernage dans le nord du détroit de Davis a déjà été rapportée pour deux narvals mâles suivis en 1993 et 1994 depuis la baie Melville, au N.-O. du Groenland. Les baleines affichaient une préférence pour des zones profondes, y compris des fjords encaissés et la pente continentale, où la profondeur allait de 500 à 1500 m. De temps à autre, les baleines se rendaient aussi dans des zones encore plus profondes, où les plongées maximales quotidiennes dépassaient les 1000 m

Abundance and distribution of narwhals (Monodon monoceros) on the summering grounds in Greenland between 2007-2019

Narwhal abundance in West Greenland (WG) and East Greenland (EG) was estimated from aerial surveys conducted between 2007 and 2019 at their summer grounds. Analyses were completed using Mark Recapture Distance Sampling and Hidden Markov Line Transect Models taking account of the stochastic availability of diving whales. No statistically significant difference in abundance of narwhals could be detected for the two summer grounds (Melville Bay and Inglefield Bredning) in WG between 2007 and 2019. The distribution of narwhals in Inglefield Bredning was similar between years but in Melville Bay, area usage has decreased >80% since the first survey in 2007. Few detections of narwhals were obtained during the surveys in EG and a common detection function was fitted from combining sightings from seven surveys. Narwhals were found in small aggregations distributed between Nordostrundingen and south to and including Tasiilaq. Abundance of narwhals was estimated for the first time in the relatively unexplored Northeast Greenland (Dove Bay and a restricted coastal area of the Greenland Sea). The abundance in these two areas was 2908 narwhals (CV=0.30; 95% CI:1639-5168) estimated in 2017 for the Greenland Sea and 2297 (0.38; 1123-4745) and 1395 (0.33; 744-2641) narwhals were estimated for Dove Bay in 2017 and 2018, respectively. Both abundance and distribution range of narwhals in Southeast Greenland, where narwhals are subject to subsistence harvest, has decreased significantly between 2008-2017 and narwhals have even disappeared at the southernmost area since the first surveys in 2008.Peer reviewe

A comparison of image and observer based aerial surveys of narwhal

From 25 to 30 August 2014 a double-observer line-transect survey was conducted over Melville Bay, home to one of two summering populations of narwhal (Monodon monoceros) off West Greenland. A total of 1,932 linear kilometers was surveyed along 33 transects. In addition to using observers, the aircraft was equipped with two oblique cameras to capture a comparable data set. Analysts reviewed the images for narwhal sightings, which were then matched to the observer sightings. The objectives of the study were to determine advantages and disadvantages of the detection capabilities of both methodologies, and to conduct a comparative analysis of population abundance estimates. Correcting for the truncated detection distance of the images (500 m), the image analysts recorded more sightings (62) and a lower mean group size (2.2) compared to aerial observers (36 and 3.5, respectively), resulting in comparable numbers of individuals detected by both platforms (135 vs. 126). The abundance estimate based on the image sightings was 2,536 (CV = 0.51, 95% CI: 1,003-6,406), which was not significantly different from the aerial observers estimate of 2,596 individuals (CV = 0.51; 95% CI: 961-7,008). This study supports the potential of using UAS for marine mammal abundance studies

Autumn movements of fin whales (Balaenoptera physalus) from Svalbard, Norway, revealed by satellite tracking

Insight into animal movements is essential for understanding habitat use by individuals as well as population processes and species life-history strategies. In this study, we instrumented 25 fin whales with ARGOS satellite-transmitters in Svalbard, Norway, to study their movement patterns and behaviour (Area Restricted Search (ARS), transiting or unknown) during boreal autumn/early winter. Ten of the whales stayed in the tagging area (most northerly location: 81.68°N) for their entire tracking periods (max 45 days). The other 15 whales moved in a south-westerly direction; the longest track ended off the coast of northern Africa (> 5000 km from the tagging location) after 96 days. The whales engaged in ARS behaviour intermittently throughout their southward migrations. During transit phases the whales moved quickly; one individual maintained an average horizontal speed of 9.3 km/h (travelling 223 km per day) for a period of a week. This study documents that: (1) some fin whales might remain at high latitudes during winter; (2) the whales that do migrate probably feed along the way; (3) they can maintain high transiting speed for long periods and; (4) one breeding area for this species is likely located in deep, warm water some 100 km west of Morocco.publishedVersio

Lost Highway Not Forgotten: Satellite Tracking of a Bowhead Whale (Balaena mysticetus) from the Critically Endangered Spitsbergen Stock

