bluuebunny/crossref_metadata_2025 huggingface dataset:
A METHOD FOR ESTIMATING MASS OF LARGE PINNIPEDS
Authors: Haley Michael P. , Deutsch Charles J. , Boeuf Burney J. Le
Published: August 2006

Abstract

Fifty‐two male elephant seals were weighed and photographed at Año Nuevo State Reserve, California, to establish a predictive relationship between photographically measured morphological variables (length, side area, and girth area) and body mass. Regression of mass on these variables revealed that side area, roughly equivalent to a longitudinal cross‐section, was the most useful single variable for predicting mass, and that adding the other two variables to side area slightly improved the accuracy of the photogrammetric technique. Curvilinear regressions based on a power model provided the best predictive relationships. This technique may prove useful for estimating body mass of other pinnipeds.
AN EPIZOOTIC OF FLORIDA MANATEES ASSOCIATED WITH A DINOFLAGELLATE BLOOM
Authors: O'Shea Thomas J. , Rathbun Galen B. , Bonde Robert K. , Buergelt Claus D. , Odell Daniel K.
Published: August 2006

Abstract

Over a 10‐wk period in early 1982, 39 Florida manatees (Trichechus manatus latirostris) were found dead in the lower Caloosahatchee River and nearby waters of southwestern Florida. Two were killed by boats. The remainder showed no evidence of trauma. Lesions indicative of infectious agents were not identified, and bacteriological and contaminant residue findings were unremarkable. Nonspecific lesions of congestion and hemorrhage were identified in brain tissue. Numerous reports were also received of manatee morbidity. Some distressed manatees showed no biochemical lesions in clinical analyses of blood samples and recovered quickly. Timing of manatee illnesses coincided with fish and double‐crested cormorant (Phalacrocorax auritus) mortality and morbidity. A widespread bloom of the dinoflagellate red tide organism (Gymnodinium breve) also coincided with these incidents. G. breve produces potent neurotoxins (brevetoxins). Circumstantial evidence links these events, and possible routes of exposure may include ingestion of filter‐feeding ascidians. Ecological conditions that magnified the extent of the epizootic included an early dispersal of manatees into the area from a nearby winter aggregation site and unusually high salinities that facilitated the inshore spread of the red tide bloom. Management responses to future episodes of red tide in manatee areas are suggested.
EFFECTIVENESS OF VARIOUS CATTLE EAR TAGS AS MARKERS FOR WEDDELL SEALS
Authors: Testa J. Ward , Rothery Peter
Published: August 2006

Abstract

Methods for estimating tag loss and sightability of tags are presented. Rates of tag loss were estimated for metal and several varieties of plastic cattle ear tags in a long‐term population study of Weddell seals. Tags were lost at a higher rate in the first year after application than in subsequent years, and pups lost tags at a higher rate than older seals given the same tag types. Medium‐sized plastic tags (Dalton, Allflex and Fearing) were retained at higher rates and were overlooked less frequently than metal tags on adult seals. Dalton Jumbo Rototags showed the lowest loss rates on pups in comparison to larger, flexible plastic tags, but were harder to read in the field.
CETACEAN LENS ZONES OF DISCONTINUITY—INDICES OF HEALTH AND DEVELOPMENT
Authors: Dawson William W. , Hope G. M. , Dawson Judyth C. , Nachtigall Paul E. , Schroeder J. Pete
Published: August 2006

Abstract

Details of the lenses of eyes in two living Tursiops truncatus and one Grampus griseus were photographed. In the laboratory the lens cortex could be retro‐illuminated by a fundus camera and spatially periodic stria could be visualized, in large part because of the highly developed tapetum of the cetacean eye. Varying spaces were present between the stria. On a three‐dimensional basis, the best analogy is the layering of an onion. One photograph was digitized giving good quantification of the sizes of the layers and their number. Similar, but less easily resolved, lens cortex organization has been described frequently in humans as “zones of optical discontinuity.” These have been explained as a periodic temporal consequence of normal aging with layer thickness depending on general health. We found that young cetaceans have few “zones” and older cetaceans have many. Lens zones measurement may be developed to Provide objective data on history of cetacean health and age.
AN ANALYSIS OF CALIFORNIA SEA OTTER (ENHYDRA LUTRIS) PELAGE AND INTEGUMENT
Authors: Williams Thomas D. , Allen D. Diane , Groff Joseph M. , Glass Robert L.
Published: August 2006

Abstract

The sea otter is associated with a cold, marine habitat, has no insulating fat layer, and relies on its fur layer for insulation. Soiled pelage provides inadequate insulation and can lead to hypothermia and death. Information on sea otter pelage, the surface and bound lipids found in the pelage, and histology of the integument is thus relevant to the development of rehabilitation and management techniques for sea otters soiled with oil. We present detailed data on the sea otter pelage and integument, including hair bundle density (737–2,465 bundles per cm2), hair density per bundle (19–91.1), total hair density (26,413–164,662 hairs per cm2), guardhair length (8.2–26.9 mm), underfur length (4.6–15.8 mm), guardhair diameter (44.0–106.0 μ), underfur diameter (7.6–11.9 μ), angle of hair with respect to the skin (61.9°‐ 84.3°) and structure of individual hairs as seen with a scanning electron microscope. The hydrocarbon squalene was found to be the major component of the lipids associated with the pelage. Various layers of skin from eight sites on a single animal are described histologically. With the exception of density of the hair coat, sea otter integument is similar to that of domestic carnivores.
PHOCINE DISTEMPER VIRUS INFECTION IN HARP SEALS (PHOCA GROENLANDICA)
Authors: Markussen Nina Hedlund , Have Per
Published: August 2006

