Synthetic marine habitats such as artificial reefs (ARs) are deployed to offset marine habitat losses and aid conservation of marine communities, including species at risk. Though environmental benefit is often assumed, AR’s ability to support northern temperate marine fish communities has rarely been tested. The structural orientation and location of a reef can strongly influence biodiversity and productivity of faunal communities inhabiting it. For ARs, understanding how reef characteristics affect species and community composition are key in optimizing their use in conservation initiatives. I used ROV and sonar to survey threatened rockfish (Sebastes spp.) and other groundfish species associated with 18 ARs and natural reefs (NRs) along the northeast Pacific coastal shelf, along the coast of BC, Canada. In my second chapter, I investigate how ARs compare to NRs in achieving conservation objectives as measured by fish abundance and species richness. I found that community composition significantly differed between NRs and ARs. ARs had high variability in rockfish abundance, while NRs consistently supported intermediate rockfish abundances. Groundfish diversity was markedly greater on NRs. Depth and relief significantly explained variability in abundance and species richness. Interestingly, rockfish abundance was negatively associated with proximity to nearest rockfish conservation area. In my third chapter, I assess variation between AR fish communities on six reefs to better understand efficacy of meeting conservation objectives. I quantified structural characteristics of each reef using high-definition sonar data to create three-dimensional models and calculate measurements of reef structure. I also examined the effects of surrounding habitat associated with reef locations. I found that depth, conservation status, rugosity, and reef age significantly explained rockfish abundance. Groundfish species richness was significantly associated with conservation status, relief, reef size, and an interaction between depth and reef age. This research is a first step in proposing underlying mechanisms for differences between fish communities on ARs in BC, and which reef attributes facilitate successful contributions to conservation. Though ARs show promise in the conservation of some threatened species, the maintenance of diverse fish communities may depend on protection of heterogeneous natural reef communities. Given that a critical component of AR success is structure, using three-dimensional technologies can be used as a tool to understand species-habitat association on existing reefs and help predict the success of future reefs. / Graduate

The distribution, abundance, chemical composition, metabolism, and feeding ecology of the tentaculate ctenophore, Callianira antarctica (Chun 1897), were investigated during austral winter 2001and autumn & winter 2002, in the vicinity of Marguerite Bay west of the Antarctic Peninsula. Callianira antarctica had a widespread distribution during autumn and winter, and variable abundance (0.02 to 2.6 ind. m-2) during winter 2001 associated with specific circulation features. Size frequency distributions for autumn and winter suggest that more than half of the C. antarctica population may have experienced 'degrowth' during winter due to low food availability. Callianira antarctica is a fairly robust ctenophore with geometric mean (geomean) carbon (C) and nitrogen (N) values of 8.41 and 1.83% dry weight (DW), respectively. Winter oxygen consumption and ammonium excretion rates ranged from 0.059 to 0.410 micro l O2 [mg DW]-1 h-1 and 0.60 to 31.1 µg-at N [g DW]-1 h-1, respectively, at 0oC. Daily minimum maintenance rations based on respiration experiments were 2.7% to 3.6% of the total body carbon (TBC) for small ctenophores, and 1.4% to 1.9% TBC for larger ctenophores. Calanoid copepods and larval and juvenile Antarctic krill were offered to ctenophores in incubation experiments. Digestion times were variable, lasting 8 to 20 h, and were independent of ctenophore size and dependent on number and type of prey. Gut content analysis from one autumn and two winter seasons indicated C. antarctica preyed on both copepods and krill in situ, with an increased dependence on larval krill during winter. Lipid biomarker analysis on C. antarctica and their potential prey confirmed these results. Divers observed aggregations of C. antarctica passively drifting with tentacles extended near dense concentrations of larval Euphausia superba during winter. These observations along with gut content and lipid biomarker analysis suggest that larval krill is an important prey item for C. antarctica during winter.

<p>The purpose of this master thesis, performed at FOI, was to evaluate a range gated underwater camera, for the application identification of bottom objects. The master thesis was supported by FMV within the framework of “arbetsorder Systemstöd minjakt (Jan Andersson, KC Vapen)”. The central part has been field trials, which have been performed in both turbid and clear water. Conclusions about the performance of the camera system have been done, based on resolution and contrast measurements during the field trials. Laboratory testing has also been done to measure system specific parameters, such as the effective gate profile and camera gate distances.</p><p>The field trials shows that images can be acquired at significantly longer distances with the tested gated camera, compared to a conventional video camera. The distance where the target can be detected is increased by a factor of 2. For images suitable for mine identification, the increase is about 1.3. However, studies of the performance of other range gated systems shows that the increase in range for mine identification can be about 1.6. Gated viewing has also been compared to other technical solutions for underwater imaging.</p>

