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.

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.

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.

Evaluation of diel and seasonal patterns in offshore marine mammal activity through visual data collection can be impaired by poor weather and light limitations and by the requirement for costly ship time. As a result, relatively little is known about the diel patterns of wild dolphins. Pacific white-sided dolphins north of Southern California are particularly under-researched. Collecting acoustic data can be a cost-effective approach to evaluating activity patterns in offshore marine mammals. However, manual analysis of acoustic data is time-consuming, and impractical for large data sets. This study evaluates diel and seasonal patterns in Pacific white-sided dolphin communication through automated analysis of one year of continuous acoustic data collected from the Barkley Canyon node of Ocean Networks Canada’s NEPTUNE observatory, offshore Vancouver Island, British Columbia, Canada. In this study, marine mammal acoustic signals are manually annotated in a sub-set of the data, and used to train a random forest classifier targeting Pacific white-sided dolphin pulsed calls. Marine mammal vocalizations are classified using the resultant classifier, manually verified, and examined for seasonal and diel patterns. Pacific white-sided dolphins are shown to be vocally active during all diel periods in the spring and summer, but primarily at dusk and night in the fall and winter. Additionally, the percentage of time they are detected drops significantly in the fall and remains low during the winter. This pattern suggests that a group of day-active dolphins, possibly a unique population, leaves Barkley Canyon in the fall and returns in the spring. It is hypothesized that this group may be following the Pacific herring, which are present at the surface during the day at Barkley Canyon in the spring and summer, and migrate inshore for the fall and winter. / Graduate

Thirty - seven species of cetacean are recorded from southern African waters. Four thousand, five hundred and thirty - seven records of approximately 60 000 cetaceans were analysed to defme distribution patterns of these species, including dedicated sightings (both scientific and commercial), incidental sightings, commercial catches and specimens. Records of dedicated scientific sightings and incidental sightings were analysed by water depth, sea surface temperature and salinity and season, while commercial sightings and catches were analysed by month and water depth. Of the thirty - seven species recorded within the region, four mysticetes and one odontocele could be described as migratory, having a marked seasonal occurrence within the region, three species were defmed as possible migrators as they were not recorded in the dedicated data and showed seasonality in the incidental sighting and specimen databases, 20 species (19 odontocetes and one mysticete) could be described as resident (in that they were found throughout the year) and five species were termed "semi - resident" (certain components or forms of which showed strong seasonal occurrence, while other individuals had a year- round occurrence). Records of a further four species were too few to defme distribution patterns or seasonality. Analysis of the distribution of the large species showed three species (Eubalaena australis, Megaptera novaeangliae and Caperea marginata) to occur in nearshore waters and four species (Balaenoptera musculus, B. physalus, B. borealis and P.macrocepha/us) to occur in deep waters only. B. acutorostrata was recorded in both nearshore and offshore waters, while the two forms of B. edeni were found in nearshore and offshore waters respectively. The distribution analyses of the smaller odontocele species showed a number of component patterns including cosmopolitan, pelagic cosmopolitan, tropical, sub tropical and warm temperate components of the Agulhas Current, warm temperate component of the south coast, a component of the Agulhas Bank, a south and east coast inshore component and west coast inshore and offshore components. The high diversity of species within the region results from the complex variety of zoogeographic components found within the relatively small study area. These arise from the complex oceanographic conditions, brought about by the upwelling of cold Central Atlantic water inshore on the west coast, the movement of subtropical water into the east coast region by the Agulhas Current and the mixing of Benguela and Agulhas Current waters to the south of the sub - continent. / Dissertation (MSc)--University of Pretoria, 1989. / gm2014 / Zoology and Entomology / unrestricted

