Population composition of humpback whales, Megaptera novaeangliae, on Silver Bank, 1984

1989 ◽  
Vol 67 (2) ◽  
pp. 281-285 ◽  
Author(s):  
David K. Mattila ◽  
Phillip J. Clapham ◽  
Steven K. Katona ◽  
Gregory S. Stone
Keyword(s):  
North Atlantic ◽  
High Latitude ◽  
Gulf Of Maine ◽  
Megaptera Novaeangliae ◽  
Humpback Whales ◽  
Breeding Ecology ◽  
Population Composition ◽  
Winter Range ◽  
The North ◽  
Surface Active

Between 14 February and 19 March 1984, 19 d were spent observing humpback whales, Megaptera novaeangliae, on Silver Bank. In total, 317 whales were individually identified from photographs of ventral fluke patterns. Comparison of these photographs with the North Atlantic humpback whale catalogue revealed that 97 of the whales had previously been observed in other areas. Matches were made with all of the major known high-latitude feeding grounds: Greenland (6), Newfoundland – Labrador (43), the Gulf of St. Lawrence (7), and the Gulf of Maine (12). Matches were also made with habitats in the winter range of this population: Bermuda (1), Silver Bank in other years (26), Puerto Rico (18), Virgin Bank (1), and Anguilla Bank (1). Analysis of matches suggests that whales from the various high-latitude feeding stocks mix randomly on Silver Bank. Seven surface-active groups contained whales from different high-latitude feeding stocks, providing the strongest evidence to date for genetic mixing among these stocks. The behavior and composition of surface-active groups are discussed. Overall, the number of whales, calves, and surface-active groups observed during this study confirms the apparently singular importance of Silver Bank to the breeding ecology of western North Atlantic humpback whales.

Local and migratory movements of humpback whales (Megaptera novaeangliae) satellite-tracked in the North Atlantic Ocean

2014 ◽  
Vol 92 (1) ◽  
pp. 9-18 ◽  
Author(s):  
A.S. Kennedy ◽  
A.N. Zerbini ◽  
O.V. Vásquez ◽  
N. Gandilhon ◽  
P.J. Clapham ◽  
...  
Keyword(s):  
Dominican Republic ◽  
North Atlantic ◽  
Gulf Of Maine ◽  
North Atlantic Ocean ◽  
Megaptera Novaeangliae ◽  
Humpback Whales ◽  
The North ◽  
Breeding Grounds ◽  
Multiple Feeding ◽  
Feeding Grounds

North Atlantic humpback whales (Megaptera novaeangliae (Borowski, 1781)) migrate from high-latitude summer feeding grounds to low-latitude winter breeding grounds along the Antillean Island chain. In the winters and springs of 2008 through 2012, satellite tags were deployed on humpback whales on Silver Bank (Dominican Republic) and in Guadeloupe (French West Indies) breeding areas. Whales were monitored, on average, for 26 days (range = 4–90 days). Some animals remained near their tagging location for multiple days before beginning their northerly migration, yet some visited habitats along the northwestern coast of the Dominican Republic, northern Haiti, the Turks and Caicos islands, and off Anguilla. Individuals monitored during migration headed towards feeding grounds in the Gulf of Maine (USA), Canada, and the eastern North Atlantic (Iceland or Norway). One individual traveled near Bermuda during the migration. This study provides the first detailed description of routes used by North Atlantic humpback whales towards multiple feeding destinations. Additionally, it corroborates previous research showing that individuals from multiple feeding grounds migrate to the Antilles for the breeding season. This study indicates that North Atlantic humpbacks use an area broader than the existing boundaries of marine mammal sanctuaries, which should provide justification for their expansion.

Regional and sexual differences in fluke pigmentation of humpback whales (Megaptera novaeangliae) from the North Atlantic Ocean

1994 ◽  
Vol 72 (2) ◽  
pp. 274-279 ◽  
Author(s):  
Judith M. Allen ◽  
Howard C. Rosenbaum ◽  
Steven K. Katona ◽  
Philip J. Clapham ◽  
David K. Mattila
Keyword(s):  
Dominican Republic ◽  
Atlantic Ocean ◽  
North Atlantic ◽  
Gulf Of Maine ◽  
North Atlantic Ocean ◽  
Humpback Whales ◽  
Winter Range ◽  
The North ◽  
Breeding Grounds ◽  
Summer Range

