Austin J. Gallagher

Global shark currency: the distribution, frequency, and economic value of shark ecotourism

Ecotourism represents a highly popularised activity which has exhibited global growth in recent years. In the present paper, we examine the distribution, frequency, and economic value of shark-based ecotourism operations worldwide. A total of 376 shark ecotour operations across 83 locations and 8 geographic regions were identified. Here we describe the global and regional scope of the industry; determine the species utilised in shark ecotourism activities; and examine the recreational usage values of sharks. Further, we conducted a case study of a shark tourism operation based in South Africa by analysing 12 years of demographical and economical data, revealing increasing trends in the total number of customers served and cost per trip over the sampling period. We also compare consumptive and non-consumptive values of shark resources and discuss the potential research and conservation implications of the industry to sharks worldwide.

Ecological risk assessment and its application to elasmobranch conservation and management.

Ecological risk assessments (ERAs) are employed to quantify and predict the vulnerability of a particular species, stock or population to a specific stressor, e.g. pollution, harvesting, climate change, by-catch. Data generated from ERAs are used to identify and prioritize species for implementation of effective conservation and management strategies. At this time, ERAs are of particular importance to elasmobranchs, given the ecological importance and documented global population declines of some elasmobranch species. Here, ERAs as a tool for elasmobranch conservation and management are reviewed and a theoretical roadmap provided for future studies. To achieve these goals, a brief history of ERAs and approaches used within them (in the context of elasmobranchs) are given, and a comprehensive review conducted of all ERA studies associated with elasmobranchs published between 1998 and 2011. The hazards assessed, species evaluated and methodological approaches taken are recorded. Chronological and geographical patterns suggest that this tool has grown in popularity as a commercial fishery management instrument, while also signalling a recent precautionary approach to elasmobranch management in commercial fisheries globally. The analysis demonstrates that the predominant parameters incorporated in previous ERAs are largely based on life-history characteristics, and sharks have received the majority of attention; batoids (including skates) have received less attention. Recreational fishing and habitat degradation are discussed as hazards which warrant future investigation through ERA. Lastly, suggestions are made for incorporating descriptive ecological data to aid in the continued development and evolution of this management tool as it applies to future elasmobranch conservation.

Stable isotope analysis as a tool for elasmobranch conservation research: a primer for non-specialists

Many elasmobranch species are undergoing population declines on a global scale; however, implementation of effective conservation and management strategies is hindered, to a large extent, by a lack of sufficient data on diet, life historyandbehaviour.Thisworkisaprimerofhowstableisotopeanalysiscanbeusedasacost-effective,relativelysimple tool for examining resource use patterns (e.g. diet, habitat) and generating relevant data in support of science-based elasmobranch conservation and management. Specifically, isotopes can resolve the feeding niches of elasmobranchs, detect ontogenetic trophic shifts and calculate relative diet breadth of different species. Stable isotope analysis can also be employed to investigate the extent of anthropogenic impacts on diet or to infer the source of toxins affecting elasmobranchs. Additionally, this tool can be used to study migration patterns and habitat usage. Depending on the tissueanalysed,thistechniquecanalsobenon-lethalandminimallyinvasive.Thelimitationsofstableisotopeanalysisare discussed, and recommendations for future work are presented. Additional keywords: dietary analysis, ecotoxicology, food web analysis, individual diet specialisation, migration. Received 24 October 2011, accepted 30 April 2012, published online 2 July 2012

Evolutionary theory as a tool for predicting extinction risk

Timely and proactive wildlife conservation requires strategies for determining which species are most at the greatest threat of extinction. Here, we suggest that evolutionary theory, particularly the concept of specialization, can be a useful tool to inform such assessments and may greatly aid in our ability to predict the vulnerabilities of species to anthropogenic impacts.

White Sharks (Carcharodon carcharias) Scavenging on Whales and Its Potential Role in Further Shaping the Ecology of an Apex Predator

Scavenging, a result of a temporary pulse of resources, occurs in virtually all ecosystems containing carnivores, and is an important energy transfer pathway that can impact ecosystem structure and function, and this ecological significance has largely been considered from a terrestrial standpoint; however, little is known about the role of scavenging in shaping the behavioral ecology of marine species, specifically apex predators. Here we present findings from multiple opportunistic observations of white sharks scavenging on whale carcasses in False Bay, South Africa. Observations of white sharks scavenging over successive days provided evidence of strategic and selective scavenging by this species. Moreover, extended daily observations permitted recordings of unique social, aggregative, and feeding behaviors. We further compare these data against observations of natural predation by sharks on seals in the study area. We discuss these data in relation to environmental conditions, shark social interactions, migration patterns, whale biology, and behaviorally-mediated trophic cascades. While the appearance of a whale carcass is largely a stochastic event, we propose that white shark scavenging on whales may represent an underestimated, yet significant component to the overall foraging ecology of this species, especially as individuals attain sexual maturity.