Abstract

Antibodies against phocine distemper virus were found in liver and serum specimens of harp seals from the Barents Sea and north of Jan Mayen (West Ice) in 1987 and 1989. By immunoperoxidase testing, antibodies against phocine distemper virus could be demonstrated in 34 of 74 liver specimens (46%) from 1987 and in 44 of 126 liver specimens (35%) from 1989. The prevalence of neutralizing serum antibodies against phocine distemper virus was found to be 98% in 1989. Both findings clearly demonstrate the presence of a widespread infection with phocine distemper virus or a closely related virus in harp seals. The significance of these findings to the recent outbreak of phocine distemper virus infection in harbor seals in Northwestern Europe is discussed and it is concluded that there may be an epizootiological link between this outbreak and the large migration of harp seals in 1987.
PATTERNS OF BOWHEAD WHALE DISTRIBUTION AND ABUNDANCE NEAR BARROW, ALASKA, IN FALL 1982‐1989
Authors: Moore Sue E. , Clarke Janet T.
Published: August 2006

Abstract

Although the distribution and relative abundance of bowhead whales varied annually within the fall whaling area near Barrow, Alaska, the distance of whales from shore was not significantly different among years 1982‐1989 (ANOVA, F= 0.5, P > 0.5). The minimum detectable distance for the ANOVA was 12 km (α= 0.05, β= 0.1). Annual median distance of random bowhead sightings from shore ranged from 23 to 39 km, with an eight‐year median of 32 km. Highest annual bowhead sighting rates were positively associated with the proportion of feeding whales, indicating that whale feeding opportunities may affect the availability of whales within hunting range each fall.
AGING LIVE ANTARCTIC FUR SEALS AND SOUTHERN ELEPHANT SEALS
Authors: Arnbom T. A. , Lunn N. J. , Boyd2 I. L. , Barton T.
Published: August 2006

Abstract

This study describes a method for extracting post‐canine or incisor teeth from live antarctic fur seals (Arctocephalus gazella) and southern elephant seals (Mirounga leonina) respectively and their use to determine age in a field situation. Dental elevators were used to loosen the teeth from the alveolus and periodental ligament. Most teeth were removed within l‐2 min and a total of 214 and 81 teeth were collected by this method from antarctic fur seals and southern elephant seals respectively. No seal recaptured at intervals up to a year after a tooth was extracted showed signs of infection or distress related to removal of the tooth. Teeth were thin‐sectioned for the purpose of aging. In both species cementum growth layer groups were a more satisfactory indicator of age than dentinal growth layer groups. Estimates of age from cementum growth layers were confirmed for Antarctic fur seals using seals which had been tagged as pups up to 16 yr before sampling.
REPRODUCTIVE SYNCHRONY AND THE ESTIMATION OF MEAN DATE OF BIRTH FROM DAILY COUNTS OF NORTHERN FUR SEAL PUPS
Authors: Trites Andrew W.
Published: August 2006

Abstract

Two methods for estimating the mean date of birth from daily counts of northern fur seal pups (Callorhinus ursinus) are presented and applied to data collected on the Pribilof Islands in 1951, 1962, 1963 and 1983. The mean date of birth over the four years was July 9. Reproduction is highly synchronized and consistent from one year to the next. Pupping occurs over a five week period with over 50% of the pups being born during the first two weeks of July.
HABITAT USE PATTERNS AND RANGES OF THE BOTTLENOSE DOLPHIN IN THE GULF OF CALIFORNIA, MEXICO
Authors: Ballance Lisa Taylor
Published: August 2006

Abstract: I studied behavior and range patterns of individual bottlenose dolphins during 1984 in the mid‐eastern Gulf of California, Mexico. Dolphin sighting rate was significantly higher in areas close to estuary mouths, 0.306 sightings per hour compared with 0.155 sightings per hour in areas distant from estuary mouths. Dolphins used these estuarine areas to feed; 61% of all behavior observed near estuaries was feeding as compared with 23% elsewhere. Traveling comprised 61% of all behavior observed in areas distant from estuary mouths. Estuaries are sites of large concentrations of nutrients which support great numbers of filter‐feeding zooplankton and fish. Bottlenose dolphins may specialize on esmarine prey, or they may feed in estuarine areas simply because of the abundance of potential prey that these systems support. In either case, data on relative numbers, distribution patterns, behavior and diet indicate that this is a general trend in habitat use for many coastal populations of this species in the Pacific and Atlantic.

Ranges of a few individuals spanned a minimum of 65 km of coastline, and animals were not permanent residents of a monitored bay. In contrast, dolphins off the coast of Sarasota, Florida, have been reported to be year‐round residents with smaller ranges. This difference in degree of site fidelity may be related to habitat differences. The west coast of Florida is dotted with numerous and large estuarine systems which may host permanent prey populations and support resident groups of dolphins. The Gulf of California coastline contains few estuaries; most are small and perhaps support prey resources which are ephemeral, requiring dolphins to range over larger distances in search of food.
RESTRICTABLE DNA FROM SLOUGHED CETACEAN SKIN; ITS POTENTIAL FOR USE IN POPULATION ANALYSIS
Authors: Amos W. , Whitehead H. , Ferrari M. J. , Glockner‐Ferrari D. A. , Payne R. , Gordon J.
Published: August 2006

Abstract: Several species of cetaceans naturally slough visible quantities of skin. We have investigated the prospect of using this material as a viable alternative to the use of biopsy darts for the collection of samples for molecular analysis. Pieces of skin were collected from free‐ranging individuals of three different species—the humpback (Megaptera novaeangliae), sperm (Physeter macrocephalus) and right whales (Eubalaena glacialis). DNA was extracted from 11 pieces of sloughed skin and DNA “fingerprint” profiles prepared. All samples contained DNA of both sufficient quality and quantity for genetic analysis. The applicability of this approach is discussed generally in relation to answering problems about the population structure and breeding systems of cetaceans.
PATTERN SIMILARITY IN SHARED CODAS FROM SPERM WHALES (PHYSETER CATODON)
Authors: Moore Karen E. , Watkins William A. , Tyack Peter L.
Published: August 2006

