On the occurrence of the fin whale (Balaenoptera physalus) in the northern Adriatic

Author(s):  
Lovrenc Lipej ◽  
Jakov Dulčić ◽  
Boris Kryštufek

Twenty-three observations of 26 fin whales Balaenoptera physalus are documented for the northern Adriatic. Records were more common along the eastern coast and have increased over the last decades. The latter coincides with the increased presence of other planktivorous vertebrates (humpback whale, basking shark) and possibly follow changes in the zooplankton abundance.

2014 ◽  
Vol 74 (1) ◽  
pp. 137-144 ◽  
Author(s):  
LL Wedekin ◽  
MR Rossi-Santos ◽  
C Baracho ◽  
AL Cypriano-Souza ◽  
PC Simões-Lopes

Oceanic waters are difficult to assess, and there are many gaps in knowledge regarding cetacean occurrence. To fill some of these gaps, this article provides important cetacean records obtained in the winter of 2010 during a dedicated expedition to collect visual and acoustic information in the Vitória-Trindade seamounts. We observed 19 groups of cetaceans along a 1300-km search trajectory, with six species being identified: the humpback whale (Megaptera novaeangliae, N = 9 groups), the fin whale (Balaenoptera physalus, N = 1), the Antarctic minke whale (Balaenoptera bonaerensis, N = 1), the rough-toothed dolphin (Steno bredanensis, N = 1), the bottlenose dolphin (Tursiops truncatus, N = 2), and the killer whale (Orcinus orca, N = 1). Most humpback whale groups (N = 7; 78%) were observed in the Vitória-Trindade seamounts, especially the mounts close to the Abrolhos Bank. Only one lone humpback whale was observed near Trindade Island after a search effort encompassing more than 520 km. From a total of 28 acoustic stations, humpback whale songs were only detected near the seamounts close to the Abrolhos Bank, where most groups of this species were visually detected (including a competitive group and groups with calves). The presence of humpback whales at the Trindade Island and surroundings is most likely occasional, with few sightings and low density. Finally, we observed a significant number of humpback whales along the seamounts close to the Abrolhos Bank, which may function as a breeding habitat for this species. We also added important records regarding the occurrence of cetaceans in these mounts and in the Western South Atlantic, including the endangered fin whale.


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 ◽  
...  

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.


1992 ◽  
Vol 134 (3) ◽  
pp. 405-413 ◽  
Author(s):  
J. M. Kjeld ◽  
J. Sigurjónsson ◽  
A. Árnason

ABSTRACT Blood serum concentrations of testosterone and progesterone were measured in postmortem samples taken at sea from 814 fin whales (Balaenoptera physalus) caught during the summers (June–September) of 1981–1989. The ages of 781 of these animals were also assessed. The testosterone concentrations in samples from 352 males averaged 2 nmol/l; 41 samples had concentrations of 0·1 nmol/l or lower and 34 of these came from whales aged between 2 and 14 years and showed a Gaussian type of age distribution with a peak number at 7 to 8 years. The mean testosterone concentrations in the males increased by more than fourfold between June and August. Serum progesterone concentrations of the 462 females fell into three separate groups: (1) group I with values ≤ 0·1 nmol/l; (2) group II with intermediate values of > 0·1 nmol/l but <10 nmol/l; (3) group III with values of ≥ 10 nmol/l. These three groups of females seemed to consist respectively of young sexually immature females, mature non-pregnant females and pregnant females. The age distribution in the groups indicated that puberty in females is attained chiefly between the ages of 7 and 10. The yearly pregnancy rate (that percentage of all females caught and studied in a year which had progesterone values ≥10 nmol/l) was between 35% and 55%, except in 1987 when it was 67%. The yearly pregnancy rate would range from 56% to 93% if only mature females (i.e. those with serum progesterone >0·1 nmol/l) were considered. Serum oestradiol concentrations in male and female fin whales had no relation to age, sex or pregnancy. Journal of Endocrinology (1992) 134, 405–413


2021 ◽  
Vol 8 ◽  
Author(s):  
Sunniva Løviknes ◽  
Knut H. Jensen ◽  
Bjørn A. Krafft ◽  
Valantine Anthonypillai ◽  
Leif Nøttestad