This thesis consists of a mathematical model, autopilot and guidance design of a mini ROV (Remotely Operated Underwater Vehicle) and investigates the effects of environmental forces (ocean currents etc.) on the guidance algorithms. First of all, a non-linear 6 degrees-of-freedom (DOF) mathematical model is obtained. This model includes hydrodynamics forces and moments. There is no exact calculation method for hydrodynamic coefficients / however strip theory and results of computational fluid dynamics (CFD) analysis are used to calculate their approximate values. Linear mathematical model is obtained by linearization at trim points and it is used when designing surge speed, heading and depth controller. Guidance is examined by two methods such as way point guidance by line-of-sight (LOS) and way point guidance based on optimal control. Moreover, an online obstacle avoidance algorithm is developed. This thesis ends with the subject of navigation of the vehicle under GPS-like measurements and magnetic sensors measurements.

Europe is arguably in need of a more offensive approach towards theencouragement of entrepreneurship and research based product development.Several European initiatives have been initiated towards this aim, one ofwhich is the Knowledge and Innovation Communities (KICs); an initiativeultimately taken by the European Commission. The main purpose of the KICsis to foster innovation and commercialization in Europe by combining forcesof industry and university, much in line with the theory of the TripleHelix. This master’s thesis is a follow up report of a previously conductedRemotely Operated Vehicle (ROV) market analysis, which was a deliverable inthe OTS project; a KIC InnoEnergy initiated project, aiming towards productdevelopment within the ocean energy sector. The purpose of this thesis hasbeen to, on the one hand evaluate how such a multidisciplinary projectworks in practice, the consequences of its design and the coping of theseconsequences, and on the other hand to identify and map prerequisites for asituation regarding if, and how, the project should invite anotherparticipant from industry into a collaboration. Based on a qualitativeanalysis of seven interviews with representatives from both academia andindustry, the conclusions indicated that the structure and future of theOTS/ROV project is perceived as unclear, best remedied by strongermanagement, additional funding, and invitation of a new collaborator. Thedemands for such collaboration mainly include an explicit project plan fromthe external ROV supplier’s point of view, and the sharing of knowledge andequipment of the supplier from the internal members’ point of view.

The purpose of this study was to develop a methodology to analyse ROV video and scanning-sonar data to document the abundance and distribution of epi-benthic megafauna on the continental slope off Vancouver Island and to quantify the impact of trawling on these megafaunal assemblages. Impacts of bottom trawling on deep-sea ecosystems vary depending on habitat types and species present. Environmental factors such as depth, dissolved oxygen concentration, substratum type, and bottom roughness also affect the diversity and composition of benthic communities. We studied two transects (30km and 12km long) on the upper continental slope off Vancouver Island, BC, Canada, that included areas of seafloor with visible trawl marks. Our study area was also located in an oxygen minimum zone with very low bottom water dissolved oxygen concentrations in its core (600m-1000m). The main target for bottom trawling fisheries in this area is the longspine thornyhead (Sebastolobus altivelis). Field data were collected using the ROV ROPOS equipped with a 3CCD video camera and high-resolution scanning sonar. Megafaunal composition/abundance and bottom characteristic information were extracted from video imagery and assembled using a custom-designed MS Access database. The same database was used to compile information on trawl-door marks detected in recorded sonar imagery. The sonar surveyed a 50m radius around the submersible during transects, providing a broader view of evidence of trawling in the area than video. This thesis reports on relationships between environmental variables and faunal abundance, diversity and species distribution. Following the video and sonar analysis, diversity patterns and general species distribution for both transects were determined. Relationships of community structure to depth and trawling intensity were investigated using the hierarchical clusters technique to identify similarities in the megafauna assemblages between stations . Finally, spatial structures in the megafaunal community and their associated environmental variables were examined using the Principal Coordinates Neighbour Matrices (PCNM) and redundancy analysis tests. Differences in total abundance, species composition and distribution, and species diversity were detected between the high and low trawling intensity areas. One of the main highlights of our results was the dominance of ophiuroids and holothurians along most of the transect, except for the highly trawled area. Spatial structures were identified in the megafaunal community, showing a strong influence of bottom trawling intensity and, to a lesser extent, depth. Nearby water column measurements of dissolved oxygen concentrations suggest that depth might be associated with dissolved oxygen levels, but in situ oxygen data were not available during the ROV surveys. A deeper understanding of in situ oxygen levels would help clarify the role of this factor in shaping megafauna assemblages and its interaction with trawling. / Graduate

No description available.