Energy Landscapes and the Landscape of Fear

Animals are not distributed randomly in space and time because their movement ecology is influenced by a variety of factors. Energy landscapes and the landscape of fear have recently emerged as largely independent paradigms, both reshaping our perspectives and thinking relating to the spatial ecology of animals across heterogeneous landscapes. We argue that these paradigms are not distinct but rather complementary, collectively providing a better mechanistic basis for understanding the spatial ecology and decision-making of wild animals. We discuss the theoretical underpinnings of each paradigm and illuminate their complementary nature through case studies, then integrate these concepts quantitatively by constructing quantitative pathways of movement modulated by energy and fear to elucidate the mechanisms underlying the spatial ecology of wild animals.

How Long Is Too Long in Contemporary Peer Review? Perspectives from Authors Publishing in Conservation Biology Journals

Delays in peer reviewed publication may have consequences for both assessment of scientific prowess in academia as well as communication of important information to the knowledge receptor community. We present an analysis on the perspectives of authors publishing in conservation biology journals regarding their opinions on the importance of speed in peer-review as well as how to improve review times. Authors were invited to take part in an online questionnaire, of which the data was subjected to both qualitative (open coding, categorizing) and quantitative analyses (generalized linear models). We received 637 responses to 6,547 e-mail invitations sent. Peer-review speed was generally perceived as slow, with authors experiencing a typical turnaround time of 14 weeks while their perceived optimal review time was six weeks. Male and younger respondents seem to have higher expectations of review speed than females and older respondents. The majority of participants attributed lengthy review times to reviewer and editor fatigue, while editor persistence and journal prestige were believed to speed up the review process. Negative consequences of lengthy review times were perceived to be greater for early career researchers and to have impact on author morale (e.g. motivation or frustration). Competition among colleagues was also of concern to respondents. Incentivizing peer-review was among the top suggested alterations to the system along with training graduate students in peer-review, increased editorial persistence, and changes to the norms of peer-review such as opening the peer-review process to the public. It is clear that authors surveyed in this study viewed the peer-review system as under stress and we encourage scientists and publishers to push the envelope for new peer-review models.

Understanding the individual to implement the ecosystem approach to fisheries management

Variation of physiological and behavioural traits among individuals within a population is an important factor for ecosystem function, and correspondingly, ecosystem approaches to fisheries management (EAFM). Here, we review instances of individual level variation in fishes with practical guidance for EAFM.

Body condition predicts energy stores in apex predatory sharks.

We measured and took blood samples from large tiger sharks in the wild to determine if their body condition (a metric of health) was related to energy stores (fatty acids). Our results revealed that body condition and fatty acids were positively and significantly correlated. This is important for understanding how large, highly mobile apex predators such as tiger sharks store and use energy required for migration and mating.

Considering the fate of electronic tags: interactions with stakeholders and user responsibility when encountering tagged aquatic animals

Summary 1 The use of electronic tagging (e.g. acoustic, archival and satellite telemetry) to study the behavior and ecology of aquatic animals has increased dramatically over the past decade. As scientists continue to use these tools, it is inevitable that other researchers and the public at-large will encounter animals carrying such tags with increasing frequency. If the animals appear burdened or injured by the tag (e.g. showing signs of trauma), or if the tag is functionally impaired (e.g. cracked or severely biofouled), these encounters have the potential to generate conflict with various wildlife stakeholders (e.g. tourists/operators, divers, fishers, hunters) that can negatively affect research efforts and undermine conservation work. Yet, these encounters also present an unparalleled opportunity to advance the field of biotelemetry by improving animal welfare, tagging technology and practices, while also gaining the trust and support of wildlife stakeholders. Therefore, as scientists, it is important to consider the fate of our electronic tags. 2 Here we consider tagged animals as encountered by different user groups and discuss the potential steps and recommendations that scientists can take to improve tagging techniques and animal welfare as a result. We also discuss interactions with stakeholders and the manifold benefits if such interactions are taken into account and embraced. 3 We examine the situation where a researcher encounters, and is able and trained to handle a previously tagged animal equipped with a functionally impaired tag and/or the animal is exhibiting signs of burden due to the tag. We generate a decision tree for scientists faced with such a scenario and discuss the best course of action, whereas such a situation was relatively unlikely in the past, but is now a reality in all aquatic animal tagging studies. 4 The framework in which these issues are discussed is novel and failure to address them can significantly impede advances in the development and use of biotelemetry and even one’s ability to conduct research. It is our hope that our essay stimulates further discourse, debate, technological improvements and consideration of the fate of electronic tagging.