Dissertations / Theses on the topic 'Cetacean'
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1
Johansson, Anders Torbjörn. "Parametric modelling of cetacean calls." Thesis, University of Southampton, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.409609.
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Williams, Rob. "Cetacean studies using platforms of opportunity." Thesis, University of St Andrews, 2003. http://hdl.handle.net/10023/2836.
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As human impact on marine ecosystems continues to grow, so too does the need for sound conservation and management strategies that are informed by science. Cetaceans, the whales, dolphins and porpoises, epitomise this challenge, because they are hard to study, they have been heavily exploited in the past, and because some of their habitats, behaviours and life-history strategies make them acutely vulnerable to human activities. Unfortunately, research on free-ranging cetaceans in remote areas is costly, and financial resources are limited. The approach used in this thesis to acquire inexpensive quantitative information on cetacean populations and behaviour was to seek out platforms of opportunity. Tourism and environmental education projects provided access to remote areas of importance to cetaceans. The topic was explored in two main areas. First, studies were conducted to investigate the use of ships of opportunity in estimating distribution and abundance, namely of Antarctic baleen whales. The second area of interest was the effect of boats on killer whales in the northeast Pacific. Platforms of opportunity proved valuable for collecting data to model the role of measurement error on abundance estimation. Measurement error was found to be a potential source of bias in four distance estimation experiments. Platforms of opportunity could be used to train observers on protocols, and to learn to use range- finding photogrammetric equipment well before conducting dedicated surveys, which would eliminate this source of bias, as well as estimating abundance in some cases. Abundance and distribution of three whale species were modelled using data collected aboard Antarctic tourist ships. Spatial modelling techniques were used to model distribution of minke, fin and humpback whales using line-transect data collected from a survey that could not be randomised. Strong gradients in animal density were predicted, which could be used to inform future surveys. In the meantime, rough estimates of abundance were obtained, and this approach shows promise for other areas where lack of resources makes systematic surveys prohibitively expensive. A government-funded environmental education project provided logistical support for two studies that dealt with effects of boats on killer whale behaviour. One quantified the extent to which a particular style of whalewatching was disruptive to whale behaviour, and commercial whalewatchers agreed to halt this activity. The other found that a protected area conferred benefit to killer whales, even though it protects only a fraction of the whales' habitat for a fraction of the year. The thesis contains four case studies that illustrate how inexpensive methods may be used to obtain practical quantitative information to aid decision-making about conservation and management of wild cetaceans that interact with (i.e., whalewatching), compete with (i.e., fishing) or are exploited by (i.e., whaling) humans.
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Cooper, Lisa Noelle. "EVOLUTION AND DEVELOPMENT OF CETACEAN APPENDAGES." Kent State University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=kent1257036429.
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Gurevich, Michael Dixon. "Computational acoustic modeling of cetacean vocalizations /." May be available electronically:, 2006. http://proquest.umi.com/login?COPT=REJTPTU1MTUmSU5UPTAmVkVSPTI=&clientId=12498.
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Moore, Sue E. "Cetacean habitats in the Alaskan Arctic /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 1997. http://wwwlib.umi.com/cr/ucsd/fullcit?p9823707.
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Elliott, Vittoria Louise. "Isolation and genomic analysis of the Cetacean Y-chromosome." Thesis, Durham University, 2010. http://etheses.dur.ac.uk/492/.
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The male-specific mammalian Y-chromosome represents a powerful tool for studying malemediated gene flow and genome evolution. Here it was possible to identify 7 polymorphic microsatellites for the first time in an odontocete species, using a combination of cell culture, cytogenetics and molecular approaches. Initially, the development of an efficient and repeatable methodology for obtaining a growing lymphocyte culture that facilitated the isolation of individual chromosomes is described. Flow karyotypic characterization and isolation of individual chromosomes via flow sorting or microdissection is reported for the killer whale (Orcinus orca). Microdissected Y-chromosomes from the killer whale and bottlenose dolphin (Tursiops truncatus) were screened for sequences containing microsatellite motifs. 15 and 10 male-specific microsatellites were identified from the killer whale and bottlenose dolphin, respectively. Additional microsatellite loci were identified from previously published fin whale Y-chromosome sequence. 6 markers designed from heterologous sequences amplified from sperm whales (Physeter macrocephalus), were also screened for variation. All 31 markers were monomorphic in the bottlenose dolphin, only 2 loci showed 2 variants in the killer whale and 7 were polymorphic in the sperm whale. In addition 162 anonymous regions of the Y-chromosome, isolated from the delphinid species were used to characterize the comparative composition of the ?Y? relative to the autosomes in these species. Characteristics are discussed in the context of the genome as a whole, species-specific history and with reference to the expected patterns of mammalian Y-chromosome evolution.
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Jones, Flynn Margaret. "Microanatomic structure of cetacean skin in the urogenital region." Thesis, This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-06232009-063105/.
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Jones, Emma G. "'Burial at sea' : consumption and dispersal of large fish and cetacean food-falls by deep-sea scavengers in the abyssal Northeast Atlantic Ocean and Eastern Mediterranean Sea." Thesis, University of Aberdeen, 1999. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU484683.
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The fate of cetacean carcasses in the deep-sea was investigated using autonomous lander vehicles incorporating time-lapse camera and acoustic tracking systems, as well as fish and amphipod traps. Four lander deployments placed cetacean carcasses at depths of 4000-4800m in the Northeast Atlantic for periods of 36h, 152h, 276h and 480h, before being recovered. The photographic sequences revealed that the soft tissue of carcasses was consumed at rates varying from 0.05-0.48kg.h-1, depending on how intact the carcass was. In each deployment, approximately 1h after emplacement, the grenadier Coryphaenoides (Nematonurus) armatus and large numbers of lysianassid amphipods had arrived at the food-fall. Amphipods appeared to be the only scavengers able to feed directly on the carcass. They tunnelled through the skin and connective tissue layer to reach the blubber and muscle, which was consumed in preference to anything else. Despite being unable to feed on the carcass directly, grenadier numbers remained high until the majority of the bait had been consumed. They were believed to be preying on amphipods attracted to the food-fall. Acoustic tracking studies suggested that, although overall fish numbers remained high during this phase, individuals did not stay significantly longer at the site of the large food-fall compared to a small one, and a "conveyer-belt" of fish arrived, fed and dispersed on a scale of 10s to 100s of km. Once the soft tissue had been removed, grenadier numbers declined and mobile scavengers were replaced by a variety of more benthic fish and invertebrates, some of which took up residence amongst the bones, e.g. eelpouts and galtheid crabs. Funnel traps recovered with the carcass and from a series of fish trap deployments of varying duration indicated a succession in species composition of amphipods, with specialist necrophages such as Eurythenes gryllus and Paralicella sp. being replaced by more generalist feeders of the Orchomene species complex.
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Walker, Rebekah J. "The Seasonality of Mass Strandings: Implications for Cetacean Stranding Sites." NSUWorks, 2003. http://nsuworks.nova.edu/occ_stuetd/284.
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The occurrence of stranded cetaceans has been of interest since Aristotle and numerous theories have been advanced to explain stranding phenomena. The causes(s) of mass strandings remain unresolved, but recent investigations suggest the importance of environmental rather than biological aspects. Little emphasis has been placed on the importance of seasonal fluctuations in the number of mass strandings. Stranding data for the past 20 years in Florida, collected by the Southeastern U.S. Marine Mammal Stranding Network, show a peak in mass strandings on the Florida east coast during the winter and spring and on the Florida west coast and Keys during the summer and fall. The infrequency of mass strandings suggests that a number of factors must coexist for a stranding to occur. Correlations were found between downwelling-favorable wind conditions and stranding events. Seasonal variations in wind speed and direction create frontal convergences in the ocean environment, which can be tracked by cetaceans. Such wind induced physical oceanographic changes, if followed by cetaceans, may explain why species move from the shelf-break to the near shore environment. In addition, strandings are more likely to occur on beaches that slope gently until a point of more rapid drop-off, allowing deep water to be located nearshore. This analysis suggests that the prevailing winds and high relief areas located close to shore are important factors in the initial stages of a stranding due to their causative effect on frontal structures the week prior to an event.
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Liaw, Hibisca. "Underwater measurements of heart rate." Thesis, Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/47546.
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The objective of this project is to develop a device that can monitor the heart rate and respiration of cetaceans. This would provide a way to quantitatively measure stress and determine the impact of human activity on cetaceans, especially for certain species that have been difficult to monitor in the past. There are many challenges to developing such a device, including determining the appropriate type of sensor, reducing the effect of flow noise, and designing an effective attachment method; this paper primarily focuses on determining the most suitable acoustic transducer. Experiments were conducted to compare various acoustic sensors in detecting heart rate. The electronic stethoscope performed the best in the experiments, but the results showed that other transducers, such as accelerometers and pressure sensors, also performed well and could be successful options with further development. Data processing methods to identify heartbeats and characterize signals are also discussed in this paper. Future work on the project involves subsequent tests to address other design variables as well as replicate experiments on animals.
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Ferguson, Megan Caton. "Cetacean population density in the Eastern Pacific Ocean : analyzing patterns with predictive spatial models /." Online version in PDF format, 2005. http://swfsc.noaa.gov/uploadedFiles/Divisions/PRD/Programs/Coastal_Marine_Mammal/Ferguson2005dissertation.pdf.
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Thesis (Ph. D.)--University of California, San Diego, 2005.Vita. Includes bibliographical references. Also available online in PDF format via the National Marine Fisheries Service Coastal Marine Mammal Program (CMMP) home page.
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Embling, Clare Beth. "Predictive models of cetacean distributions off the west coast of Scotland /." St Andrews, 2008. http://hdl.handle.net/10023/640.
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May-Collado, Laura Johanna. "Phylogenetic and Ecological Significance in the Evolution of Cetacean Tonal Sounds." FIU Digital Commons, 2007. http://digitalcommons.fiu.edu/etd/44.
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Cetaceans are aquatic mammals that rely primarily on sound for most daily tasks. A compendium of sounds is emitted for orientation, prey detection, and predator avoidance, and to communicate. Communicative sounds are among the most studied Cetacean signals, particularly those referred to as tonal sounds. Because tonal sounds have been studied especially well in social dolphins, it has been assumed these sounds evolved as a social adaptation. However, whistles have been reported in ‘solitary’ species and have been secondarily lost three times in social lineages. Clearly, therefore, it is necessary to examine closely the association, if any, between whistles and sociality instead of merely assuming it. Several hypotheses have been proposed to explain the evolutionary history of Cetacean tonal sounds. The main goal of this dissertation is to cast light on the evolutionary history of tonal sounds by testing these hypotheses by combining comparative phylogenetic and field methods. This dissertation provides the first species-level phylogeny of Cetacea and phylogenetic tests of evolutionary hypotheses of cetacean communicative signals. Tonal sounds evolution is complex in that has likely been shaped by a combination of factors that may influence different aspects of their acoustical structure. At the inter-specific level, these results suggest that only tonal sound minimum frequency is constrained by body size. Group size also influences tonal sound minimum frequency. Species that live in large groups tend to produce higher frequency tonal sounds. The evolutionary history of tonal sounds and sociality may be intertwined, but in a complex manner rejecting simplistic views such as the hypothesis that tonal sounds evolved ‘for’ social communication in dolphins. Levels of social and tonal sound complexity nevertheless correlate indicating the importance of tonal sounds in social communication. At the intraspecific level, tonal sound variation in frequency and temporal parameters may be product of genetic isolation and local levels of underwater noise. This dissertation provides one of the first insights into the evolution of Cetacean tonal sounds in a phylogenetic context, and points out key species where future studies would be valuable to enrich our understanding of other factors also playing a role in tonal sound evolution.
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Embling, Clare B. "Predictive models of cetacean distributions off the west coast of Scotland." Thesis, University of St Andrews, 2008. http://hdl.handle.net/10023/640.
