Chlorophyll a concentration, and proportion of time in the water column obtained by instrumented bowhead whales

Sixty hours of direct measurements of fluorescence were collected from six bowhead whales (Balaena mysticetus) instrumented with fluorometers in Greenland in April 2005 and 2006. The data were used to (1) characterize the three-dimensional spatial pattern of chlorophyll-a (Chl-a) in the water column, (2) to examine the relationships between whale foraging areas and productive zones, and (3) to examine the correlation between whale-derived in situ values of Chl-a and those from concurrent satellite images using the NASA MODIS (Moderate Resolution Imaging Spectroradiometer) EOS-AQUA satellite (MOD21, SeaWifs analogue OC3M and SST MOD37). Bowhead whales traversed 1600 km**2, providing information on diving, Chl-a structure and temperature profiles to depths below 200 m. Feeding dives frequently passed through surface waters ( >50 m) and targeted depths close to the bottom, and whales did not always target patches of high concentrations of Chl-a in the upper 50 m. Five satellite images were available within the periods whales carried fluorometers. Whales traversed 91 pixels collecting on average 761 s (SD 826) of Chl-a samples per pixel (0-136 m). The depth of the Chl-a maximum ranged widely, from 1 to 66 m. Estimates of Chl-a made from the water-leaving radiance measurements using the OC3M algorithm were highly skewed with most samples estimated as <1 mg/m**3 Chl-a, while data collected from whales had a broad distribution with Chl-a reaching >9 mg/m**3. The correlation between the satellite-derived and whale-derived Chl-a maxima was poor, a linear fit explained only 10% of the variance.

Whale sightings, group sizes and krill biomass in West Greenland in 2005

This study combined data on fin whale Balaenoptera physalus, humpback whale Megaptera novaeangliae, minke whale B. acutorostrata, and sei whale B. borealis sightings from large-scale visual aerial and ship-based surveys (248 and 157 sightings, respectively) with synoptic acoustic sampling of krill Meganyctiphanes norvegica and Thysanoessa sp. abundance in September 2005 in West Greenland to examine the relationships between whales and their prey. Krill densities were obtained by converting relationships of volume backscattering strengths at multiple frequencies to a numerical density using an estimate of krill target strength. Krill data were vertically integrated in 25 m depth bins between 0 and 300 m to obtain water column biomass (g/m**2) and translated to density surfaces using ordinary kriging. Standard regression models (Generalized Additive Modeling, GAM, and Generalized Linear Modeling, GLM) were developed to identify important explanatory variables relating the presence, absence, and density of large whales to the physical and biological environment and different survey platforms. Large baleen whales were concentrated in 3 focal areas: (1) the northern edge of Lille Hellefiske bank between 65 and 67°N, (2) north of Paamiut at 63°N, and (3) in South Greenland between 60 and 61° N. There was a bimodal pattern of mean krill density between depths, with one peak between 50 and 75 m (mean 0.75 g/m**2, SD 2.74) and another between 225 and 275 m (mean 1.2 to 1.3 g/m**2, SD 23 to 19). Water column krill biomass was 3 times higher in South Greenland than at any other site along the coast. Total depth-integrated krill biomass was 1.3 x 10**9 (CV 0.11). Models indicated the most important parameter in predicting large baleen whale presence was integrated krill abundance, although this relationship was only significant for sightings obtained on the ship survey. This suggests that a high degree of spatio-temporal synchrony in observations is necessary for quantifying predator-prey relationships. Krill biomass was most predictive of whale presence at depths >150 m, suggesting a threshold depth below which it is energetically optimal for baleen whales to forage on krill in West Greenland.

Total length, and lipid and toxaphene content in blubber of minke whales (B. acutorostrata) from the North Atlantic

Toxaphene contamination of minke whales (Balaenoptera acutorostrata) from North Atlantic waters was examined for the first time. Total toxaphene and SumCHB (sum of 11 chlorobornanes) concentrations in blubber samples ranged from 170 ± 110 and 41 ± 39 ng/g lipid weight (l.w.) for female minke whales from southeastern Greenland to 5800 ± 4100 and 1100 ± 780 ng/g l.w. for males from the North Sea, respectively. Very large variations in toxaphene concentrations among sampling areas were observed suggesting a spatial segregation of minke whales. However, much of the apparent geographical discrimination was explained by the seasonal fluctuation of animal fat mass. Patterns of CHBs in males revealed that recalcitrant CHBs were in higher proportions in animals from the more easterly areas than in animals from the more westerly areas. This trend may be influenced by the predominance of the US, over the European, input of toxaphene to North Atlantic waters.

