Fin Whales Balaenoptera Physalus Research Articles

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

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.

A comparative study of sporta perimedullaris musculosa in the renicule of six species of cetaceans

Organs and physiological internal systems of diving mammals display diverse and peculiar features. The kidney of cetaceans has been extensively studied and characterized. This organ is subdivided in small functional units called “renicules”; displaying a peculiar structure, the sporta perimedullaris musculosa. A comparative study of renicules was made in six species belonging to mysticetes and odontocetes. In all six species, the sporta, a connective tissue basket, was located between the medullary and the cortical regions of renicules. The sporta is mainly composed of a connective stroma and, in several species, the connective tissue (histochemically studied) was interposed among muscle fibres. Within the six studied species, the sporta varied in thickness, which appears to be related to the number, thickness and discontinuity of collagenous fibre bundles. The presence of smooth muscle fibres, evidenced by immunostaining and by electron microscopy analysis, was variable: whereas fibres were numerous in examined toothed whales (Stenella, Delphinus, Grampus, Tur‐siops), they were practically absent in baleen whales such as the fin whale Balaenoptera physalus. The data in the present study shed light on the morpho‐functional characterization of diving mammal anatomy and support the need to re‐examine the general structure of cetacean phylogeny, in line with the hypothesis of Milinkovitch et al. (1994) and Hasegawa et al. (1997).

Cetacean populations on the SE Bering Sea shelf during the late 1990s: implications for decadal changes in ecosystem structure and carbon flow

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 272:281-300 (2004) - doi:10.3354/meps272281 Cetacean populations on the SE Bering Sea shelf during the late 1990s: implications for decadal changes in ecosystem structure and carbon flow Cynthia T. Tynan* Department of Physical Oceanography, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA *Email: ctynan@whoi.edu ABSTRACT: Baleen whales typically migrate to high-latitudes to feed during summer in regions of predictably high concentrations of their zooplankton or fish prey. Therefore, their presence in shelf systems is a good indicator of productive food webs. Line-transect surveys of cetaceans conducted during the late 1990s in the SE Bering Sea (160.32 to 171.08°W) indicate that the middle shelf (50 m < z < 100 m) now supports the highest whale biomass in this region. In recent decades, whales were rare and hence their ecological role on the shelf was limited. During July 1997, the density and abundance (N) of humpback whales Megaptera novaeangliae and fin whales Balaenoptera physalus were highest on the middle shelf between 163.7 and 168.1°W: 0.0236 humpback whales km-2, N = 1308 (coefficient of variation, CV = 0.65), and 0.00924 fin whales km-2, N = 513 (CV = 0.61), respectively. Similarly, during June 1999, fin whales were the most numerically dominant species of large whale in the SE Bering Sea, with highest densities and abundance in the Œcentral¹ middle shelf (163.7 to 168.1°W): 0.0169 fin whales km-2, N = 938 (CV = 0.54). During the summers of 1997 and 1999, 65 and 79% of the prey consumption by fin whales in the SE Bering Sea occurred on the central middle shelf. Prey biomass consumed by fin and humpback whales on the SE Bering Sea shelf and slope in 1997 (264474 to 723504 metric tons, mt) is equivalent to 34-94% of the 1997 echo-integration trawl estimate of walleye pollock Theragra chalcogramma biomass (age 1+) for the shelf east of 170°W (0.77 ×106 mt). Large whales were much more abundant on the middle shelf during the late 1990s than during preceding decades and, therefore, their foraging may have impacted trophic dynamics, carbon pathways and nutrient cycling. The partitioning of available carbon and energy in the pelagic and benthic systems of the shelf, as determined previously during the 1970s, when whales were rare, should now be reexamined relative to the increased ecological impact of these top-level predators. Fluxes of carbon that involve pathways through whales should be incorporated in shelf and oceanic carbon budgets. KEY WORDS: Bering Sea · Carbon · Cetaceans · Coccolithophore · Ecosystem changes · Whales Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 272. Online publication date: May 19, 2004 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2004 Inter-Research.