Abstract: Codas (patterned click sequences) produced by sperm whales (Physeter catodon) were recorded during four research cruises in the southeast Caribbean. Two coda patterns comprised more than 50% of the codas analyzed from 46 h of recording. These two patterns were called “shared” codas because they were produced by numerous whales throughout the area, both as repeated sequences by individual whales, at times simultaneously by two or more whales, and occasionally in overlapping series. Analyses of both the absolute timing and the relative timing of click intervals indicate equivalent variability in the temporal patterns of similar shared codas, whether produced by the same or different whales. The shared codas appear to have a function that is different from individual identification as hypothesized previously for some coda patterns.
MASS ESTIMATES USING BODY MORPHOLOGY IN STELLER SEA LIONS
Authors: Castellini Michael A. , Calkins Donald G.
Published: August 2006

Abstract: Analytical procedures developed from studies on phocids for relating body morphometrics (length and girth) to mass were applied to 390 Steller sea lions from the Gulf of Alaska and the Bering Sea. The equations relating body volume to mass were significant and had very high correlation coefficients for animals from about 60 to over 900 kg with a standard error of ±0.6% in fitted mass. There was a significant difference in these relationships for female sea lions studied in the 1970s and those examined in the 1980s. The latter sea lions were smaller and/or leaner than those collected in the 1970s.
POPULATION STRUCTURE OF THE BOTTLENOSE DOLPHIN (TURSIOPS TRUNCATUS) AS DETERMINED BY RESTRICTION ENDONUCLEASE ANALYSIS OF MITOCHONDRIAL DNA
Authors: Dowling Thomas E. , Brown Wesley M.
Published: August 2006

Abstract: Restriction fragment length polymorphisms of mitochondrial DNA (mtDNA) were used to test for population subdivision in the bottlenose dolphin (Tursiops truncatus). Atlantic and Pacific dolphin mtDNA samples exhibited distinctly different haplotypes (approximately 2.4% sequence divergence), indicating a lack of gene exchange. Within the Atlantic Ocean, mtDNA samples from the Gulf of Mexico and the Atlantic Coast were also found to be distinct, with a sequence divergence of approximately 0.6%. The Atlantic Coast–Gulf of Mexico dichotomy is consistent with patterns of genetic variation from other marine and coastal organisms from this region, and supports the hypothesized role of bio‐geographic events in promoting the divergence of these and other forms. Regional differentiation was identified along the Atlantic Coast, whereas low sequence divergences among haplotypes and consistent haplotype frequencies across populations suggested considerable gene exchange among Gulf of Mexico populations. A highly divergent haplotype found in two individuals from two localities in the Gulf of Mexico is best explained by dispersal from either a distinct offshore Gulf stock or an unsampled Atlantic Coast stock. Additional samples are required to test for the existence of a distinct offshore race and, if it exists, to identify its distribution and contribution to population structure.
DIET AND FORAGING BEHAVIOR OF SEA OTTERS IN SOUTHEAST ALASKA
Authors: Kvitek Rikk G. , Bowlby C. Edward , Staedler Michelle
Published: August 2006

Abstract: Direct observations of feeding sea otters (Enhydra lutris) at 11 sites in southeast Alaska showed infaunal clams to be the primary prey utilized by otters throughout the region. Foraging dive times associated with clam and sea urchin prey were significantly longer than those for more easily captured prey (crabs and mussels). Dive times and surface intervals were also generally correlated with water depth or apparent difficulty in obtaining buried prey. Male otters, which fed more extensively on clams than females, made significantly longer foraging dives than females. Foraging success remained high, even at sites where prey numbers were found to be very low during a related study. The very deeply burrowing geoduck clam (Panope abrupta), while common at several otter feeding sites, was rarely captured by otters. These results, combined with those of a companion study on prey numbers, indicate that butter clams (Saxidomus giganteus) account for the majority of the sea otter diet in southeast Alaska, and that sea urchins may represent relatively short‐term prey in comparison to infaunal bivalves in regions where both prey types co‐exist. Furthermore, the importance of butter clams in the sea otter diet and the tendency for this bivalve to retain chronically high levels of paralytic shellfish poisoning toxins in southeast Alaska increases the probability that toxic phytoplankton blooms influence sea otter distribution in this region.
THE MAXIMUM RANGE OF VOCAL COMMUNICATION IN AIR BETWEEN A HARBOR SEAL (PHOCA VITULINA) PUP AND ITS MOTHER
Authors: Reiman A. J. , Terhune J. M.
Published: August 2006

Abstract: The transmission losses with distance of four pure tones (0.5, 1, 2, 4 kHz) were measured in the air 9 cm above the surface of the coastal waters in the Bay of Fundy. The study was conducted between May and July 1992, on warm days with low winds. The measured transmission losses were as much as 11 dB less than predicted by spherical spreading (6 dB/distance doubled), at 400 m (0.5 kHz). This enhanced sound transmission is probably due to the air temperature profile which increases with height above the water's surface. Such a profile causes sound waves to refract towards the water, thereby reducing spreading losses. High‐frequency sound absorption negates enhanced transmission at 4 kHz, at distances over 500 m. On days with low winds and low ambient noise levels, a seal pup calling at 90 dB re 20, μPa at 0.5 kHz should be detectable by the mother up to 1 km away, and may be audibly recognizable up to 140 m away.
PHOTOPERIOD DEFINES THE PHENOLOGY OF BIRTH IN CAPTIVE CALIFORNIA SEA LIONS
Authors: Temte Jonathan L. , Temte Jo
Published: August 2006