<p>Social structure is a key determinant of population biology and is central to the way animals exploit their environment. The risk of predation is often invoked as an important factor influencing the evolution of social structure in cetaceans and other mammals, but little direct information is available about how cetaceans actually respond to predators or other perceived threats. The playback of sounds to an animal is a powerful tool for assessing behavioral responses to predators, but quantifying behavioral responses to playback experiments requires baseline knowledge of normal behavioral patterns and variation. The central goal of my dissertation is to describe baseline foraging behavior for the western Atlantic short-finnned pilot whales (Globicephala macrohynchus) and examine the role of social organization in their response to predators. To accomplish this I used multi-sensor digital acoustic tags (DTAGs), satellite-linked time-depth recorders (SLTDR), and playback experiments to study foraging behavior and behavioral response to predators in pilot whales. Fine scale foraging strategies and population level patterns were identified by estimating the body size and examining the location and movement around feeding events using data collected with DTAGs deployed on 40 pilot whales in summers of 2008-2014 off the coast of Cape Hatteras, North Carolina. Pilot whales were found to forage throughout the water column and performed feeding buzzes at depths ranging from 29-1176 meters. The results indicated potential habitat segregation in foraging depth in short-finned pilot whales with larger individuals foraging on average at deeper depths. Calculated aerobic dive limit for large adult males was approximately 6 minutes longer than that of females and likely facilitated the difference in foraging depth. Furthermore, the buzz frequency and speed around feeding attempts indicate this population pilot whales are likely targeting multiple small prey items. Using these results, I built decision trees to inform foraging dive classification in coarse, long-term dive data collected with SLTDRs deployed on 6 pilot whales in the summers of 2014 and 2015 in the same area off the coast of North Carolina. I used these long term foraging records to compare diurnal foraging rates and depths, as well as classify bouts with a maximum likelihood method, and evaluate behavioral aerobic dive limits (ADLB) through examination of dive durations and inter-dive intervals. Dive duration was the best predictor of foraging, with dives >400.6 seconds classified as foraging, and a 96% classification accuracy. There were no diurnal patterns in foraging depth or rates and average duration of bouts was 2.94 hours with maximum bout durations lasting up to 14 hours. The results indicated that pilot whales forage in relatively long bouts and the ADLB indicate that pilot whales rarely, if ever exceed their aerobic limits. To evaluate the response to predators I used controlled playback experiments to examine the behavioral responses of 10 of the tagged short-finned pilot whales off Cape Hatteras, North Carolina and 4 Risso’s dolphins (Grampus griseus) off Southern California to the calls of mammal-eating killer whales (MEK). Both species responded to a subset of MEK calls with increased movement, swim speed and increased cohesion of the focal groups, but the two species exhibited different directional movement and vocal responses. Pilot whales increased their call rate and approached the sound source, but Risso’s dolphins exhibited no change in their vocal behavior and moved in a rapid, directed manner away from the source. Thus, at least to a sub-set of mammal-eating killer whale calls, these two study species reacted in a manner that is consistent with their patterns of social organization. Pilot whales, which live in relatively permanent groups bound by strong social bonds, responded in a manner that built on their high levels of social cohesion. In contrast, Risso’s dolphins exhibited an exaggerated flight response and moved rapidly away from the sound source. The fact that both species responded strongly to a select number of MEK calls, suggests that structural features of signals play critical contextual roles in the probability of response to potential threats in odontocete cetaceans.</p> / Dissertation

