scholarly journals Distribution and abundance of fin whales (Balaenoptera physalus) in the Northeast and Central Atlantic as inferred from the North Atlantic Sightings Surveys 1987-2001

2013 ◽  
Vol 7 ◽  
pp. 49 ◽  
Author(s):  
Gísli A Víkingsson ◽  
Daniel G Pike ◽  
Geneviève Desportes ◽  
Nils Øien ◽  
Thorvaldur Gunnlaugsson ◽  
...  
Keyword(s):  
North Atlantic ◽  
Large Scale ◽  
High Growth ◽  
Line Transect ◽  
Annual Growth Rate ◽  
Survey Period ◽  
Balaenoptera Physalus ◽  
The North ◽  
Fin Whales ◽  
Eastern North Atlantic

North Atlantic Sightings Surveys (NASS) is a series of large scale international cetacean line transect surveys, conducted in 1987, 1989, 1995 and 2001, that covered a large part of the central and eastern North Atlantic. Target species were fin (Balaenoptera physalus), common minke (B. acutorostrata), pilot (Globicephala melas) and sei (B. borealis) whales. Here we present new estimates of abundance for fin whales from the 2 most recent surveys and analysis of trends throughout the survey period. Fin whales were found in highest densities in the Irminger Sea between Iceland and Greenland. Abundance of fin whales in the survey area of the Icelandic and Faroese vessels (Central North Atlantic) was estimated as 19,672 (95% C.I. 12,083-28,986) animals in 1995 and 24,887 (95% C.I. 18,186-30,214) in 2001. The estimates are negatively biased because of whales diving during the passage of vessels, and whales being missed by observers, but these and other potential biases are likely small for this species. The abundance of fin whales increased significantly over the survey period. For all areas combined the estimated annual growth rate was 4%. An estimated annual increase of 10% in the area between Iceland and Greenland was responsible for most of this overall increase in numbers of fin whales in the area. Although high, the estimated rates of increase are not out of bounds of biological plausibility and can thus be viewed as recovery of a depleted population. However, the apparent pattern of population growth and the whaling history in the area indicate that fin whales made a significant recovery during the first half of the 20th century and that the recent observed high growth rates cannot be explained solely by recovery after overexploitation. 

Revision of fin whale Balaenoptera physalus (Linnaeus, 1758) subspecies using genetics

2019 ◽  
Vol 100 (5) ◽  
pp. 1653-1670 ◽  
Author(s):  
Frederick I Archer ◽  
Robert L Brownell ◽  
Brittany L Hancock-Hanser ◽  
Phillip A Morin ◽  
Kelly M Robertson ◽  
...  
Keyword(s):  
North Atlantic ◽  
North Pacific ◽  
Recent Analysis ◽  
Snp Analysis ◽  
Balaenoptera Physalus ◽  
Data Set ◽  
Fin Whale ◽  
The North ◽  
Fin Whales ◽  
The North Pacific

Abstract Three subspecies of fin whales (Balaenoptera physalus) are currently recognized, including the northern fin whale (B. p. physalus), the southern fin whale (B. p. quoyi), and the pygmy fin whale (B. p. patachonica). The Northern Hemisphere subspecies encompasses fin whales in both the North Atlantic and North Pacific oceans. A recent analysis of 154 mitogenome sequences of fin whales from these two ocean basins and the Southern Hemisphere suggested that the North Pacific and North Atlantic populations should be treated as different subspecies. Using these mitogenome sequences, in this study, we conduct analyses on a larger mtDNA control region data set, and on 23 single-nucleotide polymorphisms (SNPs) from 144 of the 154 samples in the mitogenome data set. Our results reveal that North Pacific and North Atlantic fin whales can be correctly assigned to their ocean basin with 99% accuracy. Results of the SNP analysis indicate a correct classification rate of 95%, very low rates of gene flow among ocean basins, and that distinct mitogenome matrilines in the North Pacific are interbreeding. These results indicate that North Pacific fin whales should be recognized as a separate subspecies, with the name B. p. velifera Cope in Scammon 1869 as the oldest available name.

