Migration timing and distance from shore of southbound eastern Pacific gray whales (Eschrichtius robustus) off Ensenada,Baja California,Mexico

Eastern Pacific gray whales were monitored off Ensenada, Mexico, during the southbound migration. The objectives were to determine southbound migration timing and width of the migration corridor during three seasons (2003–2006). Migration timing was determined by fitting a generalized additive model to the shore counts for each season and estimating the 10, 50, and 90 percentiles of the fitted curves. To estimate abundance from shore‐based counts, a probability density function for the shore based distances was estimated by a product of a gamma distribution fit to the boat survey distance data for 2006/2007 and a half‐normal detection function using combined data of the three seasons. The parameters of the gamma distribution were corrected to account for less boat survey effort carried out 20–40 km than 0–20 km from shore. The onset of the migration off Ensenada was in late December/early January and ended around 13 February. The median date was 23–26 January for the first and third season and a week early for the second season. Boat surveys indicated a wide (20 km) migration corridor but most gray whales traveled within 9.9 km from shore. The estimated total number of whales during watch hours was 2,298 (95% CI = 1,536–4,447).     

Anthropogenic scarring of western gray whales (Eschrichtius robustus)

Western gray whales ( Eschrichtius robustus ) are critically endangered and anthropogenic threats, such as entanglement in fishing gear and collisions with vessels, may be acting to limit recovery of the population. Thus, examining the magnitude of such anthropogenic interactions using a scar-based approach is warranted. A multi-year (1995–2005) photo-identification study of western gray whales on their feeding ground off northeastern Sakhalin Island, Russia, has resulted in a large data set of digital and film images of 150 individuals. These images were reviewed and scored for anthropogenic scarring by recording the presence of visible scars resulting from fishing gear entanglement and vessel collisions in 21 defined body regions. In total, 20.0% ( n = 30) of whales identified during the study period had detectable anthropogenic scarring, with 18.7% ( n = 28) determined to have been previously entangled in fishing gear at least once and 2.0% ( n = 3) to have survived at least one vessel collision. These estimates are likely to be conservative given the nature of the photo-identification data set, but indicate that male and female western gray whales are subject to anthropogenic interactions. Future studies designed to systematically estimate the frequency and rates of anthropogenic events are needed and would have direct conservation and management implications.     

Activity budget and diving behavior of gray whales (Eschrichtius robustus) in feeding grounds off coastal British Columbia

Behavior and diving patterns of summer resident gray whales ( Eschrichtius robustus ) foraging on mysids were studied in coastal bays along the north shore of Queen Charlotte Strait, British Columbia. In this region, gray whales were found to feed primarily on planktonic prey rather than on the benthos as in their primary feeding areas further north. During the summers of 1999 and 2000, whales spent most of their time actively feeding or searching for prey (77%), whereas only 15% of their time was spent traveling and 8% socializing. The majority of the dives were short; the mean dive duration was 2.24 min with approximately three respirations per surfacing and 15 s between blows. Whales dove frequently (26.7 h⁻¹), spending only 17% of their time at the surface with an overall blow rate of 1.14 respirations per minute. Activity states were characterized by significantly different diving and respiratory parameters; feeding whales dove more frequently, with shorter intervals between respirations, thus spending less time at the surface compared to when traveling or searching. This diving pattern differs from benthic-feeding whales and likely optimizes capture of the mobile mysid swarms in shallow waters.     

Abundance estimation of gray whale (Eschrichtius robustus) calves from shore‐based surveys undertaken near Ensenada,Baja California,Mexico, 2004–2006

Gray whale calf abundance was estimated from shore‐based surveys near Ensenada, Baja California, during their northbound migration. Over the course of 129 effort‐days (756.5 observation hours), 162 calves were counted, comprising 42, 41, and 79 calves in 2004, 2005, and 2006, respectively. To estimate the number of undetected calves during the observation periods in 2006, detection probabilities were estimated by simultaneous and independent counts using a Huggins model. The detection probabilities ranged from 0.655 to 0.997. The number of calves estimated during effort periods were divided by their estimated detection probabilities, while the total number of calves were estimated by fitting a generalized additive model (GAM) to the passage rate (whales/h) and effort (time) data. The final gray whale calf abundance estimates were 451 (95% CI = 430, 513), 253 (95% CI= 245, 308), and 442 (95% CI = 396, 510) calves for 2004, 2005, and 2006, respectively. The estimates were lower than those reported for Piedras Blancas, California, during the same years, with one possible reason being that an important number of cow/calf pairs migrate too far from shore (>10 km) to be detected from the observation site used in this research.     

