bluuebunny/crossref_metadata_2025_split huggingface dataset:
WHALE REACTIONS TO HUMAN ACTIVITIES IN CAPE COD WATERS
Authors: Watkins William A. 
Published: August 2006

AbstractA review of our whale observations of more than 25 years indicated that each of the species commonly observed within 35 km of Cape Cod reacted differently to stimuli from human activities, and that these responses have gradually changed with time. Over the years of exposure to ships, for example, minke whales (Balaenoptera acutorostrata) have changed from frequent positive interest to generally uninterested reactions, finback whales (B. physalus) have changed from mostly negative to uninterested reactions, right whales (Eubalaena glacialis) have apparently continued the same variety of responses with little change, and humpbacks (Megaptera novaeangliae) have dramatically changed from mixed responses that were often negative to often strongly positive reactions. These reactions appeared to result mostly from three types of stimuli: primarily underwater sound, then light reflectivity, and tactile sensation. The whale reactions were related to their assessment of the stimuli as attractive, uninteresting or disturbing, their assessment of the movements of the sources of the stimuli relative to their own positions, and their assessment of the occurrence of stimuli as expected or unexpected. Whale reactions were modified by their previous experience and current activity: habituation often occurred rapidly, attention to other stimuli or preoccupation with other activities sometimes overcame their interest or wariness of stimuli, and inactivity seemed to allow whales to notice and react to stimuli that otherwise might have been ignored. The changes over time in the reactions of whales to stimuli from human activities were gradual and constantly varying with increased exposure to these activities.
THE OCULAR FUNDUS OF TWO CETACEANS
Authors: Dawson William W. , Schroeder J. Pete , Dawson J. French 
Published: August 2006

AbstractWe provided a water‐cornea interface to correct the usual aerial myopia encountered in fundus photography of marine mammal eyes. The 12 Tursiops eyes were consistent for vascular structure, optic papillae, dimensional components and tapetal coloration. Multiple photographs were assembled to produce one ocular fundus typical of Tursiops truncatus and one for Grampus griseus. The eyes have a vestigial hyaloid vessel and an optic disc („blind spot”) that occupies the center of the fundus. The disc is bounded in both species by a vascular structure that is continuous with a (retrobulbar) perineural organ called the ophthalmic rete. The vascular trees of the fundus do not suggest an area of specialization for high resolution. Both species exhibit total tapetalization. Tapetal spectral reflectance did not vary between Tursiops. There was, however, a difference between species in the short wavelength regions of the spectrum.
AUDIOMETRIC ASSESSMENT OF NORTHERN FUR SEALS, CALLORHINUS URSINUS
Authors: Moore Patrick W. B. , Schusterman Ronald J. 
Published: August 2006

AbstractAerial and underwater audiograms for two young female northern fur seals (Callorhinus ursinus) and one young female California sea lion (Zalophus californianus) were obtained with the same procedure and apparatus. Callorhinus hears over a larger frequency range and is more sensitive to airborne sounds than Zalophus or any other pinniped thus far tested in the frequency range of 500 Hz to 32 kHz. Sensitivity of Callorhinus to waterborne pure tones, ranging from 2 to 28 kHz, is equal or superior to all other pinnipeds tested in this same frequency range. Like Zalophus, the upper frequency limit for underwater hearing (as defined by Masterton et al. 1969) in Callorhinus is about one‐half octave lower than the three phocid species thus far tested. Callorhinus' upper frequency limit in air is about 36 kHz and under water it is about 40 kHz. Comparison of air and water audiograms shows Callorhinus is no exception to previous behavioral findings demonstrating that the „pinniped ear” is more suitable for hearing in water than in air. Similar to Zalophus and Phoca vitulina, Callorhinus shows an anomalous hearing loss at 4 kHz in air. The basis for this insensitivity to airborne sounds at 4kHz and not at lower or higher frequencies is presumably caused by specialized middle ear mechanisms matching impedance for waterborne sounds. Critical ratio curves for Callorhinus are similarly shaped to ones obtained for humans but are shifted upwards in frequency. Compared to all other marine mammals thus far evaluated, the critical ratios for Callorhinus are the smallest yet reported.
RELATIVE ABUNDANCE, DISTRIBUTION AND INTER‐SPECIFIC RELATIONSHIP OF CETACEAN SCHOOLS IN THE EASTERN TROPICAL PACIFIC
Authors: Polacheck Tmom 
Published: August 2006

