Summer social distribution of sperm whales (Physeter macrocephalus) in the Mediterranean Sea

2004 ◽  
Vol 84 (3) ◽  
pp. 675-680 ◽  
Author(s):  
Violaine Drouot ◽  
Alexandre Gannier ◽  
John C. Goold
Keyword(s):  
Mediterranean Sea ◽  
Sperm Whale ◽  
Northern Region ◽  
The Body ◽  
Southern Region ◽  
Physeter Macrocephalus ◽  
Sperm Whales ◽  
The North ◽  
Social Distribution ◽  
The Mediterranean

Sperm whale social distribution was investigated in the Mediterranean Sea, using data collected during summer surveys from 1997 to 2002. Variations in the size of sperm whale schools/underwater aggregations were assessed using both visual and acoustic data. Individual body lengths were estimated acoustically, using the click inter-pulse intervals. Regional comparisons were undertaken, taking the 41° parallel as a north/south boundary. In the southern region, schools of up to seven sperm whales were sighted and calves were relatively frequent. The animals ranged between 8·6 m and 13·1 m long. In the northern region, school sizes were significantly smaller, with a maximum of three whales sighted at the surface. However, the acoustic survey showed that sperm whales form loose aggregations of up to five animals in certain areas. Whales detected in the north were 12·6 m long on average, and the body size range was relatively small. This summer survey demonstrated a segregation of males, in the north, from larger schools including calves, which seemed to be confined to the southern region.

SST fronts and the summer sperm whale distribution in the north-west Mediterranean Sea

2007 ◽  
Vol 87 (1) ◽  
pp. 187-193 ◽  
Author(s):  
Alexandre Gannier ◽  
Emilie Praca
Keyword(s):  
Mediterranean Sea ◽  
Feeding Strategy ◽  
Sperm Whale ◽  
Western Mediterranean ◽  
Relative Distribution ◽  
Physeter Macrocephalus ◽  
Sperm Whales ◽  
The North ◽  
North Western ◽  
Sst Fronts

The relative distribution of sperm whales (Physeter macrocephalus) and sea surface temperature (SST) fronts have been studied in summer in the north-western Mediterranean Sea. We used passive acoustic data (778 samples) obtained offshore during dedicated surveys between 1999 and 2004 and Pathfinder/Modis remote sensing data to compute front maps and to calculate mean distances from sperm whale detections (N=132) to SST-fronts. Mean distances from sperm whale acoustic detections to SST-fronts were significantly lower (10.4 km) than from other acoustic samples to those fronts (17.0 km). The same result was obtained when calculating distances from sperm whales to the North Balearic Front surface signature. If sperm whales are commonly observed along the continental slope, we showed that offshore individuals were located close to SST-fronts. This bimodal distribution in the north-western Mediterranean is linked to sperm whale feeding strategy, demonstrating ecological opportunistic behaviour in this high level predator.

Occurrence of anthropozoonotic parasitic infections and faecal microbes in free-ranging sperm whales (Physeter macrocephalus) from the Mediterranean Sea

2018 ◽  
Vol 117 (8) ◽  
pp. 2531-2541 ◽  
Author(s):  
Carlos Hermosilla ◽  
J. Hirzmann ◽  
L. M. R. Silva ◽  
J. M. Brotons ◽  
M. Cerdà ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Parasitic Infections ◽  
Physeter Macrocephalus ◽  
Sperm Whales ◽  
The Mediterranean ◽  
Free Ranging

The diet of sperm whales ( Physeter macrocephalus Linnaeus 1758) off the Azores

1993 ◽  
Vol 339 (1287) ◽  
pp. 67-82 ◽  
Keyword(s):  
North Atlantic ◽  
Stomach Contents ◽  
Sperm Whale ◽  
Physeter Macrocephalus ◽  
Sperm Whales ◽  
Commercial Activities ◽  
The North ◽  
The North Atlantic ◽  
Modal Mass ◽  
Neutrally Buoyant

Stomach contents from 17 sperm whales, 15 males and two females, caught during commercial activities in 1981-1984 in the Azores region were identified and measured. A total of 28 738 cephalopods and 16 fish were represented in the collections. In addition, there were tunicates in two whales and m an-m ade products in three whales. None of the stomachs were empty. Flesh was present in 94.1% and indigestible fragments alone, including mandibles (beaks) of cephalopods, were present in 5.9% of the stomachs. Twelve species of cephalopod were represented by flesh and 40 species were represented by lower beaks. The cephalopod families contributing food to the whales in this region are, in order of their contribution by estimated mass, the O ctopoteuthidae (39.8%), the Histioteuthidae (32.7%), the Architeuthidae (12.1%), the Lepidoteuthidae (4.5% ), the Ommastrephidae (3.4% ), the Pholidoteuthidae (2.1% ), the Cycloteuthidae (1.9% ), the Cranchiidae (1.7%) and eight other families each contributing less than 1 % by mass. Presence of Gonatus beaks in the stomachs show which whales have migrated southwards to the Azores just prior to capture and the presence of a large Megalocranchia species possibly shows which whales have m igrated from higher latitudes off Iceland. However, the presence of Teuthowenia maculata shows which whales came north from the West coast of Africa, just prior to capture. The modal mass of cephalopods consumed is 400-450 g which represents 0.00001 of the whales’ body mass. 77.5% of the species eaten have luminous organs and 82% of the species are neutrally buoyant. It seems likely that the sperm whale is obtaining 77% of its food by swimming through luminous shoals of slow-swimming, neutrally bouyant squids and only about 23% by chasing faster swimming, larger cephalopods. Cephalopods not previously recorded from the North Atlantic are Onychoteuthis boreali-japonicus , and Histioteuthis bonnellii corpuscula . Histioteuthis ?miranda may have been collected by the whales much further south than the Azores. Species not recorded previously in the diet of sperm whales in the North Atlantic are Ommastrephes bartrami , Gonatus steenstrupi , Histioteuthis ?miranda , H. bonnellii corpuscula , H. meleagroteuthis , Discoteuthis laciniosa , Mastigoteulhis species, Chiroteulhis species, ?Helicocranchia , Liocranchia reinhardti , and ?Liguriella .