The Spitsbergen bowhead whale stock is critically endangered. It is believed to number in the tens. Here we report results from the first satellite transmitter ever deployed on an individual from this stock. A female whale was tagged on 3 April 2010 (at 79˚54' N, 01˚03' E), but no locations were transmitted by the tag until 30 April 2010, after which data were received continuously for 86 days. Additionally, three small clusters of locations were transmitted later in the year; the latest was received 20 December 2010 (262 days after deployment). During the 86 days of continuous tracking, the whale initially remained in the middle of the Fram Strait, between 77˚45' N, 5˚ W and 80˚10' N, 5˚ E. For a two-week period starting around 10 June 2010, the whale traveled southwest down to 73˚40' N (at least 950 km). Subsequently it remained at southern latitudes between ~70˚ and 73˚ N until the tag stopped continuous transmissions on 24 July. Movement patterns analyzed using first-passage times (FTP), fitted as functions of various environmental variables using Cox Proportional Hazards models, showed that the whale spent most of its time in waters close to the ice edge with modest ice coverage, over areas where the bottom slope was relatively steep. Winter positions (27 November – 20 December 2010) revealed that the whale was back in the North at about 80˚ N. This information, in combination with recent data from passive acoustic listening devices, suggests that the Spitsbergen bowhead stock overwinters at high-latitude locations. The north-south movements of this whale during summer are consistent with the patterns that early whalers described for bowhead whales in this region in the 16th and 17th centuries.La population de baleines boréales de Spitzberg est en danger critique d’extinction. L’on croit qu’elle se chiffrerait dans la dizaine. Ici, nous faisons état des résultats obtenus à l’aide du premier émetteur satellite à n’avoir jamais été installé sur un individu de cette population. Une baleine femelle a été marquée le 3 avril 2010 (à 79˚54' N, 01˚03' E), mais aucun signal n’a été transmis par ce marquage avant le 30 avril 2010, après quoi nous avons reçu des données continuelles pendant 86 jours. Plus tard dans le courant de l’année, nous avons également reçu trois petits blocs d’information, dont le dernier a été transmis le 20 décembre 2010 (262 jours après la date du marquage). Au cours des 86 jours d’information continuelle, la baleine restait d’abord au milieu du détroit de Fram, entre 77˚45' N, 5˚ O et 80˚10' N, 5˚ E. Pendant une période de deux semaines commençant vers le 10 juin 2010, la baleine s’est déplacée vers le sud-ouest jusqu’à 73˚40' N (au moins 950 km). Par la suite, elle est restée dans les latitudes du sud entre ~70˚ et 73˚ N jusqu’à ce que le marquage cesse les transmissions continuelles le 24 juillet. Les habitudes de déplacement analysées en recourant aux temps du premier passage (FTP), ajustées à titre de fonctions de diverses variables environnementales s’appuyant sur les modèles des hasards proportionnels de Cox, ont laissé entrevoir que la baleine passait la plus grande partie de son temps dans les eaux à proximité des lisières de glace dont la couverture était modeste par rapport aux endroits où la pente du fond était relativement abrupte. Les positions enregistrées en hiver (du 27 novembre au20 décembre 2010) ont révélé que la baleine était retournée dans le nord à environ 80˚ N. Cette information, alliée aux récentes données provenant d’appareils d’écoute acoustique, suggère que la population de baleines boréales de Spitzberg passe l’hiver à de hautes latitudes. Pendant l’été, les mouvements nord-sud de cette baleine sont conformes aux habitudes de déplacement de la baleine boréale, telles que décrites par les anciens baleiniers dans cette région au cours des XVIe et XVIIe siècles

Breast cancer recurrence after reoperation for surgical bleeding.

BACKGROUND: Bleeding activates platelets that can bind tumour cells, potentially promoting metastatic growth in patients with cancer. This study investigated whether reoperation for postoperative bleeding is associated with breast cancer recurrence. METHODS: Using the Danish Breast Cancer Group database and the Danish National Patient Register (DNPR), a cohort of women with incident stage I-III breast cancer, who underwent breast-conserving surgery or mastectomy during 1996-2008 was identified. Information on reoperation for bleeding within 14 days of the primary surgery was retrieved from the DNPR. Follow-up began 14 days after primary surgery and continued until breast cancer recurrence, death, emigration, 10 years of follow-up, or 1 January 2013. Incidence rates of breast cancer recurrence were calculated and Cox regression models were used to quantify the association between reoperation and recurrence, adjusting for potential confounders. Crude and adjusted hazard ratios according to site of recurrence were calculated. RESULTS: Among 30 711 patients (205 926 person-years of follow-up), 767 patients had at least one reoperation within 14 days of primary surgery, and 4769 patients developed breast cancer recurrence. Median follow-up was 7·0 years. The incidence of recurrence was 24·0 (95 per cent c.i. 20·2 to 28·6) per 1000 person-years for reoperated patients and 23·1 (22·5 to 23·8) per 1000 person-years for non-reoperated patients. The overall adjusted hazard ratio was 1·06 (95 per cent c.i. 0·89 to 1·26). The estimates did not vary by site of breast cancer recurrence. CONCLUSION: In this large cohort study, there was no evidence of an association between reoperation for bleeding and breast cancer recurrence

Seasonal variability of the warm Atlantic Water layer in the vicinity of the Greenland shelf break

The warmest water reaching the east and west coast of Greenland is found between 200?m and 600?m. Whilst important for melting Greenland's outlet glaciers, limited winter observations of this layer prohibit determination of its seasonality. To address this, temperature data from Argo profiling floats, a range of sources within the World Ocean Database and unprecedented coverage from marine-mammal borne sensors have been analysed for the period 2002-2011. A significant seasonal range in temperature (~1-2?°C) is found in the warm layer, in contrast to most of the surrounding ocean. The phase of the seasonal cycle exhibits considerable spatial variability, with the warmest water found near the eastern and southwestern shelf-break towards the end of the calendar year. High-resolution ocean model trajectory analysis suggest the timing of the arrival of the year's warmest water is a function of advection time from the subduction site in the Irminger Basin