178 research outputs found
Metazoan parasites of the lesser-spotted dogfish Scyliorhinus canicula and their potential as stock discrimination tools
The metazoan parasites of 101 lesser-spotted dogfish Scyliorhinus canicula from locations off the coast of England (Plymouth and the eastern Solent) and Wales (Cardigan Bay) were surveyed and assessed for their potential as stock discrimination tools. A total of ten parasite species was found using a relatively rapid host examination technique suitable for non-parasitologists. On the basis of established criteria, larval anisakid nematodes and the copepod Lernaeopoda galei were selected as being potentially useful as stock discrimination tools. The monogeneans Leptocotyle minor and Hexabothrium appendiculatum may be suitable as markers following further investigation of their response to handling stress
Tracing the Colonial Dimensions of ‘Special Education’: History, Disability, and Settler Colonialism
This thesis proposes that there are intersections between settler colonialism, disability, and education, that can help to clarify how and why national recognition of violence against Indigenous communities is a central project of the nation-state. For this reason, the exacerbating impacts of ableism and (settler) colonialism are studied for their impact on schooling and education in Canada. Using Critical Discourse Analysis as a method of inquiry, the Ontario First Nations Special Education Review Report is analyzed for its relation to history, pedagogy, and colonialism. The report is useful to investigation of the connection between current and historical conceptualizations of disability and the history/present of settler colonialism within the Canadian nation-state. The thesis is framed through the understanding that ableism and colonialism, as they appear in "special education", are intertwined forces which are often founded upon white supremacy and framed through Eurocentric discourse. As such, this thesis engages the fields of Critical Disability Studies, Settler Colonialism, Indigenous Studies, and Education, to describe how special education is informed by colonial constructs of schooling. Conclusions drawn through applying these theories to a reading of the Ontario First Nations Special Education Review Report suggested that there is an apprehension to adopt disability discourse because of the history of colonialism and the ongoing presence of Debility. As well, there is an immediate need to address the systemic issues regarding funding, resource access, and self-determination because of the historical and continued injustices that occur within First Nations education
Identifying critical habitat with archives: 275-year-old naturalist's notes provide high-resolution spatial evidence of long-term core habitat for a critically endangered shark
Deep-water observation of scalloped hammerhead Sphyrna lewini in the western Indian Ocean off Tanzania
A scalloped hammerhead Sphyrna lewini was observed opportunistically from a remotely operated vehicle 1 m off the seabed at 1042 m depth, during hydrocarbon exploration activities in the Ruvuma Basin off Tanzania. The observation, which occurred during night hours, is the deepest accurately recorded for this species and the first deep-water record for the Indian Ocean. The record adds support for the occurrence in deep water during night hours being a widespread and possibly common behaviour in this species, and further expands a small but growing literature that meso- and bathypelagic environments may be of greater importance to elasmobranchs previously considered to be primarily epipelagic
Internet trade of a previously unknown wildlife product from a critically endangered marine fish
Applications for Machine Learning on Readily Available Data from Virtual Reality Training Experiences
The purpose of the research presented in this dissertation is to improve virtual reality (VR) training systems by enhancing their understanding of users. While the field of intelligent tutoring systems (ITS) has seen value in this approach, much research into making use of biometrics to improve user understanding and subsequently training, relies on specialized hardware. Through the presented research, I show that with machine learning (ML), the VR system itself can serve as that specialized hardware for VR training systems. I begin by discussing my explorations into using an ecologically valid, specialized training simulation as a testbed to predict knowledge acquisition by users unfamiliar with the task being trained. Then I look at predicting the cognitive and psychomotor outcomes retained after a one week period. Next I describe our work towards using ML models to predict the transfer of skills from a non-specialized VR assembly training environment to the real-world, based on recorded tracking data. I continue by examining the identifiability of participants in the specialized training task, allowing us to better understand the associated privacy concerns and how the representation of the data can affect identifiability. By using the same tasks separated temporally by a week, we expand our understanding of the diminishing identifiability of user\u27s movements. Finally, I make use of the assembly training environment to explore the feasibility of across-task identifiability, by making use of two different tasks with the same context
Using opportunistic data to study the distribution and abundance of a warm water elasmobranch at the northern edge of its range
Detecting changes in the distribution and abundance of marine species that are cryptic or occurring in very low abundances is difficult, but essential for assessing their status and informing management. One way of quantifying these changes is through the collation of opportunistic records. We reconstruct the population trajectory and distribution of the common stingray Dasyatis pastinaca around Great Britain, using opportunistic records, mostly obtained by recreational anglers. We tested if D. pastinaca declined in abundance and body size in response to fishing and if their distribution has shifted northwards in response to warming seas. We obtained 518 records covering the period 1838-2020. After correcting for observation effort, D. pastinaca catches reported by anglers showed no long-term trend over 50 years, but with a decrease from 1970-1995 and an increase in abundance since 1995. While records of species occurrence were found around much of Great Britain, nearly all were from south of 54° latitude, and records have contracted southwards since 2000. No trend in maximum size through time was detected. In conclusion, we did not find support for the hypothesized declines in abundance and body size or a northward shift in distribution of D. pastinaca and instead found a southward contraction
Risks to biodiversity and coastal livelihoods from artisanal elasmobranch fisheries in a Least Developed Country: The Gambia (West Africa)
Developing nations in tropical regions harbour rich biological resources on which humans depend for food, income and employment, yet data to aid their management is often lacking. In West Africa, the diversity and fisheries of elasmobranchs are poorly documented, despite them being known to be economically important and vulnerable to overexploitation. Rapid qualitative surveys of fish processing and landing sites in The Gambia from 2010-2018 revealed valuable new data on species composition, biology, relative abundance, fisheries and utilisation by humans. Diversity and abundance was dominated by batoids, with a major component comprising a large guitarfish (Glaucostegus cemiculus) that was apparently targeted, and a small whipray (Fontitrygon margaritella). Nearly all taxa recorded are classified by the IUCN Red List as Critically Endangered (angel sharks Squatina spp.), Endangered, Data Deficient, or Not Evaluated; several were endemic, of exceptional evolutionary distinctness, cryptic, possibly undescribed, and rare (including stingray Hypanus rudis not apparently recorded since description in 1870). Significant threats to biodiversity, coastal livelihoods and possibly food security are identified based on the apparent importance of elasmobranch fisheries and processing; the known inability of key taxa to withstand intensive fisheries; ‘fishing down the food web’ by intensive utilisation of F. margaritella; and the absence or rarity of previously common elasmobranch species that may be severely depleted in the region. This study provides data that may act as a starting point to aid sustainability accreditation of local fin-fisheries, and demonstrates the value of inexpensive and low-resolution data collection in developing countries
Bycatch in northeast Atlantic lobster and crab pot fisheries (Irish Sea, Celtic Sea and Bristol Channel)
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