44 research outputs found

    ETN Technical Standards Report

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    Development of technical standards for specific European lines and tagging projects in the form of a report

    Ghosts in the data: false detections in VEMCO pulse position modulation acoustic telemetry monitoring equipment

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    Background: False-positive data (better known as "false detections") in VEMCO VR2 acoustic telemetry monitoring studies that use pulse position modulation coding can cause biased or erroneous outcomes in data analysis. To understand the occurrence of false detections in acoustic monitoring data sets, the results of a range test experiment using eight acoustic receivers and 12 transmitters were examined. Results: One hundred and fifty one tag ID codes were recorded, 137 of which were identified as likely from false detections, 12 were from test tags, and two were from tagged sharks. False detections accounted for < 0.05 % of detections (918) in the experiment. False detection tag ID codes were not randomly distributed amongst the available codes, being more likely to occur at IDs close to tags used in the experiment. Receivers located near the bottom recorded the most false detections and tag ID codes from false detections. Receivers at the same depth did not differ significantly in the mean number of daily false detections. The daily number of false detections recorded by a receiver did not conform to a random pattern, and was not strongly correlated with daily receiver performance. Conclusions: In an era of increasing data sharing and public storage of scientific data, the occurrence of false detections is of significant concern and the results of this study demonstrate that while rare they do occur and can be identified and accounted for in analyses

    A review of acoustic telemetry in Europe and the need for a regional aquatic telemetry network

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    Background Globally, there are a large and growing number of researchers using biotelemetry as a tool to study aquatic animals. In Europe, this community lacks a formal network structure. The aim of this study is to review the use of acoustic telemetry in Europe and document the contribution of cross-boundary studies and inter-research group collaborations. Based on this, we explore the potential benefits and challenges of a network approach to identify future priorities and best practices for aquatic biotelemetry research in Europe. Results Over the past decade, there was an approximately sevenfold increase in the number of acoustic telemetry studies published on marine and diadromous species in Europe compared to a sixfold increase globally. Over 90% of these studies were conducted on fishes and undertaken in coastal areas, estuaries, or rivers. 75% of these studies were conducted by researchers based in one of five nations (Norway, UK, France, Portugal, and Spain) and, even though 34% were based on collaborations between scientists from several countries, there was only one study with an acoustic receiver array that extended beyond the borders of a single country. In recent years, acoustic telemetry in European waters has evolved from studying behavioural aspects of animals (82.2%), into more holistic approaches addressing management-related issues (10%), tagging methods and effects (5%), and technology and data analysis development (2.8%). Conclusions Despite the increasing number of publications and species tracked, there is a prominent lack of planned and structured acoustic telemetry collaborations in Europe. A formal pan-European network structure would promote the development of (1) a research platform that could benefit the acoustic telemetry community through capacity building, (2) a centralized database, and (3) key deployment sites and studies on priority species requiring research in Europe. A network may increase efficiency, expand the scope of research that can be undertaken, promote European science integration, enhance the opportunities and success of acquiring research funding and, ultimately, foster regional and transatlantic collaborations. It may also help address research priorities such as the large-scale societal challenges arising from climate change impacts and assist the EU’s Marine Strategy Framework Directive via identification of good environmental status of endangered or commercially important species.info:eu-repo/semantics/publishedVersio

    Data Descriptor: Australia’s continental-scale acoustic tracking database and its automated quality control process

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    Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/ The Creative Commons Public Domain Dedication waiver http://creativecommons.org/publicdomain/zero/1.0/ applies to the metadata files made available in this article.Our ability to predict species responses to environmental changes relies on accurate records of animal movement patterns. Continental-scale acoustic telemetry networks are increasingly being established worldwide, producing large volumes of information-rich geospatial data. During the last decade, the Integrated Marine Observing System’s Animal Tracking Facility (IMOS ATF) established a permanent array of acoustic receivers around Australia. Simultaneously, IMOS developed a centralised national database to foster collaborative research across the user community and quantify individual behaviour across a broad range of taxa. Here we present the database and quality control procedures developed to collate 49.6 million valid detections from 1891 receiving stations. This dataset consists of detections for 3,777 tags deployed on 117 marine species, with distances travelled ranging from a few to thousands of kilometres. Connectivity between regions was only made possible by the joint contribution of IMOS infrastructure and researcher-funded receivers. This dataset constitutes a valuable resource facilitating meta-analysis of animal movement, distributions, and habitat use, and is important for relating species distribution shifts with environmental covariates

    Best practice framework and principles for monitoring the effect of coastal development on marine mammals

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    As the worlds human population increases along the coastal zone with major alteration of coastal embayments increased on-water activities and a plethora of other intrusions into the coastal zone there is a simultaneous increase in pressures on marine mammals. Growing evidence indicates that many marine mammals are highly susceptible to declines resulting from direct and indirect impacts arising from diverse human activities. Too frequently assessment of the impact from coastal developments on marine mammals has been inadequate or completely lacking. At worst this has led to catastrophic decline in some populations. Without rigorous ecological assessments along with adaptive management frameworks prior to the initiation of developments the number of marine mammal populations likely to be adversely impacted will continue to rise. To address these shortcomings we present a globally applicable best practice framework by; (i) describing guiding principles and; (ii) reviewing appropriate procedures for assessment and monitoring of impacts of coastal developments on marine mammals. The approach outlined is embedded in Environmental Impact Assessment processes as a means by which decision makers and stakeholders can be informed. Recommendations presented are designed to encourage the application of robust scientific evaluation that applies appropriate survey design with sufficient statistical power to detect changes before trigger thresholds are reached. We emphasize that there is an urgent need to ensure assessments are comprehensive effective and integrated with monitoring and adaptive management actions in order to minimize or effectively mitigate the impacts of human activities on marine mammal population

