440 research outputs found

    Marine mammal tourism in the Bay of Plenty, New Zealand : effects, implications and management : a thesis submitted in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Marine Ecology at Massey University, Albany, New Zealand

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    Worldwide expansion of marine mammal tourism over recent decades has raised international concerns in terms of the effects of these tourism practices on the species they target. Moreover, the growth and success of the industry have often outpaced conservation planning, including in New Zealand. To illustrate, tour vessels have been operating for ca. 25 years in the Bay of Plenty (BOP), situated on the east coast of North Island, New Zealand. By 2010, a total of eight permits had been granted across the region. However, development of this local industry occurred without any baseline data on species occurrence, distribution, habitat use or behaviour. This study sought to assess the historical occurrence of the marine mammal species off the BOP and determine their spatial and temporal distribution. Current distribution, density and group dynamics were examined for common dolphins (Delphinus sp.) and New Zealand fur seals (Arctocephalus forsteri), the two most frequently encountered species in the BOP and therefore, the primarily targeted species by tour operators. The extent of anthropogenic interactions with common dolphins was investigated and their effects on dolphin behaviour examined. The number of common dolphin individuals closely interacting with tour vessels was estimated and dolphin-vessel interactions were quantified to assess repetitive encounters. In the absence of previously undertaken systematic dedicated surveys, the present study investigated the historical spatial and temporal occurrence of dolphins, whales and pinnipeds in the BOP region. The examination of opportunistic data, collected between December 2000 and November 2010 via various platforms of opportunity including but not limited to tour vessels, identified fourteen species of dolphins, whales and pinnipeds occurring in the region. Confidence criteria in successful species identification were assigned based on observer expertise, diagnostic features of reported species and percentage of records reported by observer type. Common dolphins were the most frequently encountered species, followed by killer whales (Orcinus orca), bottlenose dolphins (Tursiops truncatus) and New Zealand fur seals, other species being infrequently encountered. A detailed examination of common dolphin habitat use revealed discrepancies with previous findings (e.g. higher use of shallower waters), possibly explained by inherent biases to the opportunistic dataset. Dedicated surveys, conducted between November 2010 and May 2013, investigated the current distribution, density and habitat use of common dolphins and New Zealand fur seals. Both species exhibited a strong seasonality with contrasting occurrence in summer and autumn for common dolphins and in winter and spring for fur seals. Dolphin seasonality is suggested to be linked to movements into deeper offshore waters and/or potentially to neighbouring regions (i.e. the Hauraki Gulf) and most likely related to foraging opportunities. Fur seal seasonality suggests that the western BOP supports a non-breeding colony and that foraging reasons may explain the species occurrence in the region. Higher density of common dolphins and fur seals identified over the shelf break and reefs can be explained by enhanced productivity. First application of Markov chain analyses to common dolphin within oceanic waters, allowed examination of the effects of tourism activities on common dolphins in the BOP. Dolphin foraging behaviour was significantly affected, as dolphins spent less time foraging during interactions with tour vessels and took longer to return to foraging once disrupted by vessel presence. Disruption to feeding may be particularly detrimental to common dolphins in the BOP open oceanic habitat, where prey resources are typically widely dispersed and unpredictable. While the overall level of tour operator compliance with regulations in the bay was relatively high, non-compliance was recorded with regards to swimming with calves and extended time interacting with dolphins. Evidence of repetitive interactions between tour vessels and common dolphins were examined using photo-identification to assess potential cumulative impacts. An estimated minimum of 1,278 common dolphin individuals were identified in the region, for which the majority (86.9%) showed low levels of site fidelity (i.e. only one encounter). At least 61.7% of identified dolphins were exposed to tour vessel interactions. However, spatial (i.e. between the western and eastern sub-regions) and temporal (i.e. daily, seasonal and annual) cumulative exposure to tourism activities was observed for less than 10% of these individuals. This is likely explained by tour operators “handing over” groups or returning to areas preferentially frequented by dolphins (i.e. presumed foraging hotspots). Due to the opportunistic methods used for photo-identification, these results are indicative only of the absolute minimum of repeated interactions common dolphins may face in the region. The present thesis represents the first comprehensive assessment of marine mammal tourism in the BOP. It offers important contributions to research and conservation in this area via the critical assessment of historical occurrence of marine mammals in the region. This thesis also provides comprehensive and detailed insights into common dolphin and New Zealand fur seal temporal and spatial distribution in the area. This can serve management agencies to implement efficient conservation plans. While identifying that tourism operations significantly affect common dolphin behaviour and repetitive interactions result in cumulative exposure, this thesis supports adaptive management and further long-term monitoring of marine mammal species in general, and in the BOP region more specifically