Abstract

A population‐based analysis was used to evaluate the role of photoperiod in regulating the precise annual birth timing of captive California sea lions. Latitudinal variation of 463 birth dates was explained by a response to a common photoperiod, 11.48 h/d, occurring 242 d pre‐partum and immediately before blastocyst implantation. The lengths of the pupping seasons at the 18 largest captive colonies were significantly correlated to those estimated by the photoperiod model. Hence, the phenology of birth in this species is defined by photoperiod.
REACTIONS OF HUMPBACK WHALES TO SKIN BIOPSY SAMPLING ON A WEST INDIES BREEDING GROUND
Authors: Clapham Phillip J. , Mattila David K.
Published: August 2006

Abstract: Reactions of humpback whales, Megaptera novaeangliae, to the taking of skin biopsies and to associated activities were studied on one of their principal West Indies breeding grounds on Silver Bank (Dominican Republic). Results were in some cases different from those reported from a similar study of this species in a high‐latitude feeding area. Almost half (44.1%) of 565 biopsied whales showed no immediate reaction to a hit, while a further 22.5% showed only low‐level reactions. A total of 375 (87.8%) of 427 misses involved no reaction. Only one strong reaction was recorded. Behavior changes were recorded following 31 (5.5%) of 569 hits, and 18 (4.5%) of 404 misses. Evasive behavior related to vessel approach was exhibited prior to 72 (12.0%) of 598 hits and 100 (24.1%) of 415 misses. Mothers showed significantly fewer reactions to hits than other whales, and a similar frequency and type of behavior changes, although they tended to be more evasive before a shot was made. Presumed males in competitive groups also showed significantly fewer reactions to shots, and very few behavior changes. Overall, this study supports the belief that the biopsy itself has little effect on a whale and that, if the associated vessel approach is conducted with care, samples can usually be taken with minimal disturbance to the target animal. However, approaches may affect the probability of obtaining fluke photographs for individual identification.
USE OF BIOELECTRICAL IMPEDANCE ANALYSIS TO ASSESS BODY COMPOSITION OF SEALS
Authors: Gales Rosemary , Renouf Deane , Worthy G. A. J.
Published: August 2006

Abstract: Bioelectrical impedance analysis (BIA) measures resistance and reactance of a current as it passes through an organism. The validity of using BIA as a tool to measure body water content, and hence body composition and condition, was tested on harp and ringed seals. The resistance and reactance readings from BIA were compared to estimates of total body water (TBW) determined via tritiated water dilution. The relationship between resistance and TBW (% of body mass) was linear after logarithmic transformation and the two variables were highly correlated. We describe the electrode configuration and placements which provide reliable results in these seals. Our findings indicate that BIA has considerable potential as an inexpensive, rapid, and reliable technique for estimating body composition of phocid seals.
CHARACTERIZATION OF A BOTTLENOSE DOLPHIN (TURSIOPS TRUNCATUS) KIDNEY EPITHELIAL CELL LINE
Authors: Carvan Michael J. , SANTOSTEFANO MICHAEL , SAFE STEPHEN , BUSBEE DAVID
Published: August 2006

Abstract: An epithelial cell line, Carvan dolphin kidney (CDK), isolated from a prematurely born female bottlenose dolphin, Tursiops truncatus, exhibited growth characteristics not previously reported for cetacean cells in culture. CDK cells were cytokeratin positive and demonstrated a maximum doubling time of 1.31 days, with plating and colony forming efficiencies approaching 100% for the early population doublings. Despite an unusually efficient colony‐forming ability and rapid growth, these cells were neither transformed nor immortal, displaying normal contact inhibition, anchorage dependence, and the requirement for high concentrations of fetal bovine serum in the growth medium. CDK cells exhibited age‐dependent changes in growth rate, colony‐forming efficiency, and cytoplasmic profile, and showed a finite lifespan of about 50 population doublings and a stable 2N = 44 karyotype which correlates with previously reported cytogenetic analyses. Velocity sedimentation analysis showed that CDK cells contained nuclear aryl hydrocarbon receptor (Ah), indicating their potential to be induced for cytochrome P450. These data suggest that CDK cells may have utility as an in vitro toxicological model for evaluating hydrocarbon contaminant effects on Tursiops truncatus, a protected marine mammal.
THE INFLUENCE OF CLIMATIC SEASONALITY ON THE LIFE CYCLE OF THE PRIBILOF NORTHERN FUR SEAL
Authors: Trites Andrew W. , Antonelis George A.
Published: August 2006

Abstract

Weather conditions recorded from 1956 to 1986 on St. Paul Island, Alaska, were probed to establish their influence upon the northern fur seal's life cycle (Callorhinus ursinus). Air temperatures, wind speeds, and relative humidity levels were seasonally decomposed and compared with the timing of pupping and migration. Most pups are born in early July when air temperatures and relative humidity approach their highest annual levels and wind speeds are at their lowest. Weather conditions favor growth and survival of pups from July to September but are unfavorable in June. A rapid deterioration in weather through October and November corresponds with the fall migration of pups and lactating females. The data suggest the pivotal event in the fur seal's life cycle is the timing of birth and survival of nursing pups. As such, the ultimate determinant of the precisely timed fur seal life cycle appears to be climatic seasonality during the breeding season.
INTERACTIONS BETWEEN SOUTH AFRICAN FUR SEALS and THE PURSE‐SEINE FISHERY
Authors: Wickens Patti
Published: August 2006