Travel time and speed of gray whales and amphipod abundance along Chukotka Peninsula in 2006

The purpose of this study was to evaluate summer and fall residency and habitat selection by gray whales, Eschrichtius robustus, together with the biomass of benthic amphipod prey on the coastal feeding grounds along the Chukotka Peninsula. Thirteen gray whales were instrumented with satellite transmitters in September 2006 near the Chukotka Peninsula, Russia. Nine transmitters provided positions from whales for up to 81 days. The whales travelled within 5 km of the Chukotka coast for most of the period they were tracked with only occasional movements offshore. The average daily travel speeds were 23 km/day (range 9-53 km/day). Four of the whales had daily average travel speeds <1 km/day suggesting strong fidelity to the study area. The area containing 95% of the locations for individual whales during biweekly periods was on average 13,027 km**2 (range 7,097-15,896 km**2). More than 65% of all locations were in water <30 m, and between 45 and 70% of biweekly kernel home ranges were located in depths between 31 and 50 m. Benthic density of amphipods within the Bering Strait at depths <50 m was on average ~54 g wet wt/m**2 in 2006. It is likely that the abundant benthic biomass is more than sufficient forage to support the current gray whale population. The use of satellite telemetry in this study quantifies space use and movement patterns of gray whales along the Chukotka coast and identifies key feeding areas.

(Table 2) Concentrations of polychlorinated naphthalene congeners in blubber samples from whales, seals and porpoises between 1986-2009

A selection of PCN congeners was analyzed in pooled blubber samples of pilot whale (Globicephala melas), ringed seal (Phoca hispida), minke whale (Balaenoptera acutorostrata), fin whale (Balaenoptera physalus), harbour porpoise (Phocoena phocoena), hooded seal (Cystophora cristata) and Atlantic whitesided dolphin (Lagenorhynchus acutus), covering a time period of more than 20 years (1986-2009). A large geographical area of the North Atlantic and Arctic areas was covered. PCN congeners 48, 52, 53, 66 and 69 were found in the blubber samples between 0.03 and 5.9 ng/g lw. Also PCBs were analyzed in minke whales and fin whales from Iceland and the total PCN content accounted for 0.2% or less of the total non-planar PCB content. No statistically significant trend in contaminant levels could be established for the studied areas. However, in all species except minke whales caught off Norway the lowest Sum PCN concentrations were found in samples from the latest sampling period.

(Table 1) Tagging date, total length and sex of bowhead whales (Balaena mysticetus) tagged at Point Barrow, Alaska

Working with subsistence whale hunters, we tagged 19 mostly immature bowhead whales (Balaena mysticetus) with satellite-linked transmitters between May 2006 and September 2008 and documented their movements in the Chukchi Sea from late August through December. From Point Barrow, Alaska, most whales moved west through the Chukchi Sea between 71° and 74° N latitude; nine whales crossed in six to nine days. Three whales returned to Point Barrow for 13 to 33 days, two after traveling 300 km west and one after traveling ~725 km west to Wrangel Island, Russia; two then crossed the Chukchi Sea again while the other was the only whale to travel south along the Alaskan side of the Chukchi Sea. Seven whales spent from one to 21 days near Wrangel Island before moving south to northern Chukotka. Whales spent an average of 59 days following the Chukotka coast southeastward. Kernel density analysis identified Point Barrow, Wrangel Island, and the northern coast of Chukotka as areas of greater use by bowhead whales that might be important for feeding. All whales traveled through a potential petroleum development area at least once. Most whales crossed the development area in less than a week; however, one whale remained there for 30 days.

(Table 1) Observations of bowhead whales (Balaena mysticetus) in the Svalbard area 1940-2008

Forty-six sightings of bowhead whales have been reported from the Svalbard area between 1940 and 2009. But, only three of these sightings are reported prior to 1980. Most observations involve only one or two whales, but groups of up to seven individuals have been seen recently. Increased ship traffic, particularly cruise-based tourism, in the north undoubtedly provides more opportunities for spotting this species, and the establishment of a structured cetacean sighting programme, as well as increase in effort in documenting sightings from a wider marine user-community, likely all play a role in more records being documented in recent years. The absence of a dedicated monitoring programme for ice-associated cetaceans and the generally low scientific activity level in this field in Svalbard Waters hampers firm conclusions about the trends in abundance of bowhead whales in the Svalbard area.

(Table 2) Polybrominated diphenyl ether concentration in blubber samples from whales, seals and porpoises between 1986-2009

A selection of MeO-BDE and BDE congeners were analyzed in pooled blubber samples of pilot whale (Globicephala melas), ringed seal (Phoca hispida), minke whale (Balaenoptera acutorostrata), fin whale (Balaenoptera physalus), harbor porpoise (Phocoena phocoena), hooded seal (Cystophora cristata), and Atlantic white-sided dolphin (Lagenorhynchus acutus), covering a time period of more than 20 years (1986-2009). The analytes were extracted and cleaned-up using open column extraction and multi-layer silica gel column chromatography. The analysis was performed using both low resolution and high resolution GC-MS. MeO-PBDE concentrations relative to total PBDE concentrations varied greatly between sampling periods and species. The highest MeO-PBDE levels were found in the toothed whale species pilot whale and white-sided dolphin, often exceeding the concentration of the most abundant PBDE, BDE-47. The lowest MeO-PBDE levels were found in fin whales and ringed seals. The main MeO-BDE congeners were 6-MeO-BDE47 and 2'-MeO-BDE68. A weak correlation only between BDE47 and its methoxylated analog 6-MeO-BDE47 was found and is indicative of a natural source for MeO-PBDEs.