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The main purpose of this study was to produce and test the reliability of predictive models of cetacean distributions off the west coast of Scotland. Passive acoustic and visual surveys were carried out from platforms of opportunity between 2003 and 2005. Acoustic identifications were made primarily of harbour porpoises (Phocoena phocoena), delphinids, and sperm whales (Physeter macrocephalus). Generalised Additive Models (GAMs) were used to relate species’ distributions to a range of environmental variables over a range of temporal and spatial scales. Predictive models of delphinid distributions showed both inter-annual and inter-month variations. Combining all data for all months and years resulted in a model that combined the environmental influences from each monthly and yearly model. Overall, delphinids were found to associate with the deep (> 400m) warm water (10.5°C-12.5°C), and in areas of deep thermocline. Relationships between sperm whales and environmental variables were consistent over changes in grain size (9 km or 18 km), but not between areas. Although sperm whales were distributed in deep water characterised by weak thermoclines and strong haloclines in the most northerly area (Faroe-Shetland Channel), they were found in deep productive areas with cold surface temperature in the more southerly waters (Rockall Trough). Within the southern Inner Hebrides, high use areas for harbour porpoises were consistently predicted over time (in years) and with differing survey techniques (acoustic versus visual), but not over space (southern Inner Hebrides versus whole of the Inner Hebrides). Harbour porpoises were mainly distributed in areas with low tidal currents and with higher detection rates during spring tides. The use of prey as a predictor variable within models of delphinid distribution shows some promise: there were correlations between delphinid and herring (Clupea harengus) in shelf-waters in 2005 but not in 2004. These models can be used in mitigating acoustic threats to cetaceans in predicted high use areas off the west coast of Scotland.
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Teng, Hsia-chen Sophia. "The EIA process: conservation of local cetacean population in Hong Kong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B45170095.
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Canning, Sarah Jane. "Cetacean distribution and habitat use along the East coast of Scotland." Thesis, University of Aberdeen, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.445139.
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The main aim of this project, co-ordinated by the University of Aberdeen and The Sea Watch Foundation, was to describe spatial and temporal trends in cetacean occurrence along the south Aberdeenshire coastline and to identify any environmental factors that may be influencing distribution. The most frequently sighted cetacean was the bottlenose dolphin and previous work confirmed that these animals are part of the population known to reside in the Moray Firth. The entrance to the River Dee (Aberdeen) is highlighted as an important feeding area for these dolphins. Bottlenose dolphins were frequently sighted in the coastal waters south of Aberdeen and these groups tended to be larger and of animals that were primarily travelling, as opposed to the foraging groups observed at Aberdeen. The harbour porpoise was the second most frequently cetacean during this study. They were sighted all along the coast in all months of the year, although notably, they were not recorded during the land-surveys at Aberdeen during the winter. Tidal height and sea depth appears to have a strong influence on where and when porpoises were sighted and it is thought this is a reflection of prey behaviour. The third species examined was the white-beaked dolphin. This is a seasonal visitor to the coastal waters around Aberdeen with all sightings occurring during the summer. Seabed depth and slope influence the distribution of this species within the study area and again, this was thought to related to prey distribution. Stomach content analysis highlighted haddock and whiting as being important in the diet of this species in Scottish water. Sea temperature was highlighted as influencing white-beaked dolphin group size, with smaller groups being recorded at higher temperatures. Analysis of the stranding database also suggested that higher sea temperature restricts the distribution of this species around the UK.
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Benti, Benjamin. "Behavioural responses of two cetacean species to natural and anthropogenic sounds." Thesis, Strasbourg, 2020. http://www.theses.fr/2020STRAJ002.
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Il est crucial pour les animaux de se servir des stimuli environnementaux pour localiser et évaluer la qualité des ressources et menaces présentes dans les environs. Dans l’océan, les stimuli acoustiques sont privilégiés. Les cétacés sont susceptibles de détecter les sons produits par une multitude de sources, dont les autres espèces et les sources anthropiques. J’ai étudié les réponses comportementales de deux espèces de cétacé, la baleine à bosse et le globicéphale noir, à des stimuli acoustiques d’origine naturelle (sons d’orques) et anthropique (sonars militaires). J’ai montré que les baleines à bosse sont capables de différencier les sons de différents écotypes d’orques. J’ai développé un algorithme de classification des vocalisations animales qui prend en compte la nature graduelle de certains répertoires vocaux et ai utilisé cet algorithme pour décrire les réponses vocales des globicéphales noirs aux sons d’orques et aux sonars militairesIt is crucial for animals to use environmental stimuli to locate and evaluate the quality of resources and threats present in their surroundings. In the ocean, acoustic stimuli are privileged. Cetaceans are susceptible to detect acoustic stimuli produced by a multitude of sources, including other cetacean species and anthropogenic sources. I studied the behavioural responses of two cetacean species, the humpback whale and the long-finned pilot whale, to natural and anthropogenic acoustic stimuli (respectively killer whale sounds and naval sonars). I found that humpback whales were able to discriminate between the sounds of different killer whale ecotypes. I developed an unsupervised classification algorithm which takes into account the graded nature of animal vocalisations, and used this algorithm to describe the vocal responses of long-finned pilot whales to killer whale sounds and naval sonars
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Hogg, Carolyn J. "Development of a non-invasive technique to determine reproductive hormones in cetaceans." Faculty of Veterinary Science, 2006. http://hdl.handle.net/2123/1865.
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Doctor of Philosophy (PhD)Reproductive physiology plays a vital role in population growth and vitality. Baseline data on reproductive physiology and a comprehensive knowledge of breeding biology are essential to conservation management. Great whales have been hunted from the 16th century to the present day. Although many populations are increasing there are populations with low or declining reproductive rates. In 2001 it was recommended to the International Whaling Commission that new techniques be developed to assess the internal physiology of great whales. This study, based on this recommendation, aims to develop analytical methods to assess reproductive hormones in cetacean blow samples and determine the feasibility of its use with free-swimming great whales. A method for the assessment of steroid hormone concentrations using liquid chromatography-mass spectrometry (LC-MS) was developed and validated. These methods were then used to determine testosterone and progesterone concentrations in saliva and blow of bottlenose dolphins. The stability of testosterone and progesterone was found to be a major issue. Without inhibitors, hormone concentrations increased by up to 65% over three hours at 21oC. Storing samples at low temperatures (-20oC or -80oC) slowed but did not cease the rate of change. The addition of inhibitors, manganese chloride and amoxycillin potassium/clavulanate, improved the stability of testosterone and progesterone. It is proposed that when using dolphin saliva and blow samples to measure reproductive hormones the samples are extracted as soon as possible after collection to prevent degradation. This study highlighted the need to address steroid hormone stability prior to any longterm biological program, to ensure that changes seen in hormone concentration are due to biological activity rather than storage. A technique to collect blow samples from free-swimming great whales was developed. This technique, in conjunction with the specially developed LC-MS methods allowed for the determination of testosterone and progesterone concentrations in humpback whale blow. The techniques developed in this study to determine reproductive hormones in cetacean saliva and blow have applications for both captive and wild population studies. In captive institutions, saliva and/or blow can be used to monitor reproductive cycling in both females and males. As it is noninvasive it can be used on a daily basis with minimal stress to the animals. The use of blow sampling has the capacity to improve our understanding of reproductive cycling in great whales as it can be used to sample animals in both the breeding and feeding areas. This technique may allow us to now examine whether reproductive dysfunction is playing a role in the slow recovery of critically endangered species such as the North Atlantic right whale.
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Hogg, Carolyn J. "Development of a non-invasive technique to determine reproductive hormones in cetaceans." Thesis, The University of Sydney, 2005. http://hdl.handle.net/2123/1865.
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Reproductive physiology plays a vital role in population growth and vitality. Baseline data on reproductive physiology and a comprehensive knowledge of breeding biology are essential to conservation management. Great whales have been hunted from the 16th century to the present day. Although many populations are increasing there are populations with low or declining reproductive rates. In 2001 it was recommended to the International Whaling Commission that new techniques be developed to assess the internal physiology of great whales. This study, based on this recommendation, aims to develop analytical methods to assess reproductive hormones in cetacean blow samples and determine the feasibility of its use with free-swimming great whales. A method for the assessment of steroid hormone concentrations using liquid chromatography-mass spectrometry (LC-MS) was developed and validated. These methods were then used to determine testosterone and progesterone concentrations in saliva and blow of bottlenose dolphins. The stability of testosterone and progesterone was found to be a major issue. Without inhibitors, hormone concentrations increased by up to 65% over three hours at 21oC. Storing samples at low temperatures (-20oC or -80oC) slowed but did not cease the rate of change. The addition of inhibitors, manganese chloride and amoxycillin potassium/clavulanate, improved the stability of testosterone and progesterone. It is proposed that when using dolphin saliva and blow samples to measure reproductive hormones the samples are extracted as soon as possible after collection to prevent degradation. This study highlighted the need to address steroid hormone stability prior to any longterm biological program, to ensure that changes seen in hormone concentration are due to biological activity rather than storage. A technique to collect blow samples from free-swimming great whales was developed. This technique, in conjunction with the specially developed LC-MS methods allowed for the determination of testosterone and progesterone concentrations in humpback whale blow. The techniques developed in this study to determine reproductive hormones in cetacean saliva and blow have applications for both captive and wild population studies. In captive institutions, saliva and/or blow can be used to monitor reproductive cycling in both females and males. As it is noninvasive it can be used on a daily basis with minimal stress to the animals. The use of blow sampling has the capacity to improve our understanding of reproductive cycling in great whales as it can be used to sample animals in both the breeding and feeding areas. This technique may allow us to now examine whether reproductive dysfunction is playing a role in the slow recovery of critically endangered species such as the North Atlantic right whale.
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Dionne, Lee Elton. "Situating the cetacean: Science and storytelling in Witi Ihimaera's The whale rider." CSUSB ScholarWorks, 2006. https://scholarworks.lib.csusb.edu/etd-project/2883.
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Lambert, Emily. "The resilience of whale-watching tourism to climate change impacts on cetacean distribution." Thesis, University of Aberdeen, 2012. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=186627.
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Whale-watching tourism depends upon the continued presence of cetacean species within a specific area. However, current evidence suggests that the distribution and/or abundance of cetaceans may alter in response to continued changes in sea surface temperature with global climate change (GCC). This thesis develops and applies a framework for evaluating the resilience of whale-watching tourism to these potential temperature-induced shifts in cetacean distribution. The framework identifies three key components that are likely to affect the vulnerability of an operator to climate change impacts on cetacean occurrence (and tourist numbers). These are the likelihood of observing a cetacean, the type of whale-watching trip, and the type of tourist. Together with an examination of an operator's adaptive capacity, these data provide the type of information required to make an assessment of resilience. Using Western Scotland as a case study, framework components were populated using species distribution modeling, a motivation-based segmentation of whale-watchers, an examination of tourist's attitudes to scenarios of a changing environment and a segmentation of trip activity. Finally, data on potential vulnerability were combined with investigation of an operator's adaptive capacity (using semi-structured interviews) to make an evaluation of resilience to climate change. Our results highlight four key findings: (1) operators have high inherent resilience to a variable environment in which uncertainty is accepted, (2) vulnerability to climate change is influenced by the type and number of trips offered by whale-watch operators, (3) adaptive capacity can be improved through enhanced perceptions of risk, and (4) vulnerability to climate change is not independent from vulnerability to other factors. Future research should focus on those areas where whale-watching is less diverse, more specialised and where, currently, the climate is less variable, as it is in these regions that vulnerability may be highest and, most likely, capacity to develop resilience at its lowest.
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Smith, David James. "The application of artificial neural networks to the classification of underwater cetacean sounds." Thesis, University of Exeter, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.335042.
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Butti, Camilla. "Organization of the cetacean frontal and insular cortices: cytoarchitecture,chemoarchitecture, and neuronal specializations." Doctoral thesis, Università degli studi di Padova, 2009. http://hdl.handle.net/11577/3426496.
