WorldWideScience

Sample records for underwater fisheries assessment

  1. Underwater noise modelling for environmental impact assessment

    Energy Technology Data Exchange (ETDEWEB)

    Farcas, Adrian [Centre for Environment, Fisheries and Aquaculture Science (Cefas), Pakefield Road, Lowestoft, NR33 0HT (United Kingdom); Thompson, Paul M. [Lighthouse Field Station, Institute of Biological and Environmental Sciences, University of Aberdeen, Cromarty IV11 8YL (United Kingdom); Merchant, Nathan D., E-mail: nathan.merchant@cefas.co.uk [Centre for Environment, Fisheries and Aquaculture Science (Cefas), Pakefield Road, Lowestoft, NR33 0HT (United Kingdom)

    2016-02-15

    Assessment of underwater noise is increasingly required by regulators of development projects in marine and freshwater habitats, and noise pollution can be a constraining factor in the consenting process. Noise levels arising from the proposed activity are modelled and the potential impact on species of interest within the affected area is then evaluated. Although there is considerable uncertainty in the relationship between noise levels and impacts on aquatic species, the science underlying noise modelling is well understood. Nevertheless, many environmental impact assessments (EIAs) do not reflect best practice, and stakeholders and decision makers in the EIA process are often unfamiliar with the concepts and terminology that are integral to interpreting noise exposure predictions. In this paper, we review the process of underwater noise modelling and explore the factors affecting predictions of noise exposure. Finally, we illustrate the consequences of errors and uncertainties in noise modelling, and discuss future research needs to reduce uncertainty in noise assessments.

  2. Underwater noise modelling for environmental impact assessment

    International Nuclear Information System (INIS)

    Farcas, Adrian; Thompson, Paul M.; Merchant, Nathan D.

    2016-01-01

    Assessment of underwater noise is increasingly required by regulators of development projects in marine and freshwater habitats, and noise pollution can be a constraining factor in the consenting process. Noise levels arising from the proposed activity are modelled and the potential impact on species of interest within the affected area is then evaluated. Although there is considerable uncertainty in the relationship between noise levels and impacts on aquatic species, the science underlying noise modelling is well understood. Nevertheless, many environmental impact assessments (EIAs) do not reflect best practice, and stakeholders and decision makers in the EIA process are often unfamiliar with the concepts and terminology that are integral to interpreting noise exposure predictions. In this paper, we review the process of underwater noise modelling and explore the factors affecting predictions of noise exposure. Finally, we illustrate the consequences of errors and uncertainties in noise modelling, and discuss future research needs to reduce uncertainty in noise assessments.

  3. Fishery

    Directory of Open Access Journals (Sweden)

    Muhammad Abu Bakar Siddik

    2015-12-01

    Full Text Available The aim of the present study was to establish the baseline data on fishery biology of Sillaginopsis panijus which is very endemic in the southern coastal waters of Bangladesh. Altogether 300 individuals of S. panijus were sampled from five catchment areas within the Ganges delta in which males represent 46% and females 54% of the total sampled population. The overall sex ratio in the populations agrees with the expected value of 1:1 in normal population. The values of allometric coefficient (b of the LWRs indicated positive allometric growth (b > 3 in female and combined sexes, while male showed a negative allometric growth (b 0.900. The mean values of CFs for males were higher than those of females in all different length classes. The study would expedite future studies on population assessment and sustainable conservation of the fish species along the southern coastal region of Bangladesh.

  4. Reconstruction Accuracy Assessment of Surface and Underwater 3D Motion Analysis: A New Approach

    Directory of Open Access Journals (Sweden)

    Kelly de Jesus

    2015-01-01

    Full Text Available This study assessed accuracy of surface and underwater 3D reconstruction of a calibration volume with and without homography. A calibration volume (6000 × 2000 × 2500 mm with 236 markers (64 above and 88 underwater control points—with 8 common points at water surface—and 92 validation points was positioned on a 25 m swimming pool and recorded with two surface and four underwater cameras. Planar homography estimation for each calibration plane was computed to perform image rectification. Direct linear transformation algorithm for 3D reconstruction was applied, using 1600000 different combinations of 32 and 44 points out of the 64 and 88 control points for surface and underwater markers (resp.. Root Mean Square (RMS error with homography of control and validations points was lower than without it for surface and underwater cameras (P≤0.03. With homography, RMS errors of control and validation points were similar between surface and underwater cameras (P≥0.47. Without homography, RMS error of control points was greater for underwater than surface cameras (P≤0.04 and the opposite was observed for validation points (P≤0.04. It is recommended that future studies using 3D reconstruction should include homography to improve swimming movement analysis accuracy.

  5. Integrating Fisheries Dependent and Independent Approaches to assess Fisheries, Abundance, Diversity, Distribution and Genetic Connectivity of Red Sea Elasmobranch Populations

    KAUST Repository

    Spaet, Julia L.

    2014-05-01

    The Red Sea has long been recognized as a global hotspot of marine biodiversity. Ongoing overfishing, however, is threatening this unique ecosystem, recently leading to the identification of the Red Sea as one of three major hotspots of extinction risk for sharks and rays worldwide. Elasmobranch catches in Saudi Arabian Red Sea waters are unregulated, often misidentified and unrecorded, resulting in a lack of species-specific landings information, which would be vital for the formulation of effective management strategies. Here we employed an integrated approach of fisheries dependent and independent survey methods combined with molecular tools to provide biological, ecological and fisheries data to aid in the assessment of the status of elasmobranch populations in the Red Sea. Over the course of two years, we conducted market surveys at the biggest Saudi Arabian fish market in Jeddah. Market landings were dominated by, mostly immature individuals - implying both recruitment and growth overfishing. Additionally, we employed baited remote underwater video (BRUVS) and longline surveys along almost the entire length of the Red Sea coast of Saudi Arabia as well as at selected reef systems in Sudan. The comparison of catch per unit effort (CPUE) data for Saudi Arabian Red Sea BRUVS and longline surveys to published data originating from non-Red Sea ocean systems revealed CPUE values several orders of magnitude lower for both survey methods in the Red Sea compared to other locations around the world. Finally, we infered the regional population structure of four commercially important shark species between the Red Sea and the Western Indian Ocean.We genotyped nearly 2000 individuals at the mitochondrial control region as well as a total of 20 microsatellite loci. Genetic homogeneity could not be rejected for any of the four species across the spatial comparison. Based on high levels of region-wide exploitation, we suggest that, for management purposes, the population

  6. Ocean acidification risk assessment for Alaska's fishery sector

    Science.gov (United States)

    Mathis, J. T.; Cooley, S. R.; Lucey, N.; Colt, S.; Ekstrom, J.; Hurst, T.; Hauri, C.; Evans, W.; Cross, J. N.; Feely, R. A.

    2015-08-01

    The highly productive fisheries of Alaska are located in seas projected to experience strong global change, including rapid transitions in temperature and ocean acidification-driven changes in pH and other chemical parameters. Many of the marine organisms that are most intensely affected by ocean acidification (OA) contribute substantially to the state's commercial fisheries and traditional subsistence way of life. Prior studies of OA's potential impacts on human communities have focused only on possible direct economic losses from specific scenarios of human dependence on commercial harvests and damages to marine species. However, other economic and social impacts, such as changes in food security or livelihoods, are also likely to result from climate change. This study evaluates patterns of dependence on marine resources within Alaska that could be negatively impacted by OA and current community characteristics to assess the potential risk to the fishery sector from OA. Here, we used a risk assessment framework based on one developed by the Intergovernmental Panel on Climate Change to analyze earth-system global ocean model hindcasts and projections of ocean chemistry, fisheries harvest data, and demographic information. The fisheries examined were: shellfish, salmon and other finfish. The final index incorporates all of these data to compare overall risk among Alaska's federally designated census areas. The analysis showed that regions in southeast and southwest Alaska that are highly reliant on fishery harvests and have relatively lower incomes and employment alternatives likely face the highest risk from OA. Although this study is an intermediate step toward our full understanding, the results presented here show that OA merits consideration in policy planning, as it may represent another challenge to Alaskan communities, some of which are already under acute socio-economic strains.

  7. 77 FR 66818 - Fisheries of the Gulf of Mexico; Southeast Data, Assessment, and Review (SEDAR); Assessment...

    Science.gov (United States)

    2012-11-07

    ... Gulf of Mexico Spanish Mackerel and Cobia AGENCY: National Marine Fisheries Service (NMFS), National... mackerel and cobia assessment webinar. SUMMARY: The SEDAR 28 assessment of the Gulf of Mexico Spanish mackerel and cobia fisheries will consist of a series of workshops and supplemental webinars. This notice...

  8. Breathing life into fisheries stock assessments with citizen science.

    Science.gov (United States)

    Fairclough, D V; Brown, J I; Carlish, B J; Crisafulli, B M; Keay, I S

    2014-11-28

    Citizen science offers a potentially cost-effective way for researchers to obtain large data sets over large spatial scales. However, it is not used widely to support biological data collection for fisheries stock assessments. Overfishing of demersal fishes along 1,000 km of the west Australian coast led to restrictive management to recover stocks. This diminished opportunities for scientists to cost-effectively monitor stock recovery via fishery-dependent sampling, particularly of the recreational fishing sector. As fishery-independent methods would be too expensive and logistically-challenging to implement, a citizen science program, Send us your skeletons (SUYS), was developed. SUYS asks recreational fishers to voluntarily donate fish skeletons of important species from their catch to allow biological data extraction by scientists to produce age structures and conduct stock assessment analyses. During SUYS, recreational fisher involvement, sample sizes and spatial and temporal coverage of samples have dramatically increased, while the collection cost per skeleton has declined substantially. SUYS is ensuring sampling objectives for stock assessments are achieved via fishery-dependent collection and reliable and timely scientific advice can be provided to managers. The program is also encouraging public ownership through involvement in the monitoring process, which can lead to greater acceptance of management decisions.

  9. The Social in Assessing for Sustainability. Fisheries in Australia.

    Directory of Open Access Journals (Sweden)

    Kate Barclay

    2012-11-01

    Full Text Available The notion that sustainability rests on three pillars – economic, environmental and social – has been widely accepted since the 1990s. In practice, however, the economic and environmental aspects have tended to dominate the sustainability agenda, and social aspects have been sidelined. Two reasons for this are: 1 there is a lack of data collected about which to build meaningful pictures of social aspects of sustainability for populations over time, and 2 there is a lack of recognition of the role of social factors in sustainability, and a related lack of understanding of how to analyse them in conjunction with economic and environmental factors. This paper surveys the literature about sustainability in fisheries, focussing on Australia, and focussing on the way social aspects have been treated. The paper finds that the problems that have been identified for assessing the social in sustainability in general are certainly manifest in fisheries. Management of Australian fisheries has arguably made great improvements to biological sustainability over the last decade, but much remains to be done to generate similar improvements in social sustainability for fishing communities. This is the case for government-run resource management as well as for initiatives from the private sector and conservation organizations as part of movements for corporate social responsibility and ethical consumerism. A significant challenge for improving sustainability in Australian fisheries, therefore, lies in improving data collection on social factors, and in bridging disciplinary divides to better integrate social with economic and biological assessments of sustainability.

  10. Compartmental models for assessing the fishery production in the Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Dalal, S.G.; Parulekar, A.H.

    Compartmental models for assessing the fishery production in the Indian Ocean is discussed. The article examines the theoretical basis on which modern fishery sciences is built. The model shows that, large changes in energy flux from one pathway...

  11. Mercury contamination and exposure assessment of fishery products in Korea.

    Science.gov (United States)

    Yang, Hye-Ran; Kim, Na-Young; Hwang, Lae-Hong; Park, Ju-Sung; Kim, Jung-Hun

    2015-01-01

    In this study, total (T-Hg) and methyl mercury (Me-Hg) contamination was investigated in fishery products including canned fish, fish sauces, dried bonito and frozen tuna sashimi, collected from retail markets in Korea, to assess dietary exposure. Direct mercury analyser and gas chromatography-electron captured detector were employed to measure T-Hg and Me-Hg, respectively. The highest T-Hg and Me-Hg contamination was present in tuna sashimi, followed by dried bonito, respectively. Canned tuna showed more frequent detection and higher content than other canned fishery products. The weekly exposure estimate indicates that exposure to mercury from fishery products is safe, showing 2.59% provisional tolerable weekly intake (PTWI) for T-Hg, 1.82% PTWI for Me-Hg and 4.16% reference dose for Me-Hg. However, it should be addressed to monitor the mercury contamination in fish and fishery products regularly, to safeguard vulnerable population such as children, to limit intake of these food products.

  12. A Wide Area Risk Assessment Framework for Underwater Military Munitions Response

    Science.gov (United States)

    Holland, K. T.; Calantoni, J.

    2017-12-01

    Our objective was to develop a prototype statistical framework supporting Wide Area Assessment and Remedial Investigation decisions relating to the risk of unexploded ordnance and other military munitions concentrated in underwater environments. Decision making involving underwater munitions is inherently complex due to the high degree of uncertainty in the environmental conditions that force munitions responses (burial, decay, migration, etc.) and associated risks to the public. The prototype framework provides a consistent approach to accurately delineating contaminated areas at underwater munitions sites through the estimation of most probable concentrations. We adapted existing deterministic models and environmental data services for use within statistical modules that allowed the estimation of munition concentration given historic site information and environmental attributes. Ultimately this risk surface can be used to evaluate costs associated with various remediation approaches (e.g. removal, monitoring, etc.). Unfortunately, evaluation of the assessment framework was limited due to the lack of enduser data services from munition site managers. Of the 450 U.S. sites identified as having potential contamination with underwater munitions, assessment of available munitions information (including historic firing or disposal records, and recent ground-truth munitions samples) indicated very limited information in the databases. Example data types include the most probable munition types, approximate firing / disposal dates and locations, and any supportive munition survey or sampling results. However the overall technical goal to integrate trained statistical belief networks with detailed geophysical knowledge of sites, of sensors and of the underwater environment was demonstrated and should allow probabilistic estimates of the most likely outcomes and tradeoffs while managing uncertainty associated with military munitions response.

  13. Fault Risk Assessment of Underwater Vehicle Steering System Based on Virtual Prototyping and Monte Carlo Simulation

    Directory of Open Access Journals (Sweden)

    He Deyu

    2016-09-01

    Full Text Available Assessing the risks of steering system faults in underwater vehicles is a human-machine-environment (HME systematic safety field that studies faults in the steering system itself, the driver’s human reliability (HR and various environmental conditions. This paper proposed a fault risk assessment method for an underwater vehicle steering system based on virtual prototyping and Monte Carlo simulation. A virtual steering system prototype was established and validated to rectify a lack of historic fault data. Fault injection and simulation were conducted to acquire fault simulation data. A Monte Carlo simulation was adopted that integrated randomness due to the human operator and environment. Randomness and uncertainty of the human, machine and environment were integrated in the method to obtain a probabilistic risk indicator. To verify the proposed method, a case of stuck rudder fault (SRF risk assessment was studied. This method may provide a novel solution for fault risk assessment of a vehicle or other general HME system.

  14. Comparative population assessments of Nautilus sp. in the Philippines, Australia, Fiji, and American Samoa using baited remote underwater video systems.

    Directory of Open Access Journals (Sweden)

    Gregory J Barord

    Full Text Available The extant species of Nautilus and Allonautilus (Cephalopoda inhabit fore-reef slope environments across a large geographic area of the tropical western Pacific and eastern Indian Oceans. While many aspects of their biology and behavior are now well-documented, uncertainties concerning their current populations and ecological role in the deeper, fore-reef slope environments remain. Given the historical to current day presence of nautilus fisheries at various locales across the Pacific and Indian Oceans, a comparative assessment of the current state of nautilus populations is critical to determine whether conservation measures are warranted. We used baited remote underwater video systems (BRUVS to make quantitative photographic records as a means of estimating population abundance of Nautilus sp. at sites in the Philippine Islands, American Samoa, Fiji, and along an approximately 125 km transect on the fore reef slope of the Great Barrier Reef from east of Cairns to east of Lizard Island, Australia. Each site was selected based on its geography, historical abundance, and the presence (Philippines or absence (other sites of Nautilus fisheries The results from these observations indicate that there are significantly fewer nautiluses observable with this method in the Philippine Islands site. While there may be multiple possibilities for this difference, the most parsimonious is that the Philippine Islands population has been reduced due to fishing. When compared to historical trap records from the same site the data suggest there have been far more nautiluses at this site in the past. The BRUVS proved to be a valuable tool to measure Nautilus abundance in the deep sea (300-400 m while reducing our overall footprint on the environment.

  15. Stock assessment of fishery target species in Lake Koka, Ethiopia

    Directory of Open Access Journals (Sweden)

    Gashaw Tesfaye

    2015-09-01

    Full Text Available Effective management is essential for small-scale fisheries to continue providing food and livelihoods for households, particularly in developing countries where other options are often limited. Studies on the population dynamics and stock assessment on fishery target species are thus imperative to sustain their fisheries and the benefits for the society. In Lake Koka (Ethiopia, very little is known about the vital population parameters and exploitation status of the fishery target species: tilapia Oreochromis niloticus,common carp Cyprinus carpióand catfish Clarias gariepinus.Our study, therefore, aimed at determining the vital population parameters and assessing the status of these target species in Lake Koka using length frequency data collected quarterly from commercial catches from 2007-2012. A total of 20 097 fish specimens (distributed as 7 933 tilapia, 6 025 catfish and 6 139 common carp were measured for the analysis. Von Bertalanffy growth parameters and their confidence intervals were determined from modal progression analysis using ELEFAN I and applying the jackknife technique. Mortality parameters were determined from length-converted catch curves and empirical models. The exploitation status of these target species were then assessed by computing exploitation rates (E from mortality parameters as well as from size indicators i.e., assessing the size distribution of fish catches relative to the size at maturity (L m,the size that provides maximum cohort biomass (Lopt and the abundance of mega-spawners. The mean value of growth parameters L x, Kand the growth performance index 0' were 44.5 cm, 0.41/year and 2.90 for O. niloticus,74.1 cm, 0.28/year and 3.19 for C. carpioand 121.9 cm, 0.16/year and 3.36 for C. gariepinus,respectively. The 95 % confidence intervals of the estimates were also computed. Total mortality (Z estimates were 1.47, 0.83 and 0.72/year for O. niloticus, C. carpioand C. gariepinus,respectively. Our study suggest

  16. Onboard assessment of XRF spectra using genetic algorithms for decision making on an autonomous underwater vehicle

    International Nuclear Information System (INIS)

    Breen, Jeremy; Souza, P. de; Timms, G.P.; Ollington, R.

    2011-01-01

    In order to optimise use of the limited resources (time, power) of an autonomous underwater vehicle (AUV) with a miniaturised X-ray fluorescence (XRF) spectrometer on board to carry out in situ autonomous chemical mapping of the surface of sediments with desired resolution, a genetic algorithm for rapid curve fitting is reported in this paper. This method quickly converges and provides an accurate in situ assessment of metals present, which helps the control system of the AUV to decide on future sampling locations. More thorough analysis of the available data could be performed once the AUV has returned to the base (laboratory).

  17. 76 FR 45231 - Fisheries of the Caribbean; Southeastern Data, Assessment, and Review (SEDAR); Assessment...

    Science.gov (United States)

    2011-07-28

    ... Management Councils, in conjunction with NOAA Fisheries and the Atlantic and Gulf States Marine Fisheries..., South Atlantic, and Caribbean Fishery Management Councils and NOAA Fisheries Southeast Regional Office... fishermen, environmentalists, and NGO's; International experts; and staff of Councils, Commissions, and...

  18. Development of Tools and Techniques to Survey, Assess, Stabilise, Monitor and Preserve Underwater Archaeological Sites: SASMAP

    Science.gov (United States)

    Gregory, D. J.

    2015-08-01

    SASMAP's purpose is to develop new technologies and best practices in order to locate, assess and manage Europe's underwater cultural heritage in a more effective way than is possible today. SASMAP has taken an holistic- and process- based approach to investigating underwater environments and the archaeological sites contained therein. End user of the results of SASMAP are severalfold; i) to benefiet the SMEs involved in the project and development of their products for the offshore industry (not just for archaeological purposes) ii) a better understanding of the marine environment and its effect on archaeological materials iii) the collation of the results from the project into guidelines that can be used by cultural resource managers to better administer and optimise developer lead underwater archaeological project within Europe in accordance with European legislation (Treaty of Valetta (1992). Summarily the project has utilised a down scaling approach to localise archaeological sites at a large scale regional level. This has involved using innovative satellite imagery to obtain seamless topography maps over coastal areas and the seabed (accurate to a depth of 6m) as well as the development of a 3D sub bottom profiler to look within the seabed. Results obtained from the downscaling approach at the study areas in the project (Greece and Denmark) have enabled geological models to be developed inorder to work towards predictive modelling of where submerged prehistoric sites may be encountered. Once sites have been located an upscaling approach has been taken to assessing an individual site and the materials on and within it in order to better understand the state of preservation and dynamic conditions of a site and how it can best be preserved through in situ preservation or excavation. This has involved the development of equipment to monitor the seabed environment (open water and in sediments), equipment for sampling sediments and assessing the state of

  19. Participatory assessment of the Toliara Bay reef fishery, southwest ...

    African Journals Online (AJOL)

    22 déc. 2011 ... In order to ensure the sustainable management of reef fisheries, it is necessary to ... on the status and evolution of the ecosystem upon which the fishery ... En effet, de part le nombre, la qualité, la variété et la pertinence des ...

  20. Fisheries and Oceans Canada climate change risk assessment initiative

    Energy Technology Data Exchange (ETDEWEB)

    Dalpe, R. [Fisheries and Oceans, Ottawa, ON (Canada)

    2005-07-01

    This paper provided an overview of an initiative undertaken by the Department of Fisheries and Oceans (DFO) Canada to assess the risks associated with climate change on Canada's waterways and aquatic resources over the next 10 to 20 years. It discussed the risk associated with changes in water temperature and level in increasing the vulnerability of fish stocks and ecosystems. A decrease in water levels is also an issue as it will render current infrastructure ineffective. Storm surges can also have an impact on coastal community infrastructure. The purpose of the assessment was to provide DFO management with a structured understanding of the major climate change factors that pose risks to DFO's operations and to establish priorities in identifying appropriate risk mitigation responses. The presentation discussed the different stages of the initiative (planning, identification and evaluation of risk, validation, and reporting), its' challenges and benefits, as well as lessons learned from this exercises. Lessons learned from the project are as follows: get senior level buy-in from the outset; engage the right people; make it easy for others to be engaged; validate results and risk management response; be ready for surprises; and build in some flexibility to the process. figs.

  1. Best practices for assessing forage fish fisheries-seabird resource competition

    Science.gov (United States)

    Sydeman, William J.; Thompson, Sarah Ann; Anker-Nilssen, Tycho; Arimitsu, Mayumi L.; Bennison, Ashley; Bertrand, Sophie; Boersch-Supan, Philipp; Boyd, Charlotte; Bransome, Nicole C.; Crawford, Robert J.M.; Daunt, Francis; Furness, Robert W.; Gianuca, Dimas; Gladics, Amanda; Koehn, Laura; Lang, Jennifer W.; Loggerwell, Elizabeth; Morris, Taryn L.; Phillips, Elizabeth M.; Provencher, Jennifer; Punt, André E..; Saraux, Claire; Shannon, Lynne; Sherley, Richard B.; Simeone, Alejandro; Wanless, Ross M.; Wanless, Sarah; Zador, Stephani

    2017-01-01

    Worldwide, in recent years capture fisheries targeting lower-trophic level forage fish and euphausiid crustaceans have been substantial (∼20 million metric tons [MT] annually). Landings of forage species are projected to increase in the future, and this harvest may affect marine ecosystems and predator-prey interactions by removal or redistribution of biomass central to pelagic food webs. In particular, fisheries targeting forage fish and euphausiids may be in competition with seabirds, likely the most sensitive of marine vertebrates given limitations in their foraging abilities (ambit and gape size) and high metabolic rate, for food resources. Lately, apparent competition between fisheries and seabirds has led to numerous high-profile conflicts over interpretations, as well as the approaches that could and should be used to assess the magnitude and consequences of fisheries-seabird resource competition. In this paper, we review the methods used to date to study fisheries competition with seabirds, and present “best practices” for future resource competition assessments. Documenting current fisheries competition with seabirds generally involves addressing two major issues: 1) are fisheries causing localized prey depletion that is sufficient to affect the birds? (i.e., are fisheries limiting food resources?), and 2) how are fisheries-induced changes to forage stocks affecting seabird populations given the associated functional or numerical response relationships? Previous studies have been hampered by mismatches in the scale of fisheries, fish, and seabird data, and a lack of causal understanding due to confounding by climatic and other ecosystem factors (e.g., removal of predatory fish). Best practices for fisheries-seabird competition research should include i) clear articulation of hypotheses, ii) data collection (or summation) of fisheries, fish, and seabirds on matched spatio-temporal scales, and iii) integration of observational and experimental

  2. ACCURACY ASSESSMENT OF GO PRO HERO 3 (BLACK CAMERA IN UNDERWATER ENVIRONMENT

    Directory of Open Access Journals (Sweden)

    P. Helmholz,

    2016-06-01

    Full Text Available Modern digital cameras are increasing in quality whilst decreasing in size. In the last decade, a number of waterproof consumer digital cameras (action cameras have become available, which often cost less than $500. A possible application of such action cameras is in the field of Underwater Photogrammetry. Especially with respect to the fact that with the change of the medium to below water can in turn counteract the distortions present. The goal of this paper is to investigate the suitability of such action cameras for underwater photogrammetric applications focusing on the stability of the camera and the accuracy of the derived coordinates for possible photogrammetric applications. For this paper a series of image sequences was capture in a water tank. A calibration frame was placed in the water tank allowing the calibration of the camera and the validation of the measurements using check points. The accuracy assessment covered three test sets operating three GoPro sports cameras of the same model (Hero 3 black. The test set included the handling of the camera in a controlled manner where the camera was only dunked into the water tank using 7MP and 12MP resolution and a rough handling where the camera was shaken as well as being removed from the waterproof case using 12MP resolution. The tests showed that the camera stability was given with a maximum standard deviation of the camera constant σc of 0.0031mm for 7MB (for an average c of 2.720mm and 0.0072 mm for 12MB (for an average c of 3.642mm. The residual test of the check points gave for the 7MB test series the largest rms value with only 0.450mm and the largest maximal residual of only 2.5 mm. For the 12MB test series the maximum rms value is 0. 653mm.

  3. Accuracy Assessment of GO Pro Hero 3 (black) Camera in Underwater Environment

    Science.gov (United States)

    Helmholz, , P.; Long, J.; Munsie, T.; Belton, D.

    2016-06-01

    Modern digital cameras are increasing in quality whilst decreasing in size. In the last decade, a number of waterproof consumer digital cameras (action cameras) have become available, which often cost less than 500. A possible application of such action cameras is in the field of Underwater Photogrammetry. Especially with respect to the fact that with the change of the medium to below water can in turn counteract the distortions present. The goal of this paper is to investigate the suitability of such action cameras for underwater photogrammetric applications focusing on the stability of the camera and the accuracy of the derived coordinates for possible photogrammetric applications. For this paper a series of image sequences was capture in a water tank. A calibration frame was placed in the water tank allowing the calibration of the camera and the validation of the measurements using check points. The accuracy assessment covered three test sets operating three GoPro sports cameras of the same model (Hero 3 black). The test set included the handling of the camera in a controlled manner where the camera was only dunked into the water tank using 7MP and 12MP resolution and a rough handling where the camera was shaken as well as being removed from the waterproof case using 12MP resolution. The tests showed that the camera stability was given with a maximum standard deviation of the camera constant σc of 0.0031mm for 7MB (for an average c of 2.720mm) and 0.0072 mm for 12MB (for an average c of 3.642mm). The residual test of the check points gave for the 7MB test series the largest rms value with only 0.450mm and the largest maximal residual of only 2.5 mm. For the 12MB test series the maximum rms value is 0. 653mm.

  4. Designing a global assessment of climate change on inland fishes and fisheries: knowns and needs

    Science.gov (United States)

    Paukert, Craig P.; Lynch, Abigail J.; Beard, T. Douglas; Chen, Yushun; Cooke, Steven J.; Cooperman, Michael S.; Cowx, Ian G.; Infante, Dana M.; Ibengwe, Lilian; Myers, Bonnie; Nguyen, Phu Hoa; Winfield, Ian J.

    2017-01-01

    To date, there are few comprehensive assessments of how climate change affects inland finfish, fisheries, and aquaculture at a global scale, but one is necessary to identify research needs and commonalities across regions and to help guide decision making and funding priorities. Broadly, the consequences of climate change on inland fishes will impact global food security, the livelihoods of people who depend on inland capture and recreational fisheries. However, understanding how climate change will affect inland fishes and fisheries has lagged behind marine assessments. Building from a North American inland fisheries assessment, we convened an expert panel from seven countries to provide a first-step to a framework for determining how to approach an assessment of how climate change may affect inland fishes, capture fisheries, and aquaculture globally. Starting with the small group helped frame the key questions (e.g., who is the audience? What is the best approach and spatial scale?). Data gaps identified by the group include: the tolerances of inland fisheries to changes in temperature, stream flows, salinity, and other environmental factors linked to climate change, and the adaptive capacity of fishes and fisheries to adjust to these changes. These questions are difficult to address, but long-term and large-scale datasets are becoming more readily available as a means to test hypotheses related to climate change. We hope this perspective will help researchers and decision makers identify research priorities and provide a framework to help sustain inland fish populations and fisheries for the diversity of users around the globe.

  5. Lower Columbia River Terminal Fisheries Research Project : Final Environmental Assessment.

    Energy Technology Data Exchange (ETDEWEB)

    United States. Bonneville Power Administration.

    1995-04-01

    This notice announces BPA`S`s decision to fund the Oregon Department of Fish and Wildlife (ODFW), the Washington Department of Fish and Wildlife (WDFW), and the Clatsop Economic Development Committee for the Lower Columbia River Terminal Fisheries Research Project (Project). The Project will continue the testing of various species/stocks, rearing regimes, and harvest options for terminal fisheries, as a means to increase lower river sport and commercial harvest of hatchery fish, while providing both greater protection of weaker wild stocks and increasing the return of upriver salmon runs to potential Zone 6 Treaty fisheries. The Project involves relocating hatchery smolts to new, additional pen locations in three bays/sloughs in the lower Columbia River along both the Oregon and Washington sides. The sites are Blind Slough and Tongue Point in Clatsop County, Oregon, and Grays Bay/Deep River, Wahkiakum County, Washington. The smolts will be acclimated for various lengths of time in the net pens and released from these sites. The Project will expand upon an existing terminal fisheries project in Youngs Bay, Oregon. The Project may be expanded to other sites in the future, depending on the results of this initial expansion. BPA`S has determined the project is not a major Federal action significantly affecting the quality of the human environment, within the meaning of the National Environmental Policy Act (NEPA) of 1969. Therefore, the preparation of an environmental impact statement is not required, and BPA`S is issuing this FONSI.

  6. Assessment of the sea cucumber resource and fishery in the Bolinao-Anda reef system

    Directory of Open Access Journals (Sweden)

    Ronald Dionnie D. Olavides

    Full Text Available Fishery-independent and -dependent surveys were conducted to assess the status of the sea cucumber resource and fishery in Bolinao and Anda, Pangasinan. Thirty-five species of holothurians were recorded in 25 sampling stations within seagrass beds, coral reefs and mixed habitats. The estimated total population density of all aspidochirote sea cucumber species is 63 ind. ha-1. The artisanal multi-species fishery is at present primarily based on Holothuria scabra, Stichopus horrens and Bohadschia marmorata although there are indications that other high-value species were fished to local extinction. Taken together, the small sizes (<20 cm body length of the majority of aspidochirote sea cucumbers, their low population densities, and the continuous decrease in catches are clear signs of an overexploited fishery that will likely collapse without management intervention. Adaptive management strategies for Bolinao and Anda are recommended based on the findings of this survey.