AbstractThe relative abundance of the most common cetacean schools in the eastern tropical Pacific Ocean for 1977–1980 are estimated based on encounter rates with tuna purse‐seiners. No temporal trends were apparent in the relative abundance estimates. The geographic distributions for eight different school types are described. Multivariate statistical techniques are used to investigate interrelations between species and relationships to parameters of the physical environment. The results suggest three major species groupings: (1) an inshore grouping of bottlenose dolphins (Tursiops truncates), Risso's dolphin (Grampus griseus), pilot whales (Globicephala macrorhynchus) and, to a lesser extent, common dolphins (Delphinus delphis); (2) an offshore pelagic grouping of spotted and spinner dolphins (Stenella attenuate and S. longirostris); and (3) an association between pilot whales and common dolphins that overlaps the first grouping in inshore areas and also tends to be segregated from the second grouping. The results also suggest that relative densities of different school types are strongly related to physical environmental parameters, the most important being sea surface temperature, depth of the thermocline and thickness of the oxygen minimum layer.
REVISION OF THE SPOTTED DOLPHINS, STENELLA SPP.
Authors: Perrin W. F. , Mitchell E. D. , Mead J. G. , Caldwell D. K. , Caldwell M. C. , van Bree P. J. H. , Dawbin W. H. 
Published: August 2006

AbstractThe taxonomy of the spotted dolphins has been confused. Two apparent species exist, one endemic to the Atlantic and the other pantropical. They have sharply different color patterns and non‐overlapping vertebral counts. However, the holotype specimens for most of the names that have been applied to the spotted dolphins (including S. attenuata, S. frontalis, S. plagiodon and others) are skulls only, with no information on coloration or number of vertebrae. The two species overlap in all skull characters; geographical variation in both is pronounced. We used a discriminant analysis based on tooth counts and three skull measurements (standardized to skull width) to identify the type specimens to the two species. We used other criteria for assignment of nominal species for which holotype specimens do not exist. We propose that Stenella frontalis (G. Cuv., 1829) be used for the Atlantic endemic species and Stenella attenuata (Gray, 1846) for the pantropical species and here redescribe the species. Proposed common names are Atlantic spotted dolphin and pantropical spotted dolphin. S. frontalis now includes Delphinus froenatus F. Cuv., 1829, D. doris Gray, 1846 and D. plagiodon Cope, 1866. S. attenuata (a nomen conservandum) includes D. velox G. Cuv., 1829, D. pseudodelphis Wiegmann, ≤ 1840, D. brevimanus Wagner, 1846, D. microbrachium Gray, 1850, D. albirostratus Peale, 1848, Steno capensis Gray, 1865, Clymene punctatus Gray, 1866, Steno consimilis Malm, 1871 and Prodelphinus graffmani Lönnberg, 1934. Unidentifiable to either of the two valid species are D. dubius G. Cuv., 1812, D. pernettensis de Blainville, 1817 (suppressed), D. malayanus Lesson, 1826 and D. Rappii Reichenbach, 1845; these must remain incertae sedis.
CORRECT AND INCORRECT USE OF RECRUITMENT RATES FOR MARINE MAMMALS
Authors: Taylor Mitchell , Carley J. Scott , Bunnell Fred L. 
Published: August 2006

AbstractAdults of long‐lived, birth‐pulse populations (e.g., many cetaceans, polar bears and walrus) may not breed every year because of parental care, long gestation periods or nutritional constraints. Estimates of adult annual recruitment rates for such populations are necessarily an oversimplification since these rates are applied to both breeding and non‐breeding females.The weighted mean of age‐specific recruitment is insufficient for non‐stable age projections of multi‐annual populations beyond the first time interval. Restated, conventional or collapsed Leslie matrix and life‐table projections are not adequate for non‐stable age simulations of populations with multi‐annual reproduction cycles.These difficulties may be avoided by employing a parameterization that accommodates a dynamic age structure and proportion of breeding females within a given age class. This parameterization is a true description of the multiple‐year reproduction schedule.Examples, broadly mimicking the life history of polar bears, were used to identify potential qualitative errors that may occur from using overly simplified projection models.
THERMOREGULATORY ADAPTATIONS IN MARINE MAMMALS: INTERACTING EFFECTS OF EXERCISE AND BODY MASS. A REVIEW1
Authors: Whittow G. C. 
Published: August 2006