New insights into the northward migration route of gray whales between Vancouver Island,British Columbia,and southeastern Alaska

The route taken by northward migrating gray whales during spring between Vancouver Island and southeastern Alaska, a distance of about 575 km, has long been uncertain. It is generally believed that the whales closely follow the western, outer coastline of Haida Gwaii (formerly the Queen Charlotte Islands), an archipelago lying between Vancouver Island and southeastern Alaska, consistent with their pattern of migrating close to shore over the majority of their northward migratory corridor. By tracking satellite‐tagged individuals and surveying whales from shore bases, we provide evidence that this is not the primary migratory corridor, but instead that most whales migrate through Hecate Strait and Dixon Entrance, broad waterways that lie to the east and north of Haida Gwaii. By using this route, northbound gray whales potentially face a wider range of industrial activities and developments than they would by migrating along the outer coast.     

Assessment of genetic structure among eastern North Pacific gray whales on their feeding grounds

Although most eastern North Pacific (ENP) gray whales feed in the Bering, Beaufort, and Chukchi Seas during summer and fall, a small number of individuals, referred to as the Pacific Coast Feeding Group (PCFG), show intra‐ and interseasonal fidelity to feeding areas from northern California through southeastern Alaska. We used both mitochondrial DNA (mtDNA) and 12 microsatellite markers to assess whether stock structure exists among feeding grounds used by ENP gray whales. Significant mtDNA differentiation was found when samples representing the PCFG (n = 71) were compared with samples (n = 103) collected from animals feeding further north (F_ST = 0.012, P = 0.0045). No significant nuclear differences were detected. These results indicate that matrilineal fidelity plays a role in creating structure among feeding grounds but suggests that individuals from different feeding areas may interbreed. Haplotype diversities were similar between strata (h_PCFG = 0.945, h_Northern = 0.952), which, in combination with the low level of mtDNA differentiation identified, suggested that some immigration into the PCFG could be occurring. These results are important in evaluating the management of ENP gray whales, especially in light of the Makah Tribe's proposal to resume whaling in an area of the Washington coast utilized by both PCFG and migrating whales.     

Assessment of wound healing of tagged gray (Eschrichtius robustus) and blue (Balaenoptera musculus) whales in the eastern North Pacific using long‐term series of photographs

Tags have been used to examine migration routes and habitat use of large whales for >40 yr, however, evaluation of tag wound healing has largely been short‐term, anecdotal or generalized. This study developed methods for systematic photographic assessment of long‐term external consequences of tag placement, to determine potential differences in wound healing between species and tag types and thus advise future tagging efforts to possibly minimize undesirable side effects. Tag site appearance and healing characteristics were evaluated by two reviewers and a time series evaluated by five veterinarians from photographs during 995 postdeployment encounters with 34 gray and 63 blue whales tagged in the North Pacific. Blue whale resightings were less frequent, but spanned a longer time period due to earlier tag deployments than the more frequent gray whale follow‐up observations. Swelling occurred in 74% of reencountered gray whales, with the highest frequency 6 mo postdeployment. Swellings were common in blue whales with early tag designs but rare with current models. Depressions occurred in 82% of gray and 71% of blue whales. This study demonstrates the value of follow‐up studies of tagged animals and systematic scoring of photographs to quantitatively compare tag response.     