Abstract

Operational interactions occur between South African (Cape) fur seals and the purse‐seine fishery in South Africa. Seals eat fish from the nets but the main concern is the activity of seals causing fish to sound, resulting in loss, or partial loss of the catch. Detectable loss occurs on approximately 5% of hauls. In addition to this, smaller quantities may be lost on each haul as seals depress the net float line while moving into and out of the net. The cost of seal interference is difficult to quantify because the mass of fish lost is not known, and the loss is essentially one of additional fishing time required to fill the total allowable catch for the fishery. An estimate of the cost is calculated as between 1.6% and 4.1% of the landed value of the fishery. Some seals are killed by fishermen when they pose a potential threat to the safety of the crew aboard, and some may drown if caught in the net or pump. Overall this is probably fewer than a thousand seals per year. It is also known that if seals are thought to be disturbing the fish, these seals near the nets may be deliberately killed by purse‐seine fishermen. Overall this mortality, whether deliberate or incidental, is probably negligible in terms of the population size of South African fur seals.
IMMUNOLOGICAL AND HEMATOLOGICAL PARAMETERS IN CAPTIVE HARBOR SEALS (PHOCA VITULINA)
Authors: Nielsen Jens
Published: August 2006

Abstract

Peripheral blood was collected from 13 captive seals (12 harbor seals and 1 gray seal) of various ages to study different immunological and hematological parameters. In vitro mitogenic reactivity of blood lymphocytes was measured by means of a microculture lymphocyte transformation test (LTT). After stimulation with different doses of the mitogens concanavalin A (Con A) and pokeweed mitogen (PWM), all examined seals showed significant proliferative responses to each mitogen. Furthermore, mitogenic reactivity significantly decreased with animal age suggesting this parameter of seal lymphocyte function is age‐related. The present experiments support that the LTT is a suitable tool to monitor the functional capacity of seal lymphocytes. By means of the erythrocyte‐rosette (E:‐rosette) test it was demonstrated that a subpopulation of mononuclear seal bloosd leucocytes formed rosettes with sheep red blood cells (Srbc). This observation indicates that the phenomenon probably represents a marker for T lymphocytes in the seal as in several other mammalian species. Furthermore, the percentage of Srbc rosette‐forming cells decreased with the age of the animals. Total blood leucocyte counts and differential leucocyte counts were determined by light microscopy. The number of leucocytes varied considerably among individual animals. Parallel to a significant decline of the percentage of lymphocytes with age, a corresponding increase in the percentage of neutrophils was demonstrated. In all of the seals, the percentages of monocytes and eosinophils were found to be low with only minor individual variation. The LTT and the E‐rosette test are suggested as potential tools to elucidate immunological disorders in the seal.
IDENTIFICATION OF WHALE SPECIES BY LIQUID CHROMATOGRAPHIC ANALYSIS OF SARCOPLASMIC PROTEINS
Authors: Ukishima Yoshiyuki , Sakane Yumiko , Fukuda Akira , Wada Shiro , Okada Shoji
Published: August 2006

Abstract

Liquid chromatography (LC) was applied to identify whale species by analyzing water‐soluble sarcoplasmic proteins in skeletal muscles. Twenty‐five samples from four baleen whale species (fin whale, sei whale, Bryde's whale, and minke whale) and eight toothed whale species (sperm whale, Baird's beaked whale, short‐finned pilot whale, Dall's porpoise, northern right whale dolphin, Pacific white‐sided dolphin, common dolphin, and striped dolphin) were analyzed. Water‐soluble sarcoplasmic proteins were extracted from each sample and analyzed using a UV‐VIS spectrophotometric detector at 280 nm and a pho‐todiode array detector. The chromatographic profiles of each sample showed distinctive qualitative and quantitative characteristics for each whale species, making species identification possible. A photodiode array detector was useful for further accurate identification of whale species by obtaining the absorption spectra of separated protein peaks. These results suggest that the LC method is readily applicable to rapid, simple, and reliable identification of whale species.
MITOCHONDRIAL DNA VARIABILITY OF STRIPED DOLPHINS (STENELLA COERULEOALBA) IN THE SPANISH MEDITERRANEAN WATERS
Authors: Garcia‐Martinez J. , Barrio E. , Raga J. A. , Latorre A.
Published: August 2006

Abstract

Frozen muscle samples from 44 striped dolphins stranded on the Spanish Mediterranean coasts from 1990 to 1993 have been studied by means of mitochondrial DNA (mtDNA) restriction site analysis. Thirty‐five of these dolphins were affected by a die‐off occurring during this time in the western Mediterranean Sea. The mtDNA from each dolphin was digested with 15 restriction endonucleases that recognized 61 different restriction sites. The specific location of these sites on the mitochondrial gene map allowed us to determine the distribution of variability along this molecule. From the restriction analysis, a total of 15 different composite patterns or haplotypes was obtained and their phylogenetic relationships established both by cladistic and phenetic methods.

Estimates of sequence divergence among the 15 haplotypes ranged from 0.148% to 0.919%. Haplotype diversity (average heterozygosity) obtained was 0.789, a high value compared to other available data on cetaceans, especially considering that only a small area of the distribution of the species has been sampled. Neither population subdivision nor any evidence of correlation between haplotype frequencies and temporal or geographic distribution of dolphins has been detected.
VENTILATORY RATE DIFFERENCES BETWEEN SURFACE‐FEEDING AND NON‐SURFACE‐FEEDING FIN WHALES (BALAENOPTERA PHYSALUS) IN THE WATERS OFF EASTERN LONG ISLAND, NEW YORK, U.S.A., 1981–1987
Authors: Kopelman Arthur H. , Sadove Samuel S.
Published: August 2006

Abstract

Observations of feeding and ventilatory behavior of individual fin whales (Balaenoptera physalus)were made from various vessels during the months of May–September, 1981–1987, in the waters off eastern Long Island, N.Y., U.S.A. Intervals between blows were measured and recorded to the nearest second. Information about behavior was recorded, as were location, depth, and surface temperature at sounding dives. Animals observed feeding at the surface were noted as such, ail others were considered non‐surface‐feeding animals. Data were compiled by individual, month, year, and analyzed for mean interblow interval during surface activity bouts; mean dive duration; and overall mean blow interval.