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The brain of cetaceans is very large in both absolute and relative size and possesses an extremely convoluted cortex. The understanding of how the brain of these mammals fully adapted to an aquatic life is organized is important to shed light on the processes that shaped the evolution of the mammalian brain in general, including humans. Three cortical regions, the anterior cingulate (ACC), anterior insular (AI), and frontopolar cortices (FPC) have been shown to be involved in high-level cognitive function in primates and thus, the understanding of their structural organization in cetaceans is particularly meaningful given the wide evidence of their cognitive abilities. Cytoarchitecture, chemoarchitecture based on the distribution of the calcium binding (CaBP) protein calretinin, glia/neuron ratio, and neuronal specializations were assessed in the ACC, AI, and FPC of a series of cetaceans representative of the main families such as the bottlenose dolphin (Tursiops truncatus, Odontoceti, Delphinidae), Risso’s dolphin (Grampus griseus, Odontoceti, Delphinidae), harbor porpoise (Phocoena phocoena, Odontoceti, Phocoenidae), killer whale, (Orcinus orca, Odontoceti, Delphinidae), beluga whale (Delphinapterus leucas, Odontoceti, Monodontidae), sperm whale (Physeter macrocephalus, Odontoceti, Physeteridae), pigmy sperm whale (Kogia simus, Odontoceti, Kogiidae), Amazon river dolphin (Inia geoffrensis, Odontoceti, Iniidae), minke whale (Balaenoptera acutorostrata, Mysticeti, Balaenopteridae), and humpback whale (Megaptera novaeangliae, Mysticeti, Balaenopteridae). Other species including the pigmy hippopotamus (Hexaprotodon liberiensis, Cetartiodactyla, Hippopotamidae), Florida manatee (Trichecus manatus latirostris, Sirenia, Trichechidae), Atlantic walrus (Odobenus rosmarus rosmarus, Carnivora, Odobenidae), African savannah elephant (Loxodonta africana, Proboscidea, Elephantidae), black rhinoceros (Diceros bicornis, Perissodactyla, Rhinocerotidae), rock hyrax (Procavia capensis, Hyracoidea, Procavidae), lowland streaked tenrec (Hemicentetes semispinosus, Afrosoricida, Tenrecidae), and black and rufous elephant shrew (Rhynchocyon petersi, Macroscelidea, Macroscelididae), were used for comparative purposes in different parts of this study. The results show that 1) Order-specific differences in the organization of the neocortex occur among cetaceans; 2) Cetaceans share structural features of the neocortex with the artiodactyls, both at a structural and neurochemical level; 3) The glia-neuron ratio of the cetacean neocortex corresponds to what is expected for their brain size; 4) The specific cortical regions investigated contain, in most of the available cetaceans species, a neuronal specialization observed with the same pattern of distribution only in great apes and humans, the Von Economo neurons. Overall these results are further evidence for an organization of the cetacean neocortex, which, although very different from that of primates, displays complexity, challenging the classical view of its homogeneous and simple structure. Specifically, the extended development of regions involved in high-level cognitive processes such as the ACC, AI, and FPC, their diverse cortical organization, and the presence of a specific neuronal specialization, all suggest that specific evolutionary selective pressures acted on these cortical regions and thus on their functions. Based on the evidence reported in the present thesis, the brain of cetaceans can be considered of a complexity comparable to that of primates, and an evolutionary alternative to the generation of complex behaviors.L’encefalo dei cetacei è caratterizzato dal notevole volume e dalla complessità ed estensione della superficie neocorticale. La conoscenza dell’organizzazione delle strutture cerebrali di questi mammiferi completamente adattati alla vita acquatica è di primaria importanza per comprendere i meccanismi che stanno alla base dell’evoluzione del sistema nervoso centrale dei mammiferi, incluso l’uomo. In particolare, le tre regioni corticali costitute dalla corteccia cingolata anteriore (ACC), dalla insula anteriore (AI) e dalla corteccia frontopolare (FPC) hanno un ruolo primario nei processi di alto livello cognitivo nei primati e, quindi, lo studio della loro organizzazione corticale nei cetacei assume una particolare importanza in ragione delle capacità cognitive ampiamente documentate in queste specie. La citoarchitettura, la chemoarchitettura basata sulla distribuzione della proteina legante il calcio (CaBP) calretinina (CR), il rapporto cellule della glia-neuroni (GNI) e le specializzazioni neuronali di ACC, AI e FPC sono state studiate in alcune specie, rappresentanti delle maggiori famiglie di cetacei, che includono il tursiope (Tursiops truncatus, Odontoceti, Delphinidae), il grampo (Grampus griseus, Odontoceti, Delphinidae), la focena (Phocoena phocoena, Odontoceti, Phocoenidae), l’orca (Orcinus orca, Odontoceti, Delphinidae), il beluga (Delphinapterus leucas, Odontoceti, Monodontidae), il capodoglio (Physeter macrocephalus , Odontoceti, Physeteridae), il capodoglio nano (Kogia simus, Odontoceti, Kogiidae), l’inia (Inia geoffrensis, Odontoceti, Iniidae), la balenottera minore (Balaenoptera acutorostrata, Mysticeti, Balaenopteridae) e la megattera (Megaptera novaeangliae, Mysticeti, Balaenopteridae). Specie selezionate che includono l’ippopotamo nano (Hexaprotodon liberiensis, Cetartiodactyla, Hippopotamidae), il lamantino della Florida (Trichecus manatus latirostris, Sirenia, Trichechidae), il tricheco (Odobenus rosmarus rosmarus Carnivora, Odobenidae), l’elefante africano (Loxodonta africana, Proboscidea, Elephantidae), il rinoceronte nero (Diceros bicornis, Perissodactyla, Rhinocerotidae), la procavia (Procavia capensis, Hyracoidea, Procavidae), il tenrec striato di pianura, (Hemicentetes semispinosus, Afrosoricida, Tenrecidae), e il toporagno elefante di Peters (Rhynchocyon petersi, Macroscelidea, Macroscelididae) sono state utilizzate, in una prospettiva comparata, in diverse parti della presente tesi. I risultati qui riportati dimostrano che 1) Esistono differenze ordine-specifiche nell’organizzazione corticale dei cetacei; 2) Esistono similitudini strutturali e chimiche nell’organizzazione corticale di cetacei e artiodattili; 3) Il rapporto cellule della glia-neuroni nella corteccia dei cetacei è conforme a quanto previsto sulla base delle dimensioni dell’encefalo; 4) Le specifiche regioni corticali esaminate nella presente tesi contengono, nella maggior parte delle specie di cetacei, una particolare specializzazione neuronale, osservata con la medesima distribuzione solo nell’elefante e nelle scimmie antropomorfe filogeneticamente più vicine all’uomo: i neuroni di Von Economo. In conclusione, i risultati qui riportati costituiscono una ulteriore evidenza del fatto che l’organizzazione corticale dei cetacei, anche se molto diversa da quella dei primati, è caratterizzata da una specifica complessità che sfida la visione di semplicità e monotonia classicamente associata alla struttura della corteccia cerebrale di questi mammiferi marini. In particolare, il notevole sviluppo di regioni corticali associate a complessi processi cognitivi, quali ACC, AI e FPC, l’ eterogeneità dell’organizzazione corticale, e la presenza di definite specializzazioni neuronali, suggeriscono che queste regioni corticali, e le loro funzioni, siano state plasmate da specifici processi evolutivi. Sulla base dei risultati riportati nella presente tesi, l’encefalo dei cetacei può essere considerato di complessità paragonabile a quella dei primati, ed una alternativa evoluzionistica per la produzione di comportamenti strutturati.
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Marcoux, Marianne. "Narwhal communication and grouping behaviour: a case study in social cetacean research and monitoring." Thesis, McGill University, 2011. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=96800.
Full textAbstract:
Narwhals (Monodon monoceros) are gregarious, toothed whales restricted to the Arctic, where habitats are changing and shipping traffic is increasing. Challenges associated with the remoteness of narwhal populations and the general difficulty of studying deep diving mammals have resulted in a lack of knowledge of narwhal social behaviour, which can only be rectified with intensive, direct and systematic observations. I studied the grouping patterns and vocal behaviour of narwhals using non-invasive methods and developed new statistical tools to analyse the data. The field work was conducted at Bruce Head, a peninsula at the mouth of Koluktoo Bay, Nunavut, during the summers of 2006-2008. Shore-based observations were used to delineate narwhal groups by sex and age class. Narwhals travelled in clusters of 1–25 individuals of mixed sex and age class. Narwhals entered the bay in larger groups than they exited. The coloration of narwhal's backs on photographs was used to estimate their age and investigate their association with individuals of similar age. To analyse these data, I developed statistical methods that examine the distribution of observations in time and their associated characteristics. Using these methods, I found that narwhals form groups with individuals of similar age. The variability and the context of usage of narwhal calls were examined from underwater recordings. Some physical characteristics of narwhal whistles seemed behaviour-specific. Both whistles and pulsed calls might serve in individual- or group-recognition. Finally, given that there is a need for sustained, local monitoring of narwhals, I explored the potential of passive acoustic methods for narwhal monitoring. An automated detector was able to correctly identify narwhal calls in a 25-day continuous recording. There was a correlation between the number of calls manually detected in non-continuous recordings and the number of narwhals observed during the recordings. Non-invasive methods can provide valuable insight into the social organization, communication and movement patterns of large numbers of non-disturbed cetaceans.Le narval (Monodon monoceros) est un cétacé grégaire arctique dont l'habitat est en train de se modifier rapidement. Les difficultés reliées à l'accès en Arctique et à l'étude des cétacés en haute mer expliquent le manque d'information sur le comportement social des narvals. Dans le cadre de mes études doctorales j'ai étudié les groupes sociaux des narvals ainsi que leur communication vocale en utilisant des méthodes de récolte de données non invasives. De plus, j'ai développé des méthodes statistiques pour l'analyse de ces données. Le travail de terrain s'est déroulé au cours des étés 2006 à 2008 dans la baie Koluktoo, au Nunavut. À partir d'observations faites de la côte, la composition et la taille des groupes de narvals ont été compilées. Les narvals se déplaçaient en groupes de 1 à 25 individus d'âge et de sexe variés et entraient dans la baie en groupes plus nombreux que lorsqu'ils en sortaient. La coloration sur le dos des narvals pris en photo a servi à estimer leur âge et à évaluer la formation de groupe en fonction de ces âges. Pour analyser ces données, j'ai développé des méthodes statistiques qui évaluent la distribution d'observations réparties dans le temps ainsi que des caractéristiques associées à chacune des observations. Cette analyse m'a permis de conclure que les narvals forment des groupes avec des individus d'âges similaires. La variabilité et le contexte de l'utilisation des vocalisations émises par les narvals ont par la suite été étudiés à partir d'enregistrements acoustiques sous-marins. Ainsi, certaines caractéristiques acoustiques des vocalisations semblent associées spécifiquement à certains comportements. De plus, certaines de ces vocalisations pourraient être uniques à chaque groupe. Finalement, j'ai exploré la faisabilité d'un programme de surveillance acoustique à long terme pour les narvals. Les vocalisations des narvals ont été correctement détectées par un détecteur automatique appliqué à un enregistrement continu sur 25 jours. Le nombre de narvals observés visuellement et le nombre de vocalisations entendues durant ces enregistrements non continus étaient corrélés. Ces méthodes non invasives permettent d'étudier l'organisation sociale, la communication et les mouvements cétacés en grand nombre sans les perturber.
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Wang, Amy (Hui-Shan). "The Effects Of Mercuric Chloride On Cultured Atlantic Spotted Dolphin (Stenella Plagiodon) Renal Cells And The Role Of Selenium In Protection." Thesis, Virginia Tech, 1998. http://hdl.handle.net/10919/9777.
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Marine mammals are known for their low susceptibility to mercury toxicity, and it was hypothesized that selenium may play a role in protection against mercury toxicity. To gain insight into the mechanisms of the low susceptibility of cetaceans, we investigated the in vitro effects (1) of mercuric chloride (HgCl₂) on the ultrastructure and cell death of Atlantic spotted dolphin renal cells (Sp1K cells), (2) of HgCl₂ on the cell proliferation and cell cycle status of Sp1K and Rhesus monkey renal cells (MK2), and (3) of sodium selenite (Na₂SeO₃) on cell proliferation and cell death of control and HgCl₂-treated Sp1K cells.
HgCl₂ affected multiple organelles and nuclei in Sp1K cells, and induced apoptosis in a time-and dose-dependent manner. Both ultrastructural changes and induction of apoptosis were milder than seen in other cell types in previous publications. In addition, Sp1K cells were able to proliferate at 25 µM HgCl₂ while MK2 cells were killed at 15 µM HgCl₂. An increase in percentage of cells in the G0/G1 phase in the cell cycle and a decrease in S, and G2/M phase cells were seen in Sp1K cells exposed to more than 10 uM HgCl₂ more than 72 hours. MK2 cells showed cell cycle changes only at 24 hours exposure, and may be due to a sensitive subgroup. These data suggested that Sp1K cells were less susceptible than other cell types in a cell-specific way, which was independent of selenium protection.
Concurrent exposure to Na₂SeO₃ provided protection against the HgCl₂-induced decrease in cell proliferation of Sp1K. The protective effects were greater if Na₂SeO₃ and HgCl₂ were premixed, but disappeared if exposures did not overlap. Although pretreatments with Na₂SeO₃ alone did not provide protection, they increased the protection of selenium administered later. Furthermore, Na₂SeO₃ decreased HgCl₂-induced apoptosis. These data demonstrated the Na₂SeO₃ protection against HgCl₂ toxicity in Sp1K cells in terms of cell proliferation and apoptosis.
This study is the first report that reveals the existence of mercury-selenium antagonism in cultured cetacean cells. The data supported the hypothesis that selenium protection against mercury toxicity is, at least partially, through competition of binding sites and formation of mercury-selenium complex.Master of Science
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Friedman, Brielle. "Mass Cetacean Strandings in the United States- Comparison of Northeast and Southeast Strandings, 1997-2011." NSUWorks, 2013. http://nsuworks.nova.edu/occ_stuetd/169.
