Marine Mammals: Sperm Whales and Beaked Whales

2009 ◽  
pp. 643-650
Author(s):  
S.K. Hooker
Keyword(s):  
Marine Mammals ◽  
Sperm Whales ◽  
Beaked Whales

scholarly journals Cetacean strandings along the Pacific and Caribbean coasts of Nicaragua from 2014 to 2021

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Joëlle De Weerdt ◽  
Eric Angel Ramos ◽  
Etienne Pouplard ◽  
Marc Kochzius ◽  
Phillip Clapham
Keyword(s):  
Marine Mammals ◽  
Sperm Whale ◽  
Distribution Patterns ◽  
Sperm Whales ◽  
The Pacific ◽  
Toothed Whale ◽  
Beaked Whales ◽  
Causes Of Mortality ◽  
Cuvier’S Beaked Whale ◽  
Stenella Attenuata

AbstractDocumenting marine mammal strandings provides important information needed to understand the occurrence and distribution patterns of species. Here, we report on strandings of cetaceans on the Pacific (n = 11) and Caribbean (n = 2) coasts of Nicaragua, documented opportunistically from 2014 to 2021. Strandings included three species of baleen whale (blue whale Balaenoptera musculus, Bryde’s whale Balaenoptera edeni, humpback whale Megaptera novaeangliae) and five species of toothed whale (dwarf sperm whale Kogia sima, Guiana dolphin Sotalia guianensis, pantropical spotted dolphin Stenella attenuata, spinner dolphin Stenella longirostris, Cuvier’s beaked whale Ziphius cavirostris). These are the first published accounts of blue whales, Bryde’s whales, dwarf sperm whales, and Cuvier’s beaked whales in Nicaraguan waters. Limited resources and the advanced decomposition of animals prevented necropsies in most cases, the identification of the causes of mortality in all cases, and the species identification of two dolphins. Information derived from these stranding events offers new insights into the occurrence of marine mammals on the Pacific and Caribbean coasts of Nicaragua and Central America.

First record of Norwegian killer whales attacking and feeding on a harbour porpoise

2015 ◽  
Vol 8 ◽  
Author(s):  
A. Mel Cosentino
Keyword(s):  
North Atlantic ◽  
Marine Mammals ◽  
First Record ◽  
Harbour Porpoise ◽  
Sperm Whales ◽  
Killer Whales ◽  
Strait Of Gibraltar ◽  
Cetacean Species ◽  
The North ◽  
Northern Bottlenose Whales

Orcinus orcais a cosmopolitan species and the most widely distributed marine mammal. Its diet includes over 140 species of fish, cephalopods, sea birds and marine mammals. However, many populations are specialised on certain specific prey items. Three genetically distinct populations have been described in the North Atlantic. Population A (that includes the Icelandic and Norwegian sub-populations) is believed to be piscivorous, as is population C, which includes fish-eating killer whales from the Strait of Gibraltar. In contrast, population B feeds on both fish and marine mammals. Norwegian killer whales follow the Norwegian spring spawning herring stock. The only description in the literature of Norwegian killer whales feeding on another cetacean species is a predation event on northern bottlenose whales in 1968. Daily land-based surveys targeting sperm whales were conducted from the Andenes lighthouse using BigEyes®binoculars (25×, 80 mm). The location of animals at sea was approximated through the use of an internal reticule system and a graduated wheel. On 24 June 2012 at 3:12 am, an opportunistic sighting of 11 killer whales was made off Andenes harbour. The whales hunted and fed on a harbour porpoise. Despite these species having overlapping distributions in Norwegian waters, this is the first predatory event reported in the literature.