Five line transect surveys for marine mammals were conducted offshore of mainland Ecuador and the Galápagos Islands from 2008-2011. These data were used in conjunction with MODIS (Moderate Resolution Imaging Spectroradiometer) observations of ocean color and sea surface temperature (SST) to assess spatial and temporal relationships between surface oceanographic features and cetacean distribution within the Eastern Equatorial Pacific (EEP). Results from this study indicated that oceanographic processes affected cetacean distribution on inter-annual, seasonal, and weekly to monthly time scales. The spatial scales on which these processes affect cetacean distribution are small, the smallest associations being found at 4 km2 bin sizes, as well as 9 km2 and 36 km2 bin sizes. By utilizing ocean color and SST data from the MODIS instrument and analyzing variability of these parameters in addition to average concentration, cetacean distribution within the region was related to the locations of frontal boundaries. Cetaceans were grouped into two categories based on the trophic level and relative depths at which they forage. Cetaceans feeding nearer the ocean surface and lower on the trophic scale were generally found in cooler waters of higher average chlorophyll concentration and elevated variability. Those cetaceans feeding higher on the trophic scale and lower in the water column (mesopelagic and bathypelagic depths) were sighted within relatively warmer waters of reduced temperature variability near areas of high chlorophyll variability (though less variable and lower in average chlorophyll than surface feeding cetaceans), with little spatial and temporal lag between peak surface chlorophyll concentration and cetacean presence. The EEP is a biologically productive region with many competing economic and environmental interests. Ecuador is home to one of the largest artisenal fishing fleets in South America, and entanglement of various cetacean species has been a known issue for several decades (Félix and Haase, 2006; Castro and Rosero, 2010). Seismic exploration, shipping, and tourism are also found on the busy waterways surrounding both mainland Ecuador and the archipelago. The results of this study provide additional insight into the mesoscale processes affecting the distribution and habitat use of cetaceans within the EEP and South American waters and to support ongoing ecosystem management efforts.

The critical endangered species has become one of the main concerns regarding the loss of biodiversity in the 21th century. It is also a new challenge for the protection of the endangered Chinese White Dolphin (CWD) which was discovered living along the western coast of Taiwan since the year 2002. It has a large overlapping occurred in the coastal place where the CWD population is inhabited around with human¡¦s development activities. Therefore, the conservation actions are emergently needed tasks and immediately entangled with difficulties. The present study employs the qualitative tool to investigate the institutional policy on the conservation strategies related to the protection of endangered CWD. These include documental analysis of literatures, interviews, and observations to identify the key concepts for the conservation strategies. The interactions among context of the strategies, actions to impacts and threats, and scientific contributions are also analyzed. The results are assessed according to three levels of conservation objectives, i.e. the individual/population, habitat, and ecosystem. The formal regulations cover the individual/population level much less than the habitat and ecosystem levels. The policies and scientific efforts are mostly concerned on the individual/population and habitat levels. The ecosystem level is ignored. The legal guidelines have set for the impacts and threats to the conservation policy, but there is lack of scientific investigation and input. It is imperative to emphasize the intensive interaction between scientific research and conservation strategies. The scientific development is obviously one of the key institutional policies of conservation. This study examines three issues in relevance to the development of conservation strategies and the implementation of management. Furthermore, the present work concludes that the conservation strategy must perceive to a correct direction for future planning and implementation, in order to integrate the conservation capacity and achieving the comprehensive conservation results.

Following the global warming and climate change in the last twenty years, one of key actions on maintaining biodiversity is to save critical endangered species with aspect of intergrated management. Our study aims to explore integrated mechanism inside the case of Chinese White Dolphin conservation in Taiwan throught a qualitative research approach. The integrated mechanism was also understood under a concept of social-ecological system and analysed with a framework that was modified mitigation-adaptation model used to apply on climate change study. The capacity of management measures including of mitigation and adaptation was explored on three levels, i.e. animals, habitat, and society. Differences of the capacity in these three levels were compared between the cases in Taiwan and Hong Kong. The study also tried to point out possible responders who should conduct these conservation measures from a questionnaire survey. The statistical analysis revealed none of top measures must be under the responsibility of government in these three levels. The analysis showed that there is no correlation between the implementation of measures and the governmental responsibility. In addition, the top-six measures were mainly in the marine environment level and four of the measures had been implemented. In the analysis about governmental responsibility top-seven measures, should be under the responsibility of developers, instead of the government. Some suggestions were given at the end for integrated management of Chinese White Dolphin conservation in Taiwan.

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