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Marine mammal mass strandings have been documented for centuries, even going as far back as Aristotle. For just as long, the causes of these mass strandings have been questioned. With every species of cetacean known to have stranded, it is important to find trends to understand and prevent these strandings from occurring. With a heightened awareness of this issue, leading to the creation of marine mammal stranding networks throughout the United States in the 1990s, a more comprehensive approach to data collection has helped with the study. Issues such as seasonality, weather, topography, and disease have all been observed as a potential cause of these events. This study attempted to look at the Atlantic Coast of the United States, and its documented mass strandings from 1997-2011. Stranding data taken from the Northeast and Southeast US Marine Mammal stranding network database provided a basis for the study of these mass strandings. Many of the possible causes of these strandings, including seasonality, location, and species were studied. There was some correlation found between seasons and stranding, meaning there are certain times of the year when a cetacean pod may be more likely to strand.
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Vassilakos, Demetrios. "Evolution of MHC diversity in cetacean species : implications for the role of a pathogen environment." Thesis, Durham University, 2004. http://etheses.dur.ac.uk/2967/.
Full textAbstract:
Previous studies have indicated that the evolution of diversity in the immune system genes responsible for antigen presentation in terrestrial mammals is driven by selection. However, it is not clear whether mammals in the marine environment would experience the same selective pressures as terrestrial mammals, given their different pathogen environment. The diversity and pattern of radiation of exon-2 (peptide binding region) of the DQBl locus of Class II MHC molecule was investigated in a broad range of cetacean species, including an extended sample of six focal species (three Mysticeti and three Odontoceti species). The role of natural selection and of the evolutionary history of this locus was evaluated based on phylogenetic and genetic distance analyses, in order to assess the following hypotheses: i) the marine pathogen environment presents comparable selection pressures to those of the terrestrial environment, ii) social behaviour and structure will affect pathogenic pressure and iii) populations of cetacean species with a world-wide distribution across different habitats and geographic regions are under differential selective pressure. The phylogenetic comparison of the cetacean species was consistent with the trans-species evolution pattern described for terrestrial mammals. Furthermore, high non-synonymous to synonymous substitution rates suggest that polymorphism at this locus in cetaceans is maintained by natural selection. The higher number of trans- species lineages and non-synonymous substitution rates exhibited by social species suggest that social behaviour and social structure may affect pathogenic pressure. Population differentiation according to DQBl locus reveals a contrasting pattern to that inferred by neutral markers (microsatellite DNA) supporting the hypothesis that habitat and geographic regions may place populations under differential selection pressure. The results of the present investigation suggest that the pattern of evolution of the immune response in cetaceans is similar to that in terrestrial mammal species.
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Nardy, Olavo [UNESP]. "Macroecologia de cetáceos marinhos (ordem cetacea)." Universidade Estadual Paulista (UNESP), 2003. http://hdl.handle.net/11449/88528.
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nardy_o_me_rcla.pdf: 878700 bytes, checksum: 7c4568e46045ee703a406f3603721253 (MD5)A macroecologia é uma linha de pesquisa que surgiu com o intuito de realizar uma ponte entre algumas ciências como a macroevolução, biogeografia e ecologia, buscando padrões em escalas amplas, mas variadas, como gradientes latitudinais de riqueza de espécies, utilizando propriedades emergentes do sistema natural para evidenciar fenômenos ou processos que regulem a distribuição e ocorrência das espécies entre outras características ecológicas. Muitos trabalhos buscam padrões desse tipo para mamíferos e aves em ambientes terrestres e pouco se sabe sobre eles em ambientes marinhos. Assim, utilizamos os cetáceos, mamíferos exclusivamente marinhos para comparar com alguns dos padrões encontrados para organismos terrestres. Os padrões encontrados no presente estudo são muito parecidos, evidenciando a Regra de Rapoport para latitudes acima de 25º de latitude, corroborando a hipótese de que este fenômeno pode ser evidenciado em escala regional e não global. Verificou-se também uma descontinuidade da riqueza de espécies ao longo do gradiente latitudinal, possuindo picos próximos aos 25º de latitude, possuindo uma queda tanto para o Equador como para os Pólos, indicando também que pode existir uma relação entre riqueza de espécies e a Regra de Rapoport. A Regra de Bergmann também é evidenciada para os cetáceos.
The macroecology is a research line that appeared with the intention of accomplishing a bridge among some sciences as the macroevolution, biogeography and ecology, looking for patterns in wide, but varied scales, as latitudinal gradients of species richness, using emergent properties of the natural system to evidence phenomenons or processes that regulate the distribuition and occurrence of the species among other ecological characteristics. Many works look for patterns of that type for mammals and birds in terrestrial environments and not very it is known about them in marine atmospheres. Thus, we used the cetaceans, mammals exclusively marines, to compare with some of the patterns found for terrestrial organisms. The patterns found in the present very seemed study are evidencing the Rule of Rapoport for latitudes above 25th of latitude, corroborating the hypothesis that this phenomenon can be evidenced in regional and not global scale. It was also verified a descontinuity of the species richness along the latitudinal gradient, possessing close picks at the 25th of latitude, possessing a fall so much to Ecuador as for the Poles, also indicating that a relationship can exist between wealth of species and the Rule of Rapoport. The Rule of Bergmann is also evidenced for the cetaceans.
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Solsona, Berga Alba. "Advancement of methods for passive acoustic monitoring : a framework for the study of deep-diving cetacean." Doctoral thesis, Universitat Politècnica de Catalunya, 2019. http://hdl.handle.net/10803/665710.
Full textAbstract:
Marine mammals face numerous anthropogenic threats, including fisheries interactions, ocean noise, ship strikes, and marine debris. Monitoring the negative impact on marine mammals through the assessment of population trends requires information about population size, spatiotemporal distribution, population structure, and animal behavior. Passive acoustic monitoring has become a viable method for gathering long-term data on highly mobile and notoriously cryptic marine mammals. However, passive acoustic monitoring still faces major challenges requiring further development of robust analysis tools, especially as it becomes increasingly used in applied conservation for long-term and large-scale studies of endangered or data deficient species such as sperm or beaked whales. Further challenges lie in the translation of animal presence into quantitative population density estimates since methods must control for variation in acoustic detectability of the target species, environmental factors, and for species-specific vocalization rates.
The main contribution of this thesis is the advancement of the framework for long-term quantitative monitoring of cetacean species, applied to deep-divers like sperm and beaked whales. Fully-automated methods were developed and implemented to different populations of beaked whales in different conditions. This provided insight into generalization capabilities of these automatic techniques and best practices. However, implementing these tool kits is not always practical, and alternative methods for additional data processing were developed to expeditiously serve multiple purposes including annotation of individual sounds, evaluation of data in order to provide a highly dynamic technique, and classification for quantitative monitoring studies. This work also presents the longest time series of sperm whale presence using passive acoustic monitoring for over seven years in the Gulf of Mexico. Echolocation clicks were detected and discriminated from other sounds to understand the spatiotemporal distribution and structure of the population. A series of steps were implemented to provide adequate parameters and characteristics of the target population for density estimation using an echolocation click-based method. This allowed for the study of the Gulf of Mexico’s sperm whale population, providing significant progress towards the understanding of the population structure, distribution, and trends, in addition to potential long-term impacts of the well-known catastrophic Deepwater Horizon oil spill and other anthropogenic activities.
The emergence of innovative approaches for detecting the presence of marine mammals and documenting human interactions can provide insight into ecosystem change. These species can be used as sentinels of ocean health to ensure the conservation of their marine environment into the next epoch.Els mamífers marins s'enfronten a nombroses amenaces antropogèniques, incloses les interaccions pesqueres, la contaminació acústica als oceans, les coalicions amb vaixells i els residus marins. El seguiment de l'impacte d’aquestes amenaces en els mamífers marins mitjançant l'avaluació de les tendències poblacionals requereix informació sobre la mida i l’estructura poblacional, la distribució espaciotemporal i el comportament dels animals. El seguiment amb sistemes d’acústica passiva s'ha convertit en un mètode viable per recollir dades a llarg termini de mamífers marins altament mòbils i críptics. Tanmateix, el seguiment acústic passiu encara ha d’afrontar reptes importants en el desenvolupament d'eines d'anàlisi robustes, especialment de cara al recent increment en el seu ús en la conservació aplicada a seguiments a llarg termini i a gran escala d'espècies en perill d'extinció o amb dades insuficients com ara el catxalot o els zífids. Altres reptes són traduir la presència d’animals a estimacions quantitatives de densitat poblacional, degut a que els mètodes han de controlar la variabilitat en la detecció acústica de les espècies en qüestió, els factors ambientals i les freqüències de vocalització específiques de cada espècie. La principal contribució d'aquesta tesi és l'avanç en els mètodes de seguiment quantitatiu a llarg termini de les espècies de cetacis, aplicat a espècies que viuen a grans profunditats com el catxalot i els zífids. Durant aquesta tesi, s’han desenvolupat i aplicat mètodes totalment automatitzats per detectar zífids de diferents poblacions i en diferents condicions. Aquests mètodes han proporcionat informació sobre la capacitat de generalització d'aquestes tècniques automàtiques i han permès fer recomanacions de bones pràctiques. Tanmateix, degut a que la implementació d’aquestes eines no és sempre pràctic, s’han desenvolupat mètodes per al processament de dades de forma expeditiva, que tenen diversos propòsits, que inclouen l’anotació de sons individuals, l’avaluació de dades per proporcionar una tècnica més dinàmica i la classificació per a estudis de seguiment quantitatiu. Aquest treball també presenta la sèrie temporal més llarga documentada de la presència de catxalots obtinguda mitjançant tècniques de seguiment acústic passiu durant més de set anys al Golf de Mèxic. S’han detectat i discriminat les senyals d'ecolocalització d'altres sons per tal de comprendre la distribució i l'estructura espaciotemporal d’aquesta població de catxalots. S’han implementat una sèrie de passos per proporcionar paràmetres i característiques de la població amb l’objectiu d'estimar la densitat mitjançant un mètode basat en senyals d’ecolocalització. Aquesta implementació ha permès l'estudi de la població de catxalots del Golf de Mèxic i ha suposat un progrés significatiu per la comprensió de l'estructura, la distribució i les tendències poblacionals, així com dels potencials impactes a llarg termini del catastròfic vessament de petroli de la plataforma Deepwater Horizon i altres activitats antropogèniques.
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Kellar, Nicholas M. "Hormones and blubber an endocrinological approach for assessing life-history states in free-ranging cetacean populations /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2008. http://wwwlib.umi.com/cr/ucsd/fullcit?p3319846.
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Thesis (Ph. D.)--University of California, San Diego, 2008.Title from first page of PDF file (viewed September 10, 2008). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references.
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Mackay, Alice I. "An investigation of factors related to the bycatch of small cetaceans in fishing gear." Thesis, University of St Andrews, 2011. http://hdl.handle.net/10023/1888.
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The bycatch of cetaceans in fishing gear is considered to be one of the biggest conservation threats to these species. Gear modifications have the potential to reduce these bycatches in global fisheries but there is little available information on how such modifications may change the fishing performance of gear, or indeed the behavior of cetaceans interacting with fishing gear. Generalized linear models (GLMs) were used to identify factors related to cetacean bycatches in UK bottom set gillnets. Rigged net height had a significant positive relationship with harbour porpoise (Phocoena phocoena) bycatch in ICES Area VII suggesting that lowering the profile of gillnets may have the potential to reduce bycatch rates. Modifications to gillnets, such as changing the amount of floatation or increasing the density of the meshes, were found to have significant effects on the active fishing heights of these nets. However, results from a bycatch mitigation trial in Argentina showed that the reduced fishing profile of one experimental net did not result in a concurrent reduction in the bycatch rate of Franciscana dolphins (Pontoporia blainvillei). While there was no significant difference in the rate, length or intensity of harbour porpoise encounters in the presence or absence of gillnets, the proportion of fast echolocation click trains were significantly higher when a net was present, indicating that porpoises either increased acoustic inspection of the net or foraging in the vicinity of the net. An analysis of underwater video footage collected inside trawl nets in an Australia fishery showed that bottlenose dolphins (Tursiops sp.) were present inside nets more frequently than they were caught and were actively foraging inside these nets. The orientation of dolphins inside these nets indicates that the current design of excluder devices used in this fishery could be improved to further reduce bycatch rates.
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Nardy, Olavo. "Macroecologia de cetáceos marinhos (ordem cetacea) /." Rio Claro : [s.n.], 2003. http://hdl.handle.net/11449/88528.