Preliminary analysis of the social structure of killer whales,Orcinus orca,at subantarctic Marion Island

Studies of social differentiation between populations of killer whales (Orcinus orca) are important due to the cosmopolitan nature of the species, both in terms of distribution and feeding habits. The following research provides preliminary findings describing the social structure of the killer whale, Orcinus orca, population at subantarctic Marion Island. We provide evidence for consistent, observable patterns of social interactions with animals associating and disassociating in nonrandom patterns. We show that the social structure of this population may follow a new pattern of association, displaying a blend of the traditional resident/transient model displayed in the Northern Hemisphere. However, we emphasize the critical need for further studies related to the sociality, biology, and life history of Southern Ocean killer whales.     

Shore‐based observations of seasonality,movements, and group behavior of southern right whales in a nonnursery area on the South African west coast

The southern right whale's (Eubalaena australis) demography, occurrence, habitat use, and behavior off South Africa are known predominantly from an ongoing aerial survey data set that started in 1971. The fixed timeframes of these surveys and their geographical bias towards south coast nursery areas have constrained our knowledge about the right whale's seasonal distribution elsewhere. We present shore‐based observations and tracking of right whales at Saldanha Bay on the west coast (2001–2003) that reveal a near year‐round presence and strongly nearshore distribution. With seasonal progression from winter to summer we observed a gradual increase in sighting rate, reduction in swimming speed, less directionality of movement, an increase in group size, and more surface active groups. The area appears to be important for feeding and socializing but not as a calving or nursery area. Individual transits between the south and west coasts, bidirectional alongshore movements, and extended seasonal presence may all be indicative of reoccupation of their former range along the west coast. This is important given the increasing ship traffic at Saldanha Bay, the rapid expansion of the region's oil and gas industry, and the known vulnerability of the closely related North Atlantic right whale (E. glacialis) to ship strikes.     

Life history and group composition of melon‐headed whales based on mass strandings in Japan

We examined melon‐headed whales that mass‐stranded live in two events in Japan: (1) 171 animals at Tanegashima Island in 2001 and (2) 85 animals at Hasaki in 2002. We report here the results of life history traits and group composition of these strandings, and compare them to another mass stranding with 135 individuals at Aoshima in 1982. In the Hasaki event, most stranded animals, including those released were sexed and measured. The proportion of live males released was much higher than that of females, and larger animals, especially females, were more likely to have died. Females were estimated to attain sexual maturity at around 7 yr and give birth every 3–4 yr. The sex ratio was significantly different between the Hasaki and Aoshima events. Among dead specimens, females of various age classes were included in all strandings, while age distribution of males varied considerably among strandings. This suggests females show group fidelity while males move between groups. Asymptotic body length of females from Hasaki was significantly smaller than that from Tanegashima, suggesting that more than one population of melon‐headed whales exist off Japan.     

Long‐term survival of humpback whales radio‐tagged in Alaska from 1976 through 1978

Invasive tags designed to provide information on animal movements through radio or satellite monitoring have tremendous potential for the study of whales and other cetaceans. However, to date there have been no published studies on the survival of tagged animals over periods of years or decades. Researchers from the National Marine Mammal Laboratory and the Woods Hole Oceanographic Institution tracked five humpback whales with implanted radio tags in southeastern Alaska in August 1976 and July 1977, and tracked two humpback whales in Prince William Sound, Alaska, in June 1978. All seven of these individually identified humpback whales were resighted at least 20 yr after first being tagged, and five of the seven have been observed for more than 30 yr; some of them are among the most resighted humpback whales in the North Pacific. Photos of tagging sites taken during and subsequent to tagging operations show persistent but superficial scarring and no indication of infection. These pioneering field studies demonstrated both long‐term survival of the whales and the short‐term effects of deploying radio tags, which at the time were larger and more invasive than those typically used today.     