AbstractA review of thermoregulation in marine mammals led to the following conclusions: very little is known about thermoregulation in large cetaceans. The only measured value for the metabolic rate of a whale, albeit a young one, was substantially higher than the predicted value for a terrestrial mammal of similar size. Very small and newborn marine mammals rely on a high metabolic heat production to sustain their body temperature during exposure to cold or in the water. The considerable insulation of some adult marine mammals may absolve them from the need for a high level of heat production. One marine mammal in tropical or subtropical waters is hypometabolic. There is evidence for a powerful control of thermoregulatory mechanisms by the anterior hypothalamic/preoptic region of the brain in two species. Thermoregulation in marine mammals during exercise remains paradoxical.
USING ORGANOCHLORINE POLLUTANTS TO DISCRIMINATE MARINE MAMMAL POPULATIONS: A REVIEW AND CRITIQUE OF THE METHODS1
Authors: Aguilar Alex 
Published: August 2006

ABSTRACTOrganochlorine pollutants are potentially useful for identifying discrete populations of marine mammals that overlap in geographic distribution. However, many factors unrelated to geographical distribution may affect the chemical burden of individual animals or of entire population components even within a homogeneously distributed population. These factors include. among others, nutritional state, sex, age, trophic level, distance of habitat from mainland and pollution source, excretion. metabolism, and tissue composition. Sample storage and analytical methodology may also be an important source of variation. These, and any other factors, must be identified and their effect ascertained before attempting any comparison between populations. This paper critically examines the nature and magnitude of the effects of these factors on organochlorine tissue loads in marine mammals. Pollutant concentrations can be strongly biased if carefully designed sampling regimes are not followed, but they are affected only moderately by sample treatment after collection. Conversely, ratios between concentrations of compounds, such as the DDE/tDDT or the tDDT/PCB ratios, seem less dependent on sampling regime but more affected by storage. analytical procedures and ecological variations such as distance from pollutant source or trophic level. Taking these effects into account, advice is provided about sampling and strategies for selection of variables that will improve the reliability of the comparisons between populations.
STATISTICAL METHODS FOR ESTIMATING NUMBERS OF CAPE FUR SEAL PUPS FROM AERIAL SURVEYS
Authors: Cressie N. A. C. , Shaughnessy P. D. 
Published: August 2006

AbstractThe Cape fur seal Arctocephalus pusillus of South Africa and Namibia breeds in 23 colonies. Aerial surveys have been used to estimate numbers of pups during breeding seasons from December 1971 to December 1978, and the results have been presented by Shaughnessy (1987). In this paper we develop statistical methods for estimating these pup numbers, as well as variances of the estimates. We demonstrate a significant increase in numbers of seal pups between 1971 and 1976; the rate of increase is estimated to be 3.2% per annum.
A METHOD TO COLLECT AND PROCESS SKIN BIOPSIES FOR CELL CULTURE FROM FREE‐RANGING GRAY WHALES (ESCHRICHTIUS ROBUSTUS)
Authors: Mathews Elizabeth A. , Keller Steven , Weiner David B. 
Published: August 2006