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Orientador: Harold Gordon FowlerBanca: Cláudio José Von Zuben
Banca: Sandra Ap. Benite Ribeiro
Resumo: A macroecologia é uma linha de pesquisa que surgiu com o intuito de realizar uma ponte entre algumas ciências como a macroevolução, biogeografia e ecologia, buscando padrões em escalas amplas, mas variadas, como gradientes latitudinais de riqueza de espécies, utilizando propriedades emergentes do sistema natural para evidenciar fenômenos ou processos que regulem a distribuição e ocorrência das espécies entre outras características ecológicas. Muitos trabalhos buscam padrões desse tipo para mamíferos e aves em ambientes terrestres e pouco se sabe sobre eles em ambientes marinhos. Assim, utilizamos os cetáceos, mamíferos exclusivamente marinhos para comparar com alguns dos padrões encontrados para organismos terrestres. Os padrões encontrados no presente estudo são muito parecidos, evidenciando a Regra de Rapoport para latitudes acima de 25º de latitude, corroborando a hipótese de que este fenômeno pode ser evidenciado em escala regional e não global. Verificou-se também uma descontinuidade da riqueza de espécies ao longo do gradiente latitudinal, possuindo picos próximos aos 25º de latitude, possuindo uma queda tanto para o Equador como para os Pólos, indicando também que pode existir uma relação entre riqueza de espécies e a Regra de Rapoport. A Regra de Bergmann também é evidenciada para os cetáceos.
Abstract: The macroecology is a research line that appeared with the intention of accomplishing a bridge among some sciences as the macroevolution, biogeography and ecology, looking for patterns in wide, but varied scales, as latitudinal gradients of species richness, using emergent properties of the natural system to evidence phenomenons or processes that regulate the distribuition and occurrence of the species among other ecological characteristics. Many works look for patterns of that type for mammals and birds in terrestrial environments and not very it is known about them in marine atmospheres. Thus, we used the cetaceans, mammals exclusively marines, to compare with some of the patterns found for terrestrial organisms. The patterns found in the present very seemed study are evidencing the Rule of Rapoport for latitudes above 25th of latitude, corroborating the hypothesis that this phenomenon can be evidenced in regional and not global scale. It was also verified a descontinuity of the species richness along the latitudinal gradient, possessing close picks at the 25th of latitude, possessing a fall so much to Ecuador as for the Poles, also indicating that a relationship can exist between wealth of species and the Rule of Rapoport. The Rule of Bergmann is also evidenced for the cetaceans.
Mestre
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Araújo, Claryana Costa. "O papel dos impactos antrópicos nos processos locais e padrões globais de extinção em cetáceos." Universidade Federal de Goiás, 2015. http://repositorio.bc.ufg.br/tede/handle/tede/5677.
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The population of humpback dolphins Sousa chinensis that resides in the eastern Taiwan Strait (ETS) is geographically and genetically isolated from populations inhabiting the coastal waters of mainland China and appears to be facing unsustainable levels of human threats. Using VORTEX 9.99b, we modeled the viability of this Critically Endangered population under the present conditions as well as under realistic additional threat scenarios. We examined 6 different levels of bycatch mortality, 3 scenarios of habitat loss/degradation, and scenarios in which these threats were experienced together. Under the baseline (present) scenario, the population exhibited a decreasing growth rate and was predicted to be smaller than the initial population size in more than 76% of all model runs. In all scenarios with additional threats, the proportion of model runs in which population size was smaller than the initial size varied from 77.1 to 92.6%. Over the short term, fisheries-related mortality appears to have a more obvious impact on the population’s trajectory than habitat loss/degradation. Even minimal increases in mortality from the current baseline levels will increase the probability of extinction of this population. Due to the fragile situation of ETS humpback dolphins, mitigation actions to reduce the current threats to this population are needed immediately.
Sem resumo.
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Pearson, Heidi Christine. "Fission-fusion sociality in dusky dolphins (Lagenorhynchus obscurus), with comparisons to other dolphins and great apes." Texas A&M University, 2008. http://hdl.handle.net/1969.1/86073.
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I examined fission-fusion sociality in dusky dolphins (Lagenorhynchus obscurus), and investigated aspects of social convergence between dolphins and great apes. I used boat-based group focal follows and photo-identification to collect data in Admiralty Bay, New Zealand during 2005-2006. I used generalized estimating equations to examine relationships between party (group) size, rate of party fission-fusion, activity, and location; and relationships between leaping frequency and behavior. Using photo-identification images from 2001-2006, I analyzed the strength and temporal patterning of associations, short- and long-term association patterns, preferred/avoided associations, and behaviorally-specific preferred associations. To analyze social convergence between dolphins and great apes, I compared female bottlenose dolphin (Tursiops spp.) and chimpanzee (Pan troglodytes) social strategies through literature review.
I conducted 171 group focal follows, totaling 157 observation hours. Mean party size was 7.0±6.0 individuals. Party size changed every 5±.47.6 min on average. The most frequent activity was resting (37%), followed by traveling (29%), foraging (18%), and socializing (15%). Foraging was positively related to party size and rate of fission-fusion. Near mussel farms, foraging increased, traveling decreased, and rate of party fusion increased. "Clean" leaps were the most frequent leap type (84%) and were positively related to party size and foraging. Noisy and coordinated leaps were positively related to party size; noisy leaps were negatively related to foraging.
Associations during 2001-2006 (N = 228 individuals) were nonrandom for 125 days; associations within one field season were nonrandom for 60 days. Individuals formed preferred/avoided associations during most years. The strongest associations occurred during foraging and socializing; the weakest associations occurred during traveling. Individuals formed preferred associations during foraging, resting, and socializing.
Review of female bottlenose dolphin and chimpanzee sociality revealed that: 1) females form weaker bonds and are less social than males, 2) females associate mostly with other females, 3) mothers are often alone with their offspring, 4) mothers (vs. non-mothers) and non-cycling (vs. cycling) females associate less with males, and 5) non-cycling (vs. cycling) females occur in smaller parties. Female dolphins may be more social than female chimpanzees due to decreased scramble competition, increased predation risk, and decreased cost of transport for dolphins vs. chimpanzees.
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Yamato, Maya. "The auditory system of the minke whale (Balaenoptera acutorostrata) : a potential fatty sound reception pathway in a mysticete cetacean." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/77786.
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Thesis (Ph. D.)--Joint Program in Oceanography/Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Dept. of Biology; and the Woods Hole Oceanographic Institution), 2012.Cataloged from PDF version of thesis.
Includes bibliographical references.
Despite widespread concerns about the effects of anthropogenic noise on baleen whales (suborder Mysticeti), we lack basic information about their auditory physiology for comprehensive risk assessments. Hearing ranges and sensitivities could be measured if customized equipment and methods were developed based on how baleen whales receive sound. However, sound reception pathways in baleen whales are currently unknown. This thesis presents an integrative approach to understanding hearing in baleen whales through dissections, biomedical imaging, biochemical analyses, and modeling sound propagation through a whale head using the Finite Element Method (FEM). We focused on the minke whale (Balaenoptera acutorostrata) because it is one of the smallest and most abundant mysticete species, reducing logistical difficulties for dissections and experiments. We discovered a large, well-formed fat body extending from the blubber region to the ears and contacting the ossicles. Although odontocetes, or toothed whales, are thought to use specialized "acoustic fats" for sound reception, no such tissues had been described for mysticetes to date. Our study indicates that the basic morphology and biochemical composition of the minke whale "ear fats" are very different from those of odontocete acoustic fats. However, the odontocete and mysticete fatty tissues share some characteristics, such as being conserved even during starvation, containing fewer dietary signals compared to blubber, and having well-defined attachments to the tympano-periotic complex, which houses the middle and inner ears. FE models of the whale head indicated that the ear fats caused a slight increase in the total pressure magnitude by the ears, and this focusing effect could be attributed to the low density and low sound speed of the ear fats in the models. Fatty tissues are known to have lower densities and sound speeds than other types of soft tissues, which may explain why they are an important component of the auditory system of odontocetes, and perhaps mysticete cetaceans as well. In an aquatic habitat where the pinna and air-filled ear canal are no longer effective at collecting and focusing so'und towards the ears, we propose that both odontocete and mysticete cetaceans have incorporated fatty tissues into their auditory systems for underwater sound reception.
by Maya Yamato.
Ph.D.
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Mangel, Jeffrey Charles. "Interactions of Peruvian small scale fisheries with threatened marine vertebrate species." Thesis, University of Exeter, 2012. http://hdl.handle.net/10036/3483.
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Marine vertebrate species face unprecedented and ever increasing pressures as a result of human activity, primarily fishing, in the global oceans. One area of growing concern has been for the impacts of small-scale fisheries on these species. Over the past decade it has become increasingly clear that these under-studied fisheries have sizeable levels of catch and bycatch of many threatened and endangered species of sea turtles, seabirds and small cetaceans. This thesis presents a collection of chapters that investigate aspects related to the interactions of small-scale fisheries with threatened marine vertebrates. We identify sizeable rates of bycatch of small cetaceans and seabirds for multiple small-scale longline and gillnet fisheries in both Peru and Ecuador. Catch rates of small cetaceans by the Peruvian small-scale driftnet fleet are estimated to exceed 10,000 dolphins and porpoises annually. A trial of acoustic alarms (pingers) in this same fishery showed a 37% reduction in small cetacean bycatch while not reducing target catch and represents a promising bycatch mitigation measure. Seabird bycatch was also found to be high in both longline and gillnet fisheries and included a wide range of seabird species including the critically endangered waved albatross (Phoebastria irrorata). Through post-capture satellite tracking of loggerhead turtles (Caretta caretta) we show that these turtles are present in pelagic waters off the coasts of Peru and Chile for extended periods during which they are at risk of repeat interactions with small-scale longline fisheries operating throughout their foraging habitat. Through scan and focal sampling of the endangered marine otter (Lontra felina) we also show that otters making den sites in human fishing communities face additional risks due to entanglement in fishing gear or interactions with feral animals but, if properly managed, these sites could serve as stepping stones for marine otters along the coast. The results presented here, gathered using a wide range of techniques, including onboard observer and shore-based monitoring, satellite tracking, bycatch quantification, and bycatch mitigation experiments, represent an attempt to better characterize and quantify the interactions of small-scale fisheries with threatened marine vertebrates toward identifying solutions that can lead to sustainable fisheries and populations of these protected marine species.
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Groch, Kátia Regina. "Interação antropogênica e sanidade de baleias-jubarte (Megaptera novaeangliae) na costa brasileira." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/10/10133/tde-26092014-092253/.
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A exposição das baleias-jubarte (Megaptera novaeangliae) aos impactos antropogênicos está aumentando devido à crescente recuperação da população posterior à proibição da caça comercial, associado ao incremento das atividades humanas nas áreas de reprodução e migração da espécie. No entanto, pouco se sabe sobre saúde e processos patológicos em baleias-jubarte no Brasil. O presente estudo investigou o estado de saúde da população de baleias-jubarte que migra sazonalmente para a costa sudeste e nordeste do Brasil, buscando identificar eventuais enfermidades letais e não letais, por meio de análises histopatológicas e estudo de osteopatias, assim como, quantificar as ocorrências das interações antropogênicas prejudiciais à espécie. A avaliação dos efeitos decorrentes das ações antropogênicas foi realizada a partir de imagens obtidas de baleias foto-identificadas em vida livre ao longo de 5 anos (2008-2012), por meio das quais foram caracterizadas as lesões cutâneas e quantificadas as marcas decorrentes de interações antropogênicas, predatórias ou intraespecíficas. Dessa forma, obteve-se uma estimativa dos indivíduos que sobreviveram a emalhes em apetrechos de pesca, colisões com embarcações e/ou interações com predadores. A prevalência das lesões cutâneas foi estimada utilizando-se uma abordagem conservadora, porém sistemática, e poderá ser utilizada como base para o uma avaliação contínua do estado de saúde desta população de baleias-jubarte. A investigação de processos patológicos em animais encalhados foi realizada valendo-se da análise histopatológica dos tecidos de 19 animais encontrados em bom estado de conservação, enquanto as osteopatias foram estudadas por meio da análise macroscópica do tecido esquelético de 49 animais necropsiados. Análise imuno-histoquímica foi utilizada em casos selecionados para pesquisa de Morbillivirus. Os achados histopatológicos demonstraram que grande parte dos filhotes que encalham apresenta sinais de distúrbios neonatais ou perinatais, além de serem suscetíveis a processos infecciosos. O estudo de lesões esqueléticas em animais encalhados demostrou que as baleias-jubarte são suscetíveis a processos degenerativos, infecciosos, traumáticos e malformações do desenvolvimento. Este estudo apresenta uma primeira visão sobre condições sanitárias e processos patológicos em baleias-jubarte no Brasil e pode direcionar os estudos futuros nesta área. Através do monitoramento da ocorrência de lesões não-letais bem como através da investigação dos processos patológicos e causas de morte das baleias-jubarte, este estudo apresenta indicadores das condições do ambiente onde estes animais vivem, podendo contribuir para as ações de manejo e conservação da espécie.The exposure of humpback whales (Megaptera novaeangliae) to anthropogenic impacts is increasing due to population recovery following the legal ban on commercial whaling, together with the increment of human activities at the species breeding grounds and migration routes. However, little is known about the health and pathologic processes in humpback whales in Brazil. The present study investigated the health status of the population of humpback whales that seasonally migrate to the southeastern and northeastern Brazilian coast, aiming to identify possible lethal and nonlethal diseases, through histopathological analysis and study of osteopathies, as well as to quantify the occurrence of anthropogenic interactions, detrimental to the species. The evaluation was carried out through image analysis from photo-identified whales in the wild, during 5 years (2008-2012), through which skin lesions and scars were characterized, and anthropogenic, predatory or inter-specific marks were quantified. An estimate on individuals who survived to entanglement in fishing gear, collisions with vessels and/or interactions with predators was obtained. The investigation of pathologic processes in stranded animals performed by means of histopathological analysis of tissues from 19 animals found in good condition, while osteopathies were studied through macroscopic analysis on skeletal tissue of 49 necropsied animals. Immunohistochemical analysis was carried out in selected cases to search for Morbillivirus. The prevalence of skin lesions was estimated using a conservative, but systematic, approach and may be used as the basis for a long term assessment of the health status of this humpback whale population. Histopathological findings showed that most stranded calves had signs of perinatal or neonatal disorders, and are susceptible to infections. The study of skeletal lesions in stranded animals has shown that humpback whales are susceptible to degenerative, infectious and traumatic processes, and malformations. Finally, data obtained in this study present a first overview on health conditions and pathological processes in humpback whales in Brazil and may guide future studies in this area. By monitoring the occurrence of nonlethal lesions, as well as investigating pathological processes and causes of death of humpback whales, this study provides the environmental conditions in which these animals live and can contribute for the management and conservation actions for the species.
