1,721,144 research outputs found
Global tracking of shark movements, behaviour and ecology: A review of the renaissance years of satellite tagging studies, 2010–2020
No full textSatellite telemetry as a tool in marine ecological research continues to adapt and grow and has become increasingly popular in recent years to study shark species on a global scale. A review of satellite tag application to shark research was published in 2010, provided insight to the advancements in satellite shark tagging, as well as highlighting areas for improvement. In the years since, satellite technology has continued to advance, creating smaller, longer lasting, and more innovative tags, capable of expanding the field. Here we review satellite shark tagging studies to identify early successes and areas for rethinking moving forward. Triple the amount of shark satellite tagging studies have been conducted during the decade from 2010 to 2020 than ever before, tracking double the number of species previously tagged. Satellite telemetry has offered increased capacity to unravel ecological questions including predator and prey interactions, migration patterns, habitat use, in addition to monitoring species for global assessments. However, <17% of the total reviewed studies directly produced results with management or conservation outcomes. Telemetry studies with defined goals and objectives produced the most relevant findings for shark conservation, most often in tandem with secondary metrics such as fishing overlap or management regimes. To leverage the power of telemetry for the benefit of shark species, it remains imperative to continue improvements to tag function and maximize the outputs of tagging efforts including increasing data sharing capacity and standardization across the field, as well as spatial and species coverage. Ultimately, this review offers a status report of shark satellite tagging and the ways in which the field can continue to progress
The Caribbean needs big marine protected areas
Full text linkThe attached document is the author(’s’) final accepted/submitted version of the journal article. You are advised to consult the publisher’s version if you wish to cite from it.NHM Repositor
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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Survey of Fishes within a Restored Mangrove Habitat in Bill Baggs Cape Florida State Park, Key Biscayne, Florida
No full textRestoration and monitoring are important conservation tools to ensure the recovery and maintenance of human impacted habitats. Bill Baggs Cape Florida State Park, located in Key Biscayne, Florida, has been impacted by urban development and hurricanes, leading to the historical removal of much of the park’s native habitat, including mangrove forest. After Hurricane Andrew in 1992, restoration efforts led to the replanting of a 30-hectare mangrove forest within the park. Part of the forest’s design involved incorporating a series of 28 mangrove pools within the forest to act as nursery habitat. While there have been several studies examining fish using the mangrove pools early on in the forest’s recovery, no work regarding fish abundance and richness in this recovering habitat has been done in over ten years. This study examines the current relative abundance, richness, and trophic levels of fish within the restored mangrove pools and compare the current fish assemblage with historical data, and evaluates the potential impact of environmental factors on fish abundance and richness in the restored pools. To address these research goals, seven mangrove pools were sampled using BRUVS (baited remote underwater video stations) to establish the current abundance and richness of fish utilizing the pools. A subsample of BRUVS and seine was conducted to determine potential differences in fish families and feeding guilds observed between the techniques. This comparison was then assessed to examine the validity of statistically comparing historical data from previous studies (seine net sampling) to the current study (BRUVS sampling). Environmental data was also collected during each sampling for comparison against patterns of fish presence and abundance. 464 individual fish were observed over the course of BRUVS sampling. 20 taxa were observed, consisting of five families, two genera, and 13 species. Four of these species were not observed in any of the previous studies: nurse shark (Ginglymostoma cirratum), mangrove gambusia (Gambusia rhizophorae), sailfin molly (Poecilia latipinna), and schoolmaster snapper (Lutjanus apodus). The fish observed via BRUVS were categorized into three feeding guild: zoobenthivores, piscivores, and planktivores. There was a significant difference in the presence and abundance of fish families observed between BRUVS and seine but not between feeding guilds. While the current BRUVS sampling cannot be statistically compared to previous work seine sampling conducted in the park, the higher CPUE of hardhead silversides and goldspotted killifish from seine sampling in the current study indicates an increase in abundance of these ecologically important forage fish. No single environmental factor affected the presence and abundance of all fish families and feeding guilds. However, individual pools and turbidity emerged as significant factors in several instances. The presence of nursery species, occurrence of predatory species and increased abundance of small forage fish in the present study indicates that the mangrove fringed pools is acting as habitat for variety of economically and ecologically important species. Low species richness in comparison to natural forests in adjacent Biscayne Bay suggest that the young forest is still recovering as essential fish habitat and function not yet fully restored.</p
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Integrating Physiological and Reflex Biomarkers of Fishing Capture Stress in Coastal Shark Species
No full textIn both commercial and recreational fisheries, many sharks are captured and released alive due to harvest regulations, the capture of non-target species, or conservation ethics. Nevertheless, released individuals may suffer post-release fitness loss or even mortality due to capture stress. Additionally, some of these species that would otherwise be intended for release are found dead upon capture. Understanding physiological and behavioral responses of sharks to capture stress is important for determining best fishing practices and for establishing effective management strategies. In this study, I investigated sub-lethal effects of capture through monitoring blood glucose, lactate, hematocrit and reflex impairment on four species of coastal sharks: blacktip (Carcharhinus limbatus), great hammerhead (Sphyrna mokarran), nurse (Ginglymostoma cirratum) and sandbar (Carcharhinus plumbeus). A probability of impairment score was given to each individual based off reflexes developed for this study. I further evaluated inter- and intra- specific relationships between these parameters and fight time, season, and shark size. Of the physiological parameters accessed, lactate emerged as the most significant with increases associated with fight time, shark species, and reflex impairments. Reflex indices showed significant impairment with increasing fight time with the “Jaw” reflex being most significant in all evaluations. Species-specific differences were detected in all parameters with nurse sharks consistently having the lowest values and impairments while great hammerheads had the highest. These relative differences in species-specific stress responses is consistent with relative difference in fighting behavior exhibited for these species on a fishing line as well as reported at-vessel and post-release mortality rates for these species. Collectively, these results indicate that lactate can be used as a measure of shark capture stress, jaw reflex impairments can be utilized as significant indicators of shark capture stress on a species specific basis, and that species’ ecology likely contributes to these responses both physiologically and in terms of reflex impairment. This work connects species-specific reported at-vessel and post-release mortality rates with their responses to capture by revealing trends in physiological changes and reflex impairments. The drumline capture method used likely represents a more benign fishing method compared to typical recreational and commercial fishing gears and therefore these responses are likely subdued when compared to other fishing techniques. Therefore, continued investigation is warranted to better understand the varied responses among species and different capture techniques.</p
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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