Summer distribution and relative abundance of cetacean populations off north-west Scotland

A line transect survey was conducted in July/August 1998 to investigate the distribution and abundance of cetaceans off north-west Scotland. Over 2156.5 km of survey effort, 304 sightings were recorded of which 184 were identified to species. Nine species were identified: Atlantic white-sided dolphin Lagenorhynchus acutus, fin whale Balaenoptera physalus, sei whale Balaenoptera borealis, long-finned pilot whale Globicephala melas, sperm whale Physeter macrocephalus, common dolphin Delphinus delphis, harbour porpoise Phocoena phocoena, white beaked dolphin Lagenorhynchus albirostris and Risso's dolphin Grampus griseus. The Atlantic white-sided dolphin was the most relatively abundant species. The relative abundance of large whales and dolphins was greatest in the Faroe–Shetland Channel. The continental slopes of this area are undergoing development by oil industries and concerns have been raised about the potential impacts of these activities on cetaceans. These waters are used year-round by cetaceans and provide feeding and breeding grounds and are a migration route for large whales.

The fin whale Balaenoptera physalus (L. 1758) in the Mediterranean Sea

ABSTRACT 1. The ecology and status of fin whales Balaenoptera physalus in the Mediterranean Sea is reviewed. The species’ presence, morphology, distribution, movements, population structure, ecology and behaviour in this semi‐enclosed marine region are summarized, and the review is complemented with original, previously unpublished data. 2. Although the total size of the fin whale population in the Mediterranean is unknown, an estimate for a portion of the western basin, where most of the whales are known to live, was approximately 3500 individuals. High whale densities, comparable to those found in rich oceanic habitats, were found in well‐defined areas of high productivity. Most whales concentrate in the Ligurian‐Corsican‐Provençal Basin, where their presence is particularly noticeable during summer; however, neither their movement patterns throughout the region nor their seasonal cycle are clear. 3. Based on genetic studies, fin whales from the Mediterranean Sea are distinct from North Atlantic conspecifics, and may constitute a resident population, separate from those of the North Atlantic, despite the species’ historical presence in the Strait of Gibraltar. Fin whales are known to calve in the Mediterranean, with births peaking in November but occurring at lower rates throughout the year. They feed primarily on krill Meganyctiphanes norvegica which they capture by diving to depths in excess of 470 m. It is suggested that the extensive vertical migratory behaviour of its main prey may have influenced the social ecology of this population. 4. Known causes of mortality and threats, including collisions with vessels, entanglement in fishing gear, deliberate killing, disturbance, pollution and disease, are listed and discussed in view of the implementation of appropriate conservation measures to ensure the species’ survival in the region.

Marine mammals from the southern North Sea: feeding ecology data from δ13C and δ15N measurements

The harbour porpoise Phocoena phocoena, grey seal Halichoerus grypus, harbour seal Phoca vitulina and white-beaked dolphin Lagenorhynchus albirostris are regularly found stranded along southern North Sea coasts. Occasionally, offshore species such as the fin whale Balaenoptera physalus, the white-sided dolphin L. acutus and the sperm whale Physeter macrocephalus are also found stranded. In order to trace their diet, we measured δ 13 C and δ 15 N in their muscles as well as in 49 invertebrate and fish species collected from the southern North Sea. The δ 15 N data indicate that the harbour seal, grey seal and white-beaked dolphin occupy the highest trophic position, along with ichtyophageous fishes such as the cod Gadus morhua (mean muscle values of 18.7, 17.9, 18.8 and 19.2‰ respectively). The harbour porpoise occupies a slightly lower trophic position (mean δ 15 N value of 16.2 ‰), reflecting a higher amount of zooplanktivorous fishes in its diet (mean δ 15 N of 14.7‰); 2 suckling harbour porpoises displayed a significant δ 15 N enrichment of 2.2‰ compared to adult females. Adult females are δ 15 N-enriched compared to adult male harbour porpoises. Fin whales, sperm whales and white-sided dolphins are 13 C-depleted compared to southern North Sea particulate organic matter and species, suggesting that despite regular sightings, they do not feed within the southern North Sea area.