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Lopez, Carlos Julian De Luna. "The relationship between developmental stability, genomic diversity and environmental stress in two Cetacean species : the harbour porpoise (Phocoenaphocoena) and the bottlenose dolphin (Tursiops truncatusl)." Thesis, Durham University, 2005. http://etheses.dur.ac.uk/3010/.
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The relationship between developmental stability, genomic diversity and environmental stress in three eastern North Atlantic populations of the harbour porpoise {Phocoena phocoena), and in two populations of the western North Atlantic and one from the Gulf of California of the bottlenose dolphin {Tursiops truncatus) was investigated. In addition, the population structure for the two species from the study areas mentioned was also assessed. Population structure was determined using discriminant function analysis for morphological characters and a Bayesian analysis for microsatellite loci. Consistency of the results was assessed with pairwise comparisons between populations using two indices of population differentiation (F(_st) and Rho(_st)). For the harbour porpoises classification was made into three putative populations: Norwegian, British and Danish. For the bottlenose dolphin significant differentiation was found for the three populations studied. Population differentiation between the two western North Atlantic parapatric populations was the highest among the pairwise comparisons. This result highlights the importance of resource specialisation of bottlenose dolphins in causing population structure for parapatric populations. Developmental stability was assessed by fluctuating asymmetry (FA) measured on morphological traits. Genomic diversity was determined by five indices (mean cf, scaled mean cF, multilocus individual heterozygosity, standardised heterozygosity and internal relatedness). Environmental stress was assessed by the concentration of chemical pollutants in tissues, and from the literature published for chemical pollutants, by-catch rate, parasite load and mean surface ocean temperature. Significant relationships between FA and the indices of genomic diversity were found. The Norwegian population of harbour porpoises and the coastal population of the western North Atlantic of bottlenose dolphin showed the highest level of FA. Both populations also showed the least genetically diverse animals. However, no clarity was obtained in respect of the relationship between FA and environmental stress. British and Norwegian harbour porpoises did not show significant correlations between the concentration of several chemical pollutants in tissues and FA. In addition, the Norwegian population of harbour porpoise inhabits the least impacted areas in respect to the concentration of chemical pollutants in tissues, parasite load and by-catch rates. Environmental stress was difficult to assess on the bottlenose dolphins populations due to the scarcity of data. These results show the influence of genetic diversity on the disruption of developmental stability and they also show the importance of conservation practices in maintaining genetic diversity as an important factor for the subsistence of natural populations.
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Jewell, Rebecca. "Investigating the surfacing and diving behaviour and availability of long-finned pilot whales and quantifying the effects of anthropogenic sound on density and strandings of cetaceans in the northeast Atlantic." Thesis, University of St Andrews, 2014. http://hdl.handle.net/10023/6337.
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The size and trend of a population is fundamental to the assessment of its conservation status, yet cetacean abundance data are often biased and lack statistical power to detect trends. As a result, the conservation status of many species is unknown and the population-level effects of conservation pressures such as anthropogenic sound cannot be quantified. Failing to account for cetaceans that are unavailable for detection at the surface during abundance surveys will negatively bias estimates of abundance. Analysis of time-depth data revealed that pilot whale dive and surface interval durations, and availability for detection, varied with time of day, but this bias was accurately estimated using the mean dive and surface interval durations. A global analysis of cetacean density estimates compiled from multiple line-transect surveys incorporated covariates describing availability bias, and other sources of variability, to facilitate the detection of underlying temporal trends. Decadal global trends in cetacean density were detected for four species, while significant yearly ocean-scale trends were detected for six families. Exploratory analysis of data compiled from line-transect surveys found some evidence that trends in the density of minke whales and sperm whales in the northeast Atlantic varied between areas with and without seismic survey effort. However, there were insufficient data to clearly identify chronic exposure to anthropogenic sound from seismic surveys as a driver of population change. Analysis of strandings data from the UK and Ireland identified some evidence that harbour porpoise and sperm whale stranding rates were related to seismic survey effort and wind farm construction, but the results were not conclusive. Large-scale cetacean surveys provide valuable information on the density and spatial and temporal distribution of cetaceans that is vital for monitoring populations, but these surveys cannot replace dedicated studies of the population-level effects of sound on cetaceans.
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Caillat, Marjolaine. "Assessing and correcting for the effects of species misclassification during passive acoustic surveys of cetaceans." Thesis, University of St Andrews, 2013. http://hdl.handle.net/10023/4209.
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In conservation ecology, abundance estimates are an important factor from which management decisions are based. Methods to estimate abundance of cetaceans from visual detections are largely developed, whereas parallel methods based on passive acoustic detections are still in their infancy. To estimate the abundance of cetacean species using acoustic detection data, it is first necessary to correctly identify the species that are detected. The current automatic PAMGUARD Whistle Classifier used to automatically identify whistle detection of cetacean species is modified with the objective to facilitate the use of these detections to estimate cetacean abundance. Given the variability of cetacean sounds within and between species, developing an automated species classifier with a 100% correct classification probability for any species is unfeasible. However, through the examples of two case studies it is shown that large and high quality datasets with which to develop these automatic classifiers increase the probability of creating reliable classifiers with low and precise misclassification probability. Given that misclassification is unavoidable, it is necessary to consider the effect of misclassified detections on the number of observed acoustic calls detected and thus on abundance estimates, and to develop robust methods to cope with these misclassifications. Through both heuristic and Bayesian approaches it is demonstrated that if misclassification probabilities are known or estimated precisely, it is possible to estimate the true number of detected calls accurately and precisely. However, misclassification and uncertainty increase the variance of the estimates. If the true numbers of detections from different species are similar, then a small amount of misclassification between species and a small amount of uncertainty in the probabilities of misclassification does not have a detrimental effect on the overall variance and bias of the estimate. However, if there is a difference in the encounter rate between species calls associated with a large amount of uncertainty in the probabilities of misclassification, then the variance of the estimates becomes larger and the bias increases; this in return increases the variance and the bias of the final abundance estimate. This study despite not bringing perfect results highlights for the first time the importance of dealing with the problem of species misclassification for cetacean if acoustic detections are to be used to estimate abundance of cetaceans.
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Bernasconi, Matteo. "The use of active sonar to study cetaceans." Thesis, University of St Andrews, 2012. http://hdl.handle.net/10023/2580.
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Cetacean species face serious challenges worldwide due to the increasing noise pollution brought to their environment by human activities such as seismic exploration. Regulation of these activities is vaguely defined and uncoordinated. Visual observations and passive listening devices, aimed at preventing conflicts between human wealth and cetaceans’ health have some fundamental limitations and may consequently fail their mitigation purposes. Active sonar technology could be the optimal solution to implement mitigation of such human activities. In my thesis, the proper sonar unit was used to test the feasibility to detect cetaceans in situ. Omnidirectional sonars could be the optimal solution to monitor the presence of cetaceans in the proximity of potential danger areas. To use this class of sonar in a quantitative manner, the first step was to develop a calibration method. This thesis links in situ measurements of target strength (TS) with variation trends linked to the behavior, morphology and physiology of cetacean. The butterfly effect of a cetacean’s body was described for a fin whale insonified from different angles. A relationship between whale respiration and TS energy peaks was tested through a simple prediction model which seems very promising for further implementation. The effect of lung compression on cetacean TS due to increasing depth was tested through a basic mathematical model. The model fit the in situ TS measurements. TS measurements at depth of a humpback whale, when post-processed, correspond to TS measurements recorded at the surface. Sonar technology is clearly capable of detecting whale foot prints around an operating vessel. Sonar frequency response shows that frequencies between 18 and 38 kHz should be employed. This work has established a baseline and raised new questions so that active sonar can be developed and employed in the best interest for the whales involved in potentially harmful conflicts with man.
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Fontanesi, Elena. "Habitat use of migrating dwarf minke whales (Balaenoptera acutorostrata subspecies) in Tasmanian waters." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amslaurea.unibo.it/9754/.
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The Great Barrier Reef hosts the only known reliable aggregation of dwarf minke whale (Balaenoptera acutorostrata subspecies) in Australian waters. While this short seasonal aggregation is quite predictable, the distribution and movements of the whales during the rest of their annual cycle are poorly understood. In particular, feeding and resting areas on their southward migration which are likely to be important have not been described. Using satellite telemetry data, I modelled the habitat use of seven whales during their southward migration through waters surrounding Tasmania. The whales were tagged with LIMPET satellite tags in the GBR in July 2013 (2 individuals) and 2014 (5 individuals). The study area around Tasmania was divided into 10km² cells and the time spent by each individual in each cell was calculated and averaged based on the number of animals using the cell. Two areas of high residency time were highlighted: south-western Bass Strait and Storm Bay (SE Tasmania). Remotely sensed ocean data were extracted for each cell and averaged temporally during the entire period of residency. Using Generalised Additive Models I explored the influence of key environmental characteristics. Nine predictors (bathymetry, distance from coast, distance from shore, gradient of sea surface temperature, sea surface height (absolute and variance), gradient of current speed, wind speed and chlorophyll-a concentration) were retained in the final model which explained 68% of the total variance. Regions of higher time-spent values were characterised by shallow waters, proximity to the coast (but not to the shelf break), high winds and sea surface height but low gradient of sea surface temperature. Given that the two high residency areas corresponded with regions where other marine predators also forage in Bass Strait and Storm Bay, I suggest the whales were probably feeding, rather than resting in these areas.
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Moulins, Aurélie. "To the integrated approach and to the management of pelagic biodiversity inside a marine protected area : case of the cetacean populations in the Pelagos sanctuary (north-western Mediterranean sea)." Lyon 1, 2008. http://www.theses.fr/2008LYO10027.
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Jesus, Mariana Santos de. "Avalia??o agron?mica, bromatol?gica e cromoss?mica em clones de duas esp?cies de palma forrageira (Opuntia ficus-indica Mill. e Nopalea cochenillifera Salm ? Dyck)." Universidade Estadual de Feira de Santana, 2013. http://localhost:8080/tede/handle/tede/210.
