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Dataset in support of the journal article 'The impact of reintroduced Eurasian beaver (Castor fiber) dams on the upstream movement of brown trout (Salmo trutta) in upland areas of Great Britain'
No full textThis dataset contains all data used for generating Fig 2-10
Fig 2. Coarse resolution rainfall and discharge data from a nearby river.
Fig 3. Environmental data for the Monitoring periods in 2015 and 2016.
Fig 4. Movements of an individual PIT tagged trout.
Fig 5. Movement patterns of six individual brown trout. Movement patterns of six individual brown trout
Fig 6. Kaplan Meier plots for all four beaver dams
Fig 7. Covariate parameter estimates
Fig 8. Passage prediction plots
Fig 9. Mean swimming speed (m min -1) between beaver dams
Fig 10. Mean fork length of trout for each movement category
Article to be published in PLoS One</span
Quantification of the Response of Brown Trout (<i>Salmo trutta</i>) to Habitat Modification by Reintroduced Eurasian Beaver (<i>Castor fiber</i>): Implications for River Management in Great Britain
No full textThe recovery, following widescale persecution, of the Eurasian beaver Castor fiber has been ongoing throughout Europe since the 1920’s with the first reintroduction occurring in Sweden with a pair of animals from neighbouring Norway. Great Britain was slow to follow with the first licenced ‘trial’ reintroduction occurring in Western Scotland in 2009. Since then, the impetus to reintroduce, deliberately and inadvertently, has increased with wild populations now established in Scotland, England and Wales. This thesis assessed the impacts of habitat modification by reintroduced Eurasian beaver on a population of brown trout, Salmo trutta, in Northern Scotland which is an economically important salmonid species in Great Britain. The study site was selected due to its established beaver territory with multiple dams and its recognised population of brown trout. The site consisted of two stream tributaries that fed a common lake, one modified by beavers (beaver modified) and one that remained unaltered during the study period (control). Electrofishing results demonstrated that trout in the beaver modified stream (n = 990) were larger, comprised a greater variety of age-classes and had a greater abundance of age 1+ trout (n = 842), whereas the control (n = 434) supported high densities of 0+ trout but held very few 1+ individuals (n = 84). Trout in the beaver modified stream exhibited positive growth during all seasons and exceed the predicted growth based on an optimal growth model during both winter periods. Using PIT telemetry installed at a series of four beaver dams on the same tributary as above, passage efficiency and migratory delay was quantified over two successive spawning season (2015 and 2016). Passage success varied between dams, was highly correlated to rainfall (24 hr lag applied and used as a proxy for discharge) and fork length, with larger fish passing more frequently. Predictive models indicate that migratory delay is reduced if the fish are larger and if an individual has previously passed a dam, passing much quicker on subsequent passage events. By means of remote cameras, piscivorous predator presence was assessed, using grey heron as the model predator. Heron images per riverbank length were greater in the beaver modified stream in comparison to control sites, varied seasonally with greatest images / riverbank metre observed during autumn and spring respectively and was positively correlated with age 1+ trout. The results of this study suggest that under certain circumstances and river systems the presence of beavers may enhance and support a greater diversity of brown trout life stages, through creation of habitat complexity and could be used as a natural management tool to enhance trout populations. Passage over beaver dams during average and high flows should not be a management concern, however passage may be hindered in periods of low flow and during these times management intervention may be required. The habitat changes brought about by the activities of beavers, may re-distribute piscivorous predators within a local area, but further research is required in order to quantify the impact, if any, on fish stocks. The findings presented in this thesis provide the first ever investigation into the influence of beaver habitat modification on brown trout in a GB context. They demonstrate a myriad of complex ecological interactions that occur following the activities of an ecosystem engineer and they significantly enhance our understanding of how fish respond to these habitat alterations and provide crucial insights into the possible issues which may arise and the possible management implications for the future
Qualification of the Response of Brown Trout (<i>Salmo trutta</i>) to Habitat Modification by Reintroduced Eurasian Beaver (<i>Castor fiber</i>): Implications for River Management in Great Britain
No full textThe recovery, following widescale persecution, of the Eurasian beaver Castor fiber has been ongoing throughout Europe since the 1920’s with the first reintroduction occurring in Sweden with a pair of animals from neighbouring Norway. Great Britain was slow to follow with the first licenced ‘trial’ reintroduction occurring in Western Scotland in 2009. Since then, the impetus to reintroduce, deliberately and inadvertently, has increased with wild populations now established in Scotland, England and Wales. This thesis assessed the impacts of habitat modification by reintroduced Eurasian beaver on a population of brown trout, Salmo trutta, in Northern Scotland which is an economically important salmonid species in Great Britain. The study site was selected due to its established beaver territory with multiple dams and its recognised population of brown trout. The site consisted of two stream tributaries that fed a common lake, one modified by beavers (beaver modified) and one that remained unaltered during the study period (control). Electrofishing results demonstrated that trout in the beaver modified stream (n = 990) were larger, comprised a greater variety of age-classes and had a greater abundance of age 1+ trout (n = 842), whereas the control (n = 434) supported high densities of 0+ trout but held very few 1+ individuals (n = 84). Trout in the beaver modified stream exhibited positive growth during all seasons and exceed the predicted growth based on an optimal growth model during both winter periods. Using PIT telemetry installed at a series of four beaver dams on the same tributary as above, passage efficiency and migratory delay was quantified over two successive spawning season (2015 and 2016). Passage success varied between dams, was highly correlated to rainfall (24 hr lag applied and used as a proxy for discharge) and fork length, with larger fish passing more frequently. Predictive models indicate that migratory delay is reduced if the fish are larger and if an individual has previously passed a dam, passing much quicker on subsequent passage events. By means of remote cameras, piscivorous predator presence was assessed, using grey heron as the model predator. Heron images per riverbank length were greater in the beaver modified stream in comparison to control sites, varied seasonally with greatest images / riverbank metre observed during autumn and spring respectively and was positively correlated with age 1+ trout.<br/
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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
The response of a brown trout (<i>Salmo trutta</i>) population to reintroduced Eurasian beaver (<i>Castor fiber</i>) habitat modification
Get PDFGlobally, freshwaters are the most degraded and threatened of all ecosystems. In northern temperate regions, beaver (Castor spp.) reintroductions are increasingly used as a low-cost and self-sustaining means to restore river corridors. River modifications by beavers can increase availability of suitable habitat for fish, including salmonids. This study investigated the response of a population of brown trout (Salmo trutta) to reintroduced Eurasian beaver (Castor fiber) habitat modifications in northern Scotland. The field site comprised two streams entering a common loch; one modified by beavers, the other unaltered. Electrofishing and PIT telemetry surveys indicated abundance of post-young-of-the-year (post-YOY) trout was higher in the modified stream. Considering juvenile year groups (YOY and post-YOY) combined, abundance and density varied with year and season. In the modified stream, fork length and mass were greater, there was a greater variety of age classes, and mean growth was positive during all seasons. Beavers had profound effects on the local brown trout population that promoted higher abundances of larger size classes. This study provides important insight into the possible future effect of beavers on freshwater ecosystems.</p
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