The relative amount of pigmentation on the flukes of 3812 humpback whales from five feeding and three breeding regions in the western North Atlantic Ocean was ranked subjectively into categories 1 (white) through 5 (black). The distribution of rankings was examined to determine whether differences existed between regions or sexes. Fluke pigmentation differed significantly among whales photographed in the five northern feeding regions (Iceland, southwestern Greenland, Newfoundland (including the Labrador coast), the Gulf of St. Lawrence, and the Gulf of Maine). Whales photographed in the Gulf of Maine were characterized by a significantly higher proportion of dark-colored flukes than whales in all feeding regions except Iceland. Whales photographed near Greenland were characterized by significantly more light-colored flukes than other feeding regions. Fluke pigmentation also varied significantly among whales photographed in the three southern breeding regions (Virgin Bank, Puerto Rico, and the Dominican Republic). The flukes of whales photographed near Virgin Bank differed from those of whales near the Dominican Republic and included a higher proportion of light flukes. Fluke pigmentation of males and females differed significantly in the Gulf of Maine and in the Dominican Republic. Both areas showed higher proportions of dark-fluked females and light-fluked males. Sex bias differences in other regions were not examined because sample sizes were small. Fluke pigmentation of whales photographed only on the summer range did not differ significantly from the pigmentation of those photographed only on the winter range, supporting the belief that all northern feeding aggregations mix on the southern breeding grounds. Regional differences in fluke pigmentation suggest that the western North Atlantic humpback whale population includes a number of relatively isolated subunits, as suggested previously by photoidentification and DNA studies.

High-latitude-area composition of humpback whale competitive groups in Samana Bay: further evidence for panmixis in the North Atlantic population

1993 ◽  
Vol 71 (5) ◽  
pp. 1065-1066 ◽  
Author(s):  
Phillip J. Clapham ◽  
David K. Mattila ◽  
Per J. Palsbøll
Keyword(s):  
North Atlantic ◽  
High Latitude ◽  
West Indies ◽  
Humpback Whales ◽  
Atlantic Population ◽  
The North ◽  
Skin Biopsies ◽  
The North Atlantic ◽  
Molecular Determination

Competitive groups of humpback whales, Megaptera novaeangliae, were observed in Samana Bay, Dominican Republic, West Indies. Photographs of ventral fluke patterns were used to identify individuals, and skin biopsies were taken for molecular determination of sex. Nine groups contained two or more whales previously identified from different high-latitude areas. In seven groups, males from different feeding grounds were observed to compete with each other, and in six cases the group's female was from a different area than at least one of her male escorts. These results provide further support for the hypothesis that the western North Atlantic population of this species can be considered a single panmictic unit.

scholarly journals Global diversity and oceanic divergence of humpback whales ( Megaptera novaeangliae )

2014 ◽  
Vol 281 (1786) ◽  
pp. 20133222 ◽  
Author(s):  
Jennifer A. Jackson ◽  
Debbie J. Steel ◽  
P. Beerli ◽  
Bradley C. Congdon ◽  
Carlos Olavarría ◽  
...  
Keyword(s):  
Southern Hemisphere ◽  
North Atlantic ◽  
North Pacific ◽  
Megaptera Novaeangliae ◽  
Population History ◽  
Humpback Whales ◽  
Restricted Gene Flow ◽  
Geological Time ◽  
The North ◽  
The North Pacific

Humpback whales ( Megaptera novaeangliae ) annually undertake the longest migrations between seasonal feeding and breeding grounds of any mammal. Despite this dispersal potential, discontinuous seasonal distributions and migratory patterns suggest that humpbacks form discrete regional populations within each ocean. To better understand the worldwide population history of humpbacks, and the interplay of this species with the oceanic environment through geological time, we assembled mitochondrial DNA control region sequences representing approximately 2700 individuals (465 bp, 219 haplotypes) and eight nuclear intronic sequences representing approximately 70 individuals (3700 bp, 140 alleles) from the North Pacific, North Atlantic and Southern Hemisphere. Bayesian divergence time reconstructions date the origin of humpback mtDNA lineages to the Pleistocene (880 ka, 95% posterior intervals 550–1320 ka) and estimate radiation of current Northern Hemisphere lineages between 50 and 200 ka, indicating colonization of the northern oceans prior to the Last Glacial Maximum. Coalescent analyses reveal restricted gene flow between ocean basins, with long-term migration rates (individual migrants per generation) of less than 3.3 for mtDNA and less than 2 for nuclear genomic DNA. Genetic evidence suggests that humpbacks in the North Pacific, North Atlantic and Southern Hemisphere are on independent evolutionary trajectories, supporting taxonomic revision of M. novaeangliae to three subspecies.