Το μεγαλύτερο μέρος της επιφάνεια του πλανήτη καλύπτεται από τους ωκεανούς. Η περιέργεια του ανθρώπου να εξερευνήσει και να καταλάβει το πώς λειτουργεί το περιβάλλον του, σε συνδυασμό με την αναζήτηση νέων πόρων, ώθησε τον άνθρωπο στον υδάτινο κόσμο. Δεδομένου του βάθους της θάλασσας, οι αρχικές αυτόνομες καταδύσεις, αλλά και οι καταδύσεις με την βοήθεια αναπνευστικών συσκευών δεν κάλυψαν παρά στο ελάχιστο την πρόσβαση στον κόσμο αυτό. Η ανάπτυξη κάποιου διαμεσολαβητή ήταν όχι μόνο χρήσιμη αλλά και απαραίτητη για να προσεγγίσουμε μεγάλα βάθη αλλά και επικίνδυνα, για τους δύτες, μέρη. Στην παρούσα εργασία παρουσιάζεται η χρησιμότητα των υποβρύχιων οχημάτων, σε διάφορους τομείς των ανθρώπινων δραστηριοτήτων. Αναπτύσσονται φυσικές έννοιες και βασικοί ορισμοί για την περιγραφή του περιβάλλοντος στο οποίο λειτουργούν τα υποβρύχια οχήματα. Στη συνέχεια γίνεται αναφορά των διαφόρων κατηγοριών των υποβρύχιων οχημάτων που έχουν αναπτυχθεί μέχρι σήμερα. Αναλύονται λεπτομερώς οι τεχνολογικές τους δυσκολίες, τα πλεονεκτήματα και τα μειονεκτήματα του κάθε είδους υποβρύχιου οχήματος, καθώς επίσης και οι τεχνολογικές εξελίξεις στον τομέα αυτό. Για παράδειγμα, οι ακουστικές επικοινωνίες, η υποβρύχια πλοήγηση και η αποφυγή εμποδίων, ώστε να καταστεί εφικτή η υποβρύχια εξερεύνηση. Τέλος, παρουσιάζονται τα σπουδαιότερα υποβρύχια οχήματα που έχουν κατασκευαστεί μέχρι σήμερα και έχουν οδηγήσει σε σημαντικές ανακαλύψεις στον υδάτινο κόσμο. / -

Submitted by Diogo Barreiros (diogo.barreiros@ufba.br) on 2017-02-17T15:18:14Z No. of bitstreams: 1 mestrado_Luiz.pdf: 2296935 bytes, checksum: cfe40df7ba936424cec5e47234d51af1 (MD5) / Approved for entry into archive by Vanessa Reis (vanessa.jamile@ufba.br) on 2017-02-17T15:30:29Z (GMT) No. of bitstreams: 1 mestrado_Luiz.pdf: 2296935 bytes, checksum: cfe40df7ba936424cec5e47234d51af1 (MD5) / Made available in DSpace on 2017-02-17T15:30:29Z (GMT). No. of bitstreams: 1 mestrado_Luiz.pdf: 2296935 bytes, checksum: cfe40df7ba936424cec5e47234d51af1 (MD5) / O ROV, VeÍculo Operado Remotamente, É um robÔ subaquático que permite ao operador permanecer em um ambiente seguro enquanto este veículo efetua uma tarefa perigosa. Para facilitar a navega¸c˜ao com estes ve´ıculos s˜ao necess´arios dados que forne¸cam informa¸c˜oes sobre o posicionamento e o estado do ve´ıculo. Esta disserta¸c˜ao descreve o desenvolvimento de um sistema eletrˆonico de sensoriamento para navega¸c˜ao de ROV atuando em ´aguas rasas, at´e 30 metros. S˜ao consideradas v´arias estrat´egias, t´ecnicas e teorias envolvendo o projeto, o desenvolvimento, a montagem e os testes de circuitos eletrˆonicos, da calibra¸c˜ao de sensores, dos protocolos de comunica¸c˜ao e linhas de transmiss˜ao para robˆos submers´ıveis. O sistema de sensoriamento ´e composto por sensores que informam: perfis em trˆes dimens˜oes do campo magn´etico terrestre (b´ussola), acelera¸c˜ao, velocidade, posi¸c˜ao do ve´ıculo, medida da profundidade, vis˜ao colorida em duas dimens˜oes e o estado de carga da bateria de bordo. A combina¸c˜ao destes dados fornece ao operador informa¸c˜oes sobre o estado do ve´ıculo, o que possibilita uma navega¸c˜ao segura e eficiente. Para a leitura dos sinais dos sensores e transmiss˜ao destes dados `a central de controle foi desenvolvido um sistema embarcado baseado em um microcontrolador PIC. Toda a eletrˆonica desenvolvida neste trabalho foi projetada de forma modular, de modo que os diversos elementos desenvolvidos possam ser reaproveitados em outros trabalhos. Como resultados mais relevantes podemos destacar: a unidade de medida de acelera¸c˜ao que mostrou-se sens´ıvel para est´ımulos da ordem de 0,03 g, a b´ussola eletrˆonica que apresentou um erro m´aximo de 9o para as medidas de ˆangulo e o profundimetro que apresentou uma resolu¸c˜ao de 0,04 m. Estes resultados s˜ao extremamente vi alentadores e mostram que, com a continuidade e a consolida¸c˜ao das pesquisas em rob´otica m´ovel no Laborat´orio de Propriedades Opticas (LaPO), melhores resultados podem ser obtidos em um futuro pr´oximo. . Aplicações para os ROVs incluem resgate, manutenção e construção de estrutura submarinas, manutenção de plantas nucleares, medidas de poluição da água e observação.