Overall mean blow intervals (±SE) of 47.89 ± 0.81 set for surface‐feeding (n= 10,411), and 57.92 ±0.97 sec for non‐surface‐feeding animals (n= 11,024), differed significantly (Mann‐Whitney U, P < 0.001). Interblow intervals for surface activity bouts (±SE) of 12.29 ± 0.05 set for surface‐feeding (n= 7,894), and 13.58 ± 0.06 set, for non‐surface‐feeding animals (n = 8,187), also differed significantly (Mann‐Whitney U, P < 0.001), as did mean dive duration (159.53 ± 2.16 sec, n= 2,517, for surface‐feeding animals; 185.86 ± 2.53 set, n= 2,837, for non‐surface‐feeding animals). Yearly comparisons of blow intervals between surface‐feeding and non‐surface‐feeding animals during surface activity bouts yielded significant differences for each year except 1981, while comparisons of dive durations yielded significant differences for all years except 1981, 1982, and 1985.
MORBILLIVIRUS INFECTION IN MANATEES
Authors: Duignan Pádraig J. , House Carol , Walsh Michael T. , Campbell Terry , Bossart Gregory D. , Duffy Noel , Fernandes Peter J. , Rima Bert K. , Wright Scott , Geraci Joseph R.
Published: August 2006

Abstract

The first evidence of exposure of free‐ranging Florida manatees (Trichechus manatees latirostris) to a morbillivirus is reported. Blood samples were collected from 148 Florida manatees between 1977 and 1994. The sample included manatees that were under rehabilitation (n = 97), free‐ranging (n = 40) and fresh necropsy specimens (n = 11). Serum from six animals (4%) neutralized porpoise and dolphin morbilliviruses to a higher titer than any other member of the Morbillivirus genus. Antibodies were not detected in sera from 12 free‐ranging Antillean manatees (T. manatus manatus) from Guyana sampled in 1992 or from 12 hand‐reared Amazonian manatees (T. inunguis) sampled in 1984. Immunoprecipitation studies using radio‐labelled canine distemper virus protein and serum from Florida manatees showed precipitation of the nucleo‐capsid (N) protein. The combination of low antibody titers and absence of clinical disease suggest that the Florida manatee is a dead‐end host. Sporadic infection may occur following contact with another species in which infection is enzootic. Morbillivirus could, either by fatal infection or more insidious effects on the immune system or reproduction, pose a problem to this already threatened species.
LOW FREQUENCY NARROW‐BAND SOUNDS PRODUCED BY BOTTLENOSE DOLPHINS
Authors: Schultz Ken W. , Cato Douglas H. , Corkeron Peter J. , Bryden M. M.
Published: August 2006

Abstract

We present a new sound type recorded from bottlenose dolphins, Tursiops truncatus, in eastern Australian waters: low‐frequency, narrow‐band (LFN) harmonic sounds (defined as less than 2 kHz). Most of these sounds were of frequencies less than 1 kHz and were recorded commonly from socializing dolphins. These sounds differ significantly from narrow‐band whistles, which are higher in frequency and longer in duration. The absence of these sounds in most studies of the acoustic behavior of bottlenose dolphins may reflect geographic differences in repertoires or result from insufficient sampling. Alternatively, these sounds may have been ignored where the focus of research was on other sound types.
ACCLIMATION TO CAPTIVITY: A QUANTITATIVE ESTIMATE BASED ON SURVIVAL OF BOTTLENOSE DOLPHINS AND CALIFORNIA SEA LIONS
Authors: Small Robert J. , Demaster Douglas P.
Published: August 2006

Abstract

An estimate of how long marine mammals need to acclimate to captivity would permit more precise comparisons of husbandry practices, yet no quantitative analysis of acclimation has been performed. Therefore, we estimated the duration of acclimation to captivity for bottlenose dolphins (BD) and California sea lions (CSL) by comparing 5‐d survival rates during the first 90 d of captivity with a survival rate based on days 91‐365 in captivity. Wild‐born BD (n = 1,270) and CSL (n = 1,650) acclimate to captivity in approximately 35 and 40 d, respectively, whereas captive born BD (n = 332) and CSL (n = 992) acclimate in approximately 50 and 40 d, respectively. When transferred between two institutions, BD (n = 911) acclimated in the same amount of time (45 d) as when first transferred from the wild, whereas transferred CSL (n = 336) acclimated more rapidly (15 VJ. 40 d) than when first transferred from the wild. Based on results from these two species, a 60‐d acclimation period is recognized as a distinct interval of relatively high mortality that should be treated separately from long‐term survival estimates when evaluating husbandry practices of ocean‐aria and zoos.
STUDY OF VITAMIN A SUPPLEMENTATION IN CAPTIVE NORTHERN FUR SEALS (CALLORHINUS URSINUS) AND ITS EFFECT ON SERUM VITAMIN E
Authors: Mazzaro Lisa M. , Dunn J. Lawrence , Furr Harold C. , Clark Richard M.
Published: August 2006