  7. Assessing the impact of fisheries co-management interventions in developing countries: a meta-analysis.

    Science.gov (United States)

    Evans, Louisa; Cherrett, Nia; Pemsl, Diemuth

    2011-08-01

    Co-management is now established as a mainstream approach to small-scale fisheries management across the developing world. A comprehensive review of 204 potential cases reveals a lack of impact assessments of fisheries co-management. This study reports on a meta-analysis of the impact of fisheries co-management in developing countries in 90 sites across 29 case-studies. The top five most frequently measured process indicators are participation, influence, rule compliance, control over resources, and conflict. The top five most frequently measured outcome indicators are access to resources, resource well-being, fishery yield, household well-being, and household income. To deal with the diversity of the 52 indicators measured and the different ways these data are collected and analysed, we apply a coding system to capture change over time. The results of the meta-analysis suggest that, overall fisheries co-management delivers benefits to end-users through improvements in key process and outcome indicators. However, the dataset as a whole is constituted primarily of data from the Philippines. When we exclude this body of work, few generalisations can be made about the impact of fisheries co-management. The lack of comparative data suitable for impact assessment and the difficulties in comparing data and generalising across countries and regions reiterates calls in other fields for more systematic approaches to understanding and evaluating governance frameworks. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. Using grizzly bears to assess harvest-ecosystem tradeoffs in salmon fisheries.

    Science.gov (United States)

    Levi, Taal; Darimont, Chris T; Macduffee, Misty; Mangel, Marc; Paquet, Paul; Wilmers, Christopher C

    2012-01-01

    Implementation of ecosystem-based fisheries management (EBFM) requires a clear conceptual and quantitative framework for assessing how different harvest options can modify benefits to ecosystem and human beneficiaries. We address this social-ecological need for Pacific salmon fisheries, which are economically valuable but intercept much of the annual pulse of nutrient subsidies that salmon provide to terrestrial and aquatic food webs. We used grizzly bears, vectors of salmon nutrients and animals with densities strongly coupled to salmon abundance, as surrogates for "salmon ecosystem" function. Combining salmon biomass and stock-recruitment data with stable isotope analysis, we assess potential tradeoffs between fishery yields and bear population densities for six sockeye salmon stocks in Bristol Bay, Alaska, and British Columbia (BC), Canada. For the coastal stocks, we find that both bear densities and fishery yields would increase substantially if ecosystem allocations of salmon increase from currently applied lower to upper goals and beyond. This aligning of benefits comes at a potential cost, however, with the possibility of forgoing harvests in low productivity years. In contrast, we detect acute tradeoffs between bear densities and fishery yields in interior stocks within the Fraser River, BC, where biomass from other salmon species is low. There, increasing salmon allocations to ecosystems would benefit threatened bear populations at the cost of reduced long-term yields. To resolve this conflict, we propose an EBFM goal that values fisheries and bears (and by extension, the ecosystem) equally. At such targets, ecosystem benefits are unexpectedly large compared with losses in fishery yields. To explore other management options, we generate tradeoff curves that provide stock-specific accounting of the expected loss to fishers and gain to bears as more salmon escape the fishery. Our approach, modified to suit multiple scenarios, provides a generalizable method

  9. Using grizzly bears to assess harvest-ecosystem tradeoffs in salmon fisheries.

    Directory of Open Access Journals (Sweden)

    Taal Levi

    Full Text Available Implementation of ecosystem-based fisheries management (EBFM requires a clear conceptual and quantitative framework for assessing how different harvest options can modify benefits to ecosystem and human beneficiaries. We address this social-ecological need for Pacific salmon fisheries, which are economically valuable but intercept much of the annual pulse of nutrient subsidies that salmon provide to terrestrial and aquatic food webs. We used grizzly bears, vectors of salmon nutrients and animals with densities strongly coupled to salmon abundance, as surrogates for "salmon ecosystem" function. Combining salmon biomass and stock-recruitment data with stable isotope analysis, we assess potential tradeoffs between fishery yields and bear population densities for six sockeye salmon stocks in Bristol Bay, Alaska, and British Columbia (BC, Canada. For the coastal stocks, we find that both bear densities and fishery yields would increase substantially if ecosystem allocations of salmon increase from currently applied lower to upper goals and beyond. This aligning of benefits comes at a potential cost, however, with the possibility of forgoing harvests in low productivity years. In contrast, we detect acute tradeoffs between bear densities and fishery yields in interior stocks within the Fraser River, BC, where biomass from other salmon species is low. There, increasing salmon allocations to ecosystems would benefit threatened bear populations at the cost of reduced long-term yields. To resolve this conflict, we propose an EBFM goal that values fisheries and bears (and by extension, the ecosystem equally. At such targets, ecosystem benefits are unexpectedly large compared with losses in fishery yields. To explore other management options, we generate tradeoff curves that provide stock-specific accounting of the expected loss to fishers and gain to bears as more salmon escape the fishery. Our approach, modified to suit multiple scenarios, provides a

  10. Underwater robots

    CERN Document Server

    Antonelli, Gianluca

    2014-01-01

    This book, now at the third edition, addresses the main control aspects in underwater manipulation tasks. The mathematical model with significant impact on the control strategy is discussed. The problem of controlling a 6-degrees-of-freedoms autonomous underwater vehicle is deeply investigated and a survey of fault detection/tolerant strategies for unmanned underwater vehicles is provided. Inverse kinematics, dynamic and interaction control for underwater vehicle-manipulator systems are then discussed. The code used to generate most of the numerical simulations is made available and briefly discussed.       

  11. Evolutionary impact assessment: accounting for evolutionary consequences of fishing in an ecosystem approach to fisheries management.

    Science.gov (United States)

    Laugen, Ane T; Engelhard, Georg H; Whitlock, Rebecca; Arlinghaus, Robert; Dankel, Dorothy J; Dunlop, Erin S; Eikeset, Anne M; Enberg, Katja; Jørgensen, Christian; Matsumura, Shuichi; Nusslé, Sébastien; Urbach, Davnah; Baulier, Loїc; Boukal, David S; Ernande, Bruno; Johnston, Fiona D; Mollet, Fabian; Pardoe, Heidi; Therkildsen, Nina O; Uusi-Heikkilä, Silva; Vainikka, Anssi; Heino, Mikko; Rijnsdorp, Adriaan D; Dieckmann, Ulf

    2014-03-01

    Managing fisheries resources to maintain healthy ecosystems is one of the main goals of the ecosystem approach to fisheries (EAF). While a number of international treaties call for the implementation of EAF, there are still gaps in the underlying methodology. One aspect that has received substantial scientific attention recently is fisheries-induced evolution (FIE). Increasing evidence indicates that intensive fishing has the potential to exert strong directional selection on life-history traits, behaviour, physiology, and morphology of exploited fish. Of particular concern is that reversing evolutionary responses to fishing can be much more difficult than reversing demographic or phenotypically plastic responses. Furthermore, like climate change, multiple agents cause FIE, with effects accumulating over time. Consequently, FIE may alter the utility derived from fish stocks, which in turn can modify the monetary value living aquatic resources provide to society. Quantifying and predicting the evolutionary effects of fishing is therefore important for both ecological and economic reasons. An important reason this is not happening is the lack of an appropriate assessment framework. We therefore describe the evolutionary impact assessment (EvoIA) as a structured approach for assessing the evolutionary consequences of fishing and evaluating the predicted evolutionary outcomes of alternative management options. EvoIA can contribute to EAF by clarifying how evolution may alter stock properties and ecological relations, support the precautionary approach to fisheries management by addressing a previously overlooked source of uncertainty and risk, and thus contribute to sustainable fisheries.

  12. 75 FR 24883 - Fisheries of the South Atlantic; Southeast Data, Assessment, and Review (SEDAR); Public Meeting

    Science.gov (United States)

    2010-05-06

    ... Assessment Process is a stock assessment report which describes the fisheries, evaluates the status of the stock, estimates biological benchmarks, projects future population conditions, and recommends research... South Atlantic stock of red snapper will consist of a series of workshops and webinars: a Data Workshop...

  13. Assessing stocks in data-poor African fisheries: a case study on the ...

    African Journals Online (AJOL)

    Assessing stocks in data-poor African fisheries: a case study on the white grouper Epinephelus aeneus of Mauritania. ... African Journal of Marine Science ... The lack of reliable stock assessment for numerous exploited stocks in West Africa often results from poor-quality data, high multi-specificity of captures, and the ...

  14. 77 FR 60967 - Fisheries of the Gulf of Mexico; Southeast Data, Assessment and Review (SEDAR); Public Meeting

    Science.gov (United States)

    2012-10-05

    ...: Notice of SEDAR 28 Gulf of Mexico Spanish mackerel and cobia assessment webinars. SUMMARY: The SEDAR 28 assessment of the Gulf of Mexico Spanish mackerel and cobia fisheries will consist of a series of workshops... modeling methodologies for the Gulf of Mexico Spanish mackerel and cobia fisheries. Special Accommodations...

  15. 76 FR 47563 - Fisheries of the South Atlantic; Southeast Data, Assessment, and Review (SEDAR); South Atlantic...

    Science.gov (United States)

    2011-08-05

    ... Management Councils, in conjunction with NOAA Fisheries and the Atlantic and Gulf States Marine Fisheries... Management Councils and NOAA Fisheries Southeast Regional Office and Southeast Fisheries Science Center..., biologists, and researchers; constituency representatives including fishermen, environmentalists, and NGO's...

  16. 75 FR 51242 - Fisheries of the South Atlantic; Southeast Data, Assessment, and Review (SEDAR); Public Meeting

    Science.gov (United States)

    2010-08-19

    ... Mexico, South Atlantic, and Caribbean Fishery Management Councils, in conjunction with NOAA Fisheries and... Caribbean Fishery Management Councils; the Atlantic and Gulf States Marine Fisheries Commissions; and NOAA... representatives including fishermen, environmentalists, and NGO's; International experts; and staff of Councils...

  17. A method to assess social sustainability of capture fisheries: An application to a Norwegian trawler

    Energy Technology Data Exchange (ETDEWEB)

    Veldhuizen, L.J.L., E-mail: linda.veldhuizen@wur.nl [Animal Production Systems group, Wageningen University, P.O. Box 338, 6700 AH Wageningen (Netherlands); Berentsen, P.B.M. [Business Economics group, Wageningen University, P.O. Box 8130, 6700 EW Wageningen (Netherlands); Bokkers, E.A.M.; Boer, I.J.M. de [Animal Production Systems group, Wageningen University, P.O. Box 338, 6700 AH Wageningen (Netherlands)

    2015-07-15

    Social sustainability assessment of capture fisheries is, both in terms of method development and measurement, not well developed. The objective of this study, therefore, was to develop a method consisting of indicators and rubrics (i.e. categories that articulate levels of performance) to assess social sustainability of capture fisheries. This method was applied to a Norwegian trawler that targets cod and haddock in the northeast Atlantic. Based on previous research, 13 social sustainability issues were selected. To measure the state of these issues, 17 process and outcome indicators were determined. To interpret indicator values, rubrics were developed for each indicator, using standards set by international conventions or data retrieved from national statistics, industry agreements or scientific publications that explore rubric scales. The indicators and rubrics were subsequently used in a social sustainability assessment of a Norwegian trawler. This assessment indicated that overall, social sustainability of this trawler is relatively high, with high rubric scores, for example, for worker safety, provisions aboard for the crew and companies' salary levels. The assessment also indicated that the trawler could improve on healthy working environment, product freshness and fish welfare during capture. This application demonstrated that our method provides insight into social sustainability at the level of the vessel and can be used to identify potential room for improvement. This method is also promising for social sustainability assessment of other capture fisheries. - Highlights: • A method was developed for social sustainability assessment of capture fisheries. • This method entailed determining outcome and process indicators for important issues. • To interpret indicator values, a rubric was developed for each indicator. • Use of this method gives insight into social sustainability and improvement options. • This method is promising for social

  18. A method to assess social sustainability of capture fisheries: An application to a Norwegian trawler

    International Nuclear Information System (INIS)

    Veldhuizen, L.J.L.; Berentsen, P.B.M.; Bokkers, E.A.M.; Boer, I.J.M. de

    2015-01-01

    Social sustainability assessment of capture fisheries is, both in terms of method development and measurement, not well developed. The objective of this study, therefore, was to develop a method consisting of indicators and rubrics (i.e. categories that articulate levels of performance) to assess social sustainability of capture fisheries. This method was applied to a Norwegian trawler that targets cod and haddock in the northeast Atlantic. Based on previous research, 13 social sustainability issues were selected. To measure the state of these issues, 17 process and outcome indicators were determined. To interpret indicator values, rubrics were developed for each indicator, using standards set by international conventions or data retrieved from national statistics, industry agreements or scientific publications that explore rubric scales. The indicators and rubrics were subsequently used in a social sustainability assessment of a Norwegian trawler. This assessment indicated that overall, social sustainability of this trawler is relatively high, with high rubric scores, for example, for worker safety, provisions aboard for the crew and companies' salary levels. The assessment also indicated that the trawler could improve on healthy working environment, product freshness and fish welfare during capture. This application demonstrated that our method provides insight into social sustainability at the level of the vessel and can be used to identify potential room for improvement. This method is also promising for social sustainability assessment of other capture fisheries. - Highlights: • A method was developed for social sustainability assessment of capture fisheries. • This method entailed determining outcome and process indicators for important issues. • To interpret indicator values, a rubric was developed for each indicator. • Use of this method gives insight into social sustainability and improvement options. • This method is promising for social

  19. 77 FR 26746 - Fisheries of the Caribbean; Southeast Data, Assessment, and Review (SEDAR); Public Meetings

    Science.gov (United States)

    2012-05-07

    ... fisheries, evaluates the status of the stock, estimates biological benchmarks, projects future population... population models to evaluate stock status, estimate population benchmarks and stock status criteria, and... SEDAR assessments of the Caribbean stocks of blue tang and queen triggerfish will consist of a series of...

  20. Combining telephone surveys and fishing catches self-report: the French sea bass recreational fishery assessment.

    Science.gov (United States)

    Rocklin, Delphine; Levrel, Harold; Drogou, Mickaël; Herfaut, Johanna; Veron, Gérard

    2014-01-01

    Fisheries statistics are known to be underestimated, since they are mainly based on information about commercial fisheries. However, various types of fishing activities exist and evaluating them is necessary for implementing effective management plans. This paper assesses the characteristics and catches of the French European sea bass recreational fishery along the Atlantic coasts, through the combination of large-scale telephone surveys and fishing diaries study. Our results demonstrated that half of the total catches (mainly small fish) were released at sea and that the mean length of a kept sea bass was 46.6 cm. We highlighted different patterns of fishing methods and type of gear used. Catches from boats were greater than from the shore, both in abundance and biomass, considering mean values per fishing trip as well as CPUE. Spearfishers caught the highest biomass of sea bass per fishing trip, but the fishing rod with lure was the most effective type of gear in terms of CPUE. Longlines had the highest CPUE value in abundance but not in biomass: they caught numerous but small sea bass. Handlines were less effective, catching few sea bass in both abundance and biomass. We estimated that the annual total recreational sea bass catches was 3,173 tonnes of which 2,345 tonnes were kept. Since the annual commercial catches landings were evaluated at 5,160 tonnes, recreational landings represent 30% of the total fishing catches on the Atlantic coasts of France. Using fishers' self-reports was a valuable way to obtain new information on data-poor fisheries. Our results underline the importance of evaluating recreational fishing as a part of the total amount of fisheries catches. More studies are critically needed to assess overall fish resources caught in order to develop effective fishery management tools.

  1. Combining telephone surveys and fishing catches self-report: the French sea bass recreational fishery assessment.

    Directory of Open Access Journals (Sweden)

    Delphine Rocklin

    Full Text Available Fisheries statistics are known to be underestimated, since they are mainly based on information about commercial fisheries. However, various types of fishing activities exist and evaluating them is necessary for implementing effective management plans. This paper assesses the characteristics and catches of the French European sea bass recreational fishery along the Atlantic coasts, through the combination of large-scale telephone surveys and fishing diaries study. Our results demonstrated that half of the total catches (mainly small fish were released at sea and that the mean length of a kept sea bass was 46.6 cm. We highlighted different patterns of fishing methods and type of gear used. Catches from boats were greater than from the shore, both in abundance and biomass, considering mean values per fishing trip as well as CPUE. Spearfishers caught the highest biomass of sea bass per fishing trip, but the fishing rod with lure was the most effective type of gear in terms of CPUE. Longlines had the highest CPUE value in abundance but not in biomass: they caught numerous but small sea bass. Handlines were less effective, catching few sea bass in both abundance and biomass. We estimated that the annual total recreational sea bass catches was 3,173 tonnes of which 2,345 tonnes were kept. Since the annual commercial catches landings were evaluated at 5,160 tonnes, recreational landings represent 30% of the total fishing catches on the Atlantic coasts of France. Using fishers' self-reports was a valuable way to obtain new information on data-poor fisheries. Our results underline the importance of evaluating recreational fishing as a part of the total amount of fisheries catches. More studies are critically needed to assess overall fish resources caught in order to develop effective fishery management tools.

  2. Toward a Virtual Laboratory to Assess Biodiversity from Data Produced by an Underwater Microscope

    Science.gov (United States)

    Beaulieu, S.; Ball, M.; Futrelle, J.; Sosik, H. M.

    2016-12-01

    Real-time data from sensors deployed in the ocean are increasingly available online for broad use by scientists, educators, and the public. Such data have previously been limited to physical parameters, but data for biological parameters are becoming more prevalent with the development of new submersible instruments. Imaging FlowCytobot (IFCB), for example, automatically and rapidly acquires images of microscopic algae (phytoplankton) at the base of the food web in marine ecosystems. These images and products from image processing and automated classification are accessible via web services from an IFCB dashboard. However, until now, to process these data further into results representing the biodiversity of the phytoplankton required a complex workflow that could only be executed by scientists involved in the instrument development. Also, because these data have been collected near continuously for a decade, a number of "big data" challenges arise in attempting to implement and reproduce the workflow. Our research is geared toward the development of a virtual laboratory to enable other scientists and educators, as new users of data from this underwater microscope, to generate biodiversity data products. Our solution involves an electronic notebook (Jupyter Notebook) that can be re-purposed by users with some Python programming experience. However, when we scaled the virtual laboratory to accommodate a 2-month example time series (thousands of binned files each representing thousands of images), we needed to expand the execution environment to include batch processing outside of the notebook. We will share how we packaged these tools to share with other scientists to perform their own biodiversity assessment from data available on an IFCB dashboard. Additional outcomes of software development in this project include a prototype for time-series visualizations to be generated in near-real-time and recommendations for new products accessible via web services from the

  3. ACCURACY ASSESSMENT OF UNDERWATER PHOTOGRAMMETRIC THREE DIMENSIONAL MODELLING FOR CORAL REEFS

    Directory of Open Access Journals (Sweden)

    T. Guo

    2016-06-01

    Full Text Available Recent advances in automation of photogrammetric 3D modelling software packages have stimulated interest in reconstructing highly accurate 3D object geometry in unconventional environments such as underwater utilizing simple and low-cost camera systems. The accuracy of underwater 3D modelling is affected by more parameters than in single media cases. This study is part of a larger project on 3D measurements of temporal change of coral cover in tropical waters. It compares the accuracies of 3D point clouds generated by using images acquired from a system camera mounted in an underwater housing and the popular GoPro cameras respectively. A precisely measured calibration frame was placed in the target scene in order to provide accurate control information and also quantify the errors of the modelling procedure. In addition, several objects (cinder blocks with various shapes were arranged in the air and underwater and 3D point clouds were generated by automated image matching. These were further used to examine the relative accuracy of the point cloud generation by comparing the point clouds of the individual objects with the objects measured by the system camera in air (the best possible values. Given a working distance of about 1.5 m, the GoPro camera can achieve a relative accuracy of 1.3 mm in air and 2.0 mm in water. The system camera achieved an accuracy of 1.8 mm in water, which meets our requirements for coral measurement in this system.

  4. Accuracy Assessment of Underwater Photogrammetric Three Dimensional Modelling for Coral Reefs

    Science.gov (United States)

    Guo, T.; Capra, A.; Troyer, M.; Gruen, A.; Brooks, A. J.; Hench, J. L.; Schmitt, R. J.; Holbrook, S. J.; Dubbini, M.

    2016-06-01

    Recent advances in automation of photogrammetric 3D modelling software packages have stimulated interest in reconstructing highly accurate 3D object geometry in unconventional environments such as underwater utilizing simple and low-cost camera systems. The accuracy of underwater 3D modelling is affected by more parameters than in single media cases. This study is part of a larger project on 3D measurements of temporal change of coral cover in tropical waters. It compares the accuracies of 3D point clouds generated by using images acquired from a system camera mounted in an underwater housing and the popular GoPro cameras respectively. A precisely measured calibration frame was placed in the target scene in order to provide accurate control information and also quantify the errors of the modelling procedure. In addition, several objects (cinder blocks) with various shapes were arranged in the air and underwater and 3D point clouds were generated by automated image matching. These were further used to examine the relative accuracy of the point cloud generation by comparing the point clouds of the individual objects with the objects measured by the system camera in air (the best possible values). Given a working distance of about 1.5 m, the GoPro camera can achieve a relative accuracy of 1.3 mm in air and 2.0 mm in water. The system camera achieved an accuracy of 1.8 mm in water, which meets our requirements for coral measurement in this system.

  5. Underwater Ranging

    OpenAIRE

    S. P. Gaba

    1984-01-01

    The paper deals with underwater laser ranging system, its principle of operation and maximum depth capability. The sources of external noise and methods to improve signal-to-noise ratio are also discussed.

  6. Assessment methodology for new cooling lakes. Volume 3. Limnological and fisheries data and bibliography. Final report

    International Nuclear Information System (INIS)

    1981-10-01

    This is the data volume of the report entitled Assessment Methodology for New Cooling Lakes. Limnological and fisheries data were compiled in this volume for potential users in the utility industry. Published papers, reports, other written information, computer files, and direct contracts were used to compile a matrix of information. This volume presents data and the bibliographic sources of the power plant and geographical, limnological, and fisheries information for 181 lakes and reservoirs, of which 134 were used for cooling purposes. Data for 65 lakes were completed with respect to the limnology and fisheries parameters so that complete statistical analysis could be performed. Of these 65 lakes, 42 are used for cooling. Tables in this report contain data arranged by utility, power plant, limnology, water quality, morphoedaphic, and fishery categories. The data in the tables are keyed to a lake code. The references for the data shown are keyed to a numerical listing of the bibliography. Author, state, lake, and subject indexes facilitate searching for bibliographic information

  7. Assessments of fish catch composition of marine artisanal fishery in ...

    African Journals Online (AJOL)

    Fish is a major source of protein in human diets. Fish demand has been on the increase due to increase in human population which has resulted to wide gap between fish demand and supply. This study was carried out to elucidate the major fish species that are economically important in the study area. Assessment of fish ...

  8. Participatory assessment of the Toliara Bay reef fishery, southwest ...

    African Journals Online (AJOL)

    2011-12-22

    Dec 22, 2011 ... tory assessment methods have the potential to increase the amount of data collected at ... face au difficile contexte socio - économique et politique qui ... it takes advantage of the traditional ecological knowledge and skills of ...

  9. Large-scale assessment of benthic communities across multiple marine protected areas using an autonomous underwater vehicle.

    Science.gov (United States)

    Ferrari, Renata; Marzinelli, Ezequiel M; Ayroza, Camila Rezende; Jordan, Alan; Figueira, Will F; Byrne, Maria; Malcolm, Hamish A; Williams, Stefan B; Steinberg, Peter D

    2018-01-01

    Marine protected areas (MPAs) are designed to reduce threats to biodiversity and ecosystem functioning from anthropogenic activities. Assessment of MPAs effectiveness requires synchronous sampling of protected and non-protected areas at multiple spatial and temporal scales. We used an autonomous underwater vehicle to map benthic communities in replicate 'no-take' and 'general-use' (fishing allowed) zones within three MPAs along 7o of latitude. We recorded 92 taxa and 38 morpho-groups across three large MPAs. We found that important habitat-forming biota (e.g. massive sponges) were more prevalent and abundant in no-take zones, while short ephemeral algae were more abundant in general-use zones, suggesting potential short-term effects of zoning (5-10 years). Yet, short-term effects of zoning were not detected at the community level (community structure or composition), while community structure varied significantly among MPAs. We conclude that by allowing rapid, simultaneous assessments at multiple spatial scales, autonomous underwater vehicles are useful to document changes in marine communities and identify adequate scales to manage them. This study advanced knowledge of marine benthic communities and their conservation in three ways. First, we quantified benthic biodiversity and abundance, generating the first baseline of these benthic communities against which the effectiveness of three large MPAs can be assessed. Second, we identified the taxonomic resolution necessary to assess both short and long-term effects of MPAs, concluding that coarse taxonomic resolution is sufficient given that analyses of community structure at different taxonomic levels were generally consistent. Yet, observed differences were taxa-specific and may have not been evident using our broader taxonomic classifications, a classification of mid to high taxonomic resolution may be necessary to determine zoning effects on key taxa. Third, we provide an example of statistical analyses and

  10. Assessment of blue mussel Mytilus edulis fisheries and waterbird shellfish-predator management in the Danish Wadden Sea

    DEFF Research Database (Denmark)

    Laursen, Karsten; Kristensen, Per Sand; Clausen, Preben

    2010-01-01

    biomass and mussel bed areas in zones closed to fishery, (ii) decrease in eiders Somateria mollissima numbers and increase or stable numbers for oystercatcher Haematopus ostralegus and herring gull Larus argentatus and (iii) that energy estimations based on ecological food requirements for the mussel-eating......We assessed the blue mussel Mytilus edulis fishery management scheme introduced in 1994 in the Danish Wadden Sea that regulate fishing vessels, fishery quota, set-aside for mussel-eating birds and established zones closed to mussel fishery. The results showed (i) a reduction in the blue mussel......, it is recommended to revise the present blue mussel management scheme in the Danish Wadden Sea, to continue and improve mussel stock and bird surveys, and to consider novel studies of the mussel-eating birds’ energetics for improved set-aside estimates and future assessments....

  11. Assessing trends in fishery resources and lake-water aluminum from paleolimnological analyses of siliceous algae

    International Nuclear Information System (INIS)

    Kingston, J.C.; Birks, H.J.B.; Uutala, A.J.; Cummings, B.F.; Smol, J.P.

    1992-01-01

    Lake water aluminum concentrations have a significant influence on the composition of microfossil assemblages of diatoms and chrysophytes deposited in lake sediments. With the paleolimnological approach of multilake datasets in the Adirondack region of New York, USA, the authors use canonical correspondence analysis to describe past trends in lake water Al. Four lakes, previously investigated regarding acidification and fishery trends, are used to demonstrate that paleolimnological assessment can also provide direction, timing, and magnitude of trends for both toxic metals and fish resources. Additionally, the authors use weighted average regression and calibration to obtain quantitative reconstructions of past lake water Al concentrations. Such reconstructions provide further insight into fishery resource damage and can be compared with modelling results. According to paleolimnological reconstructions, some of the naturally most acidic lakes in the Adirondack region had preindustrial lake water concentrations of inorganic monomeric Al near 4/micromol times L. Although these high concentrations are surprising from a geochemical point of view, they may partially explain the preindustrial absence of fish, as has been independently determined by paleolimnological analysis of phantom midges (Chaoborus). Fishery resource deterioration in acidified Adirondack lakes was coincident with major increases in lake water Al concentrations

  12. Quantitative assessment of a data-limited recreational bonefish fishery using a time-series of fishing guides reports.

    Directory of Open Access Journals (Sweden)

    Rolando O Santos

    Full Text Available Recreational fisheries can be prone to severe declines, yet these fisheries, particularly catch-and-release, are often data-limited, constraining our ability to conduct stock assessments. A combination of catch and effort indices derived from fisheries-dependent data (FDD gathered from fishing logbooks could be a powerful approach to inform these data gaps. This study demonstrates the utility of using different catch metrics such as indices of abundance, species richness associated with reported catch, and the success rate of targeted trips, to assess historical shifts in the trajectory of the data-limited bonefish (Albula vulpes fishery in Florida Bay, an economically-important recreational fishery within the Caribbean Basin. We used FDD from fishing guide reports submitted to Everglades National Park to determine temporal patterns in the bonefish population over the past 35 years. These reports indicated a decline in recreational catches in Florida Bay since the late 1980s, with an accelerated decline starting in the late 1990s-early 2000s. Analyses showed an overall 42% reduction in bonefish catches. Trends in the proportion of positive trips (i.e., the probability of catching success followed the declining catch patterns, suggesting major population changes starting in 1999-2000. As bonefish catches declined, species richness in bonefish trips increased by 34%, suggesting a decrease in bonefish abundance and/or shift in fishing effort (e.g., giving-up time, changes in preferred species. Results provide additional resolution to a pattern of decline for bonefish in South Florida and highlight the value of reconstructing time-series for the development of hypotheses about the potential driving mechanisms of species decline. Further, the data-limited nature of most recreational fisheries, and the increase in a use of catch-and-release as a fisheries management strategy point to the need to develop further data integration tools to assess

  13. 77 FR 70149 - Fisheries of the Gulf of Mexico; Southeast Data, Assessment, and Review (SEDAR); Public Meetings

    Science.gov (United States)

    2012-11-23

    ... appropriate for assessment analyses. The product of the Assessment Process is a stock assessment report which describes the fisheries, evaluates the status of the stock, estimates biological benchmarks, projects future... fish stocks in the Southeast Region. SEDAR is a three-step process including: (1) Data Workshop; (2...

  14. Application of fisheries management techniques to assessing impacts: task I report

    International Nuclear Information System (INIS)

    McKenzie, D.H.; Baker, K.S.; Fickeisen, D.H.; Metzger, R.M.; Skalski, J.R.

    1979-03-01

    Task I efforts examined the available fisheries management techniques and assessed their potential application in a confirmatory monitoring program. The objective of such monitoring programs is to confirm that the prediction of an insignificant impact (usually made in the FES) was correct. Fisheries resource managers have developed several tools for assessing the fish population response to stress (exploitation) and they were thought potentially useful for detecting nuclear power plant impacts. Techniques in three categories were examined; catch removal, population dynamics, and nondestructive censuses, and the report contains their description, examples of application, advantages, and disadvantages. The techniques applied at nuclear power plant sites were examined in detail to provide information on implementation and variability of specific approaches. The most suitable techniques to incorporate into a monitoring program confirming no impact appear to be those based on Catch Per Unity Effort (CPUE) and hydroacoustic data. In some specific cases, age and growth studies and indirect census techniques may be beneficial. Recommendations for task II efforts to incorporate these techniques into monitoring program designs are presented. These include development of guidelines for; (1) designing and implementing a data collection program; (2) interpreting these data and assessing the occurrence of impact, and (3) establishment of the monitoring program's ability to detect changes in the affected populations

  15. 76 FR 34061 - Fisheries of the South Atlantic; Southeast Data, Assessment, and Review (SEDAR); Public Meeting

    Science.gov (United States)

    2011-06-10

    ...: The Gulf of Mexico, South Atlantic, and Caribbean Fishery Management Councils, in conjunction with... Workshops are appointed by the Gulf of Mexico, South Atlantic, and Caribbean Fishery Management Councils and...; constituency representatives including fishermen, environmentalists, and NGO's; International experts; and...