scholarly journals The Empirical Forcing Function as a tool for the diagnosis of large-scale atmospheric anomalies

2010 ◽  
Vol 28 (1) ◽  
pp. 75-87
Author(s):  
C. Andrade ◽  
J. A. Santos ◽  
J. G. Pinto ◽  
J. Corte-Real ◽  
S. Leite
Keyword(s):  
Atmospheric Circulation ◽  
North Atlantic ◽  
Potential Vorticity ◽  
Radiative Forcing ◽  
Large Scale ◽  
Atmospheric Flow ◽  
Material Derivative ◽  
The North ◽  
Forcing Function ◽  
Eastern North Atlantic

Abstract. The time-mean quasi-geostrophic potential vorticity equation of the atmospheric flow on isobaric surfaces can explicitly include an atmospheric (internal) forcing term of the stationary-eddy flow. In fact, neglecting some non-linear terms in this equation, this forcing can be mathematically expressed as a single function, called Empirical Forcing Function (EFF), which is equal to the material derivative of the time-mean potential vorticity. Furthermore, the EFF can be decomposed as a sum of seven components, each one representing a forcing mechanism of different nature. These mechanisms include diabatic components associated with the radiative forcing, latent heat release and frictional dissipation, and components related to transient eddy transports of heat and momentum. All these factors quantify the role of the transient eddies in forcing the atmospheric circulation. In order to assess the relevance of the EFF in diagnosing large-scale anomalies in the atmospheric circulation, the relationship between the EFF and the occurrence of strong North Atlantic ridges over the Eastern North Atlantic is analyzed, which are often precursors of severe droughts over Western Iberia. For such events, the EFF pattern depicts a clear dipolar structure over the North Atlantic; cyclonic (anticyclonic) forcing of potential vorticity is found upstream (downstream) of the anomalously strong ridges. Results also show that the most significant components are related to the diabatic processes. Lastly, these results highlight the relevance of the EFF in diagnosing large-scale anomalies, also providing some insight into their interaction with different physical mechanisms.

scholarly journals Changes in the CFC Inventories and Formation Rates of Upper Labrador Sea Water, 1997–2001

2006 ◽  
Vol 36 (1) ◽  
pp. 64-86 ◽  
Author(s):  
Dagmar Kieke ◽  
Monika Rhein ◽  
Lothar Stramma ◽  
William M. Smethie ◽  
Deborah A. LeBel ◽  
...  
Keyword(s):  
North Atlantic ◽  
Large Scale ◽  
Sea Water ◽  
North Atlantic Ocean ◽  
Formation Rate ◽  
Labrador Sea ◽  
The North ◽  
The Mean ◽  
Eastern North Atlantic ◽  
Labrador Sea Water

Abstract Chlorofluorocarbon (component CFC-11) and hydrographic data from 1997, 1999, and 2001 are presented to track the large-scale spreading of the Upper Labrador Sea Water (ULSW) in the subpolar gyre of the North Atlantic Ocean. ULSW is CFC rich and comparatively low in salinity. It is located on top of the denser “classical” Labrador Sea Water (LSW), defined in the density range σΘ = 27.68–27.74 kg m−3. It follows spreading pathways similar to LSW and has entered the eastern North Atlantic. Despite data gaps, the CFC-11 inventories of ULSW in the subpolar North Atlantic (40°–65°N) could be estimated within 11%. The inventory increased from 6.0 ± 0.6 million moles in 1997 to 8.1 ± 0.6 million moles in 1999 and to 9.5 ± 0.6 million moles in 2001. CFC-11 inventory estimates were used to determine ULSW formation rates for different periods. For 1970–97, the mean formation rate resulted in 3.2–3.3 Sv (Sv ≡ 106 m3 s−1). To obtain this estimate, 5.0 million moles of CFC-11 located in 1997 in the ULSW in the subtropical/tropical Atlantic were added to the inventory of the subpolar North Atlantic. An estimate of the mean combined ULSW/LSW formation rate for the same period gave 7.6–8.9 Sv. For the years 1998–99, the ULSW formation rate solely based on the subpolar North Atlantic CFC-11 inventories yielded 6.9–9.2 Sv. At this time, the lack of classical LSW formation was almost compensated for by the strongly pronounced ULSW formation. Indications are presented that the convection area needed in 1998–99 to form this amount of ULSW exceeded the available area in the Labrador Sea. The Irminger Sea might be considered as an additional region favoring ULSW formation. In 2000–01, ULSW formation weakened to 3.3–4.7 Sv. Time series of layer thickness based on historical data indicate that there exists considerable variability of ULSW and classical LSW formation on decadal scales.