AbstractFor researchers studying mysticere whales few methods for determining gender or for collecting biochemical and genetic information from unrestrained animals are available. The objective of this study was to develop a reliable method for collecting viable tissue samples for establishing continuous cell cultures from skin biopsies of free‐ranging whales. A method to collect and process these samples is presented. Six of seven skin biopsies from gray whales were established in cell culture. Our results suggest that the viability of the samples is improved by (1) sterile processing in the field, (2) minimizing the time between collection and delivery to the cell culture facility, (3) reducing the concentration of antifungal agent, and (4) placing tissue explants under a coverslip. While the results reported in this paper are based on a small sample size, we believe that if the procedures are followed, they will increase the probability of successfully culturing cetacean tissue. Established cell lines can supply replenishable material from identified whales still living in the wild. These cultures can then be used for determination of sex from karyotypes, and for assessing genetic relationships of cetaceans from inherited protein, chromosomal and DNA polymorphisms. These much needed analytical tools can be used to determine familial and populational relationships, leading to a better understanding of mating systems, stock identification and effective population sizes of wild cetaceans.
THE ASSESSMENT OF COMPETITION BETWEEN SEALS AND COMMERCIAL FISHERIES IN THE NORTH SEA AND THE ANTARCTIC1
Authors: Harwood John , Croxall John P. 
Published: August 2006

AbstractMost of the exploited fish stocks in the North Sea are also used as a food supply by a number of seal species; the same is true for some fish and invertebrate stocks in the Antarctic—although the fisheries there are, at present, much smaller than those in the North Sea. The information needed for a critical assessment of such interactions is reviewed. Using existing techniques it is possible to estimate the quantity and size‐classes of each fish or invertebrate species consumed by seals and to compare this with the commercial catch. If fishing mortality is known, these estimates can be used to calculate the level of mortality imposed by the seals. However, a realistic evaluation requires information on the distribution and movements of the fish, the seals' feeding effort, and the fisheries effort in time and space. At present it is difficult or impossible to obtain this information, but recent technological developments in telemetry equipment will soon make it feasible. To assess the economic effects of changes in seal numbers on the fishery, or the ecological effects of changes in fisheries effort on seal populations, requires additional information on the responses of the fishery and the seals to changes in fish abundance, and of the commercial market to changes in the supply of fish.
CAPACITY AND MODE OF PCB METABOLISM IN SMALL CETACEANS1
Authors: Tanabe Shinsuke , Watanabe Seiji , Kan Hiroshi , Tatsukawa Ryo 
Published: August 2006

AbstractBased on a comparative approach using PCB isomer and congener compositions in higher animals and their food organisms, the capacity and mode of PCB metabolism in small cetaceans were studied and the following conclusions were drawn: (1) Small cetaceans can metabolize some of the lower chlorinated biphenyls and this capacity seems to be the same in all species of these animals. (2) The values of MI, an index to evaluate the capacity of PCB metabolism, showed that the metabolic capacity of small cetaceans was extremely low as compared to those of birds and terrestrial mammals. (3) The structural requirements for PCB metabolism were different in animal species, in that small cetaceans have no capacity to metabolize a group of PCBs with adjacent non‐chlorinated meta and para carbons in biphenyl rings. (4) No development of PB (phenobarbital)‐type enzymes, and a lower activity of MC (3‐methylcholanthrene)‐type enzymes were suggested in small cetaceans, which implies long‐term accumulation and possible reproductive toxicity of persistent organochlorines in these animals. The present approach should provide an important insight into the physiological responses of small cetaceans to persistent toxic chemicals.
RAY ENCOUNTERS AS A MORTALITY FACTOR IN ATLANTIC BOTTLENOSE DOLPHINS (TURSIOPS TRUNCATUS)
Authors: Walsh Michael T. , Beusse Deke , Bossart Gregory D. , Young W. Glenn , Odell Daniel K. , Patton Geoffrey W. 
Published: August 2006

AbstractRay spines were found associated with various tissues on necropsy of seven Atlantic bottlenose dolphins (Tursiops truncatus). In at least six cases they were considered a major factor in the death of the animal. Three mature Tursiops had ray spines located in the lung parenchyma. In two other dolphins the ray spine punctured the lateral chest wall without entering the lung tissue. A sixth Tursiops contained a ray spine located in the liver tissue, while a seventh animal had a ray spine lodged in the pancreas. Five of the dolphins were wild individuals and two had been in captivity for more than one year. These findings indicate that beached dolphins and dolphins in captivity with a chronic history of illness should be examined for the presence of ray spines. Caution should be used in maintaining mixed exhibits of dolphins with stingray species.
DYNAMIC RESPONSE ANALYSIS. I. QUALITATIVE ESTIMATION OF STOCKSTATUS RELATIVE TO MAXIMUM NETPRODUCTIVITY LEVEL FROMOBSERVED DYNAMICS
Authors: Goodman Daniel 
Published: August 2006