scholarly journals Wild whale faecal samples as a proxy of anthropogenic impact

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Marianna Marangi ◽  
Sabina Airoldi ◽  
Luciano Beneduce ◽  
Claudio Zaccone
Keyword(s):  
Heavy Metals ◽  
Mediterranean Sea ◽  
Limit Of Detection ◽  
Sperm Whale ◽  
Anthropogenic Activity ◽  
Physeter Macrocephalus ◽  
Sperm Whales ◽  
Faecal Samples ◽  
Fin Whales ◽  
Free Ranging

AbstractThe occurrence of protozoan parasite, bacterial communities, organic pollutants and heavy metals was investigated in free-ranging species of fin (Balaenoptera physalus, n. 2) and sperm (Physeter macrocephalus, n. 2) whales from the Pelagos Sanctuary, Corsican-Ligurian Provencal Basin (Northern-Western Mediterranean Sea). Out of four faecal samples investigated, two from fin whales and one from sperm whale were found positive to Blastocystis sp. A higher number of sequences related to Synergistetes and Spirochaetae were found in sperm whales if compared with fin whales. Moreover, As, Co and Hg were found exclusively in sperm whale faecal samples, while Pb was found only in fin whale faecal samples. The concentration of both PAH and PCB was always below the limit of detection. This is the first report in which the presence of these opportunistic pathogens, bacteria and chemical pollutants have been investigated in faecal samples of free-ranging whale species and the first record of Blastocystis in fin and sperm whales. Thus, this study may provide baseline data on new anthropozoonotic parasite, bacterial records and heavy metals in free-ranging fin and sperm whales, probably as a result of an increasing anthropogenic activity. This survey calls for more integrated research to perform regular monitoring programs supported by national and/or international authorities responsible for preservation of these still vulnerable and threatened whale species in the Mediterranean Sea.

scholarly journals Combined line-transect and cue-count estimate of sperm whale abundance in the North Atlantic, from Icelandic NASS-2001 shipboard survey

2009 ◽  
Vol 7 ◽  
pp. 73
Author(s):  
Thorvaldur Gunnlaugsson ◽  
Gisli A Víkingsson ◽  
Daniel G Pike
Keyword(s):  
North Atlantic ◽  
Sperm Whale ◽  
Line Transect ◽  
Physeter Macrocephalus ◽  
Preliminary Estimate ◽  
Sperm Whales ◽  
Deep Dive ◽  
The North ◽  
Surface Time ◽  
Track Line

Sperm whales (Physeter macrocephalus) pose a particular problem to shipboard surveys as they dive for extended periods and are therefore likely to be missed (not available) even if they are right under the track line. To address these problems the NAMMCO planning committee for the NASS 2001 survey drew up guidelines to be followed when sperm whales were sighted. This required every deep dive to be recorded and considered to be a cue, from which a cue-count estimate is calculated if the cue rate is known. For those whales that did not dive before coming abeam, a conventional line-transect estimate is calculated, which gives an instantaneous surface estimate from which a total estimate can be obtained if the proportion of the time spent at the surface is known. These estimates are compared and combined. Precise dive cycle information is missing for the mostly single all male sperm whales in this area but a preliminary estimate of 11,185 (cv 0.34) is obtained for the surveyed area with an assumed surface time of 20% and two deep dives per hour.

Stable isotope profiles in sperm whale teeth: variations between areas and sexes

2007 ◽  
Vol 87 (2) ◽  
pp. 621-627 ◽  
Author(s):  
Sónia Mendes ◽  
Jason Newton ◽  
Robert J. Reid ◽  
Alexandros Frantzis ◽  
Graham J. Pierce
Keyword(s):  
Stable Isotope ◽  
Indian Ocean ◽  
Mediterranean Sea ◽  
Marked Change ◽  
Sperm Whale ◽  
Population Substructure ◽  
Isotopic Ratios ◽  
Physeter Macrocephalus ◽  
The Indian Ocean ◽  
The Mediterranean

Sperm whale (Physeter macrocephalus) teeth were used to investigate whether variation in the chronological profiles of carbon and nitrogen stable isotope ratios along dentine growth layers could reflect differences in ontogenetic movements and/or dietary shifts in animals from different regions and sexes, as well as to show the differences in the isotopic environments experienced by these animals. Absolute isotopic ratios ranged from -14.1 to -11.0‰ for carbon and 10.8 to 18.1‰ for nitrogen, with the whale from the Indian Ocean, the two from the Mediterranean Sea and the female from the Azores presenting the most different median isotopic ratios. The Icelandic and the Indian Ocean males showed the expected decrease in δ13C around the age of ten, denoting male segregation from natal groups. For the latter, this was larger by almost twofold compared to other teeth, probably due to the much stronger latitudinal gradient in planktonic δ13C in the southern hemisphere. The Mediterranean Sea whales exhibited the lowest median δ15N values, probably reflecting the oligotrophy of this sea, while the male showed a marked change in isotopes around the age of 20 that could indicate a move to the eastern basin or a temporal change in basal isotopic signatures. The Atlantic females did not show a marked change in δ13C as expected since they stay in low latitudes throughout their lives. Stable isotope profiles in whale teeth can be used to investigate differences in the timings of ontogenetic movements and dietary history between individuals and sexes, and the biogeochemistry of different regions inhabited, and have the potential to allow inferences to be made about population substructure.

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