Sex Hormones and Reproductive Status of the North Atlantic Fin Whales (Balaenoptera physalus) During the Feeding Season

2006 ◽  
Vol 32 (1) ◽  
pp. 75-84 ◽  
Author(s):  
Matthías Kjeld ◽  
Örn Ólafsson ◽  
Gísli A. Víkingsson ◽  
Jóhann Sigurjónsson
Keyword(s):  
Sex Hormones ◽  
North Atlantic ◽  
Reproductive Status ◽  
Balaenoptera Physalus ◽  
The North ◽  
The North Atlantic ◽  
Fin Whales

Temperature, Salinity and Plankton in the Eastern North Atlantic and Coastal Waters of Britain, 1957.: I. The Characterisation and Distribution of Surface Waters

1963 ◽  
Vol 20 (3) ◽  
pp. 789-826 ◽  
Author(s):  
B. McK. Bary
Keyword(s):  
North Sea ◽  
North Atlantic ◽  
Coastal Waters ◽  
Water Bodies ◽  
English Channel ◽  
Oceanic Water ◽  
Climatic Fluctuations ◽  
The North ◽  
The North Sea ◽  
Eastern North Atlantic

Monthly temperature-salinity diagrams for 1957 have demonstrated that three surface oceanic "water bodies" were consistently present in the eastern North Atlantic; two are regarded as modified North Atlantic Central water which give rise to the third by mixing. As well in the oceanic areas, large and small, high or low salinity patches of water were common. Effects of seasonal climatic fluctuations differed in the several oceanic water bodies. In coastal waters, differences in properties and in seasonal and annual cycles of the properties distinguish the waters from the North Sea, English Channel and the western entrance to the Channel.The geographic distributions of the oceanic waters are consistent with "northern" and "southern" water bodies mixing to form a "transitional" water. Within this distribution there are short-term changes in boundaries and long-term (seasonal) changes in size of the water bodies.Water in the western approaches to the English Channel appeared to be influenced chiefly by the mixed, oceanic transitional water; oceanic influences in the North Sea appear to have been from northern and transitional waters.

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.

scholarly journals Crassicauda boopis in a fin whale (Balaenoptera physalus) ship-struck in the eastern North Atlantic Ocean

2017 ◽  
Vol 3 ◽  
Author(s):  
LAETITIA LEMPEREUR ◽  
MORGAN DELOBELLE ◽  
MARJAN DOOM ◽  
JAN HAELTERS ◽  
ETIENNE LEVY ◽  
...  
Keyword(s):  
North Atlantic ◽  
18S Rrna ◽  
North Atlantic Ocean ◽  
18S Rrna Gene ◽  
The Body ◽  
Rrna Gene ◽  
Balaenoptera Physalus ◽  
Fin Whale ◽  
Eastern North Atlantic ◽  
The Right

SUMMARY On 9 November 2015, a juvenile male fin whale of 11·60 m length was observed on the bulb of a merchant vessel in the Channel Terneuzen – Ghent (The Netherlands – Belgium). A severe parasitosis was present in the right heart ventricle and caudal caval vein. Parasites were identified as Crassicauda boopis based on macroscopic and microscopic observations. The sequence of the 18S rRNA gene obtained from the parasite samples was 100% similar to the sequence of the 18S rRNA gene from Crassicauda magna available on GenBank. While adults of C. boopis and C. magna are morphologically distinct and found at different locations in the body, the molecular analysis of the 18S rRNA gene seems insufficient for reliable species identification. Although numerous C. boopis were found, the cause of death was identified as due to the collision with the ship, as suggested by the presence of a large haematoma, and the absence of evidence of renal failure. The young age of this whale and the absence of severe chronic reaction may suggest that the infestation was not yet at an advanced chronic stage.