AbstractA qualitative determination of whether a population is above or below its MNPL can be carried out under circumstances where the value of the MNPL itself, and other details of the production curve, cannot be estimated. This qualitative assessment may often be sufficient for management decisions. The method proceeds by locally approximating the production curve, in the neighborhood of the present population density, from data on population sizes and harvests, and then determining whether this represents the ascending or descending arm of the curve. When the harvests are small, or when the harvests are a constant fraction of the production, the population‐size data need only be relative. With adequate quantities of data, this assessment method can accommodate random measurement error and random perturbations in the dynamics of the population system.
DYNAMIC RESPONSE ANALYSIS. II.EVALUATION OF DYNAMIC RESPONSE ANALYSIS IN A SIMULATED NO‐HARVEST CASE
Authors: Gerrodette Tim 
Published: August 2006

AbstractA new method of stock assessment, dynamic response analysis, allows a qualitative assessment of stock status relative to its level of maximum net productivity to be carried out with minimal data. This paper evaluates the performance of dynamic response analysis on a simulated population under variable conditions with uncertain data. In the no‐harvest case the data consist simply of a temporal sequence of relative population sizes. Dynamic response analysis is most sensitive to the number and precision of the population estimates and least sensitive to environmental variability and the intrinsic population growth rate. Significance levels must be chosen carefully, since some combinations of parameters and error levels result in an unacceptably low proportion of correct assessments. Dynamic response analysis can be a useful stock assessment technique for the management of marine mammals, but attention must be paid to the quantity and quality of the data.
SURVIVORSHIP PATTERNS IN THREE SPECIES OF CAPTIVE CETACEANS
Authors: DeMaster Douglas P. , Drevenak Jeannie K. 
Published: August 2006

AbstractSurvival rates for three species of captive cetaceans are reported, based on records of dates of capture, birth, and death of individual animals. The annual survival rate was 0.93 for bottlenose dolphins and killer whales and 0.94 for white whales. Confidence limits of these estimates are discussed. Differences in survival rates between institutions were significant for bottlenose dolphins only. Calf survival for bottlenose dolphins was lower than non‐calf survival. Survivorship of male killer whales was significantly less than survivorship of female killer whales; sex‐specific survival rates were similar for the other two species. Estimates of average or maximum longevity alone were not useful in comparing rates of survival. Because survival in the first year of captivity may be lower than subsequent years, estimates of the expected lifespan, based on data from the first few years of captivity, may be biased.
MANAGING THE EXPLOITATION OF PACIFIC WALRUSES: A TRAGEDY OF DELAYED RESPONSE AND POOR COMMUNICATION1
Authors: Fay Francis H. , Kelly Brendan P. , Sease John L. 
Published: August 2006

AbstractThe Pacific walrus population has been depleted and subsequently allowed to recover three times in the past 150 yr. As we see it, the population has been made to fluctuate like an r‐selected species, rather than being maintained at a high, stable level, as befits a K‐selected species. The latest depletion began in the 1930s but was not recognized until 25 yr later, by which time the population had been reduced by at least half. Without benefit of communication, the U.S.S.R. and the State of Alaska put similar protective measures into place by 1960, and in the next two decades the walrus population recovered again, at least doubling in size. By 1980, it already was showing density‐dependent signs of having approached or reached the carrying capacity of its environment. As productivity and calf survival declined sharply in the late 1970s and early 1980s the catches more than doubled. We believe that the combined effects of natural curtailment and human intervention may be bringing the population down again rather rapidly. With the present, crude monitoring methods, delayed management responses, and poor international communications, however, the downward trend may not be acknowledged for at least another decade, by which time the unilateral Soviet and American corrective measures are likely to be too much, too late. Walrus management needs to be based less on response to immediate crisis and more on long term prediction than it has been in the past. Because the U.S.A. and U.S.S.R. are trying to manage the same walrus population, without sufficient communication or consensus and sometimes to opposite ends, an international joint management program needs to be implemented.