Abstract

Two experiments were conducted to determine the effect of vitamin A supplementation on serum vitamin E in adult female northern fur seals (Callorhinus ursinus). In the first experiment five animals received, in addition to their routine dietary multivitamin supplement, a high‐level vitamin A supplement (53 μmol retinyl palmitate/d) for 30 d. Five seals consuming their routine dietary supplement served as controls. Serum vitamin E decreased significantly in animals receiving high‐level vitamin A supplements. At the end of 30 d serum vitamin E averaged 18.6 μg/mL in the control animals and 13.4 μg/mL in the animals receiving the high‐Ieve1 vitamin A supplement. In experiment 2 ten animals received the high level vitamin A supplement for 60 d. After 30 d, serum vitamin E levels were reduced, but by 60 d had returned to baseline levels. However, the ratio of serum vitamin E to phospholipid, another index of vitamin E status, remained decreased. Although the exact mechanism of interaction is unknown, this study shows that when providing vitamin supplements for captive pinnipeds, vitamin interactions must be considered. The vitamin A supplementation currently used by some institutions seems unnecessary and may have detrimental effects on vitamin E status.
COUNTS OF GROWTH LAYER GROUPS IN CEMENTUM AND DENTINE IN RINGED SEALS (PHOCA HISPIDA)
Authors: Stewart Robert E. A. , Stewart Barbara E. , Stirling Ian , Street Elaine
Published: August 2006

Abstract

We compared counts of growth layer groups (GLGs) in the dentine of un‐decalcified, unstained cross‐sections and in the cementum of decalcified, stained longitudinal sections of canine teeth from 144 ringed seals (Phoca hispida). Although there was a statistically significant correlation until approximately 10 GLGs, about 75% of paired readings at ≤ 10 cementum GLGs disagreed. After 10 GLGs, the number of GLGs in the cementum usually was greater. The maximum GLG count in cementum was 33, compared to a maximum in dentine of only 19. Interobserver differences in median counts were not statistically significant using cementum or dentine counts. Regression analysis revealed that for cementum in female seals, readers differed at higher counts (P < 0.05),andfor dentine, there was a constant difference of about 0.6 GLGs (P< 0.05) for male seals and 1.1 GLGs (P< 0.05) for female seals. Counting GLGs in the cementum of decalcified and stained longitudinal sections provided higher counts and more agreement between readers,andit was the better of the methods examined for ageing ringed seals.
SPERM WHALE PHYLOGENY REVISITED: ANALYSIS OF THE MORPHOLOGICAL EVIDENCE
Authors: Heyning John E.
Published: August 2006

Abstract

Some recent analyses of three mitochondrial DNA regions suggest that sperm whales are the sister group to baleen whales and, therefore, the suborder Odontoceti (toothed whales) constitutes a paraphyletic group. I cladistically analyzed the available morphological data, including that from relevant fossil taxa, for all families of extant cetaceans to test this hypothesis. The results of this analysis unambiguously support a monophyletic Odontoceti including the sperm whales. All synapomorphies that support the Odontoceti node are decisive, not related to the evolution of highly correlated characters, and provide the same result regardless of what order of mammals is used as an outgroup. These numerous, anatomically diverse, and unambiguous characters make this clade one of the best‐supported higher‐level groupings among mammals. In addition, the fossil evidence refutes a sperm whale/baleen whale clade. Both the molecular and morphological data produce the same unrooted tree. The improper rooting of the molecular tree appears to be producing these seemingly incongruent phylogenies.
SOCIAL ECOLOGY OF BOTTLENOSE DOLPHINS IN THE KVARNERIĆ (NORTHERN ADRIATIC SEA)
Authors: Bearzi Giovanni , Notarbartolo‐DI‐Sciara Giuseppe , Politi Elena
Published: August 2006

Abstract

A bottlenose dolphin community was studied from small inflatable craft from 1987 to 1994 in a relatively large area (about 800 km2) east of the islands of Loˇsinj and Cres, northern Adriatic Sea. A total of 106 individuals were photoidentified based on natural permanent marks on their dorsal fins. Most of the dolphins were resighted on a regular basis, indicating a high level of year‐round site fidelity, although their range was evidently greater than the chosen study area. Dolphin density was highly variable and considerably lower than for most well‐known bottlenose dolphin communities. Groups averaged seven individuals, with a mode of two. Groups entirely composed of adults were the smallest, groups with calves the largest. Group fluidity was high, seasonal and yearly changes in mean group size being also considerable. Summer was the peak calving season, with a striking variation in the number of births on alternate years. Poor evidence of shark predation was found. The social organization of this dolphin community seemed to be highly flexible, possibly as an adaptation to cope with environmental changes as well as with a limited and variable availability of prey.
EVALUATION OF AN EFFECTIVE METHOD TO ESTIMATE AGE OF CAPE FUR SEALS USING GROUND TOOTH SECTIONS
Authors: Oosthuizen Wessel H.
Published: August 2006

Abstract

Teeth of known‐age Cape fur seals Arctocephalus pusillus pusillus were used to validate age estimated from ground sections. In the canines, dentine growth layer groups (GLGs) reflected age accurately but no reliable readings could be obtained from GLGs in the cementum. Upper canines were the most suitable for age estimation. By contrast, in the postcanines where the cementum is thicker, only GLGs in the cementum could be used for age determination, but not with the same accuracy as for dentine in the canines. Therefore, it is recommended that GLGs in the dentine be used to determine age in the Cape fur seal. However, pulp cavities in canines closed at about 13 yr and consequently GLGs in the cementum of the postcanines should be used where the pulp cavities of canines are closed. Accurate estimation of age is not possible from the dentine of older animals.
FIRST ESTIMATES OF VAQUITA ABUNDANCE
Authors: Barlow Jay , Gerrodette Tim , Silber Greg
Published: August 2006