Fin whales (Balaenoptera physalus) and humpback whales (Megaptera novaeangliae) are commonly found in the Norwegian Sea during the summer months. Records from around 1995 to 2004 show that their distribution patterns were mainly associated with those of macro-zooplankton. More recent studies conducted from 2009 to 2012 demonstrate marked shifts, with fin whale distribution related to pelagic fish distribution, decreasing densities of humpbacks, and increased densities of toothed whales. During the same period, historically large abundances of pelagic planktivorous fish in the Norwegian Sea were reported. The goals of this study were to examine the summer distribution of fin and humpback whales from 2013 to 2018 and to assess the potential association between distribution and environmental impact factors. Results suggest a pronounced northerly shift in distribution for both species, a feeding hotspot for fin whales at the shelf area between Svalbard and Norway, and one near Bear Island for humpback whales. Fin whale distribution was associated with that of blue whiting (Micromesistius poutassou) and capelin (Mallotus villosus), whereas humpback whale distribution was associated with that of euphausiids (Meganyctiphanes norvegica, Thysanoessa longicaudata, and Thysanoessa inermis), capelin, and herring (Clupea harengus). However, a significant negative spatial correlation was found between whale occurrence and the widely expanding population of northeast Atlantic mackerel (Scomber scombrus). The results of this study suggest that the prey composition of fin and humpback whales in recent years contain a large proportion of fish. The apparent northerly shift in the distribution of these whale species is largely determined by the availability of prey, but it likely is also impacted by direct or indirect interspecific interactions, especially with killer whales (Orcinus orca). Such large-scale pronounced changes in distribution seem to confirm a high degree of plasticity in fin and humpback whale feeding in the Norwegian Sea.


2016 ◽  
Vol 73 (8) ◽  
pp. 2085-2092 ◽  
Author(s):  
Koki Tsujii ◽  
Mayuko Otsuki ◽  
Tomonari Akamatsu ◽  
Ikuo Matsuo ◽  
Kazuo Amakasu ◽  
...  

Abstract Fin whales (Balaenoptera physalus) undergo seasonal migration in the Arctic Sea. Because their migration and distribution is likely affected by changes in global climate, we aimed to examine the migration timing of fin whales, and the relationship with prey availability within the oceanographic environment of the Arctic Sea, using passive and active acoustic monitoring methods. Automatic Underwater Sound Monitoring Systems were deployed in the southern Chukchi Sea from July 2012 to 2014 to determine the acoustic presence of fin whales. Furthermore, water temperature and salinity were recorded by a fixed data logger. An Acoustic Zooplankton Fish Profiler was additionally deployed to estimate prey abundance through backscattering strength. Sea ice concentrations were obtained by remote sensing data. Fin whale calls were automatically detected using a custom-made software, and the per cent of half-hours containing calls were counted. Fin whale calls were detected from 4 August to 20 October 2012 (78 d) and 25 July to 1 November 2013 (100 d). The extended period of acoustic presence of fin whales during 2013 when compared with 2012 is likely related to a longer ice-free period during 2013. Furthermore, generalized linear model analyses showed that half-hour periods containing calls increased with a rise in water temperature and zooplankton abundance during the initial call presence period, while they decreased with a decrease in water temperature and salinity during the end of the call presence period. Our results suggest that the rise in water temperature and zooplankton abundance affect the timing of migration of fin whales in a way that is consistent with the expansion of their suitable habitats and the extension of their presence in the Arctic Sea.


Author(s):  
Annie B. Douglas ◽  
John Calambokidis ◽  
Stephen Raverty ◽  
Steven J. Jeffries ◽  
Dyanna M. Lambourn ◽  
...  

Ship strikes of large whales cause mortalities worldwide, but there is uncertainty regarding the frequency and species involved. We examined 130 records (from 1980–2006) of large whale strandings in Washington State. Nineteen strandings (seven species) had evidence of ship-strikes. Fin whales (Balaenoptera physalus) had the highest incidence of ante-mortem ship strike (five of seven, with the remaining two possibly post-mortem) and all but one occurring since 2002. Six grey whales (Eschrichtius robustus) suffered ‘possible ship strike’ injuries, likely the result of their large numbers in the area, rather than high levels of ship strikes. Only one possible ship-struck humpback whale was recorded, despite concentrations of humpbacks feeding within shipping lanes in this region. This study shows dramatic differences in occurrences of ship-struck large whales by species, which we believe results from a combination of species' vulnerability to ship strikes, and how likely a struck whale is to be caught up on the bow of a ship and brought to waters where it can be examined.


2018 ◽  
Author(s):  
Andrea A. Cabrera ◽  
Jeroen P. A. Hoekendijk ◽  
Alex Aguilar ◽  
Susan G. Barco ◽  
Simon Berrow ◽  
...  