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Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES
The Brazilian semiarid region undergoes seasonal distribution of rainfall that is concentrated in short periods of the year, combined with shallow and stony soils with low organic matter content and ability to retain moisture. Given these limitations, has intensified in this region the use of cactus as a food source herd due to its high capacity to adapt to the climate of this region. This study evaluated for agronomic characteristics, chemical characteristics and chromosome 20 clones preselected by Oliveira 2010, forming part of the breeding program of cactus pear State University of Feira de Santana, in existence since December 2008. Two experiments were conducted. In the first containing palm girl (Nopalea cochenillifera & Salm Dyck) and the second with giant cactus (Opuntia ficus-indica Mill). The experimental design was randomized blocks with five replicates, the spacing was 0.5 x 1.0 m (x plant rows) and fertilization administered 30 t/ha-1 of manure. Data were submitted to ANOVA and Tukey test (p <0.01 and p <0.05). For agronomic characteristics, the tiny palm clones showed no significant differences between the observed means. For the giant cactus, clone 4:06 stood out compared to the other featuring the best averages for the number of cladodes per plant. In assessing chemical was observed on average 69.91% NDF, 13.09% ADF and 8.49% CP for Palm kid. For giant cactus values were 45.63% NDF, 18.20% ADF and 9.18% PB. Chromosome analysis revealed that the numbers ranged from 2n = 22 in the palm girl to 2n = 88 in the giant cactus, without occurrence of disploidias or aneupoidias plants analyzed. It was found that clones are very promising for breeding programs, and are recommended for cultivation in the region of Feira de Santana-BA.
O semi?rido brasileiro apresenta sazonalidade na distribui??o de chuvas que s?o concentradas em per?odos curtos do ano, aliados a solos pouco profundos e pedregosos com baixo teor de mat?ria org?nica e capacidade de reter umidade. Diante destas limita??es, tem-se intensificado nessa regi?o o uso da palma forrageira como fonte de alimento do rebanho devido a sua alta capacidade de adapta??o ao clima dessa regi?o. Este trabalho objetivou avaliar quanto ?s caracter?sticas agron?micas, bromatol?gicas e cromoss?micas 20 clones pr? selecionados por Oliveira (2010), que fazem parte do programa de melhoramento gen?tico da palma forrageira da universidade Estadual de Feira de Santana, existente desde Dezembro de 2008. Foram estabelecidos dois experimentos. No primeiro contendo palma mi?da (Nopalea cochenillifera Salm & Dyck) e o segundo com palma gigante (Opuntia f?cus-indica Mill). O delineamento experimental utilizado foi de blocos ao acaso com cinco parcelas, o espa?amento foi 0,5 x 1,0 m (plantas x fileiras) e a aduba??o administrada de 30 t/ha-1 de esterco bovino. Os dados foram submetidos ? an?lise de vari?ncia e teste de Scott-Knott (p<0,05). Para as caracter?sticas agron?micas, os clones de palma mi?da foram inferiores em rela??o ?s testemunhas IPA-sert?nia e IPA-mi?da para os caracteres CC, DC e AC. Para a palma gigante, o clone 04 destacou-se em rela??o aos demais diferindo estatisticamente quanto ao n?mero de clad?dios por planta. Na avalia??o bromatol?gica observou-se em m?dia 69,91% de FDN, 13,09% de FDA e 8,49% de PB para a palma mi?da. Para palma gigante os valores m?dios foram 45,63% FDN, 18,20% FDA e 9,18% PB. As an?lises cromoss?micas revelaram que os n?meros variaram de 2n=22 na palma mi?da a 2n=88 na palma gigante, sem ocorr?ncia de disploidias ou aneupoidias nas plantas analisadas. Verificou-se que os clones s?o bastante promissores para programas de melhoramento, e s?o recomend?veis para cultivo na regi?o de Feira de Santana-BA.
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Volpi, Thaís de Assis. "Filogeografia de golfinhos rotadores (Stenella longirostris Gray, 1828) no litoral brasileiro a partir de marcadores mitocondriais." Universidade Federal do Espírito Santo, 2012. http://repositorio.ufes.br/handle/10/5606.
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Previous issue date: 2012-02-28O golfinho-rotador-pantropical (Stenella longirostris longirostris) ocorre em águas tropicais e subtropicais de todos os oceanos. No litoral brasileiro, ocorre principalmente em águas tropicais entre 170 e 2700m de profundidade, sendo muito comum em Fernando de Noronha. Pouco se sabe sobre o seu fluxo gênico e diversidade genética no oceano Atlântico Sul. O presente estudo teve como objetivo avaliar a variabilidade genética de golfinhos-rotadores em diferentes localidades do litoral brasileiro. Duas regiões do DNA mitocondrial foram analisadas: região controle (D-loop) e citocromo oxidase subunidade I (COI). 82 indivíduos foram amostrados, correspondentes a quatro grupos de golfinhos amostrados no Nordeste do Brasil (G1), em Fernando de Noronha (G2 e G3) e no Sudeste e Sul do Brasil (G4). As amostras foram obtidas por raspagem de pele, biópsia com balestra e de animais mortos encalhados. 79 sequências com 414bp de D-loop e 48 com 714bp da região COI foram analisadas. Além destas, 45 sequências foram geradas a partir de fragmentos concatenados entre D-loop e COI. 115 sequências do GenBank (109 de D-loop e seis COI) foram incluídas para compreender a relação dos haplótipos brasileiros com outras populações mundiais. Os quatro grupos brasileiros avaliados apresentaram diferenciação genética significativa entre eles (Fst>0,05 com P<0,05) e, portanto, cada um deles foi considerado como sendo uma população diferente. G4 apresentou os maiores índices de diversidade nucleotídica e haplotípica, enquanto G2 e G3 apresentaram os menores. O baixo fluxo gênico entre as populações de golfinhos-rotadores de Fernando de Noronha em relação às populações não insulares pode indicar a fidelidade de sítio desses animais em águas insulares. As populações do litoral brasileiro são geneticamente diferentes; no entanto, todos compartilharam haplótipos com golfinhos dos oceanos Índico e Pacífico, além de animais da porção norte do Atlântico. G4 mostrou maior similaridade genética com golfinhos de outros oceanos do que com as populações de outros golfinhos-rotadores brasileiros. A população G2 (com maior número de amostras) apresentou maior similaridade genética com a população do Pacífico, mesmo quando comparado com a outra população de Fernando de Noronha (G3). Assim, é possível que o fluxo gênico de golfinhos no Brasil não é atribuído a distância geográfica entre eles, mas por outros fatores históricos, ecológicos e comportamentais
The pantropical spinner dolphin (Stenella longirostris longirostris) occurs in tropical and subtropical waters of all oceans. In the Brazilian coast, it occurs mainly in tropical waters between 170 and 2700m depth, being very common in Fernando de Noronha Archipelago. Little is known about its gene flow and genetic diversity in South Atlantic Ocean. The present study aimed to evaluate the genetic variability of spinner dolphin in different localities of the Brazilian coast. Two regions of the mitochondrial DNA were analyzed, control region (D-loop) and cytochrome Oxidase subunit I (COI). 82 individuals were sampled, corresponding to four putative groups of dolphins sampled in Northeast Brazil (G1), in Fernando de Noronha (G2 and G3) and in the Southeast and South of Brazil (G4). The samples were obtained by skin swabbing, skin biopsy, and dead animals found stranded. 79 sequences with 414bp for D-loop and 48 with 714bp for COI region were analyzed. In addition to these, 45 sequences were generated from the link between fragments of D-loop and COI. 115 GenBank sequences (109 of D-loop and six of COI) were included to understand the relationship of Brazilian haplotypes with other world populations. The four Brazilian groups evaluated showed significant intergroup genetic differentiation (Fst>0.05 with P<0.05), therefore, each one of them was considered to be a different population. G4 presented the highest nucleotide and haplotypic diversity indices, while G2 and G3 showed the lowest. The low gene flow between the spinner dolphin populations from Fernando de Noronha in relation to the non insular populations may indicate site fidelity of these animals to insular waters. The populations in the Brazilian coast are genetically distinct; however all share haplotypes with dolphins from Indian and Pacific oceans, in addition to animals of the northern portion of the Atlantic. G4 showed more genetic similarity with dolphins from other oceans than with other spinner dolphin Brazilian populations. The population G2 (with the highest number of samples) showed greater genetic similarity with the Pacific population, even when compared with another population of Fernando de Noronha (G3). Thus, it is possible that the gene flow of spinner dolphins in Brazil is not given by the geographical distance among them, but by other historical, ecological and behavioral factors
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GUIDI, CARLO. "Acoustic positioning systems and passive acoustic monitoring of cetaceans with the KM3NeT underwater neutrino telescope." Doctoral thesis, Università degli studi di Genova, 2022. http://hdl.handle.net/11567/1062558.
Full textAbstract:
KM3NeT (Cubic Kilometre Neutrino Telescope) is an underwater telescope for cosmic neutrinos detection and neutrino oscillation study. There are two detectors located in France, offshore the coast of Toulon (KM3NeT-ORCA, Oscillation Research with Cosmics in the Abyss) and in Italy, offshore Capo Passero, Sicily (KM3NeT-ARCA, Astroparticle Research with Cosmics in the Abyss).
Each experimental setup detects the photons produced by the Cherenkov effect due to charged particles, which derive from the interactions of neutrinos with matter.
In order to correctly reconstruct the original neutrino direction, energy and the interaction type, it is necessary to know very accurately the position of the photomultipliers. So, acoustic systems are used to monitor the flexible detector geometry.
The detectors consist of several vertical structures, called Detection Units (DUs), along which 18 Digital Optical Modules (DOMs), each containing 31 photomultipliers, are positioned.
During the deployment of the DUs the position of all the elements is measured with an acoustic positioning system, called Navigation and Absolute Acoustic Positioning System (NAAPS), with an accuracy of about 1 m.
Subsequently, through a system of acoustic emitters and receivers (RAPS - Relative Acoustic Positioning System) the position of all the sensors is refined reaching an accuracy of 10 cm, sufficient for the reconstruction of the neutrino interaction events with the requested precision. Three autonomous emitters (called “Acoustic Beacons”), not synchronized with the master clock of telescope, are installed around the detector. On each DOM an acoustic piezo sensor is present and at the base of each line there is a hydrophone.
In this PhD thesis, I have tested and improved the methods that are used to reconstruct the positions of the optical modules and line bases of the detector. This was done by using simulations of progressively more realistic configurations and subsequently applying the developed and tested RAPS methods on real data.
In addition to the positioning of the optical sensors, the KM3NeT hydrophones can be used for different purposes. The RAPS algorithms are also used for the identification and tracking of the cetaceans. In particular, it is possible to detect the clicks of some marine mammals, such as sperm whales, Cuvier's beaked whales and various species of dolphins. By observing the signal produced by these animals in different receivers it is possible to calculate the delay times and from these to reconstruct the position of the acoustic source.
In order to have a good accuracy in the reconstruction of the cetacean positions it is necessary to know very precisely the locations of the used receivers (in particular the hydrophones). For this reason the performance of the RAPS is very important also for this goal.
A statistical study on the presence of marine cetaceans in the area of the KM3NeT-ORCA experiment was then conducted. This type of research is very useful for studying the distribution, behaviour and habits of these animals.
My thesis work has demonstrated that the KM3NeT acoustic system, in addition to provide an accurate positioning of the optical sensors of the detector, is able to identify the sounds emitted by various species of cetaceans, in particular sperm whales, and to reconstruct their trajectory, at least when they move close to the detector (several kilometres).
A collaboration with Edgelab company was started in order to develop a mobile sound system for generic sources including marine animals. Due to the limitations imposed by the COVID-19 pandemic, the collaboration took place mostly remotely and it was not possible to carry out the tests on site.
The experience gained from my participation to similar experiments, such as WhaleSafe, a European project with the goal of tracking sperm whales in the Ligurian Sea, Italy, was particularly useful. The skills obtained analysing the WhaleSafe data taken in Summer 2018 have been successfully used to apply very similar reconstruction algorithms to the data coming from the KM3NeT hydrophones.
Numerous tracks of cetaceans have been reconstructed and it has been possible to evaluate the presence of different cetacean species and their movements.
Thanks to the KM3NeT-ORCA acoustic receiver system, located near the port of Toulon, the study of the underwater background was performed to evaluate the impact of anthropogenic activity on the marine ecosystem.
Finally, the exceptional presence of killer whale pod was observed in Genoa Pra during December 2019. I have participated in the self-organized acoustic data campaigns and performed analyses to make the repertoire catalogue of the signals in order to compare with known catalogues of killer whales around the world.
This PhD was founded by Regione Liguria (D.R. n. 1917 - 25/06/2018) and it took place in co-tutorship with the CPPM (Centre de Physique des Particules de Marseille), Aix-Marseille Université, France. The collaborative work with the French institute was assiduous throughout the duration of the PhD, but the periods of attendance were severely limited by the COVID-19 pandemic.
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Sardo, Giacomo. "Caratteristiche morfologiche della retina nei Cetacei." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amslaurea.unibo.it/8130/.