Estimating mean body masses of marine mammals from maximum body lengths

1998 ◽  
Vol 76 (5) ◽  
pp. 886-896 ◽  
Author(s):  
Andrew W Trites ◽  
Daniel Pauly
Keyword(s):  
Marine Mammals ◽  
Growth Curves ◽  
Survival Models ◽  
Regression Equations ◽  
Sperm Whales ◽  
Baleen Whales ◽  
Sea Lions ◽  
Living Species ◽  
Maximum Body ◽  
Maximum Body Length

Generalized survival models were applied to growth curves published for 17 species of cetaceans (5 mysticetes, 12 odontocetes) and 13 species of pinnipeds (1 odobenid, 4 otariids, 8 phocids). The mean mass of all individuals in the population was calculated and plotted against the maximum body length reported for each species. The data showed strong linearity (on logarithmic scales), with three distinct clusters of points corresponding to the mysticetes (baleen whales), odontocetes (toothed whales), and pinnipeds (seals, sea lions, and walruses). Exceptions to this pattern were the sperm whales, which appeared to be more closely related to the mysticetes than to the odontocetes. Regression equations were applied to the maximum lengths reported for 76 species of marine mammals without published growth curves. Estimates of mean body mass were thus derived for 106 living species of marine mammals.

Partitioning of the Pelagos Sanctuary (north-western Mediterranean Sea) into hotspots and coldspots of cetacean distributions

2008 ◽  
Vol 88 (6) ◽  
pp. 1273-1281 ◽  
Author(s):  
Aurélie Moulins ◽  
Massimiliano Rosso ◽  
Marco Ballardini ◽  
Maurizio Würtz
Keyword(s):  
Mediterranean Sea ◽  
Continental Slope ◽  
Western Mediterranean ◽  
Sperm Whales ◽  
Fin Whale ◽  
Striped Dolphin ◽  
Western Mediterranean Sea ◽  
Beaked Whales ◽  
Risso's Dolphin ◽  
North Western

This study used Monte Carlo methods to generate simulations that considered the effort distribution to determine the locations of significant aggregations of cetacean sightings inside the northern Pelagos Sanctuary (north-western Mediterranean Sea). For three years, monitoring has been conducted from five motor vessels covering about 30,050 km. The most frequently encountered species were the striped dolphin Stenella coeruleoalba representing 64.7% of all sightings, the fin whale Balaenoptera physalus (17.0%), Cuvier's beaked whale Ziphius cavirostris (9.9%), Risso's dolphin Grampus griseus (4.3%) and the sperm whale Physeter catodon (2.2%). Sightings' positions and effort coverage were distributed over a grid of 5′ longitude and 5′ latitude. Spatial concentrations of sightings were analysed according to the distribution of effort to identify ‘hotspots’ (locations where the species occurred at a significantly greater frequency than expected), and ‘coldspots’ (locations with a significantly lower frequency than expected). Most fin whale hotspots (14) were located on the bathyal plain between 2000 and 2500 m, four hotspots were around the 1000 m isobaths, and one is located close to the seamount off Genoa. Fin whale coldspots were mainly along the coast. Striped dolphin hotspots were widely distributed over two main areas, in waters with depths between 2000 and 2500 m and at the continental slope; coldspots for this species were also mainly along the coast in the northern part of the study area. Many hotspots were found in the Genoa Canyon, and hotspots of striped dolphins, Cuvier's beaked whales, sperm whales and Risso's dolphins overlapped in this region. Some of the hotspots of Cuvier's beaked whales were identified at the seamount in the study area, where no other species was sighted frequently. Risso's dolphin hotspots were mainly near the 1000 m isobath. For sperm whales, several hotspots were identified: three associated with steep slope features (such as canyons or the continental slope), and one was in the centre of the flat area of Pelagos where the depth is 2500 m. This study highlights the ecological importance of particular locations inside the Pelagos Sanctuary—locations that should be protected from anthropogenic degradations for marine mammal conservation.

scholarly journals Repeated mass strandings of Miocene marine mammals from Atacama Region of Chile point to sudden death at sea