A simple photograph‐based approach for discriminating between free‐ranging long‐finned (Globicephala melas) and short‐finned (G. macrorhynchus) pilot whales off the east coast of the United States

Line transect based abundance estimation is complicated for long‐finned (LFPW, Globicephala melas) and short‐finned (SFPW, G. macrorhynchus) pilot whales because of their similarity in appearance and their overlapping summertime range in some areas. We developed a photograph‐based approach to distinguish between species of free‐ranging pilot whales in the northwest Atlantic. We collected skin samples and photographs during the summers of 2004–2007 and used skin samples to distinguish species based on mitochondrial DNA. Relative morphometric measurements from photographs were examined using mixed‐effect models and logistic regression. The best model among 94 candidate models had an overall classification error rate of 2.5%. We tested the presence/absence of pigmentation in four regions of the dorsal body (melon, eye, cape, and saddle) for differences. Pigmentation was present in all four regions in 100% of the SFPWs sampled. Melon patch, blaze, and saddle patch pigmentation were present in 6%, 68%, and 50%, respectively, of the LFPWs, but the cape was completely absent. Both types of analyses provided positive species discrimination of free‐ranging animals. We created a cost‐effective, simple tool which could ultimately assist in providing appropriate management, mitigation, and conservation strategies for both northwest Atlantic species of pilot whales.     

Accurate assessment of cell density in low cellular liquid‐based cervical cytology

A. G. Siebers, J. A. W. M. van der Laak, R. Huberts‐Manders, J. E. M. Vedder and J. Bulten Accurate assessment of cell density in low cellular liquid‐based cervical cytology Objective: Scant cellularity is the most important source of unsatisfactory liquid‐based cytology. Although still being debated, low cellularity is thought to compromise the detection of squamous lesions. Thus, reliable assessment of cellularity is essential. The aim of the present study was to determine the cellularity range for ThinPrep^® slides of low cellularity and to establish the most accurate cell‐counting protocol. Methods: A series of 60 ThinPrep cases representing the full spectrum of adequate, ‘satisfactory but limited by’ (SBLB) and unsatisfactory reports were included. Two cell‐counting protocols with three different magnifications, using ×10, ×20 and ×40 objectives, were evaluated and related to the true cellularity, together with a reassessment of the degree of adequacy originally reported. The cell‐counting protocol that showed the highest correlation coefficient was considered the most accurate. Results: Based on seven (re)assessments a majority score for adequacy was established. There were 42 cases with a majority score ‘unsatisfactory’ or ‘SBLB’ (low cellularity) of which 41 contained fewer than 20 000 squamous cells; and 18 cases with a majority score ‘satisfactory’ of which one had fewer than 20 000 cells. The cell‐counting protocol that showed the significantly highest correlation with the reference standard was the Stichting Kwaliteitsbewaking Medische Laboratoriumdiagnostiek (SKML) protocol with a ×10 objective. Conclusions: ThinPrep slides reported as unsatisfactory or SBLB were shown to contain fewer than 20 000 squamous cells. The most accurate protocol for estimating the cellularity of these slides was cell counting in five non‐adjacent microscope fields along the horizontal axis and five along the vertical axis of the slide with a ×10 objective and applying a correction factor of 1.24× to correct for underestimation of the true cellularity.     

Observations and tracking of killer whales (Orcinus orca) with shore‐based X‐band marine radar at a marine energy test site

The Atlantic killer whale (Orcinus orca) is a top‐level marine predator with a global range, being found in all of Earth's oceans. The potential interaction between killer whales and marine renewable energy projects requires surveillance and monitoring efforts that call for new technologies, with marine radar showing promise in the field. Marine radar images recorded at the European Marine Energy Centre (EMEC) were used to track a pair of male killer whales undertaking Surface Active Behavior (SAB) with visual observations used as validation. Using a tidal prediction model, the tide‐adjusted, radar‐derived target speeds between SAB events provide estimates of swim speeds averaging 4 m/s and time between SAB events of 30 s. The similarities between the radar signatures of the animals and sea clutter, combined with their low occurrence compared to other imaged phenomena renders automatic detection with this system difficult. However, the combination of opportunistic radar imagery and independent visual observation has allowed the radar signature of one form of killer whale SAB to be documented. It is hoped that with a greater number of validated observations such as these that automated, radar‐based identification and the benefits it will bring to long‐term observations at MRE sites will be possible.     