Genetic identification of a small and highly isolated population of fin whales (Balaenoptera physalus) in the Sea of Cortez, Mexico

For many years, researchers have speculatedthat fin whales are year-round residents in theSea of Cortez (= Gulf of California). Previouswork by Berube and co-workers has shownthat the degree of genetic diversity among finwhales in the Sea of Cortez at nuclear andmitochondrial loci is highly reduced. However,the relatively unobstructed connection with theNorth Pacific Ocean argues that Sea of Cortezfin whales are part of a much larger easternNorth Pacific population given the extensivemigratory ranges observed in fin whales andbaleen whales in general. The low degree ofgenetic variation might thus simply be due tohistoric fluctuations in the effectivepopulation size of an eastern North Pacificpopulation. In order to test if the reducedgenetic variation detected among fin whales inthe Sea of Cortez is due to small populationsize or a past bottleneck in an otherwise largeeastern North Pacific population, we analyzedthe geographic distribution of geneticvariation at a single mitochondrial (controlregion) and 16 nuclear loci in samplescollected from fin whales in the eastern NorthPacific (n = 12) as well as the Sea of Cortez(n = 77). Our results showed that fin whalesobserved in the Sea of Cortez constitute ahighly isolated and thus evolutionary uniquepopulation, which warrants special conservationmeasures given the current low estimate ofabundance of approximately 400 individuals.

Satellite tracking of a fin whale (Balaenoptera physalus) in the north-western Mediterranean Sea and fractal analysis of its trajectory

Satellite tracking of whales was the aim of the ARGOCET program in the western Mediterranean Sea. With the tracking technology and the development of telemetry, we can study large mammals under natural conditions. In 1991, a satellite tracking during 42 days on a fin whale (Balaenoptera physalus) was obtained. The Argos system allowed us to know the location of this tagged fin whale 263 times. In this study, we can distinguish two kinds of movements: linear segments and tortuous segments with loops drawn in a clockwise direction. Such loops may be superficial oscillations of inertia due to the inertia of the water mass combined with earth's rotation. With this trial study, which is the best we have obtained, we can estimate the fractal dimension d of this trajectory at different observation scales. These d values seem to be scale-independent, so the fin whale path is fractal-like or scale-independent. Fractal dimension, which is a scale-independent measure, summarizes interactions between an organism and its ecosystem and depends on the heterogeneity of the whale's environment (exogeneous factors) and the whale's ability to perceive it (endogeneous factors). For the fin whale trajectory we calculated d = 1.03 +/−0.01 with the divider method. The aggregated distribution of available resources for the fin whale in the western Mediterranean Sea can explain this result close to 1. The heterogeneity of this food resources is not a `measured heterogeneity' but is a `functional heterogeneity'. The low fractal dimension also points to the low probability that the tagged fin whale and the zooplankton aggregates will meet in the western Mediterranean Sea so the fin whale must cover long straight lines from one patch of available zooplankton to another.

How deep can baleen whales dive?

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 187:309-311 (1999) - doi:10.3354/meps187309 How deep can baleen whales dive? Simone Panigada*, Margherita Zanardelli, Simonepietro Canese, Maddalena Jahoda Tethys Research Institute, Acquario Civico, Viale G.B. Gadio 2, 20121 Milan, Italy *E-mail: panigada@tin.it ABSTRACT: This paper presents evidence of deep diving performances by fin whales Balaenoptera physalus in the Mediterranean Sea, never directly recorded for any other species of baleen whales. By means of velocity-time-depth-recorders applied to the whales with suction cups, depths of at least 470 m were registered twice, over 7 dives below 150 m recorded during a total of 12 h 38 min of remote tracking. The deep bouts occurred in late afternoon, in coincidence with the diel vertical upward migration of krill Meganyctiphanes norvegica, the principal prey species for Mediterranean fin whales. The data presented indicate that fin whale diving capabilities are opportunistically adapted to deep prey availability in the area. KEY WORDS: Deep diving · Fin whale · Mediterranean Sea · Feeding ecology · Telemetry · Krill migration Full text in pdf format PreviousExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 187. Publication date: October 14, 1999 Print ISSN:0171-8630; Online ISSN:1616-1599 Copyright © 1999 Inter-Research.