Differential rates of killer whale attacks on humpback whales in the North Atlantic as determined by scarification

2013 ◽  
Vol 94 (6) ◽  
pp. 1311-1315 ◽  
Author(s):  
Jessica A. McCordic ◽  
Sean K. Todd ◽  
Peter T. Stevick
Keyword(s):  
North Atlantic ◽  
Gulf Of Maine ◽  
Killer Whale ◽  
Ecological Impact ◽  
Humpback Whale ◽  
Humpback Whales ◽  
Killer Whales ◽  
West Greenland ◽  
The North ◽  
The North Atlantic

As in other populations of killer whales, Orcinus orca, prey selectivity in the North Atlantic population may indicate behaviourally or ecologically distinct types of killer whales. Some killer whale ecotypes are known to prey on large whales, but the ecological impact of such predation events is unknown. Since killer whale attacks on humpback whales, Megaptera novaeangliae, are rarely witnessed, resultant scars may be used to determine the frequency of non-fatal predatory interactions. Using images from the North Atlantic Humpback Whale Catalogue (NAHWC), we examined humpback whale flukes for the presence of rake marks from killer whales (N = 5040). Scarring frequencies range from 2.7 to 17.4% and differ significantly among five regions of the North Atlantic (Gulf of Maine, Canada, West Greenland, Iceland and Norway). The scarring rate in the Canada region is significantly higher than all other regions, and Norway has a significantly lower scarring rate than all other regions, despite more frequently reported killer whale sightings in that region. Within the western North Atlantic, Canada has a scarring rate nearly twice that of either the Gulf of Maine or West Greenland. These data may reflect differential prey choice among killer whale ecotypes and/or the distribution of specific ecotypes across the North Atlantic basin.

Occurrence, population composition, and habitat use of humpback whales in Samana Bay, Dominican Republic

1994 ◽  
Vol 72 (11) ◽  
pp. 1898-1907 ◽  
Author(s):  
David K. Mattila ◽  
Phillip J. Clapham ◽  
Oswaldo Vásquez ◽  
Robert S. Bowman
Keyword(s):  
Dominican Republic ◽  
North Atlantic ◽  
West Indies ◽  
Gulf Of Maine ◽  
Humpback Whales ◽  
Mammal Species ◽  
The West ◽  
The North ◽  
The Mean ◽  
Almost All

A study of humpback whales (Megaptera novaeangliae) was conducted between 1988 and 1991 in Samana Bay, Dominican Republic. Humpbacks were observed as early as the earliest survey (3 January) and as late as the latest (16 March). Local abundance varied from 0 whales per hour to a maximum of 3.2 whales per hour (mean = 1.70, SD = 0.79), and densities calculated from track surveys ranged from 0.09 to 0.82 whales per square nautical mile (mean = 0.31). Abundance generally peaked in February, but variation was observed both within a season and between years. Almost all whales were observed in the eastern part of the bay, towards or at its mouth. In all, 397 individuals were photographically identified during the study period. Of these, 18 were observed in more than 1 year (17 in 2 years, 1 in 3 years). A total of 15.8% of identified individuals were observed on more than 1 day in a year (maximum 5 days), with mothers representing 33.3% of all resightings. Observed occupancies of resighted animals ranged from 1 to 33 days (mean = 6.3 days, SD = 7.14). The mean group size was 1.95 (range = 1–15, SD = 1.30, n = 652 groups). Ninety-nine groups contained a calf, and all groups larger than three (n = 45) were competitive in nature. Comparisons of fluke photographs with the North Atlantic Humpback Whale Catalogue revealed 141 matches of 118 individuals to other areas. Of these, 76 were to high-latitude feeding grounds (including the Gulf of Maine, Newfoundland, Labrador, the Gulf of St. Lawrence, and west Greenland), while the remaining 65 were to other areas of the West Indies (Silver Bank, Navidad Bank, Puerto Rico, Virgin Bank, or Anguilla Bank) or to Bermuda. We suggest that Samana Bay is one of the most important winter habitats in the West Indies for humpback whales from all over the western North Atlantic, although whaling records suggest that the abundance of whales in this area may be a relatively recent phenomenon. Sightings of other marine mammal species in Samana Bay are summarized.

A longitudinal study of humpback whales in Irish waters

2015 ◽  
Vol 96 (4) ◽  
pp. 877-883 ◽  
Author(s):  
Conor Ryan ◽  
Pádraig Whooley ◽  
Simon D. Berrow ◽  
Colin Barnes ◽  
Nick Massett ◽  
...  
Keyword(s):  
Longitudinal Study ◽  
North Atlantic ◽  
Spatial Scales ◽  
Humpback Whales ◽  
Migratory Species ◽  
The Public ◽  
Photo Identification ◽  
The North ◽  
Breeding Grounds ◽  
Eastern North Atlantic

Knowledge on the ecology of humpback whales in the eastern North Atlantic is lacking by comparison with most other ocean basins. Humpback whales were historically over-exploited in the region and are still found in low relative abundances. This, coupled with their large range makes them difficult to study. With the aim of informing more effective conservation measures in Ireland, the Irish Whale and Dolphin Group began recording sightings and images suitable for photo-identification of humpback whales from Irish waters in 1999. Validated records submitted by members of the public and data from dedicated surveys were analysed to form a longitudinal study of individually recognizable humpback whales. The distribution, relative abundance and seasonality of humpback whale sighting records are presented, revealing discrete important areas for humpback whales in Irish coastal waters. An annual easterly movement of humpback whales along the southern coast of Ireland is documented, mirroring that of their preferred prey: herring and sprat. Photo-identification images were compared with others collected throughout the North Atlantic (N = 8016), resulting in matches of two individuals between Ireland and Iceland, Norway and the Netherlands but no matches to known breeding grounds (Cape Verde and West Indies). This study demonstrates that combining public records with dedicated survey data is an effective approach to studying low-density, threatened migratory species over temporal and spatial scales that are relevant to conservation and management.