  16. Trophic dynamics and fishery potentials of the Indian Occean - critical assessment

    Digital Repository Service at National Institute of Oceanography (India)

    Dalal, S.G.; Parulekar, A.H.

    A critical review of the status of the Indian Ocean marine fisheries reveals that the presently exploited annual catch is less than one third of the projected potentials as estimated from the biological productivity and exploratory fishery survey...

  17. 75 FR 54597 - Fisheries of the South Atlantic; Southeast Data, Assessment, and Review (SEDAR); South Atlantic...

    Science.gov (United States)

    2010-09-08

    ... Atlantic, and Caribbean Fishery Management Councils, in conjunction with NOAA Fisheries and the Atlantic... are appointed by the Gulf of Mexico, South Atlantic, and Caribbean Fishery Management Councils; the..., environmentalists, and NGO's; International experts; and staff of Councils, Commissions, and state and federal...

  18. 78 FR 36525 - Fisheries of the Atlantic and the Gulf of Mexico; Southeast Data, Assessment, and Review (SEDAR...

    Science.gov (United States)

    2013-06-18

    ... workshop to employ assessment models to evaluate stock status, estimate population benchmarks and... for determining the status of fish stocks in the Southeast Region. SEDAR is a multi-step process... appropriate for assessment analyses, describes the fisheries, evaluates the status of the stock, estimates...

  19. 77 FR 51771 - Fisheries of the Gulf of Mexico and South Atlantic; Southeast Data, Assessment, and Review (SEDAR...

    Science.gov (United States)

    2012-08-27

    ... Process Webinar for Gulf of Mexico and South Atlantic Spanish Mackerel and Cobia AGENCY: National Marine... of SEDAR 28 Gulf of Mexico and South Atlantic Spanish mackerel and cobia assessment webinar. SUMMARY: The SEDAR 28 assessment of the Gulf of Mexico and South Atlantic Spanish mackerel and cobia fisheries...

  20. Manual on sample-based data collection for fisheries assessment : Examples from Viet Nam

    DEFF Research Database (Denmark)

    Sparre, Per Johan

    with through both detailed discussion and by using simple examples. These examples are mostly based on situations in tropical fisheries and, in particular, experience has been drawn from developing a data collection programme in Viet Nam. The main questions addressed in the manual are which fisheries data...... to collect, where and when to collect them. Only data collected from commercial marine capture fisheries are considered (data from freshwater fisheries, cultured fish and experimental fisheries are excluded). The methodologies used are mainly appropriate for a tropical developing country with many small...

  1. Low-contrast underwater living fish recognition using PCANet

    Science.gov (United States)

    Sun, Xin; Yang, Jianping; Wang, Changgang; Dong, Junyu; Wang, Xinhua

    2018-04-01

    Quantitative and statistical analysis of ocean creatures is critical to ecological and environmental studies. And living fish recognition is one of the most essential requirements for fishery industry. However, light attenuation and scattering phenomenon are present in the underwater environment, which makes underwater images low-contrast and blurry. This paper tries to design a robust framework for accurate fish recognition. The framework introduces a two stage PCA Network to extract abstract features from fish images. On a real-world fish recognition dataset, we use a linear SVM classifier and set penalty coefficients to conquer data unbalanced issue. Feature visualization results show that our method can avoid the feature distortion in boundary regions of underwater image. Experiments results show that the PCA Network can extract discriminate features and achieve promising recognition accuracy. The framework improves the recognition accuracy of underwater living fishes and can be easily applied to marine fishery industry.

  2. Underwater Hyperspectral Imaging (UHI) for Assessing the Coverage of Drill Cuttings on Benthic Habitats

    Science.gov (United States)

    Erdal, I.; Sandvik Aas, L. M.; Cochrane, S.; Ekehaug, S.; Hansen, I. M.

    2016-02-01

    Larger-scale mapping of seabed areas requires improved methods in order to obtain effective and sound marine management. The state of the art for visual surveys today involves video transects, which is a proven, yet time consuming and subjective method. Underwater hyperspectral imaging (UHI) utilizes high color sensitive information in the visible light reflected from objects on the seafloor to automatically identify seabed organisms and other objects of interest (OOI). A spectral library containing optical fingerprints of a range of OOI's are used in the classification. The UHI is a push-broom hyperspectral camera utilizing a state of the art CMOS sensor ensuring high sensitivity and low noise levels. Dedicated lamps illuminate the imaging area of the seafloor. Specialized software is used both for processing raw data and for geo-localization and OOI identification. The processed hyperspectral image are used as a reference when extracting new spectral data for OOI's to the spectral library. By using the spectral library in classification algorithms, large sea floor areas can automatically be classified. Recent advantages in UHI classification includes mapping of areas affected by drill cuttings. Tools for automated classification of seabed that have a different bottom composition than adjacent baseline areas are under development. Tests have been applied to a transect in gradient from the drilling hole to baseline seabed. Some areas along the transect were identified as different compared to baseline seabed. The finding was supported by results from traditional seabed mapping methods. We propose that this can be a useful tool for tomorrows environmental mapping and monitoring of drill sites.

  3. The eastern Baltic cod fishery: a fleet-based management strategy evaluation framework to assess the cod recovery plan of 2008

    DEFF Research Database (Denmark)

    Bastardie, Francois; Nielsen, J. Rasmus; Kraus, Gerd

    2010-01-01

    The eastern Baltic cod fishery: a fleet-based management strategy evaluation framework to assess the cod recovery plan of 2008. - ICES Journal of Marine Science, 67: 71-86.......The eastern Baltic cod fishery: a fleet-based management strategy evaluation framework to assess the cod recovery plan of 2008. - ICES Journal of Marine Science, 67: 71-86....

  4. 75 FR 52510 - Fisheries of the Gulf of Mexico and South Atlantic; Southeast Data, Assessment, and Review for...

    Science.gov (United States)

    2010-08-26

    ... Management Councils, in conjunction with NOAA Fisheries and the Atlantic and Gulf States Marine Fisheries... Caribbean Fishery Management Councils and NOAA Fisheries Southeast Regional Office, HMS Management Division... fishermen, environmentalists, and NGO's; International experts; and staff of Councils, Commissions, and...

  5. 77 FR 27716 - Fishery of the Gulf of Mexico; Southeast Data, Assessment, and Review (SEDAR); Public Meetings

    Science.gov (United States)

    2012-05-11

    [email protected] . SUPPLEMENTARY INFORMATION: The Gulf of Mexico Fishery Management Council, in conjunction... Fishery Management Council, NOAA Fisheries Southeast Regional Office, and NOAA Southeast Fisheries Science..., biologists, and researchers; constituency representatives including fishermen, environmentalists, and NGO's...

  6. 75 FR 23676 - Fisheries of the Gulf of Mexico and South Atlantic; Southeast Data, Assessment, and Review (SEDAR...

    Science.gov (United States)

    2010-05-04

    ... Caribbean Fishery Management Councils, in conjunction with NOAA Fisheries and the Atlantic and Gulf States... of Mexico, South Atlantic, and Caribbean Fishery Management Councils and NOAA Fisheries Southeast... fishermen, environmentalists, and NGO's; International experts; and staff of Councils, Commissions, and...

  7. 75 FR 51983 - Fisheries of the South Atlantic and Gulf of Mexico; Southeast Data, Assessment, and Review (SEDAR...

    Science.gov (United States)

    2010-08-24

    ... INFORMATION: The Gulf of Mexico, South Atlantic, and Caribbean Fishery Management Councils, in conjunction... Caribbean Fishery Management Councils and NOAA Fisheries Southeast Regional Office and Southeast Fisheries..., biologists, and researchers; constituency representatives including fishermen, environmentalists, and NGO's...

  8. 75 FR 53951 - Fisheries of the Gulf of Mexico; Southeast Data, Assessment, and Review (SEDAR) Update; Greater...

    Science.gov (United States)

    2010-09-02

    ... Gulf of Mexico, South Atlantic, and Caribbean Fishery Management Councils, in conjunction with NOAA... Caribbean Fishery Management Councils and NOAA Fisheries Southeast Regional Office and Southeast Fisheries..., biologists, and researchers; constituency representatives including fishermen, environmentalists, and NGO's...

  9. Fisheries economics and fisheries management

    DEFF Research Database (Denmark)

    Andersen, Peder

    2013-01-01

    spent too much time on fundamentals in fisheries economics at the expense of the development of applicable models for fisheries managers? Of course, this question is relevant only IF fisheries economics and fisheries economists have a role to play in fisheries management.......Professor Rögnvaldur Hannesson's influence on the development and history of fisheries economics is unquestionable. Also, he has strongly pointed out the potential gains from a more active use of fisheries economics in fisheries management. In light of this, one may ask if fisheries economists have...

  10. 75 FR 55745 - Pacific Fishery Management Council; Public Meeting

    Science.gov (United States)

    2010-09-14

    ... Pacific Fishery Management Council's (Pacific Council) Coastal Pelagic Species Management Team (CPSMT) and... Fishery Management Council; Public Meeting AGENCY: National Marine Fisheries Service (NMFS), National... sardine stock assessment for 2010. Other issues relevant to Coastal Pelagic Species fisheries management...

  11. 77 FR 29981 - Fisheries of the Gulf of Mexico; Southeast Data, Assessment, and Review (SEDAR); Public Meetings

    Science.gov (United States)

    2012-05-21

    ... describes the fisheries, evaluates the status of the stock, estimates biological benchmarks, projects future... population models to evaluate stock status, estimate population benchmarks and Magnuson-Stevens... assessment of the Gulf of Mexico stock of red snapper will consist of a series of three workshops: a Data...

  12. 78 FR 15708 - Fisheries of the Gulf of Mexico; Southeast Data, Assessment, and Review (SEDAR); Public Meeting

    Science.gov (United States)

    2013-03-12

    ...: Notice of SEDAR 28 Gulf of Mexico Spanish mackerel and cobia Review Workshop. SUMMARY: The SEDAR 28 assessment of the Gulf of Mexico Spanish mackerel and cobia fisheries will consist of a series of workshops... and cobia. Although non-emergency issues not contained in this agenda may come before this group for...

  13. Assessment on dioxin-like compounds intake from various marine fish from Zhoushan Fishery, China.

    Science.gov (United States)

    Wang, Xiangyong; Zhang, Hongxia; Zhang, Lei; Zhong, Kai; Shang, Xiaohong; Zhao, Yunfeng; Tong, Zhendong; Yu, Xinwei; Li, Jingguang; Wu, Yongning

    2015-01-01

    Sea fish consuming is an important intake source of dioxin-like compounds, especially for the coastal residents. To assess the intake levels of these contaminants from sea fish and to provide risk-based consumption advice, concentrations of 17 polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and 12 dioxin-like polychlorinated biphenyls (dl-PCBs) were measured in 32 commonly consumed fish species from Zhoushan Fishery, China. Due to the different accumulation influenced by fat content, feed habits and living zone in the sea area, the levels of PCDDs, PCDFs and dl-PCBs in different fish species varied significantly ranging from 0.002 to 0.078pg WHO-TEQ/g fresh weight, from 0.002 to 0.553pg WHO-TEQ/g fresh weight and from 0.003 to 2.059pg WHO-TEQ/g fresh weight, respectively. Based on mean fish consuming rate in China, the estimated maximum possible dioxin-like compounds intake through different fish species ranged from 0.26 to 65.61pgTEQkg(-1)bwmonth(-1). Bullet mackerel has the highest monthly intake level which was much higher than other fish species and very close to the provisional tolerable monthly intake (70pgTEQkg(-)(1)bwmonth(-)(1)) proposed by the Joint FAO/WHO Expert Committee on Food Additives. Hence, comparing to other fish species, the consumption of Bullet mackerel from Zhoushan Fishery should be cautious to reduce the potential health risk. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Evolutionary impact assessent: accounting for evolutionary consequences of fishing in an ecosystem approach to fisheries management

    NARCIS (Netherlands)

    Laugen, A.T.; Engelhard, G.H.; Whitlock, R.; Mollet, F.M.; Rijnsdorp, A.D.

    2014-01-01

    Managing fisheries resources to maintain healthy ecosystems is one of the main goals of the ecosystem approach to fisheries (EAF). While a number of international treaties call for the implementation of EAF, there are still gaps in the underlying methodology. One aspect that has received substantial

  15. 75 FR 1753 - Fisheries of the Atlantic; Southeast Data, Assessment, and Review (SEDAR); Atlantic croaker and...

    Science.gov (United States)

    2010-01-13

    ... Management Councils, in conjunction with NOAA Fisheries and the Atlantic and Gulf States Marine Fisheries... researchers; constituency representatives including fishermen, environmentalists, and NGO's; international... Conservation and Management Act, provided the public has been notified of the Council's intent to take final...

  16. Assessing Guinea Bissau's Legal and Illegal Unreported and Unregulated Fisheries and the Surveillance Efforts to Tackle Them

    Directory of Open Access Journals (Sweden)

    Jeremias Francisco Intchama

    2018-04-01

    Full Text Available Fisheries in Guinea Bissau contribute greatly to the economy and food security of its people. Yet, as the ability of the country to monitor its fisheries is at most weak, and confronted with a heavy foreign fleet presence, the impact of industrial foreign fleets on fisheries catches is unaccounted for in the region. However, their footprint in terms of catch and value on the small-scale sector is heavily felt, through declining availability of fish. Fisheries in Guinea Bissau are operated by both legal (small-scale and industrial, and illegal (foreign unauthorized fleets, whose catches are barely recorded. In this paper, we assess catches by both the legal and illegal sector, and the economic loss generated by illegal fisheries in the country, then attempt to evaluate the effectiveness of Monitoring Control and Surveillance (MCS of Guinea Bissau's fisheries. Two main sectors were identified through official reports and a literature review, the large-scale (industrial sector, which between 2011 and 2017 included exclusively catches by foreign owned and flagged vessels, and catches by the small-scale sector, which remain largely unmonitored in official statistics. We use the available data on the number of legal and illegal vessels and/or fishers, and their respective catch per unit of effort to estimate catches, and we analyze monitoring outcomes against the registered industrial and artisanal fleets. We find that of the legal industrial vessels, 20% were linked to criminal activities in the past 7 years. These activities range widely from using an illegal mesh size, to fishing in a prohibited area, to labor abuse. Overall, total small-scale and industrial catches were estimated at 370,000 t/year in 2017, of which less than 2% is ever reported to the FAO. Small-scale catches represented 8% of the total catch, and this contribution was found to be declining. Industrial fisheries generate over $458 million US, or which $75 million US is taken

  17. Rapid Fishery Assessment by Market Survey (RFAMS--an improved rapid-assessment approach to characterising fish landings in developing countries.

    Directory of Open Access Journals (Sweden)

    William T White

    Full Text Available The complex multi-gear, multi-species tropical fisheries in developing countries are poorly understood and characterising the landings from these fisheries is often impossible using conventional approaches. A rapid assessment method for characterising landings at fish markets, using an index of abundance and estimated weight within taxonomic groups, is described. This approach was developed for contexts where there are no detailed data collection protocols, and where consistent data collection across a wide range of fisheries types and geographic areas is required, regardless of the size of the site and scale of the landings. This methodology, which was demonstrated at seven fish landing sites/fish markets in southern Indonesia between July 2008 and January 2011, provides a rapid assessment of the abundance and diversity in the wild catch over a wide variety of taxonomic groups. The approach has wider application for species-rich fisheries in developing countries where there is an urgent need for better data collection protocols, monitoring future changes in market demographics, and evaluating health of fisheries.

  18. Assessing broad life cycle impacts of daily onboard decision-making, annual strategic planning, and fisheries management in a northeast Atlantic trawl fishery

    NARCIS (Netherlands)

    Ziegler, F.; Groen, E.A.; Hornborg, S.; Bokkers, E.A.M.; Karlsen, K.M.; Boer, de I.J.M.

    2015-01-01

    Purpose: Capture fisheries are the only industrial-scale harvesting of a wild resource for food. Temporal variability in environmental performance of fisheries has only recently begun to be explored, but only between years, not within a year. Our aim was to better understand the causes of temporal

  19. 78 FR 27957 - Fisheries of the South Atlantic, Southeast Data, Assessment, and Review (SEDAR); Public Meetings

    Science.gov (United States)

    2013-05-13

    ..., describes the fisheries, evaluates the status of the stock, estimates biological benchmarks, projects future... to evaluate stock status, estimate population benchmarks and management criteria, and project future... South Atlantic stock of snowy [[Page 27958

  20. Manual on sample-based data collection for fisheries assessment: examples from Viet Nam

    National Research Council Canada - National Science Library

    Sparre, Per

    2000-01-01

    .... The data collection programme is developed through a top-down approach, from the identification of the objectives down to the practical recording and management of data obtained from the fishery...

  1. 75 FR 20985 - Fisheries of the South Atlantic and Gulf of Mexico; Southeastern Data, Assessment, and Review...

    Science.gov (United States)

    2010-04-22

    ....net SUPPLEMENTARY INFORMATION: The Gulf of Mexico, South Atlantic, and Caribbean Fishery Management... Atlantic, and Caribbean Fishery Management Councils and NOAA Fisheries Southeast Regional Office and..., environmentalists, and NGO's; International experts; and staff of Councils, Commissions, and state and federal...

  2. 75 FR 39918 - Fisheries of the South Atlantic and Gulf of Mexico; Southeast Data, Assessment, and Review (SEDAR...

    Science.gov (United States)

    2010-07-13

    ...-4366. SUPPLEMENTARY INFORMATION: The Gulf of Mexico, South Atlantic, and Caribbean Fishery Management... Management Councils and NOAA Fisheries Southeast Regional Office and Southeast Fisheries Science Center... researchers; constituency representatives including fishermen, environmentalists, and NGO's; International...

  3. Assessing future economic impacts of acidic deposition on the recreational fishery of eastern Canada

    International Nuclear Information System (INIS)

    1990-01-01

    A study was carried out to assess the socio-economic impacts and net economic value effects related to potential reduction in acidic deposition on the sports fishery of eastern Canada. Impacts and net economic effects that would have occurred from 1950 to 1985 if emission/deposition controls were in place are measured. Impacts and net economic effects that will occur from 1986 to 2021 if controls are put in place in the future are also measured. The study incorporated the latest data describing the relationship of acidic deposition to lake pH levels and ultimate impact on fish survival, and applies a spatial analysis system to model changes in sport fish availability with respect to pH changes and fish survival responses. It was found that if emission controls were put in place beginning in 1950 the Canadian economy would have accrued $4.3 billion in net economic value from 1950 to 1985 inclusive. The 1986 value of the historical stream of losses that occurred because controls were not put in place is $24 billion assuming a 10% rate of return. If controls were put in place in the future, net economic value to Canada due to increased angler activity would be $4.2 billion for the period 1986-2021. The value in 1986 would be $925 million. 9 figs., 34 tabs

  4. Assessing angler effort, catch, and harvest and the efficacy of a use-estimation system on a multi-lake fishery in middle Georgia

    Science.gov (United States)

    Roop, Hunter J.; Poudyal, Neelam C.; Jennings, Cecil A.

    2018-01-01

    Creel surveys are valuable tools in recreational fisheries management. However, multiple‐impoundment fisheries of complex spatial structure can complicate survey designs and pose logistical challenges for management agencies. Marben Public Fishing Area in Mansfield, GA is a multi‐impoundment fishery with many access points, and these features prevent or complicate use of traditional on‐site contact methods such as standard roving‐ or access‐point designs because many anglers may be missed during the survey process. Therefore, adaptation of a traditional survey method is often required for sampling this special case of multi‐lake fisheries to develop an accurate fishery profile. Accordingly, a modified non‐uniform probability roving creel survey was conducted at the Marben PFA during 2013 to estimate fishery characteristics relating to fishing effort, catch, and fish harvest. Monthly fishing effort averaged 7,523 angler‐hours (h) (SD = 5,956) and ranged from 1,301 h (SD = 562) in December to 21,856 h (SD = 5909) in May. A generalized linear mixed model was used to determine that angler catch and harvest rates were significantly higher in the spring and summer (all p < 0.05) than in the other seasons, but did not vary by fishing location. Our results demonstrate the utility of modifying existing creel methodology for monitoring small, spatially complex, intensely managed impoundments that support quality recreational fisheries and provide a template for the assessment and management of similar regional fisheries.

  5. 78 FR 54869 - Fisheries of the Gulf of Mexico; Southeast Data, Assessment, and Review (SEDAR); Public Meetings

    Science.gov (United States)

    2013-09-06

    ... NOAA Fisheries Southeast Regional Office, Highly Migratory Species Management Division, and Southeast... describes the fisheries, evaluates the status of the stock, estimates biological benchmarks, projects future...

  6. Assessment of the sardine (Sardina pilchardus Walbaum, 1792 fishery in the eastern Mediterranean basin (North Aegean Sea

    Directory of Open Access Journals (Sweden)

    K. ANTONAKAKIS

    2011-06-01

    Full Text Available The aim of this study was to describe the biometric characteristics of the European sardine (Sardina pilchardus catches and assess the current status of sardine stock in North Aegean Sea based on population characteristics and abundance trends. The stock was dominated by age groups 1 and 2, not exceeding age group 4. The sardine stock in this area was assessed through an Integrated Catch-at-Age model which implements a separable Virtual Population Analysis on catch at age data with weighted tuning indices. Sardine landings data derived from the commercial purse seine fishery over the period 2000-2008 were combined with the age structure of the stock as resulted from fisheries independent acoustic surveys. Sensitivity analysis of the impact of natural mortality values on stock assessment results was applied. Additionally forecast of the sardine population parameters and catches under different exploitation scenarios was implemented in a medium term basis. Results indicated that the North Aegean Sea sardine stock is considered fully exploited with the fishery operating close but over the empirical exploitation level for sustainability. Finally, the status of the sardine stock in N. Aegean Sea is discussed in relation to the sardine stocks from the western and the central Mediterranean basin.

  7. Development and assessment of two decontamination processes: closed electropolishing system for decontamination of underwater surfaces -vibratory decontamination with abrasives

    International Nuclear Information System (INIS)

    Benavides, E.; Fajardo, M.

    1992-01-01

    Two decontamination processes have been developed to decontaminate the stainless steel components of nuclear power plants. The first process uses an underwater closed electropolishing system for the decontamination of large stainless steel surfaces in flooded systems without loss of electrolyte. Large underwater contaminated areas can be treated with an electropolishing head covering an area of 2 m 2 in one step. The decontamination factors achieved with this technique range between 100 and 1000. The second process consists in the decontamination of nuclear components using vibratory equipment with self-cleaning abrasives generating a minimum quantity of waste. This technique may reach contamination factors similar to those obtained with other abrasive methods (brush abrasion, abrasive blasting, etc...). The obtained decontamination factors range between 5 and 50. Only a small quantity of waste is generated, which is treated and reduced in volume by filtration and evaporation

  8. Multi-dimensional water quality assessment of an urban drinking water source elucidated by high resolution underwater towed vehicle mapping.

    Science.gov (United States)

    Lock, Alan; Spiers, Graeme; Hostetler, Blair; Ray, James; Wallschläger, Dirk

    2016-04-15

    Spatial surveys of Ramsey Lake, Sudbury, Ontario water quality were conducted using an innovative underwater towed vehicle (UTV) equipped with a multi-parameter probe providing real-time water quality data. The UTV revealed underwater vent sites through high resolution monitoring of different spatial chemical characteristics using common sensors (turbidity, chloride, dissolved oxygen, and oxidation/reduction sensors) that would not be feasible with traditional water sampling methods. Multi-parameter probe vent site identification is supported by elevated alkalinity and silica concentrations at these sites. The identified groundwater vent sites appear to be controlled by bedrock fractures that transport water from different sources with different contaminants of concern. Elevated contaminants, such as, arsenic and nickel and/or nutrient concentrations are evident at the vent sites, illustrating the potential of these sources to degrade water quality. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Assessment of the applicability of AWJ technique for dismantling the reactor of Fugen. Performance of underwater-cutting thick plate and testing of sound-based monitoring for underwater-cutting process

    International Nuclear Information System (INIS)

    Maruyama, Shin-ichiro; Nishio, Shin-ichi

    2010-01-01

    The reactor of Fugen is characterized by its double-walled pressure tube construction that is composed of pressure tubes and calandria tubes. The reactor dismantlement has been planning on dismantling it under water and the abrasive water jet (AWJ) underwater-cutting method is chosen as an option among simultaneous double tubes cutting technologies. For assessing the applicability of the AWJ cutting technology, a thick plate was cut under water by the small AWJ cutting machine. In addition, since cutting causes muddiness in water, cutting was monitored by the sound-based monitoring system which was adopted as a secondary cutting monitoring method. As a results, it was demonstrated that one-phase cutting was possible under water for a stainless-steel plate with 150mm thickness and that the relationship between cutting depth and capable cutting speed could be predictable. As for the sound-based cutting monitoring, the predictability whether or not cutting would be successful was verified by checking the change of sounds level. (author)

  10. Blind equalization for underwater communications

    NARCIS (Netherlands)

    Blom, K.C.H.

    2014-01-01

    Underwater wireless (sensor) networks would vastly improve man's ability to explore and exploit remote aquatic environments. Despite underwater sensor and vehicle technology being relatively mature, underwater communications is still a major challenge. The most challenging characteristics of the

  11. Assessing and mitigating of bottom trawling. Final BENTHIS project Report (Benthic Ecosystem Fisheries Impact Study)

    DEFF Research Database (Denmark)

    Rijnsdorp, Adriaan D; Eigaard, Ole Ritzau; Kenny, Andrew

    2017-01-01

    the fuel cost without affecting the catch rate of the target species. Replacing mechanical stimulation by tickler chains with electrical stimulation In the beam trawl fishery for sole, reduced footprint and penetration depth as well as the fuel cost. Electrical stimulation is also a promising innovation...... to reduce the bycatch and bottom contact in the beam trawl fishery for brown shrimps. Sea trials to replace bottom trawls with pots were inconclusive. Results suggest that creels may offer an alternative for small Nephrops fishers in the Kattegat. In waters off Greece, the catch rates were very low. Sea...... trials with the blue mussel fishery showed that fishers could reduce their footprint by deploying acoustic equipment to detect mussel concentrations that allow the fishers to more precisely target the mussel beds and hence reduce fishing in areas with low mussel density. A review of the various case...

  12. 75 FR 61705 - Fisheries of the South Atlantic and Gulf of Mexico; Southeast Data, Assessment, and Review (SEDAR...

    Science.gov (United States)

    2010-10-06

    ... Management Councils, in conjunction with NOAA Fisheries and the Atlantic and Gulf States Marine Fisheries... Atlantic, and Caribbean Fishery Management Councils and NOAA Fisheries Southeast Regional Office and..., environmentalists, and NGO's; International experts; and staff of Councils, Commissions, and state and federal...

  13. Fishery Biology Database (AGDBS)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Basic biological data are the foundation on which all assessments of fisheries resources are built. These include parameters such as the size and age composition of...

  14. Fisheries products export training Vietnam: On Risk assessment, HACCP auditing and EU legislation & monitoring

    NARCIS (Netherlands)

    Schelvis, R.; Poelman, M.

    2012-01-01

    IMARES and RIKILT developed a training program for fisheries inspectors and private sector quality controllers in Vietnam, in close cooperation with the Dutch Ministry of Economic Affairs, Agriculture and Innovation (EL&I) and the Dutch Ministry of Foreign Affairs (buza) and the Vietnamese fish

  15. A Decade in Climate Changes and Marine Fisheries: Assessing the Catchment Volume in Peninsular Malaysia

    Science.gov (United States)

    Kamal, A. H. M.

    2016-12-01

    Global climate change variations over the past 30 years have produced numerous impacts in the abundance and production performance of marine fish and fisheries worldwide. The consequences in terms of flooding of low-lying estuarine habitats due to over rainfall, fluctuation of temperature, dilution of water parameters, devastation of feeding and breeding habitats, salinity fluctuations and acidification of waters, high siltation in coastal area, changes in the sea water table and breeding triggers have raised serious concerns for the well-being of marine fisheries and their production. This study shows that the overall total catchment of marine fisheries was decreased 38% in 2009 compared to 1998 while considers the fishing gears and vessels number used in Peninsular Malaysia. Registered vessels number was increased up to 92% in 2009 compared to 1998 which eventually increased the total catchment volume of marine fisheries. In 2009, the catching efforts and performance was far low as per vessels compared to 1998. Analysis of climate change variables shows that temperature was decreased as rainfall was increased within the year from 1998 to 2009. However, it is still early to conclude that whether climate change variables could have unpleasant impacts on fish production in the tropical seas like Malaysia. In spite of that it is predicted that the prolong exists of monsoon and increases of rainfall in this area resulting the stresses and sometimes interfering on the habitat, reproductive cycle and their related ecosystems in this coastal marine environment in tropics.

  16. A assessment of the fishery resources for non-penaeid prawns in India

    Digital Repository Service at National Institute of Oceanography (India)

    George, M.J.

    prawn fishery of the different zones of the Indian coast the non-penaeids average to 47.9% Nearly 90% of these catches come from the Maharashtra and Gujarat coast The species which are most abundant are Acetes indicus, Palaemon tenuipes, Palaemon...

  17. Benthos and demersal fishery resources assessment in the shelf region of Indian coast

    Digital Repository Service at National Institute of Oceanography (India)

    Harkantra, S.N.

    coast. An overall increase of double in exploitation of demersal fishery resources is envisaged compared to the present exploitation of 0.12 m.m.t.y. However, one should keep in mind the conservation strategies before exploiting these resources....

  18. An assessment of the nkacha net fishery of Lake Malombe, Malawi ...

    African Journals Online (AJOL)

    length at maturity. Comparisons with previous work show that C. virginalis, L. turneri and O. argyrosoma sp. 'red' declined in abundance in nkachanet catches between 1991 and 2000. The fishery therefore tends towards both growth and recruitment overfishing. African Journal of Aquatic Science 2004, 29(1): 47–55 ...

  19. 78 FR 25702 - Notice of Availability of a Draft Programmatic Environmental Assessment for Fisheries Research...

    Science.gov (United States)

    2013-05-02

    ... environment. Cumulative effects of external actions and the contribution of fisheries research activities to... may also be viewed, by appointment, during regular business hours, at the aforementioned address. FOR.... Potential direct and indirect effects on the environment are evaluated under each alternative in the DPEA...

  20. Economic Vulnerability Assessment of U.S. Fishery Revenues to Ocean Acidification

    Science.gov (United States)

    Cooley, S. R.; Doney, S. C.

    2008-12-01

    Ocean acidification, a predictable consequence of rising anthropogenic CO2 emissions, is poised to change marine ecosystems profoundly by decreasing average ocean pH and the carbonate mineral saturation state worldwide. These conditions slow or reverse marine plant and animal calcium carbonate shell growth, thereby harming economically valuable species. In 2006, shellfish and crustaceans provided 50% of the 4 billion U.S. domestic commercial harvest value; value added to commercial fishery products contributed 35 billion to the gross national product that year. Laboratory studies have shown that ocean acidification decreases shellfish calcification; ocean acidification--driven declines in commercial shellfish and crustacean harvests between now and 2060 could decrease nationwide time-integrated primary commercial revenues by 860 million to 14 billion (net present value, 2006 dollars), depending on CO2 emissions, discount rates, biological responses, and fishery structure. This estimate excludes losses from coral reef damage and possible fishery collapses if ocean acidification pushes ecosystems past ecological tipping points. Expanding job losses and indirect economic costs will follow harvest decreases as ocean acidification broadly damages marine habitats and alters marine resource availability. Losses will harm many regions already possessing little economic resilience. The only true solution to ocean acidification is reducing atmospheric CO2 emissions, but implementing regional adaptive responses now from an ecosystem-wide, fisheries perspective will help better preserve sustainable ecosystem function and economic yields. Comprehensive management strategies must include monitoring critical fisheries, explicitly accounting for ocean acidification in management models, reducing fishing pressure and environmental stresses, and supporting regional economies most sensitive to acidification's impacts.