Full textAbstract:
Le caratteristiche strutturali dell’occhio dei Cetacei sono state in passato oggetto di studio. Tuttavia, i dati relativi alla stratigrafia della retina ed alle caratteristiche morfologiche dei neuroni gangliari in essa presenti sono piuttosto ridotti; per questo motivo, l’obiettivo della presente ricerca è stato quello di studiare, mediante metodiche di immunoistochimica, l’uso della microscopia ottica e di opportuni software di analisi immagine, le caratteristiche morfologiche della retina e delle cellule gangliari in essa presenti in differenti specie di Cetacei.
Per la presente ricerca sono stati utilizzate come specie di riferimento i seguenti Delfinidi: tursiope (Tursiops truncatus) e stenella striata (Stenella coeruleoalba). Le analisi sulle sezioni interessano l’area, la densità dei neuroni gangliari, la stratigrafia della retina e l’analisi morfometrica degli strati e dei neuroni.
I risultati ottenuti indicano come la retina del tursiope e della stenella striata, nonostante un'organizzazione di base assai simile a quella degli altri Mammiferi, mostri caratteristiche qualitative sue proprie. Gli strati retinici sono quelli che si osservano in tutti i Mammiferi e lo spessore totale della retina è, nel tursiope (101,23 µm ) e nella stenella striata (108.35 µm ), pressochè simile ai Mammiferi terrestri (110-220 µm). Nell'ambito della retina, lo strato che presento lo spesso medio maggiore è quello dei granuli interni (SNE); tale dato non coincide con quanto osservato in altri Mammiferi. I neuroni gangliari presenti nella retina di tursiope e stenella striata mostrano, analogamente a quanto osservato in altri Cetacei, una bassa densità cellulare. Nel tursiope e nella stenella striata le aree a maggiore densità cellulare presentano neuroni multipolari di dimensioni minori rispetto a quelle con bassa densità. Questo dato potrebbe indicare una "cellularità" (quantità di superficie occupata da cellule) costante nei differenti distretti retinici.
I neuroni gangliari presenti nella retina di tursiope e stenella striata sono disposti in un unico strato, come osservato in numerosi altri Cetacei, ma differisce da quanto osservato nel capodoglio (Physeter macrocephalus) dove tali cellule si dispongono in strati multipli. Neuroni gangliari di grandi dimensioni sono stati osservati sia nel tursiope che nella stenella striata. Tale dato coincide con quanto osservato in altri Odontoceti ed in alcuni Misticeti.
Allo stato attuale non è ancora stato dato un chiaro significato funzionale alle cellule gangliari giganti. Un possibile ruolo potrebbe essere quello di condurre, in animali di grossa mole, l'impulso nervoso molto velocemente, grazie alla presenza di un assone provvisto di un diametro notevole. Tale interpretazione non è da tutti accettata in quanto Mammiferi terrestri di grandi dimensioni non presentano nella loro retina neuroni gangliari giganti.
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Genoves, Rodrigo Cezar. "Estrutura social do boto Tursiops truncatus (CETACEA: DELPHINIDAE), no estuário da Lagoa dos Patos e águas costeiras adjacentes, sul do Brasil." reponame:Repositório Institucional da FURG, 2013. http://repositorio.furg.br/handle/1/4272.
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Dissertação(mestrado) - Universidade Federal do Rio Grande, Programa de Pós–Graduação em Oceanografia Biológica, Instituto de Oceanografia, 2013Submitted by Cristiane Gomides (cristiane_gomides@hotmail.com) on 2013-12-16T11:59:50Z No. of bitstreams: 1 rodrigo.pdf: 2838178 bytes, checksum: 0ed5e3967d18f3075d7e2c1c3f615170 (MD5)
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Investigamos a estrutura social e padrões espaciais de uso da área por uma população de golfinhos, Tursiops truncatus, que habitam o estuário da Lagoa dos Patos e águas costeiras adjacentes, no sul do Brasil. Nós estimamos o índice de associação a partir de 102 indivíduos regularmente observados em 243 saídas de foto-identificação realizadas entre agosto de 2005 e outubro de 2012. As análises sociais e de rede, com a divisão proposta pela modularidade, indicou que esta população de botos é composta por três unidades sociais principais. Embora exista certa sobreposição espacial, houve distinção entre as zonas preferenciais de cada unidade. Uma das unidades esta fortemente associada com o estuário da Lagoa dos Patos, enquanto as outras duas ocuparam, respectivamente, as áreas marinhas adjacentes norte e sul. Dentro das unidades, as associações entre os indivíduos foram predominantemente de curta duração (dinâmica de fissão-fusão), embora tenham sido identificadas algumas associações de longa duração. Embora tenham ocorrido interações entre as unidades sociais, as associações foram rápidas e ocorreram apenas entre alguns indivíduos. A segregação destes indivíduos é motivada, pelo menos em parte, pelos padrões de associação entre os indivíduos e sua fidelidade a áreas específicas. Recomenda-se que as unidades sociais sejam a base para modelar a viabilidade e dinâmica intrapopulacional, bem como para investigação de padrões de fluxo gênico dentro e entre unidades sociais.
We investigated the social structure and spatial patterns of area usage by a population of bottlenose dolphins, Tursiops truncatus, inhabiting the Patos Lagoon estuary and adjacent coastal waters, in southern Brazil. We estimated the association index from 102 individuals regularly sighted in 243 photo-identification surveys carried out between August 2005 and October 2012. Social and network analyses, with the division proposed by modularity, indicated that this bottlenose dolphin population consists of three social units. Although some spatial overlap exists, preferred areas of each unit were distinct. One of the units was strongly associated with the Patos Lagoon estuary while the other two occupied, respectively, the southern and northern adjacent marine coasts. Within unit associations among individuals were predominantly of short duration (fission-fusion dynamics), though a few long-lasting bonds were detected. Although interactions between social units occurred, the associations were brief and occurred only among a few individuals. The segregation of these individuals is motivated, at least in part, by the bonding patterns among individuals and their fidelity to specific areas. It is recommended that the social units be the framework for modeling the intrapopulation dynamic and viability as well as for investigating patterns of gene flow within and between social units.
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Souza, Shirley Pacheco de. "Etnobiologia de cetáceos por pescadores artesanais da costa brasileira." [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/316350.
Full textAbstract:
Orientador: Alpina BegossiTese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia
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Resumo: Este estudo registra e analisa o conhecimento ecológico dos pescadores artesanais da costa brasileira. O conhecimento dos pescadores é empírico, prático e contém registros em longo prazo sobre espécies e eventos ambientais, incluindo informações biológicas, ecológicas e culturais. Tendo a Ecologia Humana e a Etnobiologia como bases conceituais e metodológicas caracterizamos o conhecimento dos pescadores sobre a classificação, a nomenclatura e a ecologia dos cetáceos. Entrevistamos 171 pescadores artesanais de comunidades localizadas em Soure (Ilha do Marajó) na região norte, em Ponta Negra (Natal) na região nordeste, em São Sebastião (São Paulo) na região sudeste e em Pântano do Sul (Florianópolis) na região sul do Brasil. Os cetáceos fazem parte da megafauna impactada pela captura acidental na pesca. Cerca de metade das espécies existentes no Brasil está classificada pela Lista Vermelha da IUCN como espécies com dados insuficientes, devido à falta de informação sobre elas. Conforme os resultados desta pesquisa, os pescadores reconheceram 17 espécies de cetáceos e as agruparam em quatro etnogêneros e 37 etnoespécies. O conhecimento dos pescadores sobre as áreas de ocorrência, habitats preferenciais, sazonalidade, tamanhos de grupo e reprodução dos cetáceos forneceu informações para 16 espécies. O boto-cinza (Sotalia guianensis) e o golfinho-nariz-de-garrafa (Tursiops truncatus) foram as espécies mais citadas nas quatro áreas. Os tópicos mais conhecidos foram áreas de ocorrência e tamanhos de grupo, e o menos conhecido foi reprodução. Em relação às interações entre cetáceos e atividades pesqueiras, as informações obtidas indicaram os seguintes tipos de interações: competição (com os peixes e os pescadores), cooperação (com os pescadores) e predação (sobre as espécies-alvo da pesca ou como presa para outros predadores de topo). As espécies mais comuns em cada área (S. guianensis, T. truncatus, Inia geoffrensis, Stenella clymene, Pontoporia blainvillei e Eubalaena australis) são as mais conhecidas e as mais mencionadas como principais competidores ou cooperadores. A captura acidental de cetáceos foi a interação mais citada. Os pescadores conhecem detalhes sobre os hábitos alimentares de alguns cetáceos, descrevendo 28 tipos diferentes de comportamentos alimentares e listando 48 espécies de peixes, moluscos e crustáceos como presas preferenciais. Fatores culturais e ambientais, tais como variações oceanográficas nas áreas de estudo e variações no uso de recursos influenciaram o conhecimento dos pescadores. Comparando as informações dos pescadores sobre as espécies mais comuns de cetáceos com aquelas contidas na literatura científica encontramos grande concordância em relação aos aspectos ecológicos e às interações com a pesca. Apenas para duas espécies (Stenella clymene e Inia geoffrensis) o conhecimento dos pescadores foi discordante da literatura. Estes casos de inconsistência entre os dois tipos de conhecimento podem refletir alguma falta de conhecimento dos pescadores sobre estas espécies ou, por outro lado, podem sugerir novas linhas de pesquisa. O conhecimento dos pescadores sobre as interações envolvendo cetáceos são úteis ao manejo das capturas acidentais, fornecendo informações sobre áreas críticas de captura e sugerindo locais e designs alternativos para as redes de espera. Sugerimos que este conhecimento seja considerado nas estratégias de manejo pesqueiro, já que pode contribuir para minimizar as interações negativas entre os cetáceos e a pesca
Abstract: This study records and analyzes fishers' local ecological knowledge (LEK) on cetaceans in the Brazilian coast. Fishers' (LEK) is empirical, practical-oriented, embedded with long-term records on local species or environmental events, and includes important biological, ecological and cultural information. Choosing Human Ecology and Ethnobiology as methodological base and considering cultural and oceanographic variations in the studied areas, we present fishers' knowledge through Folk Taxonomy and Ethnoecology. We interviewed 171 fishers from communities situated in four areas in Brazil: Soure (at Marajó Island, northern coast), Ponta Negra (at Natal, northeastern coast), São Sebastião (at southeastern coast) and Pântano do Sul (at Florianópolis, southern coast). Cetaceans are among the megafauna impacted by bycatch in fisheries. Nearly half of the cetacean species occurring in Brazil are classified by the IUCN Red List as "data deficient" due to lack of information about them. We studied fishers' LEK on cetaceans' classification and nomenclature. Fishers recognized 17 cetacean species and included them in four folk genera and 37 folk species. We recorded fishers' knowledge on cetaceans' ecology. Fishers reported 112 occurrence areas, providing information on preferential habitats, seasonality patterns, group sizes and reproduction for cetacean species. The topics most known by the fishers are occurrence areas and group sizes, and the least known is reproduction. The Guiana dolphin (Sotalia guianensis) and the bottlenose dolphin (Tursiops truncatus) are the most cited species. Fishers' LEK on cetaceans' interactions with fisheries indicated the following kinds of interactions: competition (with local fish and fishers), cooperation (to the fishers), and predation (on fisheries' target species or as prey for other top predators). The most common species in each place (Sotalia guianensis, Tursiops truncatus, Inia geoffrensis, Stenella clymene, Pontoporia blainvillei and Eubalaena australis) are the most known by the fishers, and those mentioned as the main cooperators or competitors. As a result of these interactions some cetaceans are accidentally caught by gillnets used near the coast. Fishers know details about the feeding habits of some species, describing 28 different feeding behaviors and listing 48 species of fishes, mollusks and crustaceans as preferential prey. There were variations among fishers' LEK in the study areas, probably influenced by the level of communities' dependence on natural resources and by variations in oceanographic parameters. We compare fishers' knowledge on the most common species with the information in the scientific literature and we found great concordance in relation to cetaceans' occurrence areas, seasonality, group sizes, prey items and their interactions with fisheries except for two species (Stenella clymene and Inia geoffrensis), to which fishers' information was discordant. These cases of inconsistency between LEK and scientific literature could reflect the fishers' lack of knowledge on these species or, conversely, could suggest new lines of investigation. Fishers' knowledge on the cetaceans' feeding behavior and their interactions to fisheries can be helpful, through the indication of bycatch critical areas and alternative location for setting gillnets, as well as possible alterations in gillnets' designs. We suggest that fishers' knowledge should be considered in fisheries management plans, helping to minimize the negative interactions between cetaceans and fisheries
Doutorado
Ecologia
Doutor em Ecologia
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Forney, Karin A. "Patterns of variability and environmental models of relative abundance for California cetaceans /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 1997. http://wwwlib.umi.com/cr/ucsd/fullcit?p9823699.
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