Efficient carbon drawdown allows for a high future carbon uptake in the North Atlantic

2021 ◽  
Author(s):  
Nadine Goris ◽  
Jerry Tjiputra ◽  
Are Ohlsen ◽  
Jörg Schwinger ◽  
Siv Lauvset ◽  
...  
Keyword(s):  
North Atlantic ◽  
High Latitude ◽  
Deep Convection ◽  
Deep Ocean ◽  
Nutrient Supply ◽  
Global Ocean ◽  
Carbon Uptake ◽  
Model Ensemble ◽  
The North ◽  
The North Atlantic

<p>As one of the major carbon sinks in the global ocean, the North Atlantic is a key player in mediating and ameliorating the ongoing global warming. Projections of the North Atlantic carbon sink in a high-CO<sub>2</sub> future vary greatly among models, with some showing that a slowdown in carbon uptake has already begun and others predicting that this slowdown will not occur until nearly 2100.</p><p>Discrepancies among models largely originate because of differences in the efficiency of the high-latitude transport of carbon from the surface to the deep ocean. This transport occurs through biological production, deep convection and subsequent transport via the deep western boundary current. For an ensemble of 11 CMIP5-models, we studied the efficiency of this transport and identified two indicators of contemporary model behavior that are highly correlated with a model´s projected future carbon-uptake. The first indicator is the high latitude summer pCO<sub>2</sub><sup>sea</sup>-anomaly of a model, which is tightly linked to winter mixing and nutrient supply, but also to deep convection. The second indicator is the fraction of the anthropogenic carbon-inventory stored below 1000-m depth, indicating how efficient carbon is transported into the deep ocean. By comparing to the observational database, these indicators allow us to better constrain the model ensemble, and demonstrate that the models with more efficient surface to deep transport are best aligned with current observations. These models also show the largest future North Atlantic carbon uptake, which we then conclude is the more plausible future evolution. We further study if the high correlations between our contemporary indicators and a model´s future North Atlantic carbon uptake is also upheld for the next model generation, CMIP6. We hypothesize that this is the case and that our indicators can not only help us to constrain the CMIP6 model ensemble but also inform us about progress made between CMIP5 and CMIP6 in terms of North Atlantic carbon uptake, winter mixing, nutrient supply, deep convection and transport of carbon into the deep ocean.</p>

scholarly journals Fluctuating reproductive rates in Hawaii's humpback whales, Megaptera novaeangliae , reflect recent climate anomalies in the North Pacific

2019 ◽  
Vol 6 (3) ◽  
pp. 181463 ◽  
Author(s):  
R. Cartwright ◽  
A. Venema ◽  
V. Hernandez ◽  
C. Wyels ◽  
J. Cesere ◽  
...  
Keyword(s):  
Climate Change ◽  
North Pacific ◽  
Megaptera Novaeangliae ◽  
Anthropogenic Climate Change ◽  
Humpback Whales ◽  
Encounter Rates ◽  
The North ◽  
The Impact ◽  
The North Pacific ◽  
Population Segment

Alongside changing ocean temperatures and ocean chemistry, anthropogenic climate change is now impacting the fundamental processes that support marine systems. However, where natural climate aberrations mask or amplify the impacts of anthropogenic climate change, identifying key detrimental changes is challenging. In these situations, long-term, systematic field studies allow the consequences of anthropogenically driven climate change to be distinguished from the expected fluctuations in natural resources. In this study, we describe fluctuations in encounter rates for humpback whales, Megaptera novaeangliae , between 2008 and 2018. Encounter rates were assessed during transect surveys of the Au'Au Channel, Maui, Hawaii. Initially, rates increased, tracking projected growth rates for this population segment. Rates reached a peak in 2013, then declined through 2018. Specifically, between 2013 and 2018, mother–calf encounter rates dropped by 76.5%, suggesting a rapid reduction in the reproductive rate of the newly designated Hawaii Distinct Population Segment of humpback whales during this time. As this decline coincided with changes in the Pacific decadal oscillation, the development of the NE Pacific marine heat wave and the evolution of the 2016 El Niño, this may be another example of the impact of this potent trifecta of climatic events within the North Pacific.

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