  1. Underwater welding of steel

    International Nuclear Information System (INIS)

    Ibarra, S.; Olson, D.L.

    1992-01-01

    A fundamental basis to understand the behavior of wet underwater welding of steel is introduced. Both the pyrometallurgical and physical metallurgy concepts are discussed. Modifications of welding consumables and practice are suggested. This chapter promotes further contributions of meatllurgical research to improve and promote wet underwater welding. (orig.)

  2. Underwater Scene Composition

    Science.gov (United States)

    Kim, Nanyoung

    2009-01-01

    In this article, the author describes an underwater scene composition for elementary-education majors. This project deals with watercolor with crayon or oil-pastel resist (medium); the beauty of nature represented by fish in the underwater scene (theme); texture and pattern (design elements); drawing simple forms (drawing skill); and composition…

  3. Underwater Acoustic Networking Techniques

    CERN Document Server

    Otnes, Roald; Casari, Paolo; Goetz, Michael; Husøy, Thor; Nissen, Ivor; Rimstad, Knut; van Walree, Paul; Zorzi, Michele

    2012-01-01

    This literature study presents an overview of underwater acoustic networking. It provides a background and describes the state of the art of all networking facets that are relevant for underwater applications. This report serves both as an introduction to the subject and as a summary of existing protocols, providing support and inspiration for the development of network architectures.

  4. Underwater Acoustic Tracer System

    Science.gov (United States)

    2009-03-13

    for controlling and utilizing supercavitating projectile dynamics to produce a distinctive radiated noise signal. (2) Description of the Prior Art...metallic objects which travel relatively closely to a magnetic pickup. For larger, high speed, underwater projectiles, supercavitating underwater vehicles...have been proposed for use. The conditions for supercavitation are known in the art. Supercavitation allows for higher speeds to be sustainable

  5. Impact of Vessel Noise on Oyster Toadfish (Opsanus tau) Behavior and Implications for Underwater Noise Management

    Science.gov (United States)

    Krahforst, Cecilia S.

    Underwater noise and its impacts on marine life are growing management concerns. This dissertation considers both the ecological and social concerns of underwater noise, using the oyster toadfish (Opsanus tau) as a model species. Oyster toadfish call for mates using a boatwhistle sound, but increased ambient noise levels from vessels or other anthropogenic activities are likely to influence the ability of males to find mates. If increased ambient noise levels reduce fish fitness then underwater noise can impact socially valued ecosystem services (e.g. fisheries). The following ecological objectives of the impacts of underwater noise on oyster toadfish were investigated: (1) to determine how noise influences male calling behavior; (2) to assess how areas of high vessel activity ("noisy") and low vessel activity ("quiet") influence habitat utilization (fish standard length and occupancy rate); and (3) to discover if fitness (number of clutches and number of embryos per clutch) is lower in "noisy" compared with "quiet" sites. Field experiments were executed in "noisy" and "quiet" areas. Recorded calls by males in response to playback sounds (vessel, predator, and snapping shrimp sounds) and egg deposition by females ("noisy" vs. "quiet" sites) demonstrated that oyster toadfish are impacted by underwater noise. First, males decreased their call rates and called louder in response to increased ambient noise levels. Second, oyster toadfish selected nesting sites in areas with little or no inboard motorboat activity. Third, male oyster toadfish at "noisy" sites either had no egg clutches on their shelters or the number of embryos per clutch was significantly lower than in the "quiet" areas. Underwater noise and disturbance from vessels are influencing the fitness of the oyster toadfish. The social significance of the growing concerns regarding underwater noise was investigated by identifying dominant themes found within two types of texts: four recent underwater noise

  6. Spatial assessment of fishing effort around European marine reserves: implications for successful fisheries management.

    Science.gov (United States)

    Stelzenmüller, Vanessa; Maynou, Francesc; Bernard, Guillaume; Cadiou, Gwenaël; Camilleri, Matthew; Crec'hriou, Romain; Criquet, Géraldine; Dimech, Mark; Esparza, Oscar; Higgins, Ruth; Lenfant, Philippe; Pérez-Ruzafa, Angel

    2008-12-01

    We examined the spatial dynamic of artisanal fishing fleets around five European marine protected areas (MPAs) to derive general implications for the evaluation of MPAs as fisheries management tools. The coastal MPAs studied were located off France, Malta and Spain and presented a variety of spatial designs and processes of establishment. We developed a standardized methodology to define factors influencing effort allocation and to produce fishing effort maps by merging GIS with geostatistical modelling techniques. Results revealed that in most cases the factors "distance to the no-take", "water depth", and "distance to the port" had a significant influence on effort allocation by the fishing fleets. Overall, we found local concentration of fishing effort around the MPA borders. Thus, neglecting the pattern of fishing effort distribution in evaluating MPA benefits, such as spillover of biomass, could hamper sound interpretation of MPAs as fisheries management tools.

  7. Design of underwater work systems

    International Nuclear Information System (INIS)

    Lovelace, R.B.

    1980-01-01

    In the near future, underwater vehicles will replace divers as the principal means for inspection and maintenance work. These vehicles will provide a maneuverable work platform for an underwater viewing system and manipulator/tool package. Some of the problems faced by the underwater designer, and some areas to consider in the design of an integrated underwater work system, are considered

  8. 76 FR 30921 - South Atlantic Fishery Management Council; Public Meetings

    Science.gov (United States)

    2011-05-27

    .... SUMMARY: The South Atlantic Fishery Management Council will hold a joint meeting of its Executive/Finance... Atlantic Fishery Management Council; Public Meetings AGENCY: National Marine Fisheries Service (NMFS..., Assessment and Review (SEDAR) Committee; Law Enforcement [[Page 30922

  9. 75 FR 4535 - Fisheries of the Gulf of Mexico; Southeast Data, Assessment, and Review (SEDAR); data workshop...

    Science.gov (United States)

    2010-01-28

    ... INFORMATION: The Gulf of Mexico, South Atlantic, and Caribbean Fishery Management Councils, in conjunction... Workshops are appointed by the Gulf of Mexico, South Atlantic, and Caribbean Fishery Management Councils and...; constituency representatives including fishermen, environmentalists, and NGO's; International experts; and...

  10. 77 FR 43049 - Fisheries of the Gulf of Mexico and South Atlantic; Southeast Data, Assessment and Review (SEDAR...

    Science.gov (United States)

    2012-07-23

    ... Spanish mackerel and cobia fisheries will consist of a series of workshops and supplemental webinars. This... cobia fisheries. Special Accommodations This meeting is accessible to people with disabilities. Requests...

  11. Assessing the Underwater Acoustics of the World's Largest Vibration Hammer (OCTA-KONG) and Its Potential Effects on the Indo-Pacific Humpbacked Dolphin (Sousa chinensis)

    Science.gov (United States)

    Wang, Zhitao; Wu, Yuping; Duan, Guoqin; Cao, Hanjiang; Liu, Jianchang; Wang, Kexiong; Wang, Ding

    2014-01-01

    Anthropogenic noise in aquatic environments is a worldwide concern due to its potential adverse effects on the environment and aquatic life. The Hongkong-Zhuhai-Macao Bridge is currently under construction in the Pearl River Estuary, a hot spot for the Indo-Pacific humpbacked dolphin (Sousa chinensis) in China. The OCTA-KONG, the world's largest vibration hammer, is being used during this construction project to drive or extract steel shell piles 22 m in diameter. This activity poses a substantial threat to marine mammals, and an environmental assessment is critically needed. The underwater acoustic properties of the OCTA-KONG were analyzed, and the potential impacts of the underwater acoustic energy on Sousa, including auditory masking and physiological impacts, were assessed. The fundamental frequency of the OCTA-KONG vibration ranged from 15 Hz to 16 Hz, and the noise increments were below 20 kHz, with a dominant frequency and energy below 10 kHz. The resulting sounds are most likely detectable by Sousa over distances of up to 3.5 km from the source. Although Sousa clicks do not appear to be adversely affected, Sousa whistles are susceptible to auditory masking, which may negatively impact this species' social life. Therefore, a safety zone with a radius of 500 m is proposed. Although the zero-to-peak source level (SL) of the OCTA-KONG was lower than the physiological damage level, the maximum root-mean-square SL exceeded the cetacean safety exposure level on several occasions. Moreover, the majority of the unweighted cumulative source sound exposure levels (SSELs) and the cetacean auditory weighted cumulative SSELs exceeded the acoustic threshold levels for the onset of temporary threshold shift, a type of potentially recoverable auditory damage resulting from prolonged sound exposure. These findings may aid in the identification and design of appropriate mitigation methods, such as the use of air bubble curtains, “soft start” and “power down

  12. Assessing the underwater acoustics of the world's largest vibration hammer (OCTA-KONG and its potential effects on the Indo-Pacific humpbacked dolphin (Sousa chinensis.

    Directory of Open Access Journals (Sweden)

    Zhitao Wang

    Full Text Available Anthropogenic noise in aquatic environments is a worldwide concern due to its potential adverse effects on the environment and aquatic life. The Hongkong-Zhuhai-Macao Bridge is currently under construction in the Pearl River Estuary, a hot spot for the Indo-Pacific humpbacked dolphin (Sousa chinensis in China. The OCTA-KONG, the world's largest vibration hammer, is being used during this construction project to drive or extract steel shell piles 22 m in diameter. This activity poses a substantial threat to marine mammals, and an environmental assessment is critically needed. The underwater acoustic properties of the OCTA-KONG were analyzed, and the potential impacts of the underwater acoustic energy on Sousa, including auditory masking and physiological impacts, were assessed. The fundamental frequency of the OCTA-KONG vibration ranged from 15 Hz to 16 Hz, and the noise increments were below 20 kHz, with a dominant frequency and energy below 10 kHz. The resulting sounds are most likely detectable by Sousa over distances of up to 3.5 km from the source. Although Sousa clicks do not appear to be adversely affected, Sousa whistles are susceptible to auditory masking, which may negatively impact this species' social life. Therefore, a safety zone with a radius of 500 m is proposed. Although the zero-to-peak source level (SL of the OCTA-KONG was lower than the physiological damage level, the maximum root-mean-square SL exceeded the cetacean safety exposure level on several occasions. Moreover, the majority of the unweighted cumulative source sound exposure levels (SSELs and the cetacean auditory weighted cumulative SSELs exceeded the acoustic threshold levels for the onset of temporary threshold shift, a type of potentially recoverable auditory damage resulting from prolonged sound exposure. These findings may aid in the identification and design of appropriate mitigation methods, such as the use of air bubble curtains, "soft start" and "power down

  13. Holistic assessment of Chwaka Bay's multi-gear fishery - Using a trophic modeling approach

    Science.gov (United States)

    Rehren, Jennifer; Wolff, Matthias; Jiddawi, Narriman

    2018-04-01

    East African coastal communities highly depend on marine resources for not just income but also protein supply. The multi-species, multi-gear nature of East African fisheries makes this type of fishery particularly difficult to manage, as there is a trade-off between maximizing total catch from all gears and species and minimizing overfishing of target species and the disintegration of the ecosystem. The use and spatio-temporal overlap of multiple gears in Chwaka Bay (Zanzibar) has led to severe conflicts between fishermen. There is a general concern of overfishing in the bay because of the widespread use of small mesh sizes and destructive gears such as dragnets and spear guns. We constructed an Ecopath food web model to describe the current trophic flow structure and fishing pattern of the bay. Based on this model, we explored the impact of different gears on the ecosystem and the fishing community in order to give advice for gear based management in the bay. Results indicate that Chwaka bay is a productive, shallow water system, with biomass concentrations around the first and second trophic level. The system is greatly bottom-up driven and dominated by primary producers and invertebrates. The trophic and network indicators as well as the community energetics characterize Chwaka Bay as relatively mature. Traps and dragnets have the strongest impact on the ecosystem and on the catches obtained by other gears. Both gears potentially destabilize the ecosystem by reducing the biomass of top-down controlling key species (including important herbivores of macroalgae). The dragnet fishery is the least profitable, but provides most jobs for the fishing community. Thus, a complete ban of dragnets in the bay would require the provision of alternative livelihoods. Due to the low resource biomass of fish in the bay and the indication of a loss of structural control of certain fish groups, Chwaka Bay does not seem to provide scope for further expansion of the fishery

  14. SMART: a spatially explicit bio-economic model for assessing and managing demersal fisheries, with an application to italian trawlers in the strait of sicily.

    Directory of Open Access Journals (Sweden)

    Tommaso Russo

    Full Text Available Management of catches, effort and exploitation pattern are considered the most effective measures to control fishing mortality and ultimately ensure productivity and sustainability of fisheries. Despite the growing concerns about the spatial dimension of fisheries, the distribution of resources and fishing effort in space is seldom considered in assessment and management processes. Here we propose SMART (Spatial MAnagement of demersal Resources for Trawl fisheries, a tool for assessing bio-economic feedback in different management scenarios. SMART combines information from different tasks gathered within the European Data Collection Framework on fisheries and is composed of: 1 spatial models of fishing effort, environmental characteristics and distribution of demersal resources; 2 an Artificial Neural Network which captures the relationships among these aspects in a spatially explicit way and uses them to predict resources abundances; 3 a deterministic module which analyzes the size structure of catches and the associated revenues, according to different spatially-based management scenarios. SMART is applied to demersal fishery in the Strait of Sicily, one of the most productive fisheries of the Mediterranean Sea. Three of the main target species are used as proxies for the whole range exploited by trawlers. After training, SMART is used to evaluate different management scenarios, including spatial closures, using a simulation approach that mimics the recent exploitation patterns. Results evidence good model performance, with a noteworthy coherence and reliability of outputs for the different components. Among others, the main finding is that a partial improvement in resource conditions can be achieved by means of nursery closures, even if the overall fishing effort in the area remains stable. Accordingly, a series of strategically designed areas of trawling closures could significantly improve the resource conditions of demersal fisheries in

  15. SMART: a spatially explicit bio-economic model for assessing and managing demersal fisheries, with an application to italian trawlers in the strait of sicily.

    Science.gov (United States)

    Russo, Tommaso; Parisi, Antonio; Garofalo, Germana; Gristina, Michele; Cataudella, Stefano; Fiorentino, Fabio

    2014-01-01

    Management of catches, effort and exploitation pattern are considered the most effective measures to control fishing mortality and ultimately ensure productivity and sustainability of fisheries. Despite the growing concerns about the spatial dimension of fisheries, the distribution of resources and fishing effort in space is seldom considered in assessment and management processes. Here we propose SMART (Spatial MAnagement of demersal Resources for Trawl fisheries), a tool for assessing bio-economic feedback in different management scenarios. SMART combines information from different tasks gathered within the European Data Collection Framework on fisheries and is composed of: 1) spatial models of fishing effort, environmental characteristics and distribution of demersal resources; 2) an Artificial Neural Network which captures the relationships among these aspects in a spatially explicit way and uses them to predict resources abundances; 3) a deterministic module which analyzes the size structure of catches and the associated revenues, according to different spatially-based management scenarios. SMART is applied to demersal fishery in the Strait of Sicily, one of the most productive fisheries of the Mediterranean Sea. Three of the main target species are used as proxies for the whole range exploited by trawlers. After training, SMART is used to evaluate different management scenarios, including spatial closures, using a simulation approach that mimics the recent exploitation patterns. Results evidence good model performance, with a noteworthy coherence and reliability of outputs for the different components. Among others, the main finding is that a partial improvement in resource conditions can be achieved by means of nursery closures, even if the overall fishing effort in the area remains stable. Accordingly, a series of strategically designed areas of trawling closures could significantly improve the resource conditions of demersal fisheries in the Strait of

  16. Underwater 3D filming

    Directory of Open Access Journals (Sweden)

    Roberto Rinaldi

    2014-12-01

    Full Text Available After an experimental phase of many years, 3D filming is now effective and successful. Improvements are still possible, but the film industry achieved memorable success on 3D movie’s box offices due to the overall quality of its products. Special environments such as space (“Gravity” and the underwater realm look perfect to be reproduced in 3D. “Filming in space” was possible in “Gravity” using special effects and computer graphic. The underwater realm is still difficult to be handled. Underwater filming in 3D was not that easy and effective as filming in 2D, since not long ago. After almost 3 years of research, a French, Austrian and Italian team realized a perfect tool to film underwater, in 3D, without any constrains. This allows filmmakers to bring the audience deep inside an environment where they most probably will never have the chance to be.

  17. Underwater wireless communication system

    International Nuclear Information System (INIS)

    Goh, J H; Shaw, A; Al-Shamma'a, A I

    2009-01-01

    Underwater communication has a range of applications including remotely operated vehicle (ROV) and autonomous underwater vehicle (AUV) communication and docking in the offshore industry. Current underwater transmission techniques is primarily utilise sound waves for large distance at lower frequencies and the velocity of sound in water is approximately 1500m/s the resultant communications have problems with multi-path propagation and low bandwidth problems. The use of electromagnetic (EM) techniques underwater has largely been overlooked because of the attenuation due to the conductivity of seawater. However, for short range applications, the higher frequencies and much higher velocity can prove advantageous. This paper will outline a project which will utilise recent investigations that demonstrate EM wave propagation up to the MHz frequency range is possible in seawater.

  18. Smelling and Tasting Underwater.

    Science.gov (United States)

    Atema, Jelle

    1980-01-01

    Discusses differences between smell and taste, comparing these senses in organisms in aquatic and terrestrial environments. Describes the chemical environment underwater and in air, differences in chemoreceptors to receive stimuli, and the organs, brain, and behavior involved in chemoreception. (CS)

  19. Human Injury Criteria for Underwater Blasts.

    Directory of Open Access Journals (Sweden)

    Rachel M Lance

    Full Text Available Underwater blasts propagate further and injure more readily than equivalent air blasts. Development of effective personal protection and countermeasures, however, requires knowledge of the currently unknown human tolerance to underwater blast. Current guidelines for prevention of underwater blast injury are not based on any organized injury risk assessment, human data or experimental data. The goal of this study was to derive injury risk assessments for underwater blast using well-characterized human underwater blast exposures in the open literature. The human injury dataset was compiled using 34 case reports on underwater blast exposure to 475 personnel, dating as early as 1916. Using severity ratings, computational reconstructions of the blasts, and survival information from a final set of 262 human exposures, injury risk models were developed for both injury severity and risk of fatality as functions of blast impulse and blast peak overpressure. Based on these human data, we found that the 50% risk of fatality from underwater blast occurred at 302±16 kPa-ms impulse. Conservatively, there is a 20% risk of pulmonary injury at a kilometer from a 20 kg charge. From a clinical point of view, this new injury risk model emphasizes the large distances possible for potential pulmonary and gut injuries in water compared with air. This risk value is the first impulse-based fatality risk calculated from human data. The large-scale inconsistency between the blast exposures in the case reports and the guidelines available in the literature prior to this study further underscored the need for this new guideline derived from the unique dataset of actual injuries in this study.

  20. Local ecological knowledge and scientific data reveal overexploitation by multigear artisanal fisheries in the southwestern Atlantic.

    Directory of Open Access Journals (Sweden)

    Mariana G Bender

    Full Text Available In the last decades, a number of studies based on historical records revealed the diversity loss in the oceans and human-induced changes to marine ecosystems. These studies have improved our understanding of the human impacts in the oceans. They also drew attention to the shifting baseline syndrome and the importance of assessing appropriate sources of data in order to build the most reliable environmental baseline. Here we amassed information from artisanal fishermen's local ecological knowledge, fisheries landing data and underwater visual census to assess the decline of fish species in Southeastern Brazil. Interviews with 214 fishermen from line, beach seine and spearfishing revealed a sharp decline in abundance of the bluefish Pomatomus saltatrix, the groupers Epinephelus marginatus, Mycteroperca acutirostris, M. bonaci and M. microlepis, and large parrotfishes in the past six decades. Fisheries landing data from a 16-year period support the decline of bluefish as pointed by fishermen's local knowledge, while underwater visual census campaigns show reductions in groupers' abundance and a sharp population decline of the Brazilian endemic parrotfish Scarus trispinosus. Despite the marked decline of these fisheries, younger and less experienced fishermen recognized fewer species as overexploited and fishing sites as depleted than older and more experienced fishermen, indicating the occurrence of the shifting baseline syndrome. Here we show both the decline of multigear fisheries catches - combining anecdotal and scientific data - as well as changes in environmental perceptions over generations of fishermen. Managing ocean resources requires looking into the past, and into traditional knowledge, bringing historical baselines to the present and improving public awareness.

  1. Autonomous Underwater Gliders

    OpenAIRE

    Wood,; Stephen,

    2009-01-01

    Autonomous Underwater Vehicles are only now being marketed as robust commercial vehicles for many industries, and of these vehicles underwater gliders are becoming the new tool for oceanographers. Satellites have provided scientists and marine specialists with measurements of the sea surface such as temperature since the late 1970s, and data via subsurface oceanographic moorings since the 1950's. As stated by David Smeed of the National Oceanography Centre, Southampton, England, that "gliders...

  2. Underwater Gliders: A Review

    OpenAIRE

    Javaid Muhammad Yasar; Ovinis Mark; Nagarajan T; Hashim Fakhruldin B M

    2014-01-01

    Underwater gliders are a type of underwater vehicle that transverse the oceans by shifting its buoyancy, during which its wings develop a component of the downward motion in the horizontal plane, thus producing a forward force. They are primarily used in oceanography sensing and data collection and play an important role in ocean research and development. Although there have been considerable developments in these gliders since the development of the first glider concept in 1989, to date, no ...

  3. Stock assessment of the lizardfish Saurida tumbil (Bloch, 1795 in Jizan fisheries, Saudi Arabia

    Directory of Open Access Journals (Sweden)

    Mohamed Hosny Gabr

    2017-06-01

    Full Text Available To evaluate the current stock status of the lizardfish Saurida tumbil in Jizan fisheries, growth parameters, mortality coefficients and size at first capture were determined. Otoliths collected from 623 specimens were used for age determination and back calculations of lengths at ages. The growth parameters of von Bertalanffy were estimated and found to be L∞ = 52.98 cm, K = 0.27 yr−1, and to = -0.84 yr. The mortality coefficients were estimated to be 1.365, 0.403 and 0.962 yr−1 for the total 'Z', natural 'M', and fishing 'F' mortality coefficient, respectively. The current exploitation rate 'Ecur' was 0.705 yr−1. The length at first capture 'Lc' was determined to be 25.1 cm. The relative yield and biomass per recruit were estimated, and the results showed that the exploitation rate is currently higher than Emax = 0.685 yr−1 and E0.1 = 0.551 yr−1 as biological reference points, which indicates that the stock of Saurida tumbil in Jizan fisheries is currently overexploited.

  4. Stakeholder participation and sustainable fisheries: an integrative framework for assessing adaptive comanagement processes

    Directory of Open Access Journals (Sweden)

    Christian Stöhr

    2014-09-01

    Full Text Available Adaptive comanagement (ACM has been suggested as the way to successfully achieve sustainable environmental governance. Despite excellent research, the field still suffers from underdeveloped frameworks of causality. To address this issue, we suggest a framework that integrates the structural frame of Plummer and Fitzgibbons' "adaptive comanagement" with the specific process characteristics of Senecah's "Trinity of Voice." The resulting conceptual hybrid is used to guide the comparison of two cases of stakeholder participation in fisheries management - the Swedish Co-management Initiative and the Polish Fisheries Roundtable. We examine how different components of preconditions and the process led to the observed outcomes. The analysis shows that despite the different cultural and ecological contexts, the cases developed similar results. Triggered by a crisis, the participating stakeholders were successful in developing trust and better communication and enhanced learning. This can be traced back to a combination of respected leadership, skilled mediation, and a strong focus on deliberative approaches and the creation of respectful dialogue. We also discuss the difficulties of integrating outcomes of the work of such initiatives into the actual decision-making process. Finally, we specify the lessons learned for the cases and the benefits of applying our integrated framework.

  5. Towards sustainable fisheries of the Öresund cod (Gadus morhua) through sub-stock-specific assessment and management recommendations

    DEFF Research Database (Denmark)

    Lindegren, Martin; Waldo, Staffan; Nilsson, P. Anders

    2013-01-01

    Fisheries management traditionally relies on stock assessments assuming discrete populations within large administrational areas. However, failing to account for sub-stock structuring may result in overestimation of the stocks' true harvest potential and unsustainable exploitation of small stock...... elements. Atlantic cod (Gadus morhua) frequently occurs in spatially segregated populations, some of which exhibit fine-scaled stock structuring within current management boundaries. Here we use the locally spawning cod stock in the Sound (“Öresund”) as a case study, and perform a sub-stock......-specific assessment to evaluate biological and economic effects of managing the Sound cod as a separate stock. Our results indicate that reducing exploitation pressure, particularly through technical regulations i.e. increasing gill-net mesh sizes, would not only enhance the stock age distribution, but yield long...

  6. Assessment of Competition between Fisheries and Steller Sea Lions in Alaska Based on Estimated Prey Biomass, Fisheries Removals and Predator Foraging Behaviour.

    Directory of Open Access Journals (Sweden)

    Tabitha C Y Hui

    Full Text Available A leading hypothesis to explain the dramatic decline of Steller sea lions (Eumetopias jubatus in western Alaska during the latter part of the 20th century is a change in prey availability due to commercial fisheries. We tested this hypothesis by exploring the relationships between sea lion population trends, fishery catches, and the prey biomass accessible to sea lions around 33 rookeries between 2000 and 2008. We focused on three commercially important species that have dominated the sea lion diet during the population decline: walleye pollock, Pacific cod and Atka mackerel. We estimated available prey biomass by removing fishery catches from predicted prey biomass distributions in the Aleutian Islands, Bering Sea and Gulf of Alaska; and modelled the likelihood of sea lions foraging at different distances from rookeries (accessibility using satellite telemetry locations of tracked animals. We combined this accessibility model with the prey distributions to estimate the prey biomass accessible to sea lions by rookery. For each rookery, we compared sea lion population change to accessible prey biomass. Of 304 comparisons, we found 3 statistically significant relationships, all suggesting that sea lion populations increased with increasing prey accessibility. Given that the majority of comparisons showed no significant effect, it seems unlikely that the availability of pollock, cod or Atka mackerel was limiting sea lion populations in the 2000s.

  7. Fisheries regulation

    DEFF Research Database (Denmark)

    Jensen, Frank; Frost, Hans Staby; Abildtrup, Jens

    2017-01-01

    Economists normally claim that a stock externality arises within fisheries because each individual fisherman does not take the effect on stock size into account when making harvest decisions. Due to the stock externality, it is commonly argued that fisheries regulation is necessary, but regulatory...... decisions are complicated by a tremendous amount of uncertainty and asymmetric information. This paper provides an overview of selected parts of the literature on the regulation of fisheries under uncertainty and asymmetric information, and possible areas for future research are identified. Specifically...

  8. Fisheries Districts

    Data.gov (United States)

    Vermont Center for Geographic Information — The Fisheries districts data layer is part of a larger dataset that contains administrative boundaries for Vermont's Agency of Natural Resources. The dataset...

  9. Assessment of the dolphinfish Coryphaena hippurus(Perciformes: Coryphaenidae fishery in Pacific Panama

    Directory of Open Access Journals (Sweden)

    Héctor M Guzman

    2015-09-01

    Full Text Available The dolphinfish (Coryphaena hippurusis a highly migratory pelagic species commercially exploited by industrial, artisanal and recreational fisheries in tropical and subtropical areas of the world's oceans. Herein, we evaluated the dolphinfish industrial fishery in Pacific Panama for the first time generating a growth model and examining fluctuations in annual total catch and in catch per unit effort (CPUE over a four-year period (2006-2009. Annual and monthly catch values and biological parameters of 14 913 individuals were obtained onboard industrial vessels, landing sites and records from processing plants. Size frequency for industrial vessels showed a normal distribution between 353 and 1 715 mm (average, 1 010.85 mm; n = 10 459. Fish weight averaged 4.94 kg (SD. Sex ratio was slightly biased toward females. More than 90% of the analyzed fish were sexually mature. The length-weight relationship was positive and significant, reflecting allometric growth. Growth parameters using the von Bertalanffy equation revealed a growth efficiency of 0 = 4.61, which is within the reported range for Coryphaena hippurus(3.95-4.70. The largest fish were between age classes 2 and 3 (7001 400 mm. Total catch per year and catch per unit effort (CPUE per year fluctuated, with the highest values recorded between 2008 and 2009. Catch values reported herein are preliminary and appear to be below those recorded elsewhere in the region and cautiously may represent an indicator of sustainable use of this marine resource even considering the absence of management actions in Panama.

  10. Application of fisheries management techniques to assessing impacts: task I report. [Assessment of chemical, radiological, and thermal impacts of nuclear power plants on fish populations

    Energy Technology Data Exchange (ETDEWEB)

    McKenzie, D.H.; Baker, K.S.; Fickeisen, D.H.; Metzger, R.M.; Skalski, J.R.

    1979-03-01

    Task I efforts examined the available fisheries management techniques and assessed their potential application in a confirmatory monitoring program. The objective of such monitoring programs is to confirm that the prediction of an insignificant impact (usually made in the FES) was correct. Fisheries resource managers have developed several tools for assessing the fish population response to stress (exploitation) and they were thought potentially useful for detecting nuclear power plant impacts. Techniques in three categories were examined; catch removal, population dynamics, and nondestructive censuses, and the report contains their description, examples of application, advantages, and disadvantages. The techniques applied at nuclear power plant sites were examined in detail to provide information on implementation and variability of specific approaches. The most suitable techniques to incorporate into a monitoring program confirming no impact appear to be those based on Catch Per Unity Effort (CPUE) and hydroacoustic data. In some specific cases, age and growth studies and indirect census techniques may be beneficial. Recommendations for task II efforts to incorporate these techniques into monitoring program designs are presented. These include development of guidelines for; (1) designing and implementing a data collection program; (2) interpreting these data and assessing the occurrence of impact, and (3) establishment of the monitoring program's ability to detect changes in the affected populations.

  11. Resources for Underwater Robotics Education

    Science.gov (United States)

    Wallace, Michael L.; Freitas, William M.

    2016-01-01

    4-H clubs can build and program underwater robots from raw materials. An annotated resource list for engaging youth in building underwater remotely operated vehicles (ROVs) is provided. This article is a companion piece to the Research in Brief article "Building Teen Futures with Underwater Robotics" in this issue of the "Journal of…

  12. Assessing impacts of simulated oil spills on the Northeast Arctic cod fishery.

    Science.gov (United States)

    Carroll, JoLynn; Vikebø, Frode; Howell, Daniel; Broch, Ole Jacob; Nepstad, Raymond; Augustine, Starrlight; Skeie, Geir Morten; Bast, Radovan; Juselius, Jonas

    2018-01-01

    We simulate oil spills of 1500 and 4500m 3 /day lasting 14, 45, and 90days in the spawning grounds of the commercial fish species, Northeast Arctic cod. Modeling the life history of individual fish eggs and larvae, we predict deviations from the historical pattern of recruitment to the adult population due to toxic oil exposures. Reductions in survival for pelagic stages of cod were 0-10%, up to a maximum of 43%. These reductions resulted in a decrease in adult cod biomass of <3% for most scenarios, up to a maximum of 12%. In all simulations, the adult population remained at full reproductive potential with a sufficient number of juveniles surviving to replenish the population. The diverse age distribution helps protect the adult cod population from reductions in a single year's recruitment after a major oil spill. These results provide insights to assist in managing oil spill impacts on fisheries. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  13. Underwater 3D filming

    OpenAIRE

    Rinaldi, Roberto

    2014-01-01

    After an experimental phase of many years, 3D filming is now effective and successful. Improvements are still possible, but the film industry achieved memorable success on 3D movie’s box offices due to the overall quality of its products. Special environments such as space (“Gravity” ) and the underwater realm look perfect to be reproduced in 3D. “Filming in space” was possible in “Gravity” using special effects and computer graphic. The underwater realm is still difficult to be handled. Unde...