2014 ◽  
Vol 281 (1781) ◽  
pp. 20133316 ◽  
Author(s):  
Nicholas D. Pyenson ◽  
Carolina S. Gutstein ◽  
James F. Parham ◽  
Jacobus P. Le Roux ◽  
Catalina Carreño Chavarría ◽  
...  
Keyword(s):  
Marine Mammal ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Marine Mammals ◽  
Large Scale ◽  
Sperm Whales ◽  
Algal Toxins ◽  
Accumulation Mechanism ◽  
Taphonomic Analysis ◽  
Spatial Focusing

Marine mammal mass strandings have occurred for millions of years, but their origins defy singular explanations. Beyond human causes, mass strandings have been attributed to herding behaviour, large-scale oceanographic fronts and harmful algal blooms (HABs). Because algal toxins cause organ failure in marine mammals, HABs are the most common mass stranding agent with broad geographical and widespread taxonomic impact. Toxin-mediated mortalities in marine food webs have the potential to occur over geological timescales, but direct evidence for their antiquity has been lacking. Here, we describe an unusually dense accumulation of fossil marine vertebrates from Cerro Ballena, a Late Miocene locality in Atacama Region of Chile, preserving over 40 skeletons of rorqual whales, sperm whales, seals, aquatic sloths, walrus-whales and predatory bony fish. Marine mammal skeletons are distributed in four discrete horizons at the site, representing a recurring accumulation mechanism. Taphonomic analysis points to strong spatial focusing with a rapid death mechanism at sea, before being buried on a barrier-protected supratidal flat. In modern settings, HABs are the only known natural cause for such repeated, multispecies accumulations. This proposed agent suggests that upwelling zones elsewhere in the world should preserve fossil marine vertebrate accumulations in similar modes and densities.

scholarly journals Northern bottlenose whales in a pristine environment respond strongly to close and distant navy sonar signals

2019 ◽  
Vol 286 (1899) ◽  
pp. 20182592 ◽  
Author(s):  
Paul J. Wensveen ◽  
Saana Isojunno ◽  
Rune R. Hansen ◽  
Alexander M. von Benda-Beckmann ◽  
Lars Kleivane ◽  
...  
Keyword(s):  
Perceived Risk ◽  
Marine Mammals ◽  
Sound Sources ◽  
Acoustic Environment ◽  
Sound Levels ◽  
Medium Resolution ◽  
Source Distance ◽  
Wide Range ◽  
Beaked Whales ◽  
Northern Bottlenose Whales

Impact assessments for sonar operations typically use received sound levels to predict behavioural disturbance in marine mammals. However, there are indications that cetaceans may learn to associate exposures from distant sound sources with lower perceived risk. To investigate the roles of source distance and received level in an area without frequent sonar activity, we conducted multi-scale controlled exposure experiments ( n = 3) with 12 northern bottlenose whales near Jan Mayen, Norway. Animals were tagged with high-resolution archival tags ( n = 1 per experiment) or medium-resolution satellite tags ( n = 9 in total) and subsequently exposed to sonar. We also deployed bottom-moored recorders to acoustically monitor for whales in the exposed area. Tagged whales initiated avoidance of the sound source over a wide range of distances (0.8–28 km), with responses characteristic of beaked whales. Both onset and intensity of response were better predicted by received sound pressure level (SPL) than by source distance. Avoidance threshold SPLs estimated for each whale ranged from 117–126 dB re 1 µPa, comparable to those of other tagged beaked whales. In this pristine underwater acoustic environment, we found no indication that the source distances tested in our experiments modulated the behavioural effects of sonar, as has been suggested for locations where whales are frequently exposed to sonar.

Findings of elasmobranch eggs in the stomachs of sperm whales and other marine organisms

2003 ◽  
Vol 83 (6) ◽  
pp. 1351-1353 ◽  
Author(s):  
P.H.F. Bor ◽  
M.B. Santos
Keyword(s):  
Marine Mammals ◽  
Marine Organisms ◽  
Sperm Whales

The first records of thorny skate eggs in stomachs of sperm whales are described. Predation on elasmobranch eggs, especially by marine mammals, is reviewed.

Sign in / Sign up

Export Citation Format

Share Document