HighlightsMitochondrial monophyly is commonly employed to define evolutionary significant units.Monophyly may be caused by insufficient sampling or a recent common ancestor.Mitogenomic studies are generally based on few samples and prone to sampling issues.Expanded mitogenome sampling negates previous monophyly in fin whales.AbstractThe advent of massive parallel sequencing technologies has resulted in an increase of studies based upon complete mitochondrial genome DNA sequences that revisit the taxonomic status within and among species. Spatially distinct monophyly in mitogenomic genealogies, i.e., the sharing of a recent common ancestor among con-specific samples collected in the same region has been viewed as evidence for subspecies. Several recent studies in cetaceans have employed this criterion to suggest subsequent intraspecific taxonomic revisions. We reason that employing intra-specific, spatially distinct monophyly at non-recombining, clonally inherited genomes is an unsatisfactory criterion for defining subspecies based upon theoretical (genetic drift) and practical (sampling effort) arguments. This point is illustrated by a re-analysis of a global mitogenomic assessment of fin whales, Balaenoptera physalus spp., published by Archer et al. (2013) which proposed to further subdivide the Northern Hemisphere fin whale subspecies, B. p. physalus. The proposed revision was based upon the detection of spatially distinct monophyly among North Atlantic and North Pacific fin whales in a genealogy based upon complete mitochondrial genome DNA sequences. The extended analysis conducted in this study (1,676 mitochondrial control region, 162 complete mitochondrial genome DNA sequences and 20 microsatellite loci genotyped in 358 samples) revealed that the apparent monophyly among North Atlantic fin whales reported by Archer et al. (2013) to be due to low sample sizes. In conclusion, defining sub-species from monophyly (i.e., the absence of para-or polyphyly) can lead to erroneous conclusions due to relatively “trivial” aspects, such as sampling. Basic population genetic processes (i.e., genetic drift and migration) also affect the time to most recent common ancestor and hence the probability that individuals in a sample are monophyletic.


2005 ◽  
Vol 6 (4) ◽  
pp. 631-636 ◽  
Author(s):  
Martine Bérubé ◽  
Mary Beth Rew ◽  
Hans Skaug ◽  
Hanne Jørgensen ◽  
Jooke Robbins ◽  
...  

PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0256815
Author(s):  
Eric M. Keen ◽  
James Pilkington ◽  
Éadin O’Mahony ◽  
Kim-Ly Thompson ◽  
Benjamin Hendricks ◽  
...  

Fin whales (Balaenoptera physalus) are widely considered an offshore and oceanic species, but certain populations also use coastal areas and semi-enclosed seas. Based upon fifteen years of study, we report that Canadian Pacific fin whales (B. p. velifera) have returned to the Kitimat Fjord System (KFS) in the Great Bear Rainforest, and have established a seasonally resident population in its intracoastal waters. This is the only fjord system along this coast or elsewhere in which fin whales are known to occur regularly with strong site fidelity. The KFS was also the only Canadian Pacific fjord system in which fin whales were commonly found and killed during commercial whaling, pointing to its long-term importance. Traditional knowledge, whaling records, and citizen science databases suggest that fin whales were extirpated from this area prior to their return in 2005–2006. Visual surveys and mark-recapture analysis documented their repopulation of the area, with 100–120 whales using the fjord system in recent years, as well as the establishment of a seasonally resident population with annual return rates higher than 70%. Line transect surveys identified the central and outer channels of the KFS as the primary fin whale habitat, with the greatest densities occurring in Squally Channel and Caamaño Sound. Fin whales were observed in the KFS in most months of the year. Vessel- and shore-based surveys (27,311 km and 6,572 hours of effort, respectively) indicated regular fin whale presence (2,542 detections), including mother-calf pairs, from June to October and peak abundance in late August–early September. Seasonal patterns were variable year-to-year, and several lines of evidence indicated that fin whales arrived and departed from the KFS repeatedly throughout the summer and fall. Additionally, we report on the population’s social network and morphometrics. These findings offer insights into the dynamics of population recovery in an area where several marine shipping projects are proposed. The fin whales of the Great Bear Rainforest represent a rare exception to general patterns in this species’ natural history, and we highlight the importance of their conservation.


1993 ◽  
Vol 71 (12) ◽  
pp. 2546-2550 ◽  
Author(s):  
Paul F. Brodie

The fin whale (Balaenoptera physalus) is representative of baleen whales, which feed by engulfing up to 70 t of seawater in an elastic throat pouch, prior to filtering. This represents (i) the greatest biomechanical action in the animal kingdom, and (ii) a deviation from the flowthrough design of fishing trawls, most filter-feeders, and sampling devices. Based upon observations of fresh carcasses, it is proposed that during the brief period at full gape agile prey may be startled and retained within the pouch by noise: a synovial joint-crack generated during realignment of the tips of the mandibles. It is argued that the previous detection of nonvocal sounds, attributed to the body movements of feeding fin whales, may also include noise resulting from this action.


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