    RELATING FLUVIAL GEOMORPHOLOGY TO MACROINVERTEBRATE DISTRIBUTION

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    Modern rivers undergo constant stress from disturbances such as bank stabilization, channelization, dams, and water expenditures. As these anthropogenic activities persist, efficient methods of characterizing rivers remain essential. Macroinvertebrates are an important feature in evaluating fluvial health, because they are often the first to react to contaminants. These toxins can be transferred through macroinvertebrates to other trophic levels. The purpose of this research was to use a geospatial model to differentiate instream macroinvertebrate habitats, and determine if the model is a viable method for stream evaluation. Through the use of ArcGIS and digital elevation models, the geomorphology of the Qu’Appelle River, Saskatchewan was assessed. Four geomorphological characteristics of the river were isolated (sinuosity, slope, fractal dimension, stream width) and clustered through a Principle Component Analysis, yielding sets of river reaches with similar geomorphological characteristics, called typologies. These typologies were mapped to form a geospatial model of the river, and grouped into geomorphological response units (GRUs). Macroinvertebrate data were aligned to the model, revealing relationships between macroinvertebrate taxa and fluvial geomorphology. A Kruskal-Wallis analysis and post hoc pairwise multiple comparisons pinpointed significant relationships between several genera and typologies. Furthermore, certain GRUs contained more sensitive macroinvertebrate families and healthier levels of diversity than other GRUs. Typologies were better suited to relate geomorphology to macroinvertebrate taxa, because they represented a more direct relationship to localised geomorphological characteristics than GRUs

    Editorial

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    Trafficked Proteins—Druggable in Plasmodium falciparum

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    Malaria is an infectious disease that results in serious health problems in the countries in which it is endemic. Annually this parasitic disease leads to more than half a million deaths; most of these are children in Africa. An effective vaccine is not available, and the treatment of the disease is solely dependent on chemotherapy. However, drug resistance is spreading, and the identification of new drug targets as well as the development of new antimalarials is urgently required. Attention has been drawn to a variety of essential plasmodial proteins, which are targeted to intra- or extracellular destinations, such as the digestive vacuole, the apicoplast, or into the host cell. Interfering with the action or the transport of these proteins will impede proliferation of the parasite. In this mini review, we will shed light on the present discovery of chemotherapeutics and potential drug targets involved in protein trafficking processes in the malaria parasite

    Melatonin activate FIS1, DYN1 and DYN2 Plasmodium falciparum related-genes for mitochondria fission: mitoemerald-GFP as a tool to visualize mitochondria structure