The development of an intermediate‐duration tag to characterize the diving behavior of large whales

The development of high‐resolution archival tag technologies has revolutionized our understanding of diving behavior in marine taxa such as sharks, turtles, and seals during their wide‐ranging movements. However, similar applications for large whales have lagged behind due to the difficulty of keeping tags on the animals for extended periods of time. Here, we present a novel configuration of a transdermally attached biologging device called the Advanced Dive Behavior (ADB) tag. The ADB tag contains sensors that record hydrostatic pressure, three‐axis accelerometers, magnetometers, water temperature, and light level, all sampled at 1 Hz. The ADB tag also collects Fastloc GPS locations and can send dive summary data through Service Argos, while staying attached to a whale for typical periods of 3–7 weeks before releasing for recovery and subsequent data download. ADB tags were deployed on sperm whales (Physeter macrocephalus; N = 46), blue whales (Balaenoptera musculus; N = 8), and fin whales (B. physalus; N = 5) from 2007 to 2015, resulting in attachment durations from 0 to 49.6 days, and recording 31 to 2,539 GPS locations and 27 to 2,918 dives per deployment. Archived dive profiles matched well with published dive shapes of each species from short‐term records. For blue and fin whales, feeding lunges were detected using peaks in accelerometer data and matched corresponding vertical excursions in the depth record. In sperm whales, rapid orientation changes in the accelerometer data, often during the bottom phase of dives, were likely related to prey pursuit, representing a relative measure of foraging effort. Sperm whales were documented repeatedly diving to, and likely foraging along, the seafloor. Data from the temperature sensor described the vertical structure of the water column in all three species, extending from the surface to depths >1,600 m. In addition to providing information needed to construct multiweek time budgets, the ADB tag is well suited to studying the effects of anthropogenic sound on whales by allowing for pre‐ and post‐exposure monitoring of the whale's dive behavior. This tag begins to bridge the gap between existing long‐duration but low‐data throughput tags, and short‐duration, high‐resolution data loggers.     

An EBV‐based plasmid can replicate and maintain in stem cells

Viral vectors have a wide range of applications in biology, particularly in gene therapy. Based on their integration capacity, viral vectors are classified as either integrating or non‐integrating vectors. Although integrating vectors, such as lentivectors, have the ability to direct prolonged expression of exogenous genes, manipulation of the host genome is an inappropriate feature of these gene delivery tools. Non‐integrating vectors, such as episomal replicating plasmids, can replicate and persist in host cells for long periods without any chromosomal interruption. These advantages made them good tools for gene induction purposes in gene therapy and basic studies. Due to the necessity of gene induction in stem cells for study of mammalian development and targeted differentiation, the use of integrating vectors for prolonged expression of genes of interest has been developed. Application of replicating plasmids can overcome some drawbacks associated with integrating vectors, although replication and maintenance of these plasmids can differ between cell types. Previously, it has been shown that such plasmids can be maintained in human embryonic stem cells for more than one month, but the rate of the plasmid replication during the host cell cycle has not been elucidated. In the present study, we showed that an EBV‐based plasmid can replicate simultaneously with host in pluripotent and multipotent human and mouse stem cells and can be sustained for long time periods in dividing cells. © 2015 American Institute of Chemical Engineers Biotechnol. Prog., 31:1579–1585, 2015     

Effects of age‐based movement on the estimation of growth assuming random‐at‐age or random‐at‐length data

Simulation methods were used to generate paired data from a simulated population that included the age‐based process of movement and the length‐based process of gear selection. The age‐based process caused bias in the estimates of growth parameters assuming random at length, even when relatively few age classes were affected. Methods that assumed random at age were biased by the subsequent inclusion of the length‐based process of gear selection. Additional knowledge of the age structure of the sampled area is needed to ensure an unbiased estimate of the growth parameters when using the length‐conditional approach in the presence of age‐based movement. Estimates of the variability in the length‐at‐age relationship were better estimated with the length‐conditional than the traditional method even when the assumptions of random at length were violated. Inclusion of paired observations of length and associated age inside the population dynamics model may be the most appropriate way of estimating growth.