Whale sightings during POLARSTERN cruise ANT-XXVIII/4

From 13 March to 09 April 2012 Germany conducted a fisheries survey on board RV Polarstern in the Scotia Sea (Elephant Island - South Shetland Island - Joinville Island area) under the auspices of CCAMLR. During this expedition, ANT-XXVIII/4, an opportunistic marine mammal survey was carried out. Data were collected for 26 days along the externally preset cruise track, resulting in 295 hrs on effort. Within the study area 248 sightings were collected, including three different species of baleen whales (fin whale (Balaenoptera physalus), humpback whale (Megaptera novaeangliae), and Antarctic minke whale (Balaenoptera bonaerensis) and one toothed whale species, killer whale (Orcinus orca). More than 62% of the sightings recorded were fin whales (155 sightings) which were mainly related to the Elephant Island area (116 sightings). Usual group sizes of the total fin whale sightings ranged from one to five individuals, also including young animals associated with adults during some encounters. Larger groups of more than 20 whales, and on two occasions more than 100 indivuduals, were observed as well. These large pods of fin whales were observed feeding in shallow waters (< 300 m) on the north-western shelf off Elephant Island, concordant with large aggregations of Antarctic krill (Euphausia superba). This observation suggests that Elephant Island constitutes an important feeding area for fin whales in early austral fall, with possible implications regarding the regulation of (krill) fisheries in this area.

A new Eocene archaeocete (Mammalia, Cetacea) from India and the time of origin of whales

Himalayacetus subathuensis is a new pakicetid archaeocete from the Subathu Formation of northern India. The type dentary has a small mandibular canal indicating a lack of auditory specializations seen in more advanced cetaceans, and it has Pakicetus-like molar teeth suggesting that it fed on fish. Himalayacetus is significant because it is the oldest archaeocete known and because it was found in marine strata associated with a marine fauna. Himalayacetus extends the fossil record of whales about 3.5 million years back in geological time, to the middle part of the early Eocene [≈53.5 million years ago (Ma)]. Oxygen in the tooth-enamel phosphate has an isotopic composition intermediate between values reported for freshwater and marine archaeocetes, indicating that Himalayacetus probably spent some time in both environments. When the temporal range of Archaeoceti is calibrated radiometrically, comparison of likelihoods constrains the time of origin of Archaeoceti and hence Cetacea to about 54–55 Ma (beginning of the Eocene), whereas their divergence from extant Artiodactyla may have been as early as 64–65 Ma (beginning of the Cenozoic).

Retroposon analysis of major cetacean lineages: The monophyly of toothed whales and the paraphyly of river dolphins

SINE (short interspersed element) insertion analysis elucidates contentious aspects in the phylogeny of toothed whales and dolphins (Odontoceti), especially river dolphins. Here, we characterize 25 informative SINEs inserted into unique genomic loci during evolution of odontocetes to construct a cladogram, and determine a total of 2.8 kb per taxon of the flanking sequences of these SINE loci to estimate divergence times among lineages. We demonstrate that: (i) Odontocetes are monophyletic; (ii) Ganges River dolphins, beaked whales, and ocean dolphins diverged (in this order) after sperm whales; (iii) three other river dolphin taxa, namely the Amazon, La Plata, and Yangtze river dolphins, form a monophyletic group with Yangtze River dolphins being the most basal; and (iv) the rapid radiation of extant cetacean lineages occurred some 28–33 million years B.P., in strong accord with the fossil record. The combination of SINE and flanking sequence analysis suggests a topology and set of divergence times for odontocete relationships, offering alternative explanations for several long-standing problems in cetacean evolution.

Patterns of kinship in groups of free-living sperm whales (Physeter macrocephalus) revealed by multiple molecular genetic analyses.

Mature female sperm whales (Physeter macrocephalus) live in socially cohesive groups of 10-30, which include immature animals of both sexes, and within which there is communal care of the young. We examined kinship in such groups using analyses of microsatellite DNA, mitochondrial DNA sequence, and sex-linked markers on samples of sloughed skin collected noninvasively from animals in three groups off the coast of Ecuador. Social groups were defined through photographic identification of individuals. Each group contained about 26 members, mostly female (79%). Relatedness was greater within groups, as compared to between groups. Particular mitochondrial haplotypes were characteristic of groups, but all groups contained more than one haplotype. The data are generally consistent with each group being comprised of several matrillines from which males disperse at about the age of 6 years. There are indications of paternal relatedness among grouped individuals with different mitochondrial haplotypes, suggesting long-term associations between different matrilines.