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

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.

1982 ◽  
Vol 60 (9) ◽  
pp. 2203-2211 ◽  
Author(s):  
Hal Whitehead ◽  
Michael J. Moore

The humpback whales which winter in the West Indies are principally found over banks which are at latitudes between 10° and 22° N, have substantial areas of flat bottom between 15 and 60 m deep, and lie less than 30 km from the North Atlantic 2000 m contour. The surface sea temperatures in these areas are between 24 and 28 °C. The major concentrations of the humpbacks, which feed little in winter, are on Silver and Navidad banks. On Silver Bank the humpback and humpback song densities peak in the centre of the Bank. Mothers with calves are generally found in areas of calm water, and singers are found over areas with a flat bottom, where they meander slowly. Larger groups move considerably faster and in straighter lines. There is no evidence of whales possessing particular movement patterns, preferred ranges, or territories within the Bank. The concentration of humpbacks may be a significant feature for other humpbacks.


2021 ◽  
Author(s):  
Nadine Goris ◽  
Jerry Tjiputra ◽  
Are Ohlsen ◽  
Jörg Schwinger ◽  
Siv Lauvset ◽  
...  

<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>


Author(s):  
Steven Ruggles ◽  
Evan Roberts ◽  
Sula Sarkar ◽  
Matthew Sobek

2017 ◽  
Vol 459 ◽  
pp. 170-182 ◽  
Author(s):  
Matthew C. Baddock ◽  
Tom Mockford ◽  
Joanna E. Bullard ◽  
Throstur Thorsteinsson

1988 ◽  
Vol 120 (S144) ◽  
pp. 13-24 ◽  
Author(s):  
William L. Peters

AbstractThe complex origins of the North American Ephemeroptera fauna extended from the Lower Permian to the Recent. This paper discusses origins of North American genera of the cosmopolitan family Leptophlebiidae with a few examples from other mayfly families. The two extant subfamilies, Leptophlebiinae and Atalophlebiinae, probably evolved at least by the mid-Cretaceous, or about 100 million years before present. The primitive Leptophlebiinae are distributed throughout most of the Northern Hemisphere and the ancestors of the Leptophlebia–Paraleptophlebia complex within this subfamily dispersed widely by the North Atlantic route as early as the mid-Cretaceous and later probably by northern trans-Pacific dispersals through Beringia. The ancestors of Habrophlebia dispersed through the North Atlantic route at an early time, but the vicariant distribution of Habrophlebiodes in several areas of the Oriental Region and eastern North America correlates with the Arcto-Tertiary forest that covered most of the Northern Hemisphere including Beringia from the Early Tertiary into the Pleistocene. Within the nearly cosmopolitan Atalophlebiinae, Traverella is austral in origin and probably dispersed north through the Mexican Transition Zone during the mid-Tertiary as an ancient dispersal and then dispersed to its northern and eastern limits following the last Pleistocene deglaciation by way of the Missouri River tributaries. Thraulodes and Farrodes are both austral in origin and probably dispersed north through the Mexican Transition Zone during the Early Pleistocene as a relatively recent dispersal. The origins of Choroterpes sensu stricto and Neochoroterpes in North America are unknown. The mayfly fauna of the West Indies is Neotropical in origins, and no affinities between the West Indies and North America through Florida have ever been confirmed.


2021 ◽  
pp. 1-52

Abstract Recent rapid melting of summer Greenland ice sheet (GrIS) and its impact on the Earth’s climate has attracted much attention. In this paper, we establish a connection between the melting of GrIS and the variability of summer sea surface temperature (SST) anomalies over North Atlantic on interannual to interdecadal timescales through changes in sub-seasonal Greenland blocking (GB). It is found that the latitude and width of GB are important for the spatial patterns of the GrIS melting. The melting of GrIS on interdecadal timescales is most prominent for the positive Atlantic Multidecadal Oscillation phase (AMO+) because the high latitude GB and its large width, long lifetime and slow decay are favored. However, the North Atlantic mid-high latitude warm-cold-warm (cold-warm-cold) tripole or NAT+ (NAT−) pattern on interannual timescales tends to strengthen (weaken) the role of AMO+ in the GrIS melting especially on the northern or northeastern periphery of Greenland by promoting (inhibiting) high-latitude GB and increasing (decreasing) its width. It is further revealed that AMO+ (NAT+) favors the persistence and width of GB mainly through producing weak summer zonal winds and small summer meridional potential vorticity gradient (PVy) in the North Atlantic mid-high latitudes 55°-70°N (55°-65°N) compared to the role of AMO− (NAT−). The event frequency and zonal width of GB events and their poleward shift are favored by the combination of NAT+ with AMO+. In contrast, the combination of NAT− and AMO+ tends to suppress reduced summer zonal winds and PVy, thus inhibiting the event frequency of GB events and their poleward shift and zonal width.


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