Distribution of mtDNA haplotypes in North Atlantic humpback whales: the influence of behaviour on population structure

Samples from 136 humpback whales Megaptera novaeangliae, representing 5 feeding aggregations in the North Atlantic and 1 in the Antarctic, were analyzed with respect to the sequence variation in the mitochondrial (mt) control region. A total of 288 base pairs was sequenced by direct sequencing of asymmetrically amplified DNA. Thirty-one different haplotypes were identified. The nucleotide diversity for the total sample was estimated to be 2.6 %, which is high relative to other North Atlantic cetaceans. The degree of genetic differentiation in various subsets of the samples was estimated and tested for statistical significance by Monte Carlo simulations. Significant degrees of heterogeneity were found between the Antarctic and all North Atlantic areas, as well as between Iceland and the western North Atlantic samples. A genealogical tree was estimated for the 31 haplotypes and rooted with the homologous sequence from a fin whale Balaenoptera physalus. The branching pattern in the genealogical tree suggests that the North Atlantic Ocean has been populated by 2 independent influxes of humpback whales. The combined results from the homogeneity tests and the genealogical tree indicate that behaviour (in this case maternally directed site fidelity to a foraging area) can influence the population structure of marine cetaceans on an evolutionary time scale.

Corneal anatomy of marine mammals

The corneal anatomy of fin whales (Balaenoptera physalus), minke whales (Balaenoptera acutorostrata), harp seals (Phoca groenlandica), ringed seals (Phoca hispida), and bearded seals (Eriganthus barbatus) was examined to determine if marine mammals have evolved specialized corneas for life in a marine habitat. One to seven eyes of each species were analyzed: paraffin sections stained with haematoxylin and eosin for light microscopy; and ultrathin sections for transmission electron microscopy. All corneas contain the five typical mammalian layers: epithelium, Bowman's layer, stroma, Descemet's membrane, and endothelium. The corneas of these marine mammals are thicker than human corneas because of a thicker stromal layer. The other layers are thinner than those found in humans, except for the epithelial layer in the bearded seal and the cetaceans where it may provide extra protection for the eye during feeding behaviour. The epithelial cells in all corneas studied have an abundance of tonofilaments, which may strengthen the cells and distribute force across the corneal surface. No special organization of collagen fibrils was found in the stroma that would offer protection from ultraviolet radiation or glare for pinnipeds when on ice. The thickness of the sclera in the cetaceans may serve to hold the inner globe of the eye in an elliptical shape, while the thinning of the sclera in the equatorial region in pinnipeds may flatten the eye in air to reduce aerial myopia.

Resightings of Independent Fin Whales, Balaenoptera physalus, on Maternal Summer Ranges

Between 1981 and 1987 in Massachusetts Bay, 16 different fin whale ( Balaenoptera physalus ) calves were individually identified. Separation of mother and calf occurred after the 1st year in at least nine instances. Four calves were observed to return to the area in subsequent years, suggesting that, in at least some instances, fidelity to a summer feeding ground is determined matrilineally.

Fluoride in the bone and diet of fin whales, Balaenoptera physalus

Bone samples were taken from fin whales Balaenoptera physalus from the North Atlantic to examine the relationship between fluoride concentration in skeletal tissue and age, sex, body length and anatomic location. By the use of an ion-selective electrode, the fluoride concentration in these samples were found to be higher than that normally occurring in any mammalian species, ranging from 4340 to 18 570 ppm. The positive correlation observed with age, along with high fluoride concentrations found in krill taken from the stomachs of these whales, indicated a probable bioaccumulation of fluoride from dietary sources. These results confirmed and extended earlier findings that bone tissue in fin whales naturally contains very high concentrations of fluoride and indicate that this baleen whale is tolerant to a significant extent of the high fluoride concentrations found in krill.

How fast should a dead whale cool?