The distribution, cellular structure, and metabolism of adipose tissue in the fin whale, Balaenoptera physalus

1988 ◽  
Vol 66 (2) ◽  
pp. 534-537 ◽  
Author(s):  
Caroline M. Pond ◽  
Christine A. Mattacks
Keyword(s):  
Adipose Tissue ◽  
North Atlantic ◽  
Glucose Utilization ◽  
Significant Activity ◽  
Balaenoptera Physalus ◽  
Tissue Samples ◽  
Fin Whale ◽  
Terrestrial Mammals ◽  
The North ◽  
Adipocyte Volume

The gross mass, mean adipocyte volume, and hexokinase and phosphofructokinase activities of blubber and internal adipose tissue were measured from fin whales (Balaenoptera physalus) caught in the North Atlantic west of Iceland. Fin whale adipocytes are smaller but more numerous than predictions from allometric equations relating adipose tissue structure to body mass, but the deviations are no greater than those of some terrestrial mammals, including humans. Significant activity of the glycolytic enzymes was measured from all adipose tissue samples except those around the eyeball; the activities of hexokinase and phosphofructokinase measured at room temperature are only slightly lower in the blubber than in the internal adipose depots. There was little evidence for metabolic correlates of the site-specific differences in the structure and chemistry of blubber. The highest capacity for glucose utilization was measured in adipose tissue from depots in the neck and the thorax, both of which may contain thermogenic tissue in neonates.

Seasonal Predictability of Wintertime mid-latitude Cyclonic Activity over the North Atlantic and Europe

2021 ◽  
Author(s):  
Alvise Aranyossy ◽  
Sebastian Brune ◽  
Lara Hellmich ◽  
Johanna Baehr
Keyword(s):  
North Atlantic ◽  
Large Scale ◽  
Jet Stream ◽  
Cyclonic Activity ◽  
Max Planck ◽  
Pressure System ◽  
Wind Speeds ◽  
Average Lifespan ◽  
The North ◽  
The North Atlantic

<p>We analyse the connections between the wintertime North Atlantic Oscillation (NAO), the eddy-driven jet stream with the mid-latitude cyclonic activity over the North Atlantic and Europe. We investigate, through the comparison against ECMWF ERA5 and hindcast simulations from the Max Planck Institute Earth System Model (MPI-ESM), the potential for enhancement of the seasonal prediction skill of the Eddy Kinetic Energy (EKE) by accounting for the connections between large-scale climate and the regional cyclonic activity. Our analysis focuses on the wintertime months (December-March) in the 1979-2019 period, with seasonal predictions initialized every November 1st. We calculate EKE from wind speeds at 250 hPa, which we use as a proxy for cyclonic activity. The zonal and meridional wind speeds are bandpass filtered with a cut-off at 3-10 days to fit with the average lifespan of mid-latitude cyclones. </p><p>Preliminary results suggest that in ERA5, major positive anomalies in EKE, both in quantity and duration, are correlated with a northern position of the jet stream and a positive phase of the NAO. Apparently, a deepened Icelandic low-pressure system offers favourable conditions for mid-latitude cyclones in terms of growth and average lifespan. In contrast, negative anomalies in EKE over the North Atlantic and Central Europe are associated with a more equatorward jet stream, these are also linked to a negative phase of the NAO.  Thus, in ERA5, the eddy-driven jet stream and the NAO play a significant role in the spatial and temporal distribution of wintertime mid-latitude cyclonic activity over the North Atlantic and Europe. We extend this connection to the MPI-ESM hindcast simulations and present an analysis of their predictive skill of EKE for wintertime months.</p>

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