Dissertação(mestrado) - Universidade Federal do Rio Grande, Programa de Pós-Graduação em Engenharia Oceânica, Escola de Engenharia, 2007. / Submitted by Lilian M. Silva (lilianmadeirasilva@hotmail.com) on 2013-04-23T20:52:40Z No. of bitstreams: 1 Projeto e construção de um veículo subaquático não tripulado de baixo custo.pdf: 1267914 bytes, checksum: de003a4ec22d232cb5b78deb87dd39c5 (MD5) / Approved for entry into archive by Bruna Vieira(bruninha_vieira@ibest.com.br) on 2013-06-08T23:09:06Z (GMT) No. of bitstreams: 1 Projeto e construção de um veículo subaquático não tripulado de baixo custo.pdf: 1267914 bytes, checksum: de003a4ec22d232cb5b78deb87dd39c5 (MD5) / Made available in DSpace on 2013-06-08T23:09:06Z (GMT). No. of bitstreams: 1 Projeto e construção de um veículo subaquático não tripulado de baixo custo.pdf: 1267914 bytes, checksum: de003a4ec22d232cb5b78deb87dd39c5 (MD5) Previous issue date: 2007 / A escassez de alguns recursos naturais como petróleo e gás na superfície terrestre, têm feito com que a raça humana volte sua atenção para as profundezas dos oceanos nestas últimas décadas. Os ROVs (Remotely Operated Vehicle) possuem função importante para o estudo, preservação e execução de tarefas em ambiente subaquático com segurança. Infelizmente no Brasil, as iniciativas de produzir um ROV com tecnologia nacional e de baixo custo, quando comparado a equivalentes importados, são ainda raras e se restringem a algumas poucas instituições acadêmicas, não tendo sido localizado nenhum fabricante comercial deste tipo de veículo no país. Visando preencher esta lacuna, o presente trabalho deu continuidade ao projeto e construção de um ROV de baixo custo iniciado por Moraes em 2005, do qual efetivamente foi aproveitado o projeto estrutural mecânico, que através de pequenas modificações, ganhou uma câmera de vídeo, propulsores mais potentes, e sistema de iluminação. A eletrônica embarcada foi totalmente modificada visando atender às novas exigências de potência do sistema, e de funções antes inexistentes tais como: zoom, foco,nível de iluminação e controle de trajetória efetivado através de um único joystick. O novo modelo de acelerômetro empregado permitiu a medição de aceleração em três eixos ortogonais. Na fase final do trabalho foi incorporado ao ROV um altímetro, o que propiciou alguns resultados experimentais envolvendo controle de profundidade em malha fechada. No último capítulo desta dissertação foram incluídas algumas conclusões e considerações que deverão colaborar para futuras melhorias deste projeto. / The scarcity of some natural resources as oil and gas in the terrestrial surface has called human race attention toward the deepness of the oceans in these last decades. ROVs(Remotely Operated Vehicles) have important function for the study, preservation and execution of tasks in subaqueous environment with security. In Brazil, the initiatives to produce a ROV with national technology and low cost, when compared with imported devices, are still rare and restrict to some academic institutions, not having been found commercial manufacturer of this type of vehicle in the country. Aiming to fill this gap, the present work gave continuity to the project and construction of the ROV of low cost initiated by Moraes in 2005, from which effectively the mechanical structural project was used and, through small modifications, it was incorporaded a video camera, more powerful propellants, and lighting system. The embarked electronics was totally modified aiming to supply the new requirements of power system, and functions before inexistent such as zoom, focus, level of illumination and control of trajectory accomplished through only one joystick. The new model of accelerometer employed allows the measurement of acceleration in three orthogonal axes. In the final phase of the work an altimeter was incorporated to the ROV, which propitiated some experimental results in depth closed loop control. In the last chapter of this dissertation were enclosed some conclusions and considerations that will collaborate for future improvements in this project.