Postmortem heat generation has recently been invoked to explain a core temperature of 28 °C in a 13-m fin whale Balaenoptera physalus 8-days after death. To investigate this suggestion further, heat transfer by a dead whale's mid-body region was modelled using finite difference equations for unsteady state conduction to predict tissue temperatures. The resulting simulations suggest that postmortem heat production is not necessary to explain Brodie's observation, and that the slow rate of cooling can be explained by the thermal inertia of a large body mass.

魚に含まれる脂肪酸アミド

The fatty acid amide compounds in organisms are known to occur in several forms, ceramide and shingolipid, N-acyl amino acid, peptidolipid, N-acyl ethanolamine, and the like. While investigating the composition of visceral lipid of fin whale Balaenoptera physalus, the authors detected another fatty acid amide compound, fatty acid amide (RCONH2), which had not been found to occur in organisms. The present report is concerned with the separation, identification and distribution of RCONH2 in fishes. The fatty acid amide fractions were prepared from red sea bream Chrysophyrys major and carp Cyprinus carpio by the method shown in Fig. 1. Although the main component of the fractions was ceramide; the minor component RCONH2 could be separated and identified by gas chromatography (Fig. 4), and then the composition of RCONH2 was compared with that of fatty acid of crude lipid (Table 2). RCONH2 in red sea bream: The amounts of RCONH2 found in the viscera were 82 μg% on the wet weight basis and in muscle 7μg%. Both tissues contained C14:0, C16:0, C17:0, C18 0 and C18 1 of RCONH2. In viscera, 53.2% of the total RCONH2 were C16 0, but in muscle, C16:0, C18 0 and C18:1 were almost evenly distributed. RCONH2 in carp: The amounts of RCONH2 found in viscera were 172 μg% and the composition is as shown in Table 2. The main component of RCONH2 was C22:0, which was not detected in red sea bream. In addition, short chain RCONH2 were also detected (Fig. 5). On the other hand, only trace amounts of RCONH2 were found in the muscle.

Lipids of the fin whale (balaenoptera physalus) from North Atlantic waters. II. Fatty acid composition of the liver lipids and gas-liquid chromatography evidence for the occurrence of 5,8,11,14-nonadecatetraenoic acid.

The fatty acid composition of the liver lipids of the fin whale (Balaenoptera physalus) closely resembles that of terrestrial mammals. Gas–liquid chromatographic evidence indicates that 5,8,11,14-nonadecatetraenoic acid is present, and the origin of this acid in association with 5,8,11,14-eicosatetraenoic acid is discussed.

Age Determination and Reproduction of Female Fin Whales Balaenoptera Physalus (Linnaeus, 1758), with Special regard to Baleen Plates and Ovaries

1. From Antarctic female Fin Whales, Balaenoptera physalus, a collection, consisting of baleen plates and the parts of these plates embedded in the gum, ovaries, and a number of earplugs was examined, in order to determine the age of these animals and to get a better insight in some characteristics of their reproduction. Data concerning pregnancy and lactation were also recorded. The material was sampled from animals worked up on board the f.f. “Willem Barendsz” during the Antarctic seasons 1953/1954 to 1959/1960 inclusive. The possibilities and values of age determination for this species were considered, based on the results of the analyses of the above material. 2. In most seasons the length distribution of the female Fin Whales, from which the material for the age determination was sampled (“examined animals”), did not differ significantly from that of the total catch of females of the “Willem Barendsz” in the same seasons. Neither was there any significant difference in length distribution between the total number of females from which the material was sampled and that of the females in the catch of the “Willem Barendsz” in all seasons. However, the length distribution of the catch of the “Willem Barendsz” differed significantly from the total Antarctic pelagic catch. 3. Baleen records were made according to the method described by RUUD (1940). In contrast with his age determinations with the aid of the part of the baleen plate protruding from the gum also the part of the plate hidden in the gum was used. A method of reading this part was developed. The advantage of this method is that the total length of baleen plate examined is much longer, and that the part hidden in the gum is not yet worn. In addition, the use of the part hidden in the gum has the undeniable advantage that the end of the cortical layer at the base of the “root” of the baleen plate represents the only exact date: the date at which the animal was killed. 4. Apart from the large waves of the cortical l