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    Malaria causes millions of deaths worldwide and is considered a huge burden to underdeveloped countries. The number of cases with resistance to all antimalarials is continuously increasing, making the identification of novel drugs a very urgent necessity. A potentially very interesting target for novel therapeutic intervention is the parasite mitochondrion. In this work we studied in P. falciparum three genes coding for proteins homologues of the mammalian FIS1 (Mitochondrial Fission Protein 1) and DRP1 (Dynamin Related Protein 1) involved in mitochondrial fission. We studied the expression of P. falciparum genes that show ample sequence and structural homologies with the mammalian counterparts, namely FIS1, DYN1 and DYN2. The encoded proteins are characterized by a distinct pattern of expression throughout the erythrocytic cycle of Plasmodium falciparum and their mRNAs are modulated by treating the parasite with the host hormone melatonin. We have previously reported that the knock out of the Plasmodium gene that codes for protein kinase 7 is essential for melatonin sensing. We here show that PfPk7 knockout results in major alterations of mitochondrial fission genes expression when compared to wild type parasites, and no change in fission protein expression upon treatment with the host hormone. Finally we have compared the morphological characteristics(using MitoTracker Red CMX Ros. and oxygen consumption properties of P. falciparum mitochondria in wild type parasites and PfPk7 Knockout strains. A novel GFP construct targeted to the mitochondrial matrix to wild type parasites was also developed to visualize Plasmodium falciparum mitochondria. We here show that, the functional characteristics of P. falciparum are profoundly altered in cells lacking protein kinase 7, suggesting that this enzyme plays a major role in the control of mitochondrial morphogenesis and maturation during the intra erythrocyte cell cycle progression. This article is protected by copyright. All rights reserved

    The Use of Placebo and Non-Specific Therapies and Their Relation to Basic Professional Attitudes and the Use of Complementary Therapies among German Physicians - A Cross-Sectional Survey

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    We aimed to investigate the use of placebos ( e. g. saline injections) and non-specific treatments ( e. g. vitamin supplements in individuals without a relevant deficiency) among physicians working in private practices in Germany, and how such use is associated with the belief in and the use of complementary and alternative treatments, and basic professional attitudes. A four-page questionnaire was sent to nationwide random samples of general practitioners ( GP),internists and orthopaedists working in private practices. The response rate was 46% ( 935 of 2018). 24% of GPs, 44% of internists and 57% of orthopaedists had neither used pure placebos nor non-specific therapies in the previous 12 months. 11% percent of GPs, 12% of internists and 7% of orthopaedists had exclusively used pure placebos;30%,33% and 26%,respectively, had exclusively used non-specific therapies;35%,12% and 9% had used both. Age, sex and agreement to the statement that physicians should harness placebo effects were not significantly associated with any pattern of use. Exclusive use of pure placebos was associated with being a GP, being an internist, and having unorthodox professional views. In addition to these three factors, a lower use of CAM therapies and a wish for having more time was associated with the exclusive use of nonspecific therapies. Among physicians using both pure placebo and non-specific therapies, heterodox views were also somewhat more pronounced. However, associations were particularly strong for being a GP ( Odds ratio 11.6 ( 95%CI 6.41;21.3)) and having orthodox views ( Odds ratio 0.10 ( 95%CI 0.06;0.18)) among this group. In conclusion, the use of placebos and non-specific treatments varies strongly between medical specialties and is associated with basic professional attitudes. The findings support the view that the use of placebos and, in particular, of non-specific therapies is primarily a coping behaviour for difficult and uncertain situations

    Use of Placebos and Nonspecific and Complementary Treatments by German Physicians - Rationale and Development of a Questionnaire for a Nationwide Survey

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    Background: We are performing a nationwide survey in a random sample ofGerman general practitioners (GPs), orthopedists, and internists on theuse of placebos and nonspecific as well as complementary treatments andtheir association with basic professional attitudes. In this article weexplain the theoretical considerations behind the study approach and thedevelopment of the questionnaire. Methods: Based on a systematic reviewof published surveys, own surveys on the topic, and on theoreticalconsiderations we developed a preliminary version of a 4-pagequestionnaire that was tested for feasibility in a convenience sample of80 participants of a general medical education event. We also performedcognitive interviews with 8 physicians to investigate whether thequestions were understood adequately. Results: The questions on typicalplacebos and complementary treatments were well understood and easy toanswer for participants. Discussions about the phrasing of questions onnonspecific treatments during interview reflected the vagueness of thisconcept; but this did not seem to create major problems when answeringthe related questions. The original questions regarding basicprofessional attitudes partly were not understood in the mannerintended. The relevant questions were modified but the interviewssuggest that these issues are difficult to grasp in a quantitativesurvey. Conclusion: Our testing procedures suggest that ourquestionnaire is well-suited to investigate our questions with somelimitations regarding the issue of basic professional attitudes
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