Abstract

The abundance of the only population of vaquitas, Gulf of California harbor porpoise (Phocoena sinus), is estimated from four surveys conducted in Mexico between 1986 and 1993, using a variety of methods. A line‐transect approach was applied, using some parameters estimated from a related species, the harbor porpoise (Phocoena phocoena). Vaquita abundance is estimated as 503 (CV = 0.63) from 1986–1988 boat surveys, 885 (CV = 0.50) from 1988–1989 aerial surveys, 572 (CV = 1.43) from a 1991 aerial survey, and 224 (CV = 0.39) from a 1993 ship survey. A weighted log‐linear regression indicates a rate of population change (decline) of −17.7% per year (95% CI =−43.2% to +19.3%) between 1986 and 1993. All of these estimates of vaquita abundance indicate that the species is at a critically low level.
AGGREGATIONS OF MATURE MALE SPERM WHALES ON THE GALÁPAGOS ISLANDS BREEDING GROUND
Authors: Christal Jenny , Whitehead Hal
Published: August 2006

Abstract

The distribution and behavior of mature (12.3–16.3 m) male sperm whales (Physeter macrocephalus) were studied on the Galápagos Islands breeding ground from April to June 1995. In contrast to previous research seasons when males were observed only in close spatial and temporal proximity to mixed schools of females and immature animals, in 1995 males were sighted in loose aggregations, separated by hours to days from our vessel's encounters with mixed schools. Only one of ten identified males was observed in spatial proximity to a mixed school.

Aggregations consisted of two to four (minimum estimates) mature males travelling within a range of a few kilometers and were characterized by consistency of heading among individuals. Aggregations moved over time. During encounters, one to three males were observed at the surface at the same time, with interindividual distances of less than 1,000 m. Synchrony of heading was apparent between spatial associates, and its extent appeared to be related to interindividual distance. Clustering (two or more individuals within 100 m) was observed on only two occasions. No agonistic behaviors were seen.

Functions of mature male aggregation on a breeding ground remain unclear. Possible explanations for our observations are local prey abundance, or some form of sociality mediated over spatial scales of hundreds to thousands of meters.
A QUANTITATIVE ASSESSMENT OF DOMINANCE RELATIONS AMONG BOTTLENOSE DOLPHINS
Authors: Samuels Amy , Gifford Tara
Published: August 2006

Abstract

Agonistic behavior of bottlenose dolphins was studied at Brookfield Zoo for nearly 4.5 yr, and dominance relationships were determined using a quantitative technique adapted from primate behavioral research. Dominance relations among dolphins were influenced by the gender of participants. Male dolphins were clearly and consistently dominant to females, and intersexual agonism occurred at moderate rates with seasonal peaks in spring and fall. Dominance relationships among female dolphins were age‐ordered and stable, even though agonism among females did occur at uniformly low rates. In contrast, the two males had a changeable dominance relationship in which periods of stability and low‐level agonism were interspersed with episodes of intense competition. Zoo‐based research revealed patterns of behavior that conformed to current knowledge about bottlenose dolphin social structure. Moreover, research in a zoo setting facilitated development of a quantitative technique that can be used to assess cetacean dominance relationships in field research.
POPULATION ANALYSIS OF NORTHERN BOTTLENOSE WHALES IN THE GULLY, NOVA SCOTIA
Authors: Whitehead HAL , Gowans Shannon , Faucher Annick , Mccarrey Stephen W.
Published: August 2006

Northern bottlenose whales (Hyperoodon ampullatus) are consistently found through the year in the Gully, a prominent submarine canyon on the edge of the Scotian Shelf. Individuals were photographically identified during field studies between 1988 and 1995. About 70% of the population is identifiable, and 29% have markings which persist reliably over periods of years. A mark‐recapture analysis of photographic individual identifications collected between 1988 and 1995 indicates that the population using the Gully numbers about 230 animals (approximate 95% confidence interval 160‐360). The rate of mortality plus emigration plus mark change (in animals with reliable long‐term marks) is about 12% per year, although this estimate has wide and uncertain confidence limits. Members of the Gully population, which includes calves and mature males, are shorter than animals caught off Labrador. The small size of the Gully population and its persistent use of a very small, bathy‐metrically unique ocean area make it vulnerable to human disturbance.
A VIDEO SONAR AS A NEW TOOL TO STUDY MARINE MAMMALS IN THE WILD: MEASUREMENTS OF DOLPHIN SWIMMING SPEED
Authors: Ridoux Vincent , Guinet Christophe , Liret Céline , Creton POL , Steenstrup Resen , Beauplet Gwenaël
Published: August 2006

The use of a multibeam sonar for fine‐scale studies of the foraging activity of bottlenose dolphins (Tursiops truncatus) was tested in a coastal environment where a group of 14 individuals is known to be resident. The sonar was set on a rubber boat and the signals were received continuously as the dolphins were foraging in a pass swept by strong tidal currents. These signals were recorded in HI 8 video standard. The system produced real‐time undistorted images of the dolphins and of their movements within the limits of the sonar beam (15° vertical width, 90° horizontal width, range set at 50 m). The average swimming speed relative to the bottom was 1.8 m ·sec−1 but swimming speed relative to the water was 2.2 m‐sec−1 when allowance was made for the average 1.2 m·sec−1 tidal current. Maximum swimming speed relative to the water was as high as 4.8 m·sec−1. It is estimated from studies of swimming energetics that continuously foraging in a current vein flowing at 1.2 m·sec1 would represent only small additional costs compared to foraging out of these currents. However, previous observations of the same pod have shown that these dolphins keep foraging in this site when current speed reaches 2.7 m·sec−1; under such circumstances, the cost of foraging in this site was calculated to increase by 96%. This suggests that foraging efficiency should be dramatically enhanced during rising tide since the dolphins consistently forage in these currents year round.