  14. 75 FR 35442 - Fisheries of the Gulf of Mexico; Southeast Data, Assessment, and Review (SEDAR) Update; Greater...

    Science.gov (United States)

    2010-06-22

    ... INFORMATION: The Gulf of Mexico, South Atlantic, and Caribbean Fishery Management Councils, in conjunction... appointed by the Gulf of Mexico, South Atlantic, and Caribbean Fishery Management Councils and NOAA... representatives including fishermen, environmentalists, and NGO's; international experts; and staff of Councils...

  15. Microbiological assessment along the fish production chain of the Norwegian pelagic fisheries sector--Results from a spot sampling programme.

    Science.gov (United States)

    Svanevik, Cecilie Smith; Roiha, Irja Sunde; Levsen, Arne; Lunestad, Bjørn Tore

    2015-10-01

    Microbes play an important role in the degradation of fish products, thus better knowledge of the microbiological conditions throughout the fish production chain may help to optimise product quality and resource utilisation. This paper presents the results of a ten-year spot sampling programme (2005-2014) of the commercially most important pelagic fish species harvested in Norway. Fish-, surface-, and storage water samples were collected from fishing vessels and processing factories. Totally 1,181 samples were assessed with respect to microbiological quality, hygiene and food safety. We introduce a quality and safety assessment scheme for fresh pelagic fish recommending limits for heterotrophic plate counts (HPC), thermos tolerant coliforms, enterococci and Listeria monocytogenes. According to the scheme, in 25 of 41 samplings, sub-optimal conditions were found with respect to quality, whereas in 21 and 9 samplings, samples were not in compliance concerning hygiene and food safety, respectively. The present study has revealed that the quality of pelagic fish can be optimised by improving the hygiene conditions at some critical points at an early phase of the production chain. Thus, the proposed assessment scheme may provide a useful tool for the industry to optimise quality and maintain consumer safety of pelagic fishery products. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  16. Fisheries in the Mediterranean

    Directory of Open Access Journals (Sweden)

    C. PAPACONSTANTINOU

    2000-06-01

    Full Text Available The aim of this paper is to give a description of the Mediterranean fisheries, and its level of exploitation and to address the main questions dealing with its management. The Mediterranean is a semi-enclosed marine area with generally narrow continental shelves. The primary production of the Mediterranean is among the lowest in the world (26-50g C m-2 y-1. The Mediterranean fisheries can be broken down into three main categories: small scale fisheries, trawling and seining fisheries, which operated on demersal, small pelagic and large pelagic resources. After a general description of the state of the resources in the different areas of the Mediterranean it is concluded that (a the overall pictures from the western to the eastern Mediterranean are not considerably different, (b the total landings in the Mediterranean have been increased the last decades, and (c from the perspective of stock assessment, the very few available time series data show stable yield levels. In general fisheries management in the Mediterranean is at a rela- tively early stage of development, judging by the criteria of North Atlantic fisheries. Quota systems are generally not applied, mesh-size regulations usually are set at low levels relative to scientific advice, and effort limitation is not usually applied or, if it is, is not always based on a formal resource assessment. The conservation/management measures applied by the Mediterranean countries can be broadly separated into two major categories: those aiming to keep the fishing effort under control and those aiming to make the exploitation pattern more rational. The most acute problems in the management of the Mediterranean resources are the multispecificity of the catches and the lack of reliable official statistics.

  17. Network lifetime-aware data collection in Underwater Sensor ...

    Indian Academy of Sciences (India)

    Jalaja Janardanan Kartha

    2017-09-07

    Sep 7, 2017 ... existing models to assess their effectiveness and to investigate the trade-offs. Results show ... coverage drops below a predefined threshold and (vi) connectivity is .... Cost Clustering Protocol (MCCP), Distributed Underwater.

  18. Peruvian anchoveta as a telecoupled fisheries system

    Directory of Open Access Journals (Sweden)

    Andrew K. Carlson

    2018-03-01

    Full Text Available Fisheries are coupled human and natural systems (CHANS across distant places, yet fisheries research has generally focused on better understanding either fisheries ecology or human dimensions in a specific place, rather than their interactions over distances. As economic and ideational globalization accelerate, fisheries are becoming more globally connected via movements of fish products and fisheries finances, information, and stakeholders throughout the world. As such, there is a pressing need for systematic approaches to assess these linkages among global fisheries, their effects on ecosystems and food security, and their implications for fisheries science and sustainability. Use of the telecoupling framework is a novel and insightful method to systematically evaluate socioeconomic and environmental interactions among CHANS. We apply the telecoupling framework to the Peruvian anchoveta (Engraulis ringens fishery, the world's largest single-species commercial fishery and a complex CHANS. The anchoveta fishery has diverse and significant telecouplings, socioeconomic and environmental interactions over distances, with the rest of the world, including fishmeal and fish oil trade, monetary flow, knowledge transfer, and movement of people. The use of the telecoupling framework reveals complex fishery dynamics such as feedbacks (e.g., profit maximization causing fishery overcapitalization and surprises (e.g., stock collapse resulting from local and long-distance ecological and socioeconomic interactions. The Peruvian anchoveta fishery illustrates how the telecoupling framework can be used to systematically assess the magnitude and diversity of local and distant fisheries interactions and thereby advance knowledge derived from traditional monothematic research approaches. Insights from the telecoupling framework provide a foundation from which to develop sustainable fisheries policy and management strategies across local, national, and international

  19. NPRB 1319 Assessment of the benthic impacts of raised groundgear for the Eastern Bering Sea pollock fishery.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Alaska pollock fishing industry, in collaboration with scientists at Alaska Pacific University, the Alaska Fisheries Science Center, and members of the fishing...

  20. Assessment and management of white mullet Mugil curema (Valencienne, 1836 (Mugilidae fisheries of the south coast of São Paulo state, Brazil

    Directory of Open Access Journals (Sweden)

    JT. Mendonça

    Full Text Available There is intense fishing activity, mainly artisanal, in the Cananéia, Iguape and Ilha Comprida Estuarine System. White mullet (Mugil curema is one of the local fishery resources and is usually caught with gillnets and fish traps. This study aimed to characterise the Mugil curema fisheries thereby underpinning the management of the species in the region. The study was developed with data collected from landings in the town of Cananéia, São Paulo state, Brazil, from 1995 to 2009. Production data, fishing effort and CPUE were used to assess the evolution of captures. The gillnets were characterised by interviewing fishermen from 16 communities in Cananéia. White mullet fishery has aroused the interest of fishermen in the region since the 80s and today it is one of the main products of artisanal estuarine fishery off the south coast of São Paulo. The major landings occur in the warmer months with fish traps and gillnets being the main fishing gear used. The largest catches occur in the spawning months of the species from October to April. The highest landings varied according to different fishing gear, showing differences primarily due to trade preferences and to the structure of the fishing gear. According to the index of abundance used in this study, the resource is overfished due to the progressive increase in fishing effort, so it is suggested that measures should be taken to control fishing effort, such as special fishing permits to catch white mullet, especially with gillnets. The current management measures neither meet the needs of fishermen nor the preservation of the resource, and must be reviewed in a participatory way with management agencies and the fishery sector, ensuring greater legitimacy and success in the sustainability of the activity.

  1. Assessment and management of white mullet Mugil curema (Valencienne, 1836) (Mugilidae) fisheries of the south coast of São Paulo state, Brazil.

    Science.gov (United States)

    Mendonça, J T; Bonfante, T M

    2011-08-01

    There is intense fishing activity, mainly artisanal, in the Cananéia, Iguape and Ilha Comprida Estuarine System. White mullet (Mugil curema) is one of the local fishery resources and is usually caught with gillnets and fish traps. This study aimed to characterise the Mugil curema fisheries thereby underpinning the management of the species in the region. The study was developed with data collected from landings in the town of Cananéia, São Paulo state, Brazil, from 1995 to 2009. Production data, fishing effort and CPUE were used to assess the evolution of captures. The gillnets were characterised by interviewing fishermen from 16 communities in Cananéia. White mullet fishery has aroused the interest of fishermen in the region since the 80s and today it is one of the main products of artisanal estuarine fishery off the south coast of São Paulo. The major landings occur in the warmer months with fish traps and gillnets being the main fishing gear used. The largest catches occur in the spawning months of the species from October to April. The highest landings varied according to different fishing gear, showing differences primarily due to trade preferences and to the structure of the fishing gear. According to the index of abundance used in this study, the resource is overfished due to the progressive increase in fishing effort, so it is suggested that measures should be taken to control fishing effort, such as special fishing permits to catch white mullet, especially with gillnets. The current management measures neither meet the needs of fishermen nor the preservation of the resource, and must be reviewed in a participatory way with management agencies and the fishery sector, ensuring greater legitimacy and success in the sustainability of the activity.

  2. 78 FR 48654 - Fisheries of the Caribbean; Southeast Data, Assessment, and Review (SEDAR); Public Meeting

    Science.gov (United States)

    2013-08-09

    ...: Participants will present summary data and will discuss data needs and treatments. Although non-emergency... the Caribbean; Southeast Data, Assessment, and Review (SEDAR); Public Meeting AGENCY: National Marine... of SEDAR 35 data webinar for Caribbean Red Hind. SUMMARY: The SEDAR assessment of the Caribbean...

  3. An Assessment of Weight-Length Relationships for Muskellunge,Northern Pike, and Chain Pickerel In Carlander's Handbook of Freshwater Fishery Biology

    OpenAIRE

    Daviscourt, Joshua; Huertas, Joshua; Courtney, Michael

    2011-01-01

    Carlander's Handbook of Freshwater Fishery Biology (1969) contains life history data from many species of freshwater fish found in North America. It has been cited over 1200 times and used to produce standard-weight curves for some species. Recent work (Cole-Fletcher et al. 2011) suggests Carlander (1969) contains numerous errors in listed weight-length equations. This paper assesses the weight-length relationships listed in Carlander for muskellunge, northern pike, and chain pickerel by comp...

  4. Nekton from Fishery-Independent Trawl Samples in U.S. Gulf of Mexico Estuaries: A Comparative Assessment of Gulf Estuarine Systems (CAGES), 1973-2007 (NODC Accession 0115183)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The purpose of CAGES (Comparative Assessment of Gulf Estuarine Systems) is to compile the fishery independent data from five Gulf States into a database to more...

  5. Study of archaeological underwater finds: deterioration and conservation

    Science.gov (United States)

    Crisci, G. M.; La Russa, M. F.; Macchione, M.; Malagodi, M.; Palermo, A. M.; Ruffolo, S. A.

    2010-09-01

    This study is aimed at an assessment of the methodologies, instruments and new applications for underwater archaeology. Research focused on study of the various kinds of degradation affecting underwater finds and stone materials aged in underwater environment, efficiency evaluation of various surface cleaning methods and study and mixing of protective products with consolidating resins and antimicrobial biocides to be applied to restored underwater finds. Transmitted light optical microscopy and scanning electron microscopy (SEM) were used to study surface biofilms and the interactions with samples of different stone materials such as brick, marble and granite immersed in the submarine archaeological area of Crotone (South of Italy). Surface cleaning tests were performed with application of ion exchange resins, EDTA, hydrogen peroxide and ultrasound techniques. Capillary water absorption, simulated solar ageing and colourimetric measurements were carried out to evaluate hydrophobic and consolidant properties; to assess biocidal efficacy, heterotrophic micro-organisms ( Aspergillus niger) were inoculated on agar plates and growth inhibition was measured.

  6. 76 FR 34656 - Fisheries of the Caribbean; Southeast Data, Assessment, and Review (SEDAR); Public Meeting

    Science.gov (United States)

    2011-06-14

    ... status of the stock, estimates biological benchmarks, projects future population conditions, and... evaluate stock status, estimate population benchmarks and stock status criteria, and project future.... SUMMARY: The SEDAR assessments of the Caribbean stocks of silk snapper, queen snapper and redtail...

  7. 75 FR 17900 - Fisheries of the South Atlantic, Gulf of Mexico, and Caribbean; Southeastern Data, Assessment...

    Science.gov (United States)

    2010-04-08

    .... ADDRESSES: The meeting will be held at the Hotel Captain Cook, 939 West 5th Avenue, Anchorage, AK 99501... assessment scheduling for 2010-2015, and discuss the SEDAR budget, conflict of interest policies, and...

  8. Colour reconstruction of underwater images

    OpenAIRE

    Hoth, Julian; Kowalczyk, Wojciech

    2017-01-01

    Objects look very different in the underwater environment compared to their appearance in sunlight. Images with correct colouring simplify the detection of underwater objects and may allow the use of visual SLAM algorithms developed for land-based robots underwater. Hence, image processing is required. Current algorithms focus on the colour reconstruction of scenery at diving depth where different colours can still be distinguished. At greater depth this is not the case. In this study it is i...

  9. Underwater Welding Techniques

    OpenAIRE

    Esam F. Alajmi; Ahmad A. Alqenaei

    2017-01-01

    Welding demand in offshore and marine applications is increased with the increasing in oil and gas activities as well as increasing in the marine transportation and industrial applications. Applications of underwater welding well be increased in Kuwait in the coming years due to the strategic directive of the country toward starting the offshore oil and gas exploration and production, and the increase in marine transportation projects. Therefore, there is a need to understand the concept of u...

  10. Underwater Gliders: A Review

    Directory of Open Access Journals (Sweden)

    Javaid Muhammad Yasar

    2014-07-01

    Full Text Available Underwater gliders are a type of underwater vehicle that transverse the oceans by shifting its buoyancy, during which its wings develop a component of the downward motion in the horizontal plane, thus producing a forward force. They are primarily used in oceanography sensing and data collection and play an important role in ocean research and development. Although there have been considerable developments in these gliders since the development of the first glider concept in 1989, to date, no review of these gliders have been done. This paper reviews existing underwater gliders, with emphasis on their respective working principles, range and payload capacity. All information on gliders available in the public domain or published in literature from the year 2000-2013 was reviewed. The majority of these gliders have an operational depth of 1000 m and a payload of less than 25 kg. The exception is a blend-body shape glider, which has a payload of approximately 800 kg and an operational depth around about 300 m. However, the commercialization of these gliders has been limited with only three know examples that have been successfully commercialized.

  11. 78 FR 43147 - Fisheries of the South Atlantic; Southeast Data, Assessment, and Review (SEDAR); Public Meetings

    Science.gov (United States)

    2013-07-19

    ... stock status, estimate population benchmarks and management criteria, and project future conditions. The... stock of Gray Triggerfish will consist of: A Data Workshop; a series of Assessment webinars; and a... status of fish stocks in the Southeast Region. SEDAR is a three-step process including: (1) Data Workshop...

  12. 78 FR 16657 - Fisheries of the South Atlantic; Southeast Data, Assessment, and Review (SEDAR); Public Meetings

    Science.gov (United States)

    2013-03-18

    ... the status of the stock, estimates biological benchmarks, projects future population conditions, and... and gray triggerfish. SUMMARY: The SEDAR 32 assessments of the South Atlantic stocks of blueline... Review (SEDAR) process, a multi-step method for determining the status of fish stocks in the Southeast...

  13. A review of the assessments of the major fisheries resources in ...

    African Journals Online (AJOL)

    The waters off South Africa's coastline boast a rich mix of commercially fished species. Quantitative assessments of these marine resources have developed from simple methods first applied in the 1970s, to models that encompass a wide range of methodologies. The more valuable resources have undergone regular ...

  14. 76 FR 17625 - Fisheries of the South Atlantic; Southeast Data, Assessment, and Review; Public Meeting

    Science.gov (United States)

    2011-03-30

    ...: Participants will present summary data, and discuss data needs and treatments. Special Accommodations The... the South Atlantic; Southeast Data, Assessment, and Review; Public Meeting AGENCY: National Marine... of Southeast Data and Review (SEDAR) 26 data webinar for Caribbean Silk snapper, Queen snapper, and...

  15. The Modular Optical Underwater Survey System

    Directory of Open Access Journals (Sweden)

    Ruhul Amin

    2017-10-01

    Full Text Available The Pacific Islands Fisheries Science Center deploys the Modular Optical Underwater Survey System (MOUSS to estimate the species-specific, size-structured abundance of commercially-important fish species in Hawaii and the Pacific Islands. The MOUSS is an autonomous stereo-video camera system designed for the in situ visual sampling of fish assemblages. This system is rated to 500 m and its low-light, stereo-video cameras enable identification, counting, and sizing of individuals at a range of 0.5–10 m. The modular nature of MOUSS allows for the efficient and cost-effective use of various imaging sensors, power systems, and deployment platforms. The MOUSS is in use for surveys in Hawaii, the Gulf of Mexico, and Southern California. In Hawaiian waters, the system can effectively identify individuals to a depth of 250 m using only ambient light. In this paper, we describe the MOUSS’s application in fisheries research, including the design, calibration, analysis techniques, and deployment mechanism.

  16. Introduction to fisheries oceanography

    Digital Repository Service at National Institute of Oceanography (India)

    Sumitra-Vijayaraghavan

    Fisheries oceanography can be applied to fisheries ecology, fisheries management and practical fishing. Physico-chemical parameters of the environment (temperature, currents, waves, light, oxygen and salinity) have profound effect on fish...

  17. Maintaining the competitiveness of the American fisheries society journals: an assessment based on influence and cost-effectiveness

    Science.gov (United States)

    Hewitt, David A.; Link, Jason S.; Steinich, Dave R.; Wahl, David H.; Mather, Martha E.

    2009-01-01

    Recent changes in the landscape of scientific publishing prompted the Publications Overview Committee of the American Fisheries Society (AFS) to review the Society's portfolio of scientific journals. We evaluated journals based on metrics in two categories: (1) citation-based measures of the influence of a journal on the scientific literature, and (2) measures of the cost-effectiveness of a journal (citation rate adjusted for subscription cost). Over the long-term, we found that ecology journals had far stronger citation-based influence than fisheries and aquatic sciences journals, and that journals publishing primarily basic research had stronger influence than journals publishing applied research (including four AFS journals and Fisheries magazine). In evaluating the current status of fisheries and aquatic sciences journals, we found that metrics of influence and cost-effectiveness provided considerably different portrayals of journals relative to their peers. In terms of citation-based influence, we found that the AFS journal Transactions of the American Fisheries Society (TAFS) and Fisheries magazine were competitive with highly regarded peer fisheries journals, but that North American Journal of Aquaculture (NAJA) and Journal of Aquatic Animal Health (JAAH) were less influential than their peers. The citation-based influence of North American Journal of Fisheries Management (NAJFM) was intermediate between TAFS/Fisheries and NAJA/JAAH. For journals like NAJFM and NAJA, we expect that much of the scientific influence on policy and management is not captured by citations in the primary literature, and alternative methods of evaluation may be needed. All of the AFS journals ranked highly with regard to cost-effectiveness because their subscription costs are low, and these rankings are in accordance with membership needs and the strategic mission of AFS to provide broad and timely dissemination of scientific information. We conclude by suggesting

  18. Use of PIT tag and underwater video recording in assessing estuarine fish movement in a high intertidal mangrove and salt marsh creek

    Science.gov (United States)

    Meynecke, Jan-Olaf; Poole, Geoffrey C.; Werry, Jonathan; Lee, Shing Yip

    2008-08-01

    We assessed movement patterns in relation to habitat availability (reflected by the extent of tidal flooding) for several commercially and recreationally important species in and out of a small mangrove creek within the subtropical Burrum River estuary (25°10'S 152°37'E) in Queensland, Australia. Movement patterns of Acanthopagrus australis, Pomadasys kaakan, Lutjanus russelli and Mugil cephalus were examined between December 2006 and April 2007 using a stationary passive integrated transponder (PIT) system adapted for saline environments (30-38 ppt) and underwater digital video cameras (DVCs). This is the second known application of a stationary PIT tag system to studying fish movement in estuarine environments. The transponder system was set in place for 104 days and recorded >5000 detections. Overall 'recapture' rate of tagged fish by the transponder system was >40%. We used PIT tags implanted in a total of 75 fish from a tidal creek connected to the main channel of the estuary. We also developed a high-resolution digital elevation (2.5 m cell size) model of the estuary derived from airborne light detection and ranging (LIDAR) and aerial imagery to estimate inundation dynamics within the tidal creek, and related the timing of inundation in various habitats to the timing of fish immigration to and emigration from the creek. Over 50% of all tagged fish were moving in and out of the creek at a threshold level when 50% of the mangrove forest became flooded. Individuals of all four species moved into and out of the tidal creek repeatedly at different times depending on species and size, indicating strong residential behaviour within the estuary. The main activity of fishes was at night time. Manual interpretation of video from >700 fish sightings at three different mangrove sites confirmed the findings of the stationary PIT system, that the function of shelter vs food in mangrove habitat may be size dependent. Our established techniques assess the spatial ecology

  19. Assessing gear modifications needed to optimize yields in a heavily exploited, multi-species, seagrass and coral reef fishery.

    Science.gov (United States)

    Hicks, Christina C; McClanahan, Timothy R

    2012-01-01

    Effective management is necessary if small-scale fisheries, such as those found in mixed habitats including seagrass and coral reefs, are to continue providing food for many of the poorest communities of the world. Gear-based management, although under represented and under studied, has the potential to be adaptive, address multiple objectives, and be crafted to the socio-economic setting. Management effectiveness in seagrass and coral reef fisheries has generally been evaluated at the scale of the fish community. However, community level indicators can mask species-specific declines that provide significant portions of the fisheries yields and income. Using a unique dataset, containing ten years of species level length frequency catch data from a multi-gear, multi-species seagrass and coral reef fishery in Kenya, we evaluate species specific fishery statuses, compare gear use to gear regulations and estimate the potential needs for further gear restrictions. Despite the high diversity of the fishery, fifteen species represented over 90% of the catch, and only three species represented 60% of the catch. The three most abundant species in the catch, Lethrinus lentjan (Lacepède), Siganus sutor (Valenciennes) and Leptoscarus vaigiensis (Quoy & Gaimard) all showed evidence of growth overfishing. Lethrinus lentjan, with an exploitation rate of 0.82, also shows evidence of recruitment overfishing. Current legal but weakly enforced gear restrictions are capable of protecting a significant portion of the catch up to maturity but optimization of yield will require that the current mesh size be increased from 6.3 to 8.8 and 9.2 cm to increase yields of L. lentjan and S. sutor, respectively. Given the difficulties of enforcing mesh size, we recommend that the economic benefits of these larger mesh sizes be communicated and enforced through co-management. This abstract is also available in Kiswahili (Abstract S1).

  20. Assessing gear modifications needed to optimize yields in a heavily exploited, multi-species, seagrass and coral reef fishery.

    Directory of Open Access Journals (Sweden)

    Christina C Hicks

    Full Text Available Effective management is necessary if small-scale fisheries, such as those found in mixed habitats including seagrass and coral reefs, are to continue providing food for many of the poorest communities of the world. Gear-based management, although under represented and under studied, has the potential to be adaptive, address multiple objectives, and be crafted to the socio-economic setting. Management effectiveness in seagrass and coral reef fisheries has generally been evaluated at the scale of the fish community. However, community level indicators can mask species-specific declines that provide significant portions of the fisheries yields and income. Using a unique dataset, containing ten years of species level length frequency catch data from a multi-gear, multi-species seagrass and coral reef fishery in Kenya, we evaluate species specific fishery statuses, compare gear use to gear regulations and estimate the potential needs for further gear restrictions. Despite the high diversity of the fishery, fifteen species represented over 90% of the catch, and only three species represented 60% of the catch. The three most abundant species in the catch, Lethrinus lentjan (Lacepède, Siganus sutor (Valenciennes and Leptoscarus vaigiensis (Quoy & Gaimard all showed evidence of growth overfishing. Lethrinus lentjan, with an exploitation rate of 0.82, also shows evidence of recruitment overfishing. Current legal but weakly enforced gear restrictions are capable of protecting a significant portion of the catch up to maturity but optimization of yield will require that the current mesh size be increased from 6.3 to 8.8 and 9.2 cm to increase yields of L. lentjan and S. sutor, respectively. Given the difficulties of enforcing mesh size, we recommend that the economic benefits of these larger mesh sizes be communicated and enforced through co-management. This abstract is also available in Kiswahili (Abstract S1.

  1. Ocean zoning for conservation, fisheries and marine renewable energy: assessing trade-offs and co-location opportunities.

    Science.gov (United States)

    Yates, Katherine L; Schoeman, David S; Klein, Carissa J

    2015-04-01

    Oceans, particularly coastal areas, are getting busier and within this increasingly human-dominated seascape, marine biodiversity continues to decline. Attempts to maintain and restore marine biodiversity are becoming more spatial, principally through the designation of marine protected areas (MPAs). MPAs compete for space with other uses, and the emergence of new industries, such as marine renewable energy generation, will increase competition for space. Decision makers require guidance on how to zone the ocean to conserve biodiversity, mitigate conflict and accommodate multiple uses. Here we used empirical data and freely available planning software to identified priority areas for multiple ocean zones, which incorporate goals for biodiversity conservation, two types of renewable energy, and three types of fishing. We developed an approached to evaluate trade-offs between industries and we investigated the impacts of co-locating some fishing activities within renewable energy sites. We observed non-linear trade-offs between industries. We also found that different subsectors within those industries experienced very different trade-off curves. Incorporating co-location resulted in significant reductions in cost to the fishing industry, including fisheries that were not co-located. Co-location also altered the optimal location of renewable energy zones with planning solutions. Our findings have broad implications for ocean zoning and marine spatial planning. In particular, they highlight the need to include industry subsectors when assessing trade-offs and they stress the importance of considering co-location opportunities from the outset. Our research reinforces the need for multi-industry ocean-zoning and demonstrates how it can be undertaken within the framework of strategic conservation planning. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. From food to feed: Assessment of the stationary lift net fishery of East Hainan, Northern South China Sea

    Science.gov (United States)

    Krumme, Uwe; Wang, Tian C.; Wang, Dao R.

    2013-04-01

    In the Asia-Pacific region, the increasing demand for low value/trash fish as feed for mariculture drives unsustainable fisheries on already overexploited marine resources. The mariculture demand may also affect artisanal nearshore fisheries operating in shallow nursery grounds, e.g., lift net fisheries, but little is known about how they work. We describe the stationary lift net artisanal fishery on the East coast of Hainan Island (northern South China Sea). A trapezoidal blanket net (mean surface area: 478 m2), stretched between four upright poles at the corners, is lowered and lifted via a rope system from a tower by a single fisher. In 2009 ˜200 households depended on 288 lift nets, 82% of which were located in the Wenchang/Wenjiao estuary. The number of lift nets decreased by 15% from 2007 to 2009. Presently, it is mainly an early retirement activity of fishers with a median age of 52 years and younger men rarely enter the fishery due to low catch rates. However, not one fisher would stop fishing even at 50% hypothetical decline in catch — due to lack of alternatives. Mean catch weight per fishing day is 12 kg (range: 0-1.7 t). In the past, the entire catch was used as food. Presently, an average of 52% of the catch is sold as feed to local pond and floating net cage mariculturists who, subsequently, supply the live food trade to markets as far as Hong Kong. Larger dead fishes are sold at village markets or at Qinglan harbor and are locally or regionally consumed. The density of lift-net operation is highest around the Wenchang/Wenjiao lagoon due to the presence of an extensive sheltered, shallow subtidal area in proximity to mariculture and export markets in Qinglan. Thus, the modern mariculture demand for low value/trash fish supports the continuation of an ancient artisanal fishery despite severe resource depletion. The existence of similar lift nets in Vietnam points to an exchange in the artisanal fishing knowledge between Vietnam and Hainan

  3. 75 FR 1023 - International Fisheries Regulations; Fisheries in the Western Pacific; Pelagic Fisheries; Hawaii...

    Science.gov (United States)

    2010-01-08

    ...; Pelagic Fisheries; Hawaii-based Shallow-set Longline Fishery; Correction AGENCY: National Marine Fisheries... process is preserved for closing the Hawaii-based shallow-set longline fishery as a result of the fishery...

  4. An Integrated Assessment Model for Helping the United States Sea Scallop (Placopecten magellanicus) Fishery Plan Ahead for Ocean Acidification and Warming.

    Science.gov (United States)

    Cooley, Sarah R; Rheuban, Jennie E; Hart, Deborah R; Luu, Victoria; Glover, David M; Hare, Jonathan A; Doney, Scott C

    2015-01-01

    Ocean acidification, the progressive change in ocean chemistry caused by uptake of atmospheric CO2, is likely to affect some marine resources negatively, including shellfish. The Atlantic sea scallop (Placopecten magellanicus) supports one of the most economically important single-species commercial fisheries in the United States. Careful management appears to be the most powerful short-term factor affecting scallop populations, but in the coming decades scallops will be increasingly influenced by global environmental changes such as ocean warming and ocean acidification. In this paper, we describe an integrated assessment model (IAM) that numerically simulates oceanographic, population dynamic, and socioeconomic relationships for the U.S. commercial sea scallop fishery. Our primary goal is to enrich resource management deliberations by offering both short- and long-term insight into the system and generating detailed policy-relevant information about the relative effects of ocean acidification, temperature rise, fishing pressure, and socioeconomic factors on the fishery using a simplified model system. Starting with relationships and data used now for sea scallop fishery management, the model adds socioeconomic decision making based on static economic theory and includes ocean biogeochemical change resulting from CO2 emissions. The model skillfully reproduces scallop population dynamics, market dynamics, and seawater carbonate chemistry since 2000. It indicates sea scallop harvests could decline substantially by 2050 under RCP 8.5 CO2 emissions and current harvest rules, assuming that ocean acidification affects P. magellanicus by decreasing recruitment and slowing growth, and that ocean warming increases growth. Future work will explore different economic and management scenarios and test how potential impacts of ocean acidification on other scallop biological parameters may influence the social-ecological system. Future empirical work on the effect of ocean

  5. Energy consumption in the Danish fishery

    DEFF Research Database (Denmark)

    Thrane, Mikkel

    2003-01-01

    Previous studies based on Life Cycle Assessment (LCA) in Denmark and Sweden have shown that the fishery is the environmental "hot spot" in the life cycle of fish products. Within the fishery, fuel consumption is one of the most important factors addressed by LCA. The present study reveals...... that there are great differences in the fuel consumption between fisheries targeting ground or shellfish and those targeting pelagic or industrial fish....

  6. Review of State-Space Models for Fisheries Science

    DEFF Research Database (Denmark)

    Aeberhard, William H.; Flemming, Joanna Mills; Nielsen, Anders

    2018-01-01

    Fisheries science is concerned with the management and understanding of the raising and harvesting of fish. Fish stocks are assessed using biological and fisheries data with the goal of estimating either their total population or biomass. Stock assessment models also make it possible to predict how...... highlights what should be considered best practices for science-based fisheries management....