    Are we killing them with kindness? Evaluation of sustainable marine wildlife tourism

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    The increasing popularity of marine wildlife tourism (MWT) worldwide calls for assessment of its conservation outcomes and the development of appropriate management frameworks to ensure the conservation of the species and habitats involved as well as the long-term sustainability of this industry. While many studies have examined the positive and/or negative implications of particular forms of MWT, few have attempted to identify factors of concern shared across different types of marine tourism, or examine their implications for sustainability in a broader perspective. We reviewed the existing literature to highlight common impacts on animal behaviour, health and ecology, and to identify successful cases based on minimal negative affects and/or lack of chronic/ irreversible impacts on target species or habitats. To ensure the achievement of both economic and ecologic objectives, the following steps should be integrated in MWT management: 1) Increase of research on the biology and ecology of target species/habitat and application of relevant information for the development of suitable policies, frameworks and management strategies; 2) Structured enforcement of existing policies and enhancement of ecological awareness of visitors through active education; 3) Application of an adaptive management framework to continuously improve the codes of conduct employed; 4) Involvement of different stakeholders and local communities in the development and improvement of the MWT activity. Combining these strategies with the extrapolation of frameworks and policies from cases where adverse ecological impacts have been addressed and successfully resolved can further contribute in ensuring the long-term health and conservation of the species/ habitats involved in MWT activities

    Male hatchling production in sea turtles from one of the world’s largest marine protected areas, the Chagos Archipelago

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    Incubation temperatures at turtle nest depths and implications for hatchling sex ratios of hawksbill turtles (Eretmochelys imbricata) and green turtles (Chelonia mydas) nesting in the Chagos Archipelago, Western Indian Ocean are reported and compared to similar measurements at rookeries in the Atlantic and Caribbean. During 2012-2014, temperature loggers were buried at depths and in beach zones representative of turtle nesting sites in Diego Garcia. Data collected for 12,546 days revealed seasonal and spatial patterns of sand temperature. Depth effects were minimal, perhaps modulated by shade from vegetation. Coolest and warmest temperatures were recorded in the sites heavily shaded in vegetation during the austral winter and in sites partially shaded in vegetation during summer respectively. Overall, sand temperatures were relatively cool during the nesting seasons of both species which would likely produce fairly balanced hatchling sex ratios of 53% and 63% male hatchlings, respectively, for hawksbill and green turtles. This result contrasts with the predominantly high female skew reported for offspring at most rookeries around the globe and highlights how local beach characteristics can drive incubation temperatures. Our evidence suggests that sites characterized by heavy shade associated with intact natural vegetation are likely to provide conditions suitable for male hatchling production in a warming world

    Managing boating impacts on dolphins in the dolphin-watching capital of Australia

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    "August 2011"Thesis by publication.Thesis (PhD)--Macquarie University, Faculty of Science, Graduate School of the Environment (GSE), Marine Mammal Research Group, 2012.Includes bibliographical references.1. Thesis introduction -- 2. Under pressure: spatial modeling identifies crucial resting habitat for resident Indo-Pacific bottlenose dolphins in Australia's dolphin-watch capital -- 3. How does Australia's largest dolphin-watching industry affect the behaviour of a small and resident population of Indo-Pacific bottlenose dolphins? -- 4. Distance does matter: close approaches by boats impede feeding and resting behaviour of Indo-Pacific bottlenose dolphins -- 5. Are speed restriction zones an effective management tool for minimising impacts of boats on dolphins in an Australian marine park? -- 6. Synthesis and management recommendations.The population of Indo-Pacific bottlenose dolphins (Tursiops aduncus) in the newly formed Port Stephens Marine Park, NSW, is the target of the largest dolphin-watching industry in Australia. I investigated (1) potential impacts of dolphin-watching boats (DWs) including aspects such as number of vessels, as well as distances from dolphin groups, (2) different experimental boat approach distances, (3) effectiveness of Speed Restriction Zones (SRZs), and (4) fine-scale habitat use of dolphins, from August 2008 to August 2010. -- (1) The presence of DWs altered both the dolphins' behavioural states and activity budgets. Dolphins spent significantly less time feeding and were never observed to rest in the presence of DWs. These effects were exacerbated as the number of boats increased and the distance from boats decreased, with feeding in particular compromised by boat number. -- (2) Analysis of experimental boat approaches showed that there was significantly less feeding and resting when boats approached them at close range. -- (3) SRZs were more intensely used than Control Zones (CZs) by DWs in summer. In contrast, dolphin groups including calves used SRZs less during summer. -- (4) Spatial modeling of habitat use showed that dolphins preferred shallow areas that are closer to shore for resting but have no preferred habitat when feeding. -- This study recommends stricter regulations than currently legislated including restricting the number of DWs to no more than one within 50 m of a dolphin group with only adults and 150 m with a group including calves to enable groups to feed. Given the critical impact of any boats on resting, the location, size, and accompanying regulations regarding SRZs have to be revised. Total Exclusion Zones should be considered to reduce pressure on dolphins undertaking critically important activities. Management plans whose stated goals include both sustainability of a dolphin-watching industry and longer-term viability of a dolphin population may reconcile conflicting objectives and improve decision-making by using these empirical measures rather than best guesses.Mode of access: World Wide Web.1 online resource (xii, 153 p.) ill. (some col.), map
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