  7. Underwater running device

    International Nuclear Information System (INIS)

    Kogure, Sumio; Matsuo, Takashiro; Yoshida, Yoji

    1996-01-01

    An underwater running device for an underwater inspection device for detecting inner surfaces of a reactor or a water vessel has an outer frame and an inner frame, and both of them are connected slidably by an air cylinder and connected rotatably by a shaft. The outer frame has four outer frame legs, and each of the outer frame legs is equipped with a sucker at the top end. The inner frame has four inner frame legs each equipped with a sucker at the top end. The outer frame legs and the inner frame legs are each connected with the outer frame and the inner frame by the air cylinder. The outer and the inner frame legs can be elevated or lowered (or extended or contracted) by the air cylinder. The sucker is connected with a jet pump-type negative pressure generator. The device can run and move by repeating attraction and releasing of the outer frame legs and the inner frame legs alternately while maintaining the posture of the inspection device stably. (I.N.)

  8. Ocean Research Enabled by Underwater Gliders.

    Science.gov (United States)

    Rudnick, Daniel L

    2016-01-01

    Underwater gliders are autonomous underwater vehicles that profile vertically by changing their buoyancy and use wings to move horizontally. Gliders are useful for sustained observation at relatively fine horizontal scales, especially to connect the coastal and open ocean. In this review, research topics are grouped by time and length scales. Large-scale topics addressed include the eastern and western boundary currents and the regional effects of climate variability. The accessibility of horizontal length scales of order 1 km allows investigation of mesoscale and submesoscale features such as fronts and eddies. Because the submesoscales dominate vertical fluxes in the ocean, gliders have found application in studies of biogeochemical processes. At the finest scales, gliders have been used to measure internal waves and turbulent dissipation. The review summarizes gliders' achievements to date and assesses their future in ocean observation.

  9. Mixed fisheries forecasts—lessons learned from their initial application to North Sea fisheries

    DEFF Research Database (Denmark)

    Holmes, S.J.; Ulrich, Clara; Reeves, S.A.

    2012-01-01

    the work with the existing single‐stock assessments. The explicit representation of the complexity of the fisheries also raises questions about the extent to which mixed fisheries science can be used to give ”advice” in the traditional sense. This paper addresses the challenges and issues that have arisen......Mixed fisheries and technical interactions in European fisheries have been a subject of research for many years. The establishment in 2010 of an ICES Working Group tasked with producing annual mixed fisheries forecasts and advice for North Sea demersal fisheries represents a commitment to use...... these approaches in routine scientific advice for the first time. The demersal fisheries of the North Sea provide a particularly interesting context for this work because of their high complexity in terms of the numbers of fleets, gears, métiers, and species involved, and also because mixedfishery effects have...

  10. Fishery stock assessment of Kiddi shrimp ( Parapenaeopsis stylifera) in the Northern Arabian Sea Coast of Pakistan by using surplus production models

    Science.gov (United States)

    Mohsin, Muhammad; Mu, Yongtong; Memon, Aamir Mahmood; Kalhoro, Muhammad Talib; Shah, Syed Baber Hussain

    2017-07-01

    Pakistani marine waters are under an open access regime. Due to poor management and policy implications, blind fishing is continued which may result in ecological as well as economic losses. Thus, it is of utmost importance to estimate fishery resources before harvesting. In this study, catch and effort data, 1996-2009, of Kiddi shrimp Parapenaeopsis stylifera fishery from Pakistani marine waters was analyzed by using specialized fishery software in order to know fishery stock status of this commercially important shrimp. Maximum, minimum and average capture production of P. stylifera was observed as 15 912 metric tons (mt) (1997), 9 438 mt (2009) and 11 667 mt/a. Two stock assessment tools viz. CEDA (catch and effort data analysis) and ASPIC (a stock production model incorporating covariates) were used to compute MSY (maximum sustainable yield) of this organism. In CEDA, three surplus production models, Fox, Schaefer and Pella-Tomlinson, along with three error assumptions, log, log normal and gamma, were used. For initial proportion (IP) 0.8, the Fox model computed MSY as 6 858 mt (CV=0.204, R 2 =0.709) and 7 384 mt (CV=0.149, R 2 =0.72) for log and log normal error assumption respectively. Here, gamma error produced minimization failure. Estimated MSY by using Schaefer and Pella-Tomlinson models remained the same for log, log normal and gamma error assumptions i.e. 7 083 mt, 8 209 mt and 7 242 mt correspondingly. The Schafer results showed highest goodness of fit R 2 (0.712) values. ASPIC computed MSY, CV, R 2, F MSY and B MSY parameters for the Fox model as 7 219 mt, 0.142, 0.872, 0.111 and 65 280, while for the Logistic model the computed values remained 7 720 mt, 0.148, 0.868, 0.107 and 72 110 correspondingly. Results obtained have shown that P. stylifera has been overexploited. Immediate steps are needed to conserve this fishery resource for the future and research on other species of commercial importance is urgently needed.

  11. OFDM for underwater acoustic communications

    CERN Document Server

    Zhou, Shengli

    2014-01-01

    A blend of introductory material and advanced signal processing and communication techniques, of critical importance to underwater system and network development This book, which is the first to describe the processing techniques central to underwater OFDM, is arranged into four distinct sections: First, it describes the characteristics of underwater acoustic channels, and stresses the difference from wireless radio channels. Then it goes over the basics of OFDM and channel coding. The second part starts with an overview of the OFDM receiver, and develops various modules for the receiver des

  12. Risk assessment and uncertainty of the shrimp trawl fishery in the Gulf of California considering environmental variability

    Directory of Open Access Journals (Sweden)

    Luis César Almendarez-Hernández

    2015-09-01

    Full Text Available The shrimp fishery off the Mexican Pacific coast is the country's most important fishery from the economic standpoint. However, it faces serious problems, including the fleet's overcapitalization and age, in addition to the environmental variability that affects the size of catches. Thus, this activity depends on a variety of factors that add uncertainty to the profitability of fishing vessels. This study aims to estimate the probability of success and economic risk of "type vessels" under two different environmental variability scenarios in the Gulf of California. The results from the economic simulation pointed to the vessel type used in Guaymas (Sonora as the most efficient one under a neutral climate change scenario, showing a homogeneous behaviour in physical characteristics and mode of operation. By contrast, under a scenario of a monotonic rise in sea surface temperature, the shrimp fishery faces a greater risk of incurring economic losses. The simulated climate behaviour scenarios revealed that the activity involves a moderate economic profitability under the neutral scenario; however, under the warming scenario, profitability may be low or even nil due to the risks and uncertainty resulting from the influence of environmental phenomena.

  13. Impact assessment of a fisheries closure with effort and landings spatial analyses: A case study in the Western Baltic Sea

    DEFF Research Database (Denmark)

    Miethe, Tanja; Bastardie, Francois; Dorrien, Christian von

    2014-01-01

    Commercial fisheries in the Western Baltic Sea (WBS; ICES Subdivisions 22–24) are dominated by Danishand German vessels. By combining and processing logbook and Vessel Monitoring System (VMS) data forGermany and Denmark, we compare patterns of spatial effort allocation and the origin of the landi......Commercial fisheries in the Western Baltic Sea (WBS; ICES Subdivisions 22–24) are dominated by Danishand German vessels. By combining and processing logbook and Vessel Monitoring System (VMS) data forGermany and Denmark, we compare patterns of spatial effort allocation and the origin...... landedin the WBS decreased, and the origin of these landings shifted farther east without affecting the seasonaleffort allocation. Landings of cod have also decreased in the Fehmarn Belt area, and since 2008, sprat hasbeen the species most landed there. The planned construction of the Fehmarn Belt Fixed...... of sprat distribution in the area. Becausehigh effort did not lead to large sprat landings in all locations, effort displacement to high effort areas maynot compensate for lost sprat landings, particularly for mixed fishery métiers that also landed herring...

  14. Underwater plasma arc cutting

    International Nuclear Information System (INIS)

    Leautier, R.; Pilot, G.

    1991-01-01

    This report describes the work done to develop underwater plasma arc cutting techniques, to characterise aerosols from cutting operations on radioactive and non-radioactive work-pieces, and to develop suitable ventilation and filtration techniques. The work has been carried out in the framework of a contract between CEA-CEN Cadarache and the Commission of European Communities. Furthermore, this work has been carried out in close cooperation with CEA-CEN Saclay mainly for secondary emissions and radioactive analysis. The contract started in May 1986 and was completed in December 1988 by a supplementary agreement. This report has been compiled from several progress reports submitted during the work period, contains the main findings of the work and encloses the results of comparative tests on plasma arc cutting

  15. Safety aspects for underwater vehicles

    Digital Repository Service at National Institute of Oceanography (India)

    Madhan, R.; Navelkar, G.S.; Desa, E.S.; Afzulpurkar, S.; Prabhudesai, S.P.; Dabholkar, N.; Mascarenhas, A.A.M.Q.; Maurya, P.

    instrumentation is intelligent small Autonomous Underwater Vehicles (AUV’s), autonomous profilers, gliders [1], etc. The ultimate aim in all autonomous platforms research and development is to reach the stage of unescorted missions with minimum failures...

  16. 78 FR 57841 - Western Pacific Fishery Management Council; Public Meetings

    Science.gov (United States)

    2013-09-20

    ... Marine Mammal Stock Assessment Reports F. False Killer Whale Take Reduction Plan Research Priorities G.... Insular Fisheries A. Report on the Main Hawaiian Islands (MHI) Bottomfish Research Working Group Outcomes.... Pacific Island Fisheries Research Program E. Report on the Fisheries Data Clients Meeting F. SSC...

  17. Ecological assessment of the marine ecosystems of Barbuda, West Indies: Using rapid scientific assessment to inform ocean zoning and fisheries management

    Science.gov (United States)

    Caselle, Jennifer E.; Estep, Andrew J.; Johnson, Ayana Elizabeth; Marhaver, Kristen L.; Richter, Lee J.; Sandin, Stuart A.; Vermeij, Mark J. A.; Smith, Jennifer E.; Grenda, David; Cannon, Abigail

    2018-01-01

    To inform a community-based ocean zoning initiative, we conducted an intensive ecological assessment of the marine ecosystems of Barbuda, West Indies. We conducted 116 fish and 108 benthic surveys around the island, and measured the abundance and size structure of lobsters and conch at 52 and 35 sites, respectively. We found that both coral cover and fish biomass were similar to or lower than levels observed across the greater Caribbean; live coral cover and abundance of fishery target species, such as large snappers and groupers, was generally low. However, Barbuda lacks many of the high-relief forereef areas where similar work has been conducted in other Caribbean locations. The distribution of lobsters was patchy, making it difficult to quantify density at the island scale. However, the maximum size of lobsters was generally larger than in other locations in the Caribbean and similar to the maximum size reported 40 years ago. While the lobster population has clearly been heavily exploited, our data suggest that it is not as overexploited as in much of the rest of the Caribbean. Surveys of Barbuda’s Codrington Lagoon revealed many juvenile lobsters, but none of legal size (95 mm carapace length), suggesting that the lagoon functions primarily as nursery habitat. Conch abundance and size on Barbuda were similar to that of other Caribbean islands. Our data suggest that many of the regional threats observed on other Caribbean islands are present on Barbuda, but some resources—particularly lobster and conch—may be less overexploited than on other Caribbean islands. Local management has the potential to provide sustainability for at least some of the island’s marine resources. We show that a rapid, thorough ecological assessment can reveal clear conservation opportunities and facilitate rapid conservation action by providing the foundation for a community-driven policymaking process at the island scale. PMID:29309413

  18. Evolutionary impact assessment: Accounting for the evolutionary consequences of fishing in an ecosystem approach to fisheries management

    DEFF Research Database (Denmark)

    Laugen, Ane T.; Engelhard, Georg H.; Whitlock, Rebecca

    2014-01-01

    substantial scientific attention recently is fisheries-induced evolution (FIE). Increasing evidence indicates that intensive fishing has the potential to exert strong directional selection on life-history traits, behaviour, physiology, and morphology of exploited fish. Of particular concern is that reversing...... evolutionary responses to fishing can be much more difficult than reversing demographic or phenotypically plastic responses. Furthermore, like climate change, multiple agents cause FIE, with effects accumulating over time. Consequently, FIE may alter the utility derived from fish stocks, which in turn can...

  19. Luring anglers to enhance fisheries

    Science.gov (United States)

    Martin, Dustin R.; Pope, Kevin L.

    2011-01-01

    Current fisheries management is, unfortunately, reactive rather than proactive to changes in fishery characteristics. Furthermore, anglers do not act independently on waterbodies, and thus, fisheries are complex socio-ecological systems. Proactive management of these complex systems necessitates an approach-adaptive fisheries management-that allows learning to occur simultaneously with management. A promising area for implementation of adaptive fisheries management is the study of luring anglers to or from specific waterbodies to meet management goals. Purposeful manipulation of anglers, and its associated field of study, is nonexistent in past management. Evaluation of different management practices (i.e., hypotheses) through an iterative adaptive management process should include both a biological and sociological survey to address changes in fish populations and changes in angler satisfaction related to changes in management. We believe adaptive management is ideal for development and assessment of management strategies targeted at angler participation. Moreover these concepts and understandings should be applicable to other natural resource users such as hunters and hikers.

  20. Acoustic telemetry and fisheries management

    Science.gov (United States)

    Crossin, Glenn T.; Heupel, Michelle R.; Holbrook, Christopher; Hussey, Nigel E.; Lowerre-Barbieri, Susan K.; Nguyen, Vivian M.; Raby, Graham D.; Cooke, Steven J.

    2017-01-01

    This paper reviews the use of acoustic telemetry as a tool for addressing issues in fisheries management, and serves as the lead to the special Feature Issue of Ecological Applications titled “Acoustic Telemetry and Fisheries Management”. Specifically, we provide an overview of the ways in which acoustic telemetry can be used to inform issues central to the ecology, conservation, and management of exploited and/or imperiled fish species. Despite great strides in this area in recent years, there are comparatively few examples where data have been applied directly to influence fisheries management and policy. We review the literature on this issue, identify the strengths and weaknesses of work done to date, and highlight knowledge gaps and difficulties in applying empirical fish telemetry studies to fisheries policy and practice. We then highlight the key areas of management and policy addressed, as well as the challenges that needed to be overcome to do this. We conclude with a set of recommendations about how researchers can, in consultation with stock assessment scientists and managers, formulate testable scientific questions to address and design future studies to generate data that can be used in a meaningful way by fisheries management and conservation practitioners. We also urge the involvement of relevant stakeholders (managers, fishers, conservation societies, etc.) early on in the process (i.e. in the co-creation of research projects), so that all priority questions and issues can be addressed effectively.

  1. Fishery Performance Indicators

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Performance indicators for landings, effort, revenue and distribution of revenue are collected for various fisheries nation-wide. The fisheries include catch and...

  2. Reservoir fisheries of Asia

    International Nuclear Information System (INIS)

    Silva, S.S. De.

    1990-01-01

    At a workshop on reservoir fisheries research, papers were presented on the limnology of reservoirs, the changes that follow impoundment, fisheries management and modelling, and fish culture techniques. Separate abstracts have been prepared for three papers from this workshop

  3. Multi-Annual Climate Predictions for Fisheries: An Assessment of Skill of Sea Surface Temperature Forecasts for Large Marine Ecosystems

    Directory of Open Access Journals (Sweden)

    Desiree Tommasi

    2017-06-01

    Full Text Available Decisions made by fishers and fisheries managers are informed by climate and fisheries observations that now often span more than 50 years. Multi-annual climate forecasts could further inform such decisions if they were skillful in predicting future conditions relative to the 50-year scope of past variability. We demonstrate that an existing multi-annual prediction system skillfully forecasts the probability of next year, the next 1–3 years, and the next 1–10 years being warmer or cooler than the 50-year average at the surface in coastal ecosystems. Probabilistic forecasts of upper and lower seas surface temperature (SST terciles over the next 3 or 10 years from the GFDL CM 2.1 10-member ensemble global prediction system showed significant improvements in skill over the use of a 50-year climatology for most Large Marine Ecosystems (LMEs in the North Atlantic, the western Pacific, and Indian oceans. Through a comparison of the forecast skill of initialized and uninitialized hindcasts, we demonstrate that this skill is largely due to the predictable signature of radiative forcing changes over the 50-year timescale rather than prediction of evolving modes of climate variability. North Atlantic LMEs stood out as the only coastal regions where initialization significantly contributed to SST prediction skill at the 1 to 10 year scale.

  4. Underwater radiation measuring device

    International Nuclear Information System (INIS)

    Seki, Noriyuki; Suzuki, Yasuo

    1998-01-01

    The present invention provides a device for measuring, under water, radiation from spent fuels (long members to be detected) of nuclear power plants and reprocessing facilities. Namely, a detecting insertion tube (insertion tube) is disposed so as to be in parallel with axial direction of the long member to be detected stored underwater. A γ-ray detector is inserted to the inside of the insertion tube. A driving mechanism is disposed for moving the γ-ray detector in axial direction inside of the insertion tube. The driving mechanism preferably has a system that it moves the γ-ray detector by winding a detection signal cable around a driving drum. The driving mechanism is formed by inserting and securing a driving tube having screws formed on the side surface and inserting it into the insertion tube. It may have a system of moving the γ-ray detector together with the driving tube while engaging the teeth of a driving transfer mechanism with the screws of the driving tube. (I.S.)

  5. An underwater shear compactor

    International Nuclear Information System (INIS)

    Biver, E.; Sims, J.

    1997-01-01

    This paper, originally presented at the WM'96 Conference in Tucson Arizona, describes a concept of a specialised decommissioning tool designed to operate underwater and to reduce the volume of radioactive components by shearing and compacting. The shear compactor was originally conceived to manage the size reduction of a variety of decommissioned stainless steel tubes stored within a reactor fuel cooling pond and which were consuming a substantial volume of the pond. The main objective of this tool was to cut the long tubes into shorter lengths and to compact them into a flat rectangular form which could be stacked on the pond floor, thus saving valuable space. The development programme, undertaken on this project, investigated a wide range of factors which could contribute to an extended cutting blade performance, ie: materials of construction, cutting blade shape and cutting loads required, shock effects, etc. The second phase was to review other aspects of the design, such as radiological protection, cutting blade replacement, maintenance, pond installation and resultant wall loads, water hydraulics, collection of products of shearing/compacting operations, corrosion of the equipment, control system, operational safety and the ability of the equipment to operate in dry environments. The paper summarises the extended work programme involved with this shear compactor tool. (author)

  6. Underwater cutting techniques developments

    International Nuclear Information System (INIS)

    Bach, F.-W.

    1990-01-01

    The primary circuit structures of different nuclear powerplants are constructed out of stainless steels, ferritic steels, plated ferritic steels and alloys of aluminium. According to the level of the specific radiation of these structures, it is necessary for dismantling to work with remote controlled cutting techniques. The most successful way to protect the working crew against exposure of radiation is to operate underwater in different depths. The following thermal cutting processes are more or less developed to work under water: For ferritic steels only - flame cutting; For ferritic steels, stainless steels, cladded steels and aluminium alloys - oxy-arc-cutting, arc-waterjet-cutting with a consumable electrode, arc-saw-cutting, plasma-arc-cutting and plasma-arc-saw. The flame cutting is a burning process, all the other processes are melt-cutting processes. This paper explains the different techniques, giving a short introduction of the theory, a discussion of the possibilities with the advantages and disadvantages of these processes giving a view into the further research work in this interesting field. (author)

  7. Development of underwater laser cutting technology

    International Nuclear Information System (INIS)

    Sato, Seiichi; Inaba, Takanori; Inose, Koutarou; Matsumoto, Naoyuki; Sakakibara, Yuji

    2015-01-01

    In is desirable to use remote underwater device for the decommissioning work of highly radioactive components such as the nuclear internals from a view point of reducing the ranitidine exposure to the worker. Underwater laser cutting technology has advantages. First advantage in underwater laser cutting technology is that low reaction force during cutting, namely, remote operability is superior. Second point is that underwater laser cutting generates a little amount of secondary waste, because cutting kerf size is very small. Third point is that underwater laser cutting has low risk of the process delay, because device trouble is hard to happen. While underwater laser cutting has many advantages, the careful consideration in the safe treatment of the offgas which underwater laser cutting generates is necessary. This paper describes outline of underwater laser cutting technology developed by IHI Corporation (IHI) and that this technology is effective in various dismantling works in water. (author)

  8. KB WOT Fisheries 2017

    NARCIS (Netherlands)

    Damme, van C.J.G.; Verver, S.W.

    2017-01-01

    The KB WOT Fisheries programme is developed to maintain and advance the expertise needed to carry out the statutory obligations in fisheries monitoring and advice of The Netherlands. The contents of the KB WOT Fisheries programme for 2017 reflects the scientific and management needs of the WOT

  9. Energy consumption in the Danish fishery

    DEFF Research Database (Denmark)

    Thrane, Mikkel

    2004-01-01

    Previous studies based on life-cycle assessment (LCA) in Denmark and Sweden have shown that the fishery is the environmental "hot spot" in the life cycle of certain fish products. Within the fishery, fuel consumption is one of the most important factors addressed by LCA. The present study reveals...... that there are great differences in fuel consumption between fisheries targeting groundfish or shellfish and those targeting pelagic fish or industrial fish. Here, I show that fuel consumption per kilogram of caught fish varies considerably as a function of fishing gear and vessel size, even considering the same......) in Denmark and Sweden have shown that the fishery is the environmental "hot spot" in the life cycle of certain fish products. Within the fishery, fuel consumption is one of the most important factors addressed by LCA. The present study reveals that there are great differences in fuel consumption between...

  10. Navigation System Fault Diagnosis for Underwater Vehicle

    DEFF Research Database (Denmark)

    Falkenberg, Thomas; Gregersen, Rene Tavs; Blanke, Mogens

    2014-01-01

    This paper demonstrates fault diagnosis on unmanned underwater vehicles (UUV) based on analysis of structure of the nonlinear dynamics. Residuals are generated using dierent approaches in structural analysis followed by statistical change detection. Hypothesis testing thresholds are made signal...... based to cope with non-ideal properties seen in real data. Detection of both sensor and thruster failures are demonstrated. Isolation is performed using the residual signature of detected faults and the change detection algorithm is used to assess severity of faults by estimating their magnitude...

  11. Underwater Gliders by Dr. Kevin Smith [video

    OpenAIRE

    Naval Postgraduate School Physics

    2015-01-01

    NPS Physics NPS Physics Research Projects Underwater glider research is currently underway in the physics department at the naval postgraduate in Monterey Ca. Dr. Kevin Smith is a specialist in underwater acoustics and sonar systems. He and his team are currently focused on autonomous underwater gliders and developing systems capable of detecting parameters in the ocean and listening for various sources of sound.

  12. Design of Autonomous Underwater Vehicle

    Directory of Open Access Journals (Sweden)

    Tadahiro Hyakudome

    2011-03-01

    Full Text Available There are concerns about the impact that global warming will have on our environment, and which will inevitably result in expanding deserts and rising water levels. While a lot of underwater vehicles are utilized, AUVs (Autonomous Underwater Vehicle were considered and chosen, as the most suitable tool for conduction survey concerning these global environmental problems. AUVs can comprehensive survey because the vehicle does not have to be connected to the support vessel by tether cable. When such underwater vehicles are made, it is necessary to consider about the following things. 1 Seawater and Water Pressure Environment, 2 Sink, 3 There are no Gas or Battery Charge Stations, 4 Global Positioning System cannot use, 5 Radio waves cannot use. In the paper, outline of above and how deal about it are explained.

  13. UNDERWATER COATINGS FOR CONTAMINATION CONTROL

    International Nuclear Information System (INIS)

    Julia L. Tripp; Kip Archibald; Ann Marie Phillips; Joseph Campbell

    2004-01-01

    The Idaho National Laboratory (INL) deactivated several aging nuclear fuel storage basins. Planners for this effort were greatly concerned that radioactive contamination present on the basin walls could become airborne as the sides of the basins became exposed during deactivation and allowed to dry after water removal. One way to control this airborne contamination was to fix the contamination in place while the pool walls were still submerged. There are many underwater coatings available on the market for marine, naval and other applications. A series of tests were run to determine whether the candidate underwater fixatives were easily applied and adhered well to the substrates (pool wall materials) found in INL fuel pools. Lab-scale experiments were conducted by applying fourteen different commercial underwater coatings to four substrate materials representative of the storage basin construction materials, and evaluating their performance. The coupons included bare concrete, epoxy painted concrete, epoxy painted carbon steel, and stainless steel. The evaluation criteria included ease of application, adherence to the four surfaces of interest, no change on water clarity or chemistry, non-hazardous in final applied form and be proven in underwater applications. A proprietary two-part, underwater epoxy owned by S. G. Pinney and Associates was selected from the underwater coatings tested for application to all four pools. Divers scrubbed loose contamination off the basin walls and floors using a ship hull scrubber and vacuumed up the sludge. The divers then applied the coating using a special powered roller with two separate heated hoses that allowed the epoxy to mix at the roller surface was used to eliminate pot time concerns. The walls were successfully coated and water was removed from the pools with no detectable airborne contamination releases

  14. Acoustic inversion with self noise of an autonomous underwater vehicle to measure sound speed in marine sediments

    NARCIS (Netherlands)

    van Leijen, A.V.; Rothkranz, L.J.M.; Groen, F.C.A.

    2009-01-01

    This work reports on an experiment from the Maritime Rapid Environmental Assessment sea trials in 2007, where autonomous underwater vehicles were deployed for environmental assessment. Even though these underwater vehicles are very quiet platforms, this work investigates the potential of vehicle

  15. Supply regimes in fisheries

    DEFF Research Database (Denmark)

    Nielsen, Max

    2006-01-01

    Supply in fisheries is traditionally known for its backward bending nature, owing to externalities in production. Such a supply regime, however, exist only for pure open access fisheries. Since most fisheries worldwide are neither pure open access, nor optimally managed, rather between the extremes......, the traditional understanding of supply regimes in fisheries needs modification. This paper identifies through a case study of the East Baltic cod fishery supply regimes in fisheries, taking alternative fisheries management schemes and mesh size limitations into account. An age-structured Beverton-Holt based bio......-economic supply model with mesh sizes is developed. It is found that in the presence of realistic management schemes, the supply curves are close to vertical in the relevant range. Also, the supply curve under open access with mesh size limitations is almost vertical in the relevant range, owing to constant...

  16. Operational experience in underwater photogrammetry

    Science.gov (United States)

    Leatherdale, John D.; John Turner, D.

    Underwater photogrammetry has become established as a cost-effective technique for inspection and maintenance of platforms and pipelines for the offshore oil industry. A commercial service based in Scotland operates in the North Sea, USA, Brazil, West Africa and Australia. 70 mm cameras and flash units are built for the purpose and analytical plotters and computer graphics systems are used for photogrammetric measurement and analysis of damage, corrosion, weld failures and redesign of underwater structures. Users are seeking simple, low-cost systems for photogrammetric analysis which their engineers can use themselves.

  17. Underwater laser imaging system (UWLIS)

    Energy Technology Data Exchange (ETDEWEB)

    DeLong, M. [Lawrence Livermore National Lab., CA (United States)

    1994-11-15

    Practical limitations with underwater imaging systems area reached when the noise in the back scattered radiation generated in the water between the imaging system and the target obscures the spatial contrast and resolution necessary for target discovery and identification. The advent of high power lasers operating in the blue-green portion of the visible spectrum (oceanic transmission window) has led to improved experimental illumination systems for underwater imaging. Range-gated and synchronously scanned devices take advantage of the unique temporal and spatial coherence properties of laser radiation, respectively, to overcome the deleterious effects of common volume back scatter.

  18. A critical assessment of marine aquarist biodiversity data and commercial aquaculture: identifying gaps in culture initiatives to inform local fisheries managers.

    Directory of Open Access Journals (Sweden)

    Joanna M Murray

    Full Text Available It is widely accepted that if well managed, the marine aquarium trade could provide socio-economic stability to local communities while incentivising the maintenance of coral reefs. However, the trade has also been implicated as having potentially widespread environmental impacts that has in part driven developments in aquaculture to relieve wild collection pressures. This study investigates the biodiversity in hobbyist aquaria (using an online survey and those species currently available from an aquaculture source (commercial data and hobbyist initiatives in the context of a traffic light system to highlight gaps in aquaculture effort and identify groups that require fisheries assessments. Two hundred and sixty nine species including clown fish, damsels, dotty backs, angelfish, gobies, sea horses and blennies, have reported breeding successes by hobbyists, a pattern mirrored by the European and US commercial organisations. However, there is a mismatch (high demand and low/non-existent aquaculture for a number of groups including tangs, starfish, anemones and hermit crabs, which we recommend are priority candidates for local stock assessments. Hobbyist perception towards the concept of a sustainable aquarium trade is also explored with results demonstrating that only 40% of respondents were in agreement with industry and scientists who believe the trade could be an exemplar of a sustainable use of coral reefs. We believe that a more transparent evidence base, including the publication of the species collected and cultured, will go some way to align the concept of a sustainable trade across industry stakeholders and better inform the hobbyist when purchasing their aquaria stock. We conclude by proposing that a certification scheme established with government support is the most effective way to move towards a self-regulating industry. It would prevent industry "greenwashing" from multiple certification schemes, alleviate conservation concerns

  19. Acquisition and tracking for underwater optical communications

    Science.gov (United States)

    Williams, Andrew J.; Laycock, Leslie L.; Griffith, Michael S.; McCarthy, Andrew G.; Rowe, Duncan P.

    2017-10-01

    There is a growing requirement to transfer large volumes of data between underwater platforms. As seawater is transmissive in the visible band, underwater optical communications is an active area of interest since it offers the potential for power efficient, covert and high bandwidth datalinks at short to medium ranges. Short range systems have been successfully demonstrated using sources with low directionality. To realise higher data rates and/or longer ranges, the use of more efficient directional beams is required; by necessity, these must be sufficiently aligned to achieve the required link margin. For mobile platforms, the acquisition and tracking of each node is therefore critical in order to establish and maintain an optical datalink. This paper describes work undertaken to demonstrate acquisition and tracking in a 3D underwater environment. A range of optical sources, beam steering technologies, and tracking sensors have been assessed for suitability. A novel scanning strategy exploiting variable beam divergence was developed to provide robust acquisition whilst minimising acquisition time. A prototype system was assembled and demonstrated in a large water tank. This utilised custom quadrant detectors based on Silicon PhotoMultiplier (SiPM) arrays for fine tracking, and a Wide Field of View (WFoV) sCMOS camera for link acquisition. Fluidic lenses provided dynamic control of beam divergence, and AC modulation/filtering enabled background rejection. The system successfully demonstrated robust optical acquisition and tracking between two nodes with only nanowatt received optical powers. The acquisition time was shown to be dependent on the initial conditions and the transmitted optical power.

  20. Assessing Caribbean Shallow and Mesophotic Reef Fish Communities Using Baited-Remote Underwater Video (BRUV) and Diver-Operated Video (DOV) Survey Techniques

    Science.gov (United States)

    Macaya-Solis, Consuelo; Exton, Dan A.; Gress, Erika; Wright, Georgina; Rogers, Alex D.

    2016-01-01

    Fish surveys form the backbone of reef monitoring and management initiatives throughout the tropics, and understanding patterns in biases between techniques is crucial if outputs are to address key objectives optimally. Often biases are not consistent across natural environmental gradients such as depth, leading to uncertainty in interpretation of results. Recently there has been much interest in mesophotic reefs (reefs from 30–150 m depth) as refuge habitats from fishing pressure, leading to many comparisons of reef fish communities over depth gradients. Here we compare fish communities using stereo-video footage recorded via baited remote underwater video (BRUV) and diver-operated video (DOV) systems on shallow and mesophotic reefs in the Mesoamerican Barrier Reef, Caribbean. We show inconsistent responses across families, species and trophic groups between methods across the depth gradient. Fish species and family richness were higher using BRUV at both depth ranges, suggesting that BRUV is more appropriate for recording all components of the fish community. Fish length distributions were not different between methods on shallow reefs, yet BRUV recorded more small fish on mesophotic reefs. However, DOV consistently recorded greater relative fish community biomass of herbivores, suggesting that studies focusing on herbivores should consider using DOV. Our results highlight the importance of considering what component of reef fish community researchers and managers are most interested in surveying when deciding which survey technique to use across natural gradients such as depth. PMID:27959907

  1. Underwater noise due to precipitation

    DEFF Research Database (Denmark)

    Crum, Lawrence A.; Pumphrey, Hugh C.; Prosperetti, Andrea

    1989-01-01

    In 1959, G. Franz published a thorough investigation of the underwater sound produced by liquid drop impacts [G. Franz, J. Acoust. Soc. Am. 31, 1080 (1959)]. He discovered that, under certain conditions, a gas bubble was entrained by the impacting droplet, and the subsequent oscillation of this b...

  2. Underwater nuclear power plant structure

    International Nuclear Information System (INIS)

    Severs, S.; Toll, H.V.

    1982-01-01

    A structure for an underwater nuclear power generating plant comprising a triangular platform formed of tubular leg and truss members upon which are attached one or more large spherical pressure vessels and one or more small cylindrical auxiliary pressure vessels. (author)

  3. Underwater Robots Surface in Utah

    Science.gov (United States)

    Hurd, Randy C.; Hacking, Kip S.; Damarjian, Jennifer L.; Wright, Geoffrey A.; Truscott, Tadd

    2015-01-01

    Underwater robots (or ROVs: Remotely Operated Vehicles as they are typically called in industry) have recently become a very popular instructional STEM activity. Nationally, ROVs have been used in science and technology classrooms for several years in cities such as Seattle, San Diego, Virginia Beach, and other coastal areas. In the past two…

  4. Ecosystem approach to inland fisheries: research needs and implementation strategies

    Science.gov (United States)

    Beard, T. Douglas; Arlinghaus, Robert; Cooke, Steven J.; McIntyre, Peter B.; De Silva, Sena; Bartley, Devin M.; Cowx, Ian G.

    2011-01-01

    Inland fisheries are a vital component in the livelihoods and food security of people throughout the world, as well as contributing huge recreational and economic benefits. These valuable assets are jeopardized by lack of research-based understanding of the impacts of fisheries on inland ecosystems, and similarly the impact of human activities associated with inland waters on fisheries and aquatic biodiversity. To explore this topic, an international workshop was organized in order to examine strategies to incorporate fisheries into ecosystem approaches for management of inland waters. To achieve this goal, a new research agenda is needed that focuses on: quantifying the ecosystem services provided by fresh waters; quantifying the economic, social and nutritional benefits of inland fisheries; improving assessments designed to evaluate fisheries exploitation potential; and examining feedbacks between fisheries, ecosystem productivity and aquatic biodiversity. Accomplishing these objectives will require merging natural and social science approaches to address coupled social–ecological system dynamics.

  5. Cooperative OFDM underwater acoustic communications

    CERN Document Server

    Cheng, Xilin; Cheng, Xiang

    2016-01-01

    Following underwater acoustic channel modeling, this book investigates the relationship between coherence time and transmission distances. It considers the power allocation issues of two typical transmission scenarios, namely short-range transmission and medium-long range transmission. For the former scenario, an adaptive system is developed based on instantaneous channel state information. The primary focus is on cooperative dual-hop orthogonal frequency division multiplexing (OFDM). This book includes the decomposed fountain codes designed to enable reliable communications with higher energy efficiency. It covers the Doppler Effect, which improves packet transmission reliability for effective low-complexity mirror-mapping-based intercarrier interference cancellation schemes capable of suppressing the intercarrier interference power level. Designed for professionals and researchers in the field of underwater acoustic communications, this book is also suitable for advanced-level students in electrical enginee...

  6. International Conference on Underwater Environment

    CERN Document Server

    Jaulin, Luc; Creuze, Vincent; Debese, Nathalie; Quidu, Isabelle; Clement, Benoît; Billon-Coat, Annick

    2016-01-01

    This volume constitutes the results of the International Conference on Underwater Environment, MOQESM’14, held at “Le Quartz” Conference Center in Brest, France, on October 14-15, 2014, within the framework of the 9th Sea Tech Week, International Marine Science and Technology Event. The objective of MOQESM'14 was to bring together researchers from both academia and industry, interested in marine robotics and hydrography with application to the coastal environment mapping and underwater infrastructures surveys. The common thread of the conference is the combination of technical control, perception, and localization, typically used in robotics, with the methods of mapping and bathymetry. The papers presented in this book focus on two main topics. Firstly, coastal and infrastructure mapping is addressed, focusing not only on hydrographic systems, but also on positioning systems, bathymetry, and remote sensing. The proposed methods rely on acoustic sensors such as side scan sonars, multibeam echo sounders, ...

  7. Cutting method and device underwater

    International Nuclear Information System (INIS)

    Takano, Genta; Kamei, Hiromasa; Beppu, Seiji

    1998-01-01

    A place of material to be cut is surrounded by an openable/closable box. The material to be cut is cut underwater, and materials generated in this case are removed from the cut portion by a pressurized water jet. The removed materials are sucked and recovered together with water in the box. Among the materials caused by the cutting underwater, solid materials not floating on water are caused to stay in the midway of a sucking and recovering channel. A large sucking force might be required for the entire region of the sucking and recovering channel when sucking and recovering large sized solid materials not floating on water, but even large sized materials can be recovered easily according to the present invention since they are recovered after being sucked and stayed in the midway of the sucking and recovering channel. (N.H.)

  8. 76 FR 54217 - Pacific Fishery Management Council; Public Meeting

    Science.gov (United States)

    2011-08-31

    ... Pacific Fishery Management Council (Pacific Council) will convene a meeting of the Stock Assessment Review... 2011 stock assessment for Pacific sardine, which will be used to develop management measures for the... 305(c) of the Magnuson-Stevens Fishery Conservation and Management Act, provided the public has been...

  9. 76 FR 20959 - Pacific Fishery Management Council; Public Meeting

    Science.gov (United States)

    2011-04-14

    ... Pacific Fishery Management Council (Pacific Council) will convene a Pacific mackerel Stock Assessment... of the meeting is to review the Pacific mackerel stock assessment for 2011, in order to inform... action under Section 305(c) of the Magnuson-Stevens Fishery Conservation and Management Act, provided the...

  10. Taiwan's underwater cultural heritage documentation management

    Science.gov (United States)

    Tung, Y.-Y.

    2015-09-01

    Taiwan is an important trading and maritime channels for many countries since ancient time. Numerous relics lie underwater due to weather, wars, and other factors. In the year of 2006, Bureau of Cultural Heritage (BOCH) entrusted the Underwater Archaeological Team of Academia Sinica to execute the underwater archaeological investigation projects. Currently, we verified 78 underwater targets, with 78 site of those had been recognized as shipwrecks sites. Up to date, there is a collection of 638 underwater objects from different underwater archaeological sites. Those artefacts are distributed to different institutions and museums. As very diverse management methods/systems are applied for every individual institution, underwater cultural heritage data such as survey, excavation report, research, etc. are poorly organized and disseminated for use. For better communication regarding to Taiwan's underwater cultural heritage in every level, a universal format of documentation should be established. By comparing the existing checklist used in Taiwan with guidelines that are followed in other countries, a more intact and appropriate underwater cultural heritage condition documentation system can be established and adapted in Taiwan.

  11. Sustainable Fisheries in Southeast Asia

    Directory of Open Access Journals (Sweden)

    Melda Kamil Ariadno

    2011-09-01

    Full Text Available Fisheries activity has increased significantly in number. As a result, we might see high investment in fisheries is due to the high demand for fish and fisheries products. Therefore, marine resources as well as other living resources are at risk in being harmed by excessive fisheries activities, for example: the use of trawl. Indonesia, as a Maritime State, need to impose sustainable fisheries because the principle of utilizing sustainable fisheries resources as adopted in the Law on Fisheries (Law No. 31 Year 2004 as amended by Law No. 45 Year 2009 to control fishery activities.Fishery activities are regulated not only by the Law on Fisheries but also international regulation adopted worldwide such as the Code of Conduct for Responsible Fisheries (CCRF. CCRF was prepared to include primary principles to elaborate the mechanism of fishery activities which is designated not to cost harmful damages in fisheries activities. CCRF is also accompanied by several technical guidelines that provide certain procedures to be applied to (1 fishing operations; (2 the precautionary approach as applied to capture fisheries and species introductions; (3 integrating fisheries into coastal area management; (4 fisheries management; (5 aquaculture development; and (6 inland fisheries. Consequently, CCRF is intended to cover any kind of fishery anywhere in the world not just marine capture fisheries, but also freshwater fisheries as well as aquaculture both marine and freshwater aquaculture. Excessive fishery activities would then not be harmful if Indonesia is willing to impose regulation which is significantly and effectively to manage these kind of fishery activities. Along with the fact that Indonesia is recognized as a Marine State, there is no reason to hold back in addressing this situation.

  12. AFSC/REFM: Beaufort Sea Marine Fish Survey, Beaufort Sea, Alaska, August 2008, Fisheries Interaction Team

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Alaska Fisheries Science Center's Status of Stocks and Multispecies Assessment (SSMA) Programs Fishery Interaction Team (FIT) conducted a fish survey in the...

  13. 78 FR 41772 - Magnuson-Stevens Act Provisions; Fisheries of the Northeastern United States; Northeast...

    Science.gov (United States)

    2013-07-11

    ... States; Northeast Multispecies Fishery; Proposed Rule To Allow Northeast Multispecies Sector Vessels.... ADDRESSES: A copy of the accompanying environmental assessment is available from the NMFS Northeast Regional.... SUPPLEMENTARY INFORMATION: Background Amendment 16 to the Northeast Multispecies Fisheries Management Plan...

  14. Underwater Coatings for Contamination Control

    International Nuclear Information System (INIS)

    Julia L. Tripp; Kip Archibald; Ann-Marie Phillips; Joseph Campbell

    2004-01-01

    The Idaho National Engineering and Environmental Laboratory (INEEL) is deactivating several fuel storage basins. Airborne contamination is a concern when the sides of the basins are exposed and allowed to dry during water removal. One way of controlling this airborne contamination is to fix the contamination in place while the pool walls are still submerged. There are many underwater coatings available on the market that are used in marine, naval and other applications. A series of tests were run to determine whether the candidate underwater fixatives are easily applied and adhere well to the substrates (pool wall materials) found in INEEL fuel pools. The four pools considered included (1) Test Area North (TAN-607) with epoxy painted concrete walls; (2) Idaho Nuclear Technology and Engineering Center (INTEC) (CPP-603) with bare concrete walls; (3) Materials Test Reactor (MTR) Canal with stainless steel lined concrete walls; and (4) Power Burst Facility (PBF-620) with stainless steel lined concrete walls on the bottom and epoxy painted carbon steel lined walls on the upper portions. Therefore, the four materials chosen for testing included bare concrete, epoxy painted concrete, epoxy painted carbon steel, and stainless steel. The typical water temperature of the pools varies from 55 F to 80 F dependent on the pool and the season. These tests were done at room temperature. The following criteria were used during this evaluation. The underwater coating must: (1) Be easy to apply; (2) Adhere well to the four surfaces of interest; (3) Not change or have a negative impact on water chemistry or clarity; (4) Not be hazardous in final applied form; and (5) Be proven in other underwater applications. In addition, it is desirable for the coating to have a high pigment or high cross-link density to prevent radiation from penetrating. This paper will detail the testing completed and the test results. A proprietary two-part, underwater epoxy owned by S. G. Pinney and Associates

  15. Population dynamics and stock assessment for Octopus maya (Cephalopoda:Octopodidae fishery in the Campeche Bank, Gulf of Mexico

    Directory of Open Access Journals (Sweden)

    Francisco Arreguín-Sánchez

    2000-06-01

    Full Text Available The octopus (Octopus maya is one of the most important fish resources in the Mexican Gulf of Mexico with a mean annual yield of 9000 ton, and a reasonable number of jobs created; O. maya represents 80% of the total octopus catch, followed by Octopus vulgaris. There are two artisanal fleets based on Octopus maya and a middle-size fleet that covers both species. Catch-at-length structured data from the artisanal fleets, for the 1994 season (August 1st to December 15th were used to analyze the O. maya population dynamics and stock and to estimate the current level of exploitation. Von Bertalanffy growth parameters were: L = 252 mm, mantle length; K=1.4 year -1; oscillation parameters C=1.0, WP=0.6; and tz=0.842 years. A rough estimate of natural mortality was M=2.2, total mortality from catch curve Z=8.77, and exploitation rate F/Z=0.75. This last value suggests an intensive exploitation, even when yield per recruit analysis indicates both fleets may increase the minimum legal size on about 10% to increase yields. The length-based VPA also shows that the stock is being exploited under its maximum acceptable biological limit. These apparently contradictory results are explained by biological and behavioral characteristics of this species. Because most females die after reproduction, a new gross estimation of natural mortality was computed as M=3.3. The new estimate of exploitation rate was F/Z=0.57. This new value coincides with results from the length-VPA and the Thompson and Bell methods, the former suggesting that a reduction of 20% in fishing mortality may provide larger yields. This fishery resource is fully exploited and current management measures must be revised to sustain and probably optimize yields.Octopus maya es uno de los recursos pesqueros más importantes del Golfo de México, con rendimientos anuales promedio de 9 000 t, y constituye el 80% de la captura total, seguido por O. vulgaris. En la pesquería participan dos flotas

  16. 75 FR 9397 - Fisheries of the South Atlantic and the Gulf of Mexico; Southeastern Data, Assessment, and Review...

    Science.gov (United States)

    2010-03-02

    ... for determining the status of fish stocks in the Southeast Region. A full benchmark assessment..., evaluates the status of the stock, estimates biological benchmarks, projects future population conditions... assessment models used in SEDAR 8 to evaluate stock status, estimate population benchmarks and management...

  17. 75 FR 47265 - Fisheries of the Gulf of Mexico; Southeast Data, Assessment, and Review (SEDAR) update; greater...

    Science.gov (United States)

    2010-08-05

    ... status of fish stocks in the Southeast Region. A full benchmark assessment conducted under SEDAR includes... the stock, estimates biological benchmarks, projects future population conditions, and recommends..., Commissions, and state and federal agencies. SEDAR conducts updates of benchmark stock assessments previously...

  18. CURRENT STATE OF FISHERIES AND ASSESSMENT OF FISH STOCKS IN THE WESTERN MIDDLE OF THE CASPIAN SEA. PROSPECTS FOR THE USE OF THE FISH RESOURCES

    Directory of Open Access Journals (Sweden)

    A. S. Abdusamadov

    2016-01-01

    Full Text Available Aim. To aim is to assess stocks and the fisheries of aquatic biological resources in the western part of the middle Caspian Sea and perspectives for the use of their resource potential.Methods. On the basis of the literature sources and our own data on the fish inventory in the western part of the Middle Caspian, we discuss possible reasons for emerging environmental, economic and other problems in the use of biological resources.Results. The main negative factors are the large-scale poaching, resulting in a catastrophic reduction in stocks of sturgeon and other valuable fish species of the Caspian Sea, a natural penetration of alien organisms (Mnemiopsis and overfishing of some species. The potential danger is large-scale development of oil and gas fields in the Caspian Sea, which can lead to even worse situation for the biological resources of the sea.Conclusions. In order to preserve the biological resources of the sea it is necessary to create conditions for steadily developing fishing and fish processing enterprises, thus ensuring the satisfaction of the constant demand for fish products and an increase in the revenue base of the budget and the well-being of the Russian population.

  19. Assessing an Adaptive Cycle in a Social System under External Pressure to Change: the Importance of Intergroup Relations in Recreational Fisheries Governance

    Directory of Open Access Journals (Sweden)

    Katrin Daedlow

    2011-06-01

    Full Text Available The adaptive cycle constitutes a heuristic originally used to interpret the dynamics of complex ecosystems in response to disturbance and change. It is assumed that socially constructed governance systems go through similar phases (K, Ω [omega], α [alpha], r as evident in ecological adaptive cycles. Two key dimensions of change shaping the four phases of an adaptive cycle are the degree of connectedness and the range of potential in the system. Our purpose was to quantitatively assess the four phases of the adaptive cycle in a social system by measuring the potential and connectedness dimensions and their different levels in each of the four phases. We assessed these dimensions using quantitative data from content analysis of magazine articles describing the transition process of East German recreational fisheries governance after the fall of the Berlin Wall in 1989. This process was characterized by the discussion of two governance alternatives amendable for implementation: a central East German and a decentralized West German approach. Contrary to assumptions in the adaptive cycle heuristic, we were unable to identify the four phases of the adaptive cycle in our governance system based on quantitatively assessed levels of connectedness and potential alone. However, the insertion of in-group (East Germans and out-group (West Germans dimensions representing the two governance alternatives in our analysis enabled us to identify the specific time frames for all four phases of the adaptive cycle on a monthly basis. These findings suggest that an unmodified "figure-eight model" of the adaptive cycle may not necessarily hold in social systems. Inclusion of disciplinary theories such as intergroup relation theory will help in understanding adaptation processes in social systems.

  20. Investigation of the Propagation Characteristics of Underwater Shock Waves in Underwater Drilling Blasting

    Directory of Open Access Journals (Sweden)

    Xin Liu

    2018-01-01

    Full Text Available During the first-stage project of the main channel of Ningbo-Zhoushan Port’s Shipu Harbor, underwater shock waves were monitored. By analyzing a typical measured pressure time history curve, the characteristics of underwater shock waves in an engineering context were obtained. We obtained a traditional exponential attenuation formula for underwater shock waves based on the measured data, simplified the model of underwater drilling blasting based on engineering practice, deduced a revised formula for underwater shock wave peak overpressure on the basis of dimensional analysis, established a linear fitting model, and obtained the undetermined coefficients of the revised formula using a linear regression analysis. In addition, the accuracies of the two formulas used to predict underwater shock wave peak overpressure and the significance order of influence and influence mechanism of factors included in the revised formula on the underwater shock wave peak overpressure were discussed.

  1. Fisheries and Oceans Canada - habitat management program in Ontario

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    On May 5, 2011, the Ontario Waterpower Association hosted the emergent hydro workshop in Peterborough. In the course of the workshop, Fisheries and Oceans Canada presented the habitat management program in Ontario. Fisheries and Oceans Canada explained that their role is to protect water resources. The Fisheries Act was passed to manage fisheries and fish habitats in Canada and to protect them from harmful alteration, disruption or destruction. The policy for the management of fish was written to interpret the Fisheries Act and enhance the productive capacity of fish habitats. In addition, two other Acts were passed, the Species at Risk Act and the Canadian Environmental Assessment Act, designed to protect species from extinction and improve coordination of, and public access to EA information. This presentation highlighted the different existing policies aimed at protecting fisheries and fish habitats in Canada.

  2. 78 FR 9372 - Fisheries of the Gulf of Mexico; Southeast Data, Assessment, and Review (SEDAR); Public Meeting

    Science.gov (United States)

    2013-02-08

    .... Gulf Council 2014 benchmark stocks. 2. Caribbean Council 2013 benchmark stocks. 3. South Atlantic... Southeast Data, Assessment and Review (SEDAR) process for determining the status of fish stocks in the...

  3. ROV Based Underwater Blurred Image Restoration

    Institute of Scientific and Technical Information of China (English)

    LIU Zhishen; DING Tianfu; WANG Gang

    2003-01-01

    In this paper, we present a method of ROV based image processing to restore underwater blurry images from the theory of light and image transmission in the sea. Computer is used to simulate the maximum detection range of the ROV under different water body conditions. The receiving irradiance of the video camera at different detection ranges is also calculated. The ROV's detection performance under different water body conditions is given by simulation. We restore the underwater blurry images using the Wiener filter based on the simulation. The Wiener filter is shown to be a simple useful method for underwater image restoration in the ROV underwater experiments. We also present examples of restored images of an underwater standard target taken by the video camera in these experiments.

  4. Quantum imaging for underwater arctic navigation

    Science.gov (United States)

    Lanzagorta, Marco

    2017-05-01

    The precise navigation of underwater vehicles is a difficult task due to the challenges imposed by the variable oceanic environment. It is particularly difficult if the underwater vehicle is trying to navigate under the Arctic ice shelf. Indeed, in this scenario traditional navigation devices such as GPS, compasses and gyrocompasses are unavailable or unreliable. In addition, the shape and thickness of the ice shelf is variable throughout the year. Current Arctic underwater navigation systems include sonar arrays to detect the proximity to the ice. However, these systems are undesirable in a wartime environment, as the sound gives away the position of the underwater vehicle. In this paper we briefly describe the theoretical design of a quantum imaging system that could allow the safe and stealthy navigation of underwater Arctic vehicles.

  5. 76 FR 52638 - Fisheries of the Gulf of Mexico and South Atlantic; Southeast Data, Assessment, and Review (SEDAR...

    Science.gov (United States)

    2011-08-23

    ... stock, estimates biological benchmarks, projects future population conditions, and recommends research... yellowtail snapper. SUMMARY: The technical stock assessments of the Gulf of Mexico stock of menhaden and the southeast U.S. stocks of yellowtail snapper will be reviewed during the Review Workshop. See SUPPLEMENTARY...

  6. 77 FR 16812 - Fisheries of the Gulf of Mexico; Southeast Data, Assessment, and Review (SEDAR); Public Meetings

    Science.gov (United States)

    2012-03-22

    ..., evaluates the status of the stock, estimates biological benchmarks, projects future population conditions... Review (SEDAR) process, a multi-step method for determining the status of fish stocks in the Southeast... collectors and database managers; stock assessment scientists, biologists, and researchers; constituency...

  7. 75 FR 28565 - Fisheries of the South Atlantic and the Gulf of Mexico; Southeast Data, Assessment, and Review...

    Science.gov (United States)

    2010-05-21

    ... for determining the status of fish stocks in the Southeast Region. A full benchmark assessment... status of the stock, estimates biological benchmarks, projects future population conditions, and... in SEDAR 8 to evaluate stock status, estimate population benchmarks and management criteria, and...

  8. 75 FR 12506 - Fisheries of the South Atlantic and Gulf of Mexico; Southeast Data, Assessment, and Review (SEDAR...

    Science.gov (United States)

    2010-03-16

    ... stock, estimates biological benchmarks, projects future population conditions, and recommends research...: The SEDAR assessments of the South Atlantic and Gulf of Mexico stocks of goliath grouper will consist... Review (SEDAR) process, a multi-step method for determining the status of fish stocks in the Southeast...

  9. 76 FR 81479 - Fisheries of the South Atlantic and Gulf of Mexico; Southeast Data, Assessment, and Review (SEDAR...

    Science.gov (United States)

    2011-12-28

    ... stock, estimates biological benchmarks, projects future population conditions, and recommends research... mackerel and cobia. SUMMARY: The SEDAR assessments of the South Atlantic and Gulf of Mexico stocks of... Review (SEDAR) process, a multi-step method for determining the status of fish stocks in the Southeast...

  10. 78 FR 34046 - Fisheries of the Gulf of Mexico; Southeast Data, Assessment, and Review (SEDAR); Public Meetings

    Science.gov (United States)

    2013-06-06

    ... population models to evaluate stock status, estimate population benchmarks and management criteria, and... Bonnethead sharks. SUMMARY: The SEDAR assessment of the HMS stocks of Atlantic Sharpnose and Bonnethead... status of fish stocks in the Southeast Region. SEDAR is a multi-step process including: (1) Data...

  11. 77 FR 11066 - Fisheries of the Gulf of Mexico; Southeast Data, Assessment, and Review (SEDAR); Public Meetings

    Science.gov (United States)

    2012-02-24

    ..., evaluates the status of the stock, estimates biological benchmarks, projects future population conditions... population models to evaluate stock status, estimate population benchmarks and management criteria, and... SEDAR assessment of the HMS stocks of Gulf of Mexico blacktip sharks will consist of one workshop and a...

  12. 78 FR 62586 - Fisheries of the Gulf of Mexico and South Atlantic; Southeast Data, Assessment, and Review (SEDAR...

    Science.gov (United States)

    2013-10-22

    .... Participants will present summary data and will discuss data needs and treatments. Although non-emergency... the Gulf of Mexico and South Atlantic; Southeast Data, Assessment, and Review (SEDAR); Public Meeting...), Commerce. ACTION: Notice of SEDAR 38 data webinar for Gulf of Mexico and South Atlantic King Mackerel...

  13. 77 FR 75613 - Fisheries of the South Atlantic; Southeast Data, Assessment and Review (SEDAR); Data Webinar for...

    Science.gov (United States)

    2012-12-21

    ... discuss data needs and treatments. Special Accommodations These meetings are physically accessible to... the South Atlantic; Southeast Data, Assessment and Review (SEDAR); Data Webinar for South Atlantic...: Notice of SEDAR 32 data webinar for South Atlantic gray triggerfish and blueline tilefish. SUMMARY: The...

  14. Fisheries Reclamation Events

    Data.gov (United States)

    Minnesota Department of Natural Resources — This layer shows waterbodies that have been treated for fish removal(i.e., reclaimed)by DNR Fisheries. Some waterbodies have had multiple treatments. Attributes...

  15. International Fisheries Agreements

    DEFF Research Database (Denmark)

    Pintassilgo, Pedro; Kronbak, Lone Grønbæk; Lindroos, Marko

    2015-01-01

    This paper surveys the application of game theory to the economic analysis of international fisheries agreements. The relevance of this study comes not only from the existence of a vast literature on the topic but especially from the specific features of these agreements. The emphasis of the survey...... is on coalition games, an approach that has become prominent in the fisheries economics literature over the last decade. It is shown that coalition games were first applied to international fisheries agreements in the late 1990s addressing cooperative issues under the framework of characteristic function games...... and stability of international fisheries agreements. A key message that emerges from this literature strand is that self-enforcing cooperative management of internationally shared fish stocks is generally difficult to achieve. Hence, the international legal framework and regulations play a decisive role...

  16. Marine Mammals :: NOAA Fisheries

    Science.gov (United States)

    Resources Habitat Conservation Science and Technology International Affairs Law Enforcement Aquaculture Application Types Apply Online (APPS) Endangered Species Permits Marine Mammal Permits Public Display of : NMFS Pacific Islands Fisheries Science Center North Atlantic right whales North Atlantic Right whales

  17. LAKE BAIKAL: Underwater neutrino detector

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    A new underwater detector soon to be deployed in Lake Baikal in Siberia, the world's deepest lake with depths down to 1.7 kilometres, could help probe the deepest mysteries of physics. One of the big unsolved problems of astrophysics is the origin of very energetic cosmic rays. However there are many ideas on how particles could be accelerated by exotic concentrations of matter and provide the majority of the Galaxy's high energy particles. Clarification would come from new detectors picking up the energetic photons and neutrinos from these sources

  18. Assessing the ecosystem-level consequences of a small-scale artisanal kelp fishery within the context of climate-change.

    Science.gov (United States)

    Krumhansl, Kira A; Bergman, Jordanna N; Salomon, Anne K

    2017-04-01

    Coastal communities worldwide rely on small-scale artisanal fisheries as a means of increasing food security and alleviating poverty. Even small-scale fishing activities, however, are prone to resource depletion and environmental degradation, which can erode livelihoods in the long run. Thus, there is a pressing need to identify viable and resilient artisanal fisheries, and generate knowledge to support management within the context of a rapidly changing climate. We examined the ecosystem-level consequences of an artisanal kelp fishery (Macrocystis pyrifera), finding small-scale harvest of this highly productive species poses minimal impacts on kelp recovery rates, survival, and biomass dynamics, and abundances of associated commercial and culturally important fish species. These results suggest that small-scale harvest poses minimal trade-offs for the other economic benefits provided by these ecosystems, and their inherent, spiritual, and cultural value to humans. However, we detected a negative impact of warmer seawater temperatures on kelp recovery rates following harvest, indicating that the viability of harvest, even at small scales, may be threatened by future increases in global ocean temperature. This suggests that negative impacts of artisanal fisheries may be more likely to arise in the context of a warming climate, further highlighting the widespread effects of global climate change on coastal fisheries and livelihoods. © 2016 by the Ecological Society of America.

  19. Turtle bycatch in the pelagic longline fishery off southern Africa ...

    African Journals Online (AJOL)

    Capture by pelagic longline fisheries has been identified as a key threat to turtle populations. This study is the first assessment of turtle bycatch in the South African pelagic longline fishery for tunas Thunnus spp. and swordfish Xiphias gladius. A total of 181 turtles was caught on observed sets between 1998 and 2005, at a ...

  20. 78 FR 73477 - List of Fisheries for 2014

    Science.gov (United States)

    2013-12-06

    ... on information contained in the U.S. Atlantic and Gulf of Mexico Marine Mammal Stock Assessments... required by the Marine Mammal Protection Act (MMPA). The proposed LOF for 2014 reflects new information on interactions between commercial fisheries and marine mammals. NMFS must classify each commercial fishery on the...

  1. Can protected areas work in artisanal fisheries of Uganda? The ...

    African Journals Online (AJOL)

    The Ecosystem Approach to Fisheries Management agitates for provision of Marine Protected Areas (MPAs) which seem to be effective in developed countries. However, efforts to control artisanal fisheries through protection have not been adequately assessed. The Uganda portion of Lake Edward, Kazinga channel and ...

  2. 78 FR 14983 - Fisheries of the Gulf of Mexico; Gulf of Mexico Fishery Management Council; Public Meeting

    Science.gov (United States)

    2013-03-08

    ... the Gulf of Mexico; Gulf of Mexico Fishery Management Council; Public Meeting AGENCY: National Marine... of Gulf of Mexico Fishery Management Council Spanish Mackerel and Cobia Stock Assessment Review Workshop. SUMMARY: Independent peer review of Gulf of Mexico Spanish Mackerel and Cobia stocks will be...

  3. A first description of the artisanal shark fishery in northern Madagascar

    African Journals Online (AJOL)

    In the past two decades, small, targeted artisanal shark fisheries have developed in the extreme north of Madagascar, largely in response to the shark fin trade. Few studies have been undertaken to assess the biological characteristics and impact of these fisheries. Here, we developed a profile of the fishery in the region of ...

  4. Integration of fisheries into marine spatial planning: Quo vadis?

    Science.gov (United States)

    Janßen, Holger; Bastardie, Francois; Eero, Margit; Hamon, Katell G.; Hinrichsen, Hans-Harald; Marchal, Paul; Nielsen, J. Rasmus; Le Pape, Olivier; Schulze, Torsten; Simons, Sarah; Teal, Lorna R.; Tidd, Alex

    2018-02-01

    The relationship between fisheries and marine spatial planning (MSP) is still widely unsettled. While several scientific studies highlight the strong relation between fisheries and MSP, as well as ways in which fisheries could be included in MSP, the actual integration of fisheries into MSP often fails. In this article, we review the state of the art and latest progress in research on various challenges in the integration of fisheries into MSP. The reviewed studies address a wide range of integration challenges, starting with techniques to analyse where fishermen actually fish, assessing the drivers for fishermen's behaviour, seasonal dynamics and long-term spatial changes of commercial fish species under various anthropogenic pressures along their successive life stages, the effects of spatial competition on fisheries and projections on those spaces that might become important fishing areas in the future, and finally, examining how fisheries could benefit from MSP. This paper gives an overview of the latest developments on concepts, tools, and methods. It becomes apparent that the spatial and temporal dynamics of fish and fisheries, as well as the definition of spatial preferences, remain major challenges, but that an integration of fisheries is already possible today.

  5. A new technique for robot vision in autonomous underwater vehicles using the color shift in underwater imaging

    Science.gov (United States)

    2017-06-01

    FOR ROBOT VISION IN AUTONOMOUS UNDERWATER VEHICLES USING THE COLOR SHIFT IN UNDERWATER IMAGING by Jake A. Jones June 2017 Thesis Advisor...techniques to determine the distances from each pixel to the camera. 14. SUBJECT TERMS unmanned undersea vehicles (UUVs), autonomous ... AUTONOMOUS UNDERWATER VEHICLES USING THE COLOR SHIFT IN UNDERWATER IMAGING Jake A. Jones Lieutenant Commander, United States Navy B.S

  6. Dynamics and Control of Underwater Gliders I: Steady Motions

    OpenAIRE

    Mahmoudian, N.; Geisbert, J.; Woolsey, C.

    2007-01-01

    This paper describes analysis of steady motions for underwater gliders, a type of highly efficient underwater vehicle which uses gravity for propulsion. Underwater gliders are winged underwater vehicles which locomote by modulating their buoyancy and their attitude. Several such vehicles have been developed and have proven their worth as efficient long-distance, long-duration ocean sampling platforms. To date, the primary emphasis in underwater glider development has been on locomotive effici...

  7. Marine fisheries in Tanzania.

    Science.gov (United States)

    Jiddawi, Narriman S; Ohman, Marcus C

    2002-12-01

    Fishery resources are a vital source of food and make valuable economic contributions to the local communities involved in fishery activities along the 850 km stretch of the Tanzania coastline and numerous islands. Small-scale artisanal fishery accounts for the majority of fish catch produced by more than 43 000 fishermen in the country, mainly operating in shallow waters within the continental shelf, using traditional fishing vessels including small boats, dhows, canoes, outrigger canoes and dinghys. Various fishing techniques are applied using uncomplicated passive fishing gears such as basket traps, fence traps, nets as well as different hook and line techniques. Species composition and size of the fish varies with gear type and location. More than 500 species of fish are utilized for food with reef fishes being the most important category including emperors, snappers, sweetlips, parrotfish, surgeonfish, rabbitfish, groupers and goatfish. Most of the fish products are used for subsistence purposes. However, some are exported. Destructive fishing methods such as drag nets and dynamite fishing pose a serious problem as they destroy important habitats for fish and other organisms, and there is a long-term trend of overharvested fishery resources. However, fishing pressure varies within the country as fishery resources are utilized in a sustainable manner in some areas. For this report more than 340 references about Tanzanian fishery and fish ecology were covered. There are many gaps in terms of information needed for successful fishery management regarding both basic and applied research. Most research results have been presented as grey literature (57%) with limited distribution; only one-fifth were scientific publications in international journals.

  8. 4th Pacific Rim Underwater Acoustics Conference

    CERN Document Server

    Xu, Wen; Cheng, Qianliu; Zhao, Hangfang

    2016-01-01

    These proceedings are a collection of 16 selected scientific papers and reviews by distinguished international experts that were presented at the 4th Pacific Rim Underwater Acoustics Conference (PRUAC), held in Hangzhou, China in October 2013. The topics discussed at the conference include internal wave observation and prediction; environmental uncertainty and coupling to sound propagation; environmental noise and ocean dynamics; dynamic modeling in acoustic fields; acoustic tomography and ocean parameter estimation; time reversal and matched field processing; underwater acoustic localization and communication as well as measurement instrumentations and platforms. These proceedings provide insights into the latest developments in underwater acoustics, promoting the exchange of ideas for the benefit of future research.

  9. USVI commercial fisheries cost data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — To assist the Caribbean Fishery Management Council in managing marine living resources in the United States Virgin Islands, the Southeast Fisheries Science Center...

  10. On the Accuracy Potential in Underwater/Multimedia Photogrammetry.

    Science.gov (United States)

    Maas, Hans-Gerd

    2015-07-24

    Underwater applications of photogrammetric measurement techniques usually need to deal with multimedia photogrammetry aspects, which are characterized by the necessity of handling optical rays that are refracted at interfaces between optical media with different refractive indices according to Snell's Law. This so-called multimedia geometry has to be incorporated into geometric models in order to achieve correct measurement results. The paper shows a flexible yet strict geometric model for the handling of refraction effects on the optical path, which can be implemented as a module into photogrammetric standard tools such as spatial resection, spatial intersection, bundle adjustment or epipolar line computation. The module is especially well suited for applications, where an object in water is observed by cameras in air through one or more planar glass interfaces, as it allows for some simplifications here. In the second part of the paper, several aspects, which are relevant for an assessment of the accuracy potential in underwater/multimedia photogrammetry, are discussed. These aspects include network geometry and interface planarity issues as well as effects caused by refractive index variations and dispersion and diffusion under water. All these factors contribute to a rather significant degradation of the geometric accuracy potential in underwater/multimedia photogrammetry. In practical experiments, a degradation of the quality of results by a factor two could be determined under relatively favorable conditions.

  11. Fisheries and climate

    DEFF Research Database (Denmark)

    Brander, Keith

    2009-01-01

    Fish stocks and the fisheries based on them have always experienced variability due to climate. Changes in temperature, salinity, winds, ocean currents, oxygen, and other factors affect their distribution, growth, survival, and recruitment. Examples of such effects are given for several regions...... of the oceans and the processes are described. Poleward distribution shifts have occurred since the 1960s and can be attributed to the effects of anthropogenic climate change with a high degree of confidence. In addition to climate effects, fisheries are subjected to other anthropogenic stresses, including high...... fishing mortality, loss of habitat, pollution, and introduction of alien species. These interact and may reduce the resilience of exploited stocks, although climate change may also increase productivity in some cases. Fisheries production depends on primary production, but to date we have low confidence...

  12. Fishery potential of the Gulf of Kachchh

    Digital Repository Service at National Institute of Oceanography (India)

    Nair, V.R.; Govindan, K.; Ramaiah, Neelam; Gajbhiye, S.N.

    Fishery potential of the interior Gulf of Kachchh and adjacent creek regions was reported for the first time as baseline data for future ecological assessment. The experimental trawling and gill netting indicated that the inner Gulf (av. 7.8 kg...

  13. Impact of fisheries on seabed bottom habitat

    NARCIS (Netherlands)

    Piet, Gerjan; Hintzen, Niels; Quirijns, Floor

    2018-01-01

    The Marine Stewardship Council (MSC) released new certification requirements in 2014. The new requirements come with new guidelines for scoring fisheries for several Performance Indicators (PIs). One of the adjusted PIs is PI 2.4.1: the Habitats outcome indicator:“The Unit of Assessment (UoA) does

  14. Underwater Object Segmentation Based on Optical Features

    Directory of Open Access Journals (Sweden)

    Zhe Chen

    2018-01-01

    Full Text Available Underwater optical environments are seriously affected by various optical inputs, such as artificial light, sky light, and ambient scattered light. The latter two can block underwater object segmentation tasks, since they inhibit the emergence of objects of interest and distort image information, while artificial light can contribute to segmentation. Artificial light often focuses on the object of interest, and, therefore, we can initially identify the region of target objects if the collimation of artificial light is recognized. Based on this concept, we propose an optical feature extraction, calculation, and decision method to identify the collimated region of artificial light as a candidate object region. Then, the second phase employs a level set method to segment the objects of interest within the candidate region. This two-phase structure largely removes background noise and highlights the outline of underwater objects. We test the performance of the method with diverse underwater datasets, demonstrating that it outperforms previous methods.

  15. Underwater photogrammetry successful in Spain and France

    International Nuclear Information System (INIS)

    Anon.

    1988-01-01

    Underwater photogrammetry has been used to measure distortions in fuel assembly alignment pins in the upper internals of the Almarez and Dampierre PWRs. Photogrammetry is a three-dimensional precision measurement method using photographic techniques for the on-site measurement phase. On the strength of the operations at the two PWRs, underwater photogrammetry is now considered as a practical and effective technique for dimensional inspection at nuclear plants. (U.K.)

  16. 3D Laser Scanner for Underwater Manipulation

    Directory of Open Access Journals (Sweden)

    Albert Palomer

    2018-04-01

    Full Text Available Nowadays, research in autonomous underwater manipulation has demonstrated simple applications like picking an object from the sea floor, turning a valve or plugging and unplugging a connector. These are fairly simple tasks compared with those already demonstrated by the mobile robotics community, which include, among others, safe arm motion within areas populated with a priori unknown obstacles or the recognition and location of objects based on their 3D model to grasp them. Kinect-like 3D sensors have contributed significantly to the advance of mobile manipulation providing 3D sensing capabilities in real-time at low cost. Unfortunately, the underwater robotics community is lacking a 3D sensor with similar capabilities to provide rich 3D information of the work space. In this paper, we present a new underwater 3D laser scanner and demonstrate its capabilities for underwater manipulation. In order to use this sensor in conjunction with manipulators, a calibration method to find the relative position between the manipulator and the 3D laser scanner is presented. Then, two different advanced underwater manipulation tasks beyond the state of the art are demonstrated using two different manipulation systems. First, an eight Degrees of Freedom (DoF fixed-base manipulator system is used to demonstrate arm motion within a work space populated with a priori unknown fixed obstacles. Next, an eight DoF free floating Underwater Vehicle-Manipulator System (UVMS is used to autonomously grasp an object from the bottom of a water tank.

  17. 3D Laser Scanner for Underwater Manipulation.

    Science.gov (United States)

    Palomer, Albert; Ridao, Pere; Youakim, Dina; Ribas, David; Forest, Josep; Petillot, Yvan

    2018-04-04

    Nowadays, research in autonomous underwater manipulation has demonstrated simple applications like picking an object from the sea floor, turning a valve or plugging and unplugging a connector. These are fairly simple tasks compared with those already demonstrated by the mobile robotics community, which include, among others, safe arm motion within areas populated with a priori unknown obstacles or the recognition and location of objects based on their 3D model to grasp them. Kinect-like 3D sensors have contributed significantly to the advance of mobile manipulation providing 3D sensing capabilities in real-time at low cost. Unfortunately, the underwater robotics community is lacking a 3D sensor with similar capabilities to provide rich 3D information of the work space. In this paper, we present a new underwater 3D laser scanner and demonstrate its capabilities for underwater manipulation. In order to use this sensor in conjunction with manipulators, a calibration method to find the relative position between the manipulator and the 3D laser scanner is presented. Then, two different advanced underwater manipulation tasks beyond the state of the art are demonstrated using two different manipulation systems. First, an eight Degrees of Freedom (DoF) fixed-base manipulator system is used to demonstrate arm motion within a work space populated with a priori unknown fixed obstacles. Next, an eight DoF free floating Underwater Vehicle-Manipulator System (UVMS) is used to autonomously grasp an object from the bottom of a water tank.

  18. 77 FR 31327 - Pacific Fishery Management Council; Public Meeting

    Science.gov (United States)

    2012-05-25

    ... Fishery Management Council; Public Meeting AGENCY: National Marine Fisheries Service (NMFS), National... fisheries, including Columbia River fisheries issues, the NOAA Habitat Blueprint, and the Council's.... Thompson, Acting Director, Office of Sustainable Fisheries, National Marine Fisheries Service. [FR Doc...

  19. Fuel use and greenhouse gas emissions of world fisheries

    Science.gov (United States)

    Parker, Robert W. R.; Blanchard, Julia L.; Gardner, Caleb; Green, Bridget S.; Hartmann, Klaas; Tyedmers, Peter H.; Watson, Reg A.

    2018-04-01

    Food production is responsible for a quarter of anthropogenic greenhouse gas (GHG) emissions globally. Marine fisheries are typically excluded from global assessments of GHGs or are generalized based on a limited number of case studies. Here we quantify fuel inputs and GHG emissions for the global fishing fleet from 1990-2011 and compare emissions from fisheries to those from agriculture and livestock production. We estimate that fisheries consumed 40 billion litres of fuel in 2011 and generated a total of 179 million tonnes of CO2-equivalent GHGs (4% of global food production). Emissions from the global fishing industry grew by 28% between 1990 and 2011, with little coinciding increase in production (average emissions per tonne landed grew by 21%). Growth in emissions was driven primarily by increased harvests from fuel-intensive crustacean fisheries. The environmental benefit of low-carbon fisheries could be further realized if a greater proportion of landings were directed to human consumption rather than industrial uses.

  20. A case study on the impact of industrial effluent disposal on the fishery of Amba River Estuary, Maharashtra

    Digital Repository Service at National Institute of Oceanography (India)

    Gajbhiye, S.N.; Mehta, P.; Mustafa, S.; Nair, V.R.

    The impact of waste discharge on fishery resources is a matter of great concern. The accepted norm in all environmental impact assessment studies is to avoid areas of high fishery potential while locating a marine outfall. Contemplating...

  1. Insights into the Underwater Diving, Feeding, and Calling Behavior of Blue Whales from a Suction-Cup-Attached Video-Imaging Tag (CRITTERCAM)

    Science.gov (United States)

    2008-01-01

    San Diego Diane Gendron Centro Interdisciplinario de Ciencias Marinas Kelly Robertson Southwest Fisheries Science Center- NMFS/NOAA P A P E R Insights...archival tags have begun to provide more details about underwater behaviors, in- cluding feeding and social behaviors (Goldbogen et al., 2006; Oleson...Volume 41, Number 4 TABLE 2 Summary of deployments of CRITTERCAMS used in this article . TABLE 3 Summary of resightings based on photo-ID of whales in this

  2. Underwater welding and repair technologies applied in PWR environment

    International Nuclear Information System (INIS)

    Scandella, Fabrice; Carpreau, Jean-Michel

    2012-01-01

    The authors describe several welding processes and technologies which have been used for underwater applications and which can be applied when repairing components of a PWR type reactor. They address, describe and discuss wet arc welding processes, the peculiarities of underwater welding, and the use of various processes such as 111, 114 and 135 processes, underwater welding with the hybrid plasma MIG-MAG process, underwater welding with the laser wire process, underwater welding with the FSW, FSP or UWFSW processes, underwater welding with variants of the friction welding process (friction surfacing, taper stitch welding, hydro-pillar processing

  3. Can protected areas work in artisanal fisheries of Uganda? The ...

    African Journals Online (AJOL)

    ACSS

    Key words: Kazinga channel, landing sites, Marine Protected Areas. Introduction ... the north via Semliki River, but water loss by evaporation currently ... The Catch Assessment and Frame survey design ..... quality, invertebrates. Fisheries and.

  4. 78 FR 20618 - New England Fishery Management Council; Public Meeting

    Science.gov (United States)

    2013-04-05

    ... affecting New England fisheries in the exclusive economic zone (EEZ). DATES: The meeting will be held on... to discuss quota trading, assessment timing, alternative management strategies and the U.S./Canada...

  5. Research into fisheries and the marine environment 1989-90

    International Nuclear Information System (INIS)

    1992-01-01

    This biannual report includes notes on the work of the Aquatic Environment Protection Division of the Directorate of Fisheries Research, Lowestoft in relation to assessment and monitoring of radioactive waste disposal and research into the environmental behaviour of radionuclides. (UK)

  6. 75 FR 17901 - Pacific Fishery Management Council; Public Meeting

    Science.gov (United States)

    2010-04-08

    ... June 2010 meeting of the Pacific Council. The CPSMT will also discuss the pending Essential Fish Habitat five-year review; the 2010 Stock Assessment and Fishery Evaluation document; Pacific mackerel...

  7. CROATIAN FISHERIES IN 2004

    Directory of Open Access Journals (Sweden)

    Irena Jahutka

    2005-10-01

    Full Text Available This work deals with all the relevant statistic data regarding fisheries of Republic of Croatia, including freshwater fisheries data (aquaculture of fish and other aquatic organisms, commercial and sports fisheries, marine fisheries data (mariculture, commercial fisheries, small–scale fisheries and processing of fish and other marine organisms, as well as data about import and export of fish and fish products and the data about financial subventions in fisheries. Regarding aquaculture (freshwater fish farming in 2004 there have been noticed slight changes comparing to 2003. The total freshwater fish production in 2004 was 5,618 tons (4,259 tons of warm–water species and 1,359 tons of cold–water species. Total areas and production areas were increased comparing to 2003 (total areas 1.94% and production areas 5.42%. Total catch of freshwater fish in 2004 was 567 tons. The total marine fish species production was increased cca. 20% comparing to 2003. Mussels farming, which is slightly increasing since 1999, during 2004 was decreased, while oysters farming were stagnating. The catch of marine fish was increased by 9.74% comparing to 2003. The biggest increase is noticed regarding catch of demersal and other fish species. As well as the increase of the total catch, the number of commercial fishermen and fishing vessels was also increased in 2003. The number of fishermen who fish for their own consumption (without the right to sell fish–small scale fishermen in 2004 was 13,700. The total production of fish products in 2004 was 14,270 tons, which is 24.89% less comparing to 2003. Along this decrease, there has been also noticed an increasing trend of the production assortments, specially salted anchovy. The value of import in 2004 was higher than the value of export, although the export/import balance was higher in amount on the import side. Financial subventions payments in 2004 were 67.21% higher comparing to the first year of payments (1997

  8. Potential production of the Caribbean spiny lobster (Decapoda, Palinura) fisheries

    OpenAIRE

    Chávez Ortiz, Ernesto Aarón

    2009-01-01

    Spiny lobster Panulirus argus (Latreille, 1804) constitutes the most important fishery of the Caribbean; it accounts for nearly 42,000 tonnes. Evidence suggests that high fishing mortality (F) may have been overexploiting most stocks. An assessment was carried out providing the basis for a sustainable exploitation of the nine most important producing countries. Values were assessed and each fishery was simulated; age structure was reconstructed linking biological, economic, and social variabl...

  9. Jellyfish Identification Software for Underwater Laser Cameras (JTRACK

    Directory of Open Access Journals (Sweden)

    Patrizio Mariani

    2018-02-01

    Full Text Available Jellyfish can form erratic blooms in response to seasonal and irregular changes in environmental conditions with often large, transient effects on local ecosystem structure as well as effects on several sectors of the marine and maritime economy. Early warning systems able to detect conditions for jelly fish proliferation can enable management responses to mitigate such effects providing benefit to local ecosystems and economies. We propose here the creation of a research team in response to the EU call for proposal under the European Maritime and Fisheries Fund called “Blue Labs: innovative solutions for maritime challenges”. The project will establish a BLUELAB team with a strong cross-sectorial component that will benefit of the expertise of researchers in IT and Marine Biology, Computer Vision and embedded systems, which will work in collaboration with Industry and Policy maker to develop an early warning system using a new underwater imaging system based on Time of Flight Laser cameras. The camera will be combined to machine learning algorithm allowing autonomous early detection of jellyfish species (e.g. polyp, ephyra and planula stages. The team will develop the system and the companion software and will demonstrate its applications in real case conditions.

  10. Small-scale fisheries bycatch jeopardizes endangered Pacific loggerhead turtles.

    Directory of Open Access Journals (Sweden)

    S Hoyt Peckham

    2007-10-01

    Full Text Available Although bycatch of industrial-scale fisheries can cause declines in migratory megafauna including seabirds, marine mammals, and sea turtles, the impacts of small-scale fisheries have been largely overlooked. Small-scale fisheries occur in coastal waters worldwide, employing over 99% of the world's 51 million fishers. New telemetry data reveal that migratory megafauna frequent coastal habitats well within the range of small-scale fisheries, potentially producing high bycatch. These fisheries occur primarily in developing nations, and their documentation and management are limited or non-existent, precluding evaluation of their impacts on non-target megafauna.30 North Pacific loggerhead turtles that we satellite-tracked from 1996-2005 ranged oceanwide, but juveniles spent 70% of their time at a high use area coincident with small-scale fisheries in Baja California Sur, Mexico (BCS. We assessed loggerhead bycatch mortality in this area by partnering with local fishers to 1 observe two small-scale fleets that operated closest to the high use area and 2 through shoreline surveys for discarded carcasses. Minimum annual bycatch mortality in just these two fleets at the high use area exceeded 1000 loggerheads year(-1, rivaling that of oceanwide industrial-scale fisheries, and threatening the persistence of this critically endangered population. As a result of fisher participation in this study and a bycatch awareness campaign, a consortium of local fishers and other citizens are working to eliminate their bycatch and to establish a national loggerhead refuge.Because of the overlap of ubiquitous small-scale fisheries with newly documented high-use areas in coastal waters worldwide, our case study suggests that small-scale fisheries may be among the greatest current threats to non-target megafauna. Future research is urgently needed to quantify small-scale fisheries bycatch worldwide. Localizing coastal high use areas and mitigating bycatch in

  11. Small-scale fisheries bycatch jeopardizes endangered Pacific loggerhead turtles.

    Science.gov (United States)

    Peckham, S Hoyt; Maldonado Diaz, David; Walli, Andreas; Ruiz, Georgita; Crowder, Larry B; Nichols, Wallace J

    2007-10-17

    Although bycatch of industrial-scale fisheries can cause declines in migratory megafauna including seabirds, marine mammals, and sea turtles, the impacts of small-scale fisheries have been largely overlooked. Small-scale fisheries occur in coastal waters worldwide, employing over 99% of the world's 51 million fishers. New telemetry data reveal that migratory megafauna frequent coastal habitats well within the range of small-scale fisheries, potentially producing high bycatch. These fisheries occur primarily in developing nations, and their documentation and management are limited or non-existent, precluding evaluation of their impacts on non-target megafauna. 30 North Pacific loggerhead turtles that we satellite-tracked from 1996-2005 ranged oceanwide, but juveniles spent 70% of their time at a high use area coincident with small-scale fisheries in Baja California Sur, Mexico (BCS). We assessed loggerhead bycatch mortality in this area by partnering with local fishers to 1) observe two small-scale fleets that operated closest to the high use area and 2) through shoreline surveys for discarded carcasses. Minimum annual bycatch mortality in just these two fleets at the high use area exceeded 1000 loggerheads year(-1), rivaling that of oceanwide industrial-scale fisheries, and threatening the persistence of this critically endangered population. As a result of fisher participation in this study and a bycatch awareness campaign, a consortium of local fishers and other citizens are working to eliminate their bycatch and to establish a national loggerhead refuge. Because of the overlap of ubiquitous small-scale fisheries with newly documented high-use areas in coastal waters worldwide, our case study suggests that small-scale fisheries may be among the greatest current threats to non-target megafauna. Future research is urgently needed to quantify small-scale fisheries bycatch worldwide. Localizing coastal high use areas and mitigating bycatch in partnership with small

  12. 76 FR 81851 - Fisheries Off West Coast States; West Coast Salmon Fisheries; Amendment 16 to the Salmon Fishery...

    Science.gov (United States)

    2011-12-29

    .... 101206604-1758-02] RIN 0648-BA55 Fisheries Off West Coast States; West Coast Salmon Fisheries; Amendment 16 to the Salmon Fishery Management Plan AGENCY: National Marine Fisheries Service (NMFS), National...) to implement Amendment 16 to the Pacific Coast Salmon Fishery Management Plan for Commercial and...

  13. 76 FR 65673 - Fisheries Off West Coast States; West Coast Salmon Fisheries; Amendment 16 to the Salmon Fishery...

    Science.gov (United States)

    2011-10-24

    .... 101206604-1620-01] RIN 0648-BA55 Fisheries Off West Coast States; West Coast Salmon Fisheries; Amendment 16 to the Salmon Fishery Management Plan AGENCY: National Marine Fisheries Service (NMFS), National... implement Amendment 16 to the Pacific Coast Salmon Fishery Management Plan for Commercial and Recreational...

  14. 77 FR 75101 - Fisheries Off West Coast States; West Coast Salmon Fisheries; Amendment 17 to the Salmon Fishery...

    Science.gov (United States)

    2012-12-19

    .... 120813333-2647-01] RIN 0648-BC28 Fisheries Off West Coast States; West Coast Salmon Fisheries; Amendment 17 to the Salmon Fishery Management Plan AGENCY: National Marine Fisheries Service (NMFS), National.... SUMMARY: NMFS proposes regulations to implement Amendment 17 to the Pacific Coast Salmon Fishery...

  15. 78 FR 10557 - Fisheries Off West Coast States; West Coast Salmon Fisheries; Amendment 17 to the Salmon Fishery...

    Science.gov (United States)

    2013-02-14

    .... 120813333-3107-02] RIN 0648-BC28 Fisheries Off West Coast States; West Coast Salmon Fisheries; Amendment 17 to the Salmon Fishery Management Plan AGENCY: National Marine Fisheries Service (NMFS), National... implement Amendment 17 to the Pacific Coast Salmon Fishery Management Plan for Commercial and Recreational...

  16. Optimal Node Placement in Underwater Wireless Sensor Networks

    KAUST Repository

    Felamban, M.; Shihada, Basem; Jamshaid, K.

    2013-01-01

    Wireless Sensor Networks (WSN) are expected to play a vital role in the exploration and monitoring of underwater areas which are not easily reachable by humans. However, underwater communication via acoustic waves is subject to several performance

  17. Underwater Sensor Networks: A New Energy Efficient and Robust Architecture

    NARCIS (Netherlands)

    Climent, Salvador; Capella, Juan Vincente; Meratnia, Nirvana; Serrano, Juan José

    2012-01-01

    The specific characteristics of underwater environments introduce new challenges for networking protocols. In this paper, a specialized architecture for underwater sensor networks (UWSNs) is proposed and evaluated. Experiments are conducted in order to analyze the suitability of this protocol for

  18. Nonuniform Illumination Correction Algorithm for Underwater Images Using Maximum Likelihood Estimation Method

    Directory of Open Access Journals (Sweden)

    Sonali Sachin Sankpal

    2016-01-01

    Full Text Available Scattering and absorption of light is main reason for limited visibility in water. The suspended particles and dissolved chemical compounds in water are also responsible for scattering and absorption of light in water. The limited visibility in water results in degradation of underwater images. The visibility can be increased by using artificial light source in underwater imaging system. But the artificial light illuminates the scene in a nonuniform fashion. It produces bright spot at the center with the dark region at surroundings. In some cases imaging system itself creates dark region in the image by producing shadow on the objects. The problem of nonuniform illumination is neglected by the researchers in most of the image enhancement techniques of underwater images. Also very few methods are discussed showing the results on color images. This paper suggests a method for nonuniform illumination correction for underwater images. The method assumes that natural underwater images are Rayleigh distributed. This paper used maximum likelihood estimation of scale parameter to map distribution of image to Rayleigh distribution. The method is compared with traditional methods for nonuniform illumination correction using no-reference image quality metrics like average luminance, average information entropy, normalized neighborhood function, average contrast, and comprehensive assessment function.

  19. Underwater Calibration of Dome Port Pressure Housings

    Science.gov (United States)

    Nocerino, E.; Menna, F.; Fassi, F.; Remondino, F.

    2016-03-01

    Underwater photogrammetry using consumer grade photographic equipment can be feasible for different applications, e.g. archaeology, biology, industrial inspections, etc. The use of a camera underwater can be very different from its terrestrial use due to the optical phenomena involved. The presence of the water and camera pressure housing in front of the camera act as additional optical elements. Spherical dome ports are difficult to manufacture and consequently expensive but at the same time they are the most useful for underwater photogrammetry as they keep the main geometric characteristics of the lens unchanged. Nevertheless, the manufacturing and alignment of dome port pressure housing components can be the source of unexpected changes of radial and decentring distortion, source of systematic errors that can influence the final 3D measurements. The paper provides a brief introduction of underwater optical phenomena involved in underwater photography, then presents the main differences between flat and dome ports to finally discuss the effect of manufacturing on 3D measurements in two case studies.

  20. Integration of fisheries into marine spatial planning: Quo vadis?

    DEFF Research Database (Denmark)

    Janssen, Holger; Bastardie, Francois; Eero, Margit

    2018-01-01

    fails. In this article, we review the state of the art and latest progress in research on various challenges in the integration of fisheries into MSP. The reviewed studies address a wide range of integration challenges, starting with techniques to analyse where fishermen actually fish, assessing...... in the future, and finally, examining how fisheries could benefit from MSP. This paper gives an overview of the latest developments on concepts, tools, and methods. It becomes apparent that the spatial and temporal dynamics of fish and fisheries, as well as the definition of spatial preferences, remain major...

  1. Green growth in fisheries

    DEFF Research Database (Denmark)

    Nielsen, Max; Ravensbeck, Lars; Nielsen, Rasmus

    2014-01-01

    harming the environment. Fishery is an environment-dependent sector and it has been argued that there is no potential for green growth in the sector owing to global overexploitation, leaving no scope for production growth. The purpose of this paper is to explain what green growth is and to develop......Climate change and economic growth have gained a substantial amount of attention over the last decade. Hence, in order to unite the two fields of interest, the concept of green growth has evolved. The concept of green growth focuses on how to achieve growth in environment-dependent sectors, without...... a conceptual framework. Furthermore, the aim is to show that a large green growth potential actually exists in fisheries and to show how this potential can be achieved. The potential green growth appears as value-added instead of production growth. The potential can be achieved by reducing overcapacity...

  2. Centralised versus Decentralised Control Reconfiguration for Collaborating Underwater Robots

    DEFF Research Database (Denmark)

    Furno, Lidia; Nielsen, Mikkel Cornelius; Blanke, Mogens

    2015-01-01

    The present paper introduces an approach to fault-tolerant reconfiguration for collaborating underwater robots. Fault-tolerant reconfiguration is obtained using the virtual actuator approach, Steen (2005). The paper investigates properties of a centralised versus a decentralised implementation an...... an underwater drill needs to be transported and positioned by three collaborating robots as part of an underwater autonomous operation....

  3. Fisheries-Independent Biological and Environmental Trawl Data from the Louisiana Department of Wildlife and Fisheries (1986-2007) as Part of the Comparative Assessment of Gulf Estuarine Systems (CAGES) Database (NODC Accession 0115183)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The CAGES program (Comparative Assessment of Gulf Estuarine Systems) is designed to examine the differences between estuarine ecosystems and investigate why some are...

  4. Survivability design for a hybrid underwater vehicle

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Biao; Wu, Chao; Li, Xiang; Zhao, Qingkai; Ge, Tong [State Key Lab of Ocean Engineering, School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2015-03-10

    A novel hybrid underwater robotic vehicle (HROV) capable of working to the full ocean depth has been developed. The battery powered vehicle operates in two modes: operate as an untethered autonomous vehicle in autonomous underwater vehicle (AUV) mode and operate under remote control connected to the surface vessel by a lightweight, fiber optic tether in remotely operated vehicle (ROV) mode. Considering the hazardous underwater environment at the limiting depth and the hybrid operating modes, survivability has been placed on an equal level with the other design attributes of the HROV since the beginning of the project. This paper reports the survivability design elements for the HROV including basic vehicle design of integrated navigation and integrated communication, emergency recovery strategy, distributed architecture, redundant bus, dual battery package, emergency jettison system and self-repairing control system.

  5. Survivability design for a hybrid underwater vehicle

    International Nuclear Information System (INIS)

    Wang, Biao; Wu, Chao; Li, Xiang; Zhao, Qingkai; Ge, Tong

    2015-01-01

    A novel hybrid underwater robotic vehicle (HROV) capable of working to the full ocean depth has been developed. The battery powered vehicle operates in two modes: operate as an untethered autonomous vehicle in autonomous underwater vehicle (AUV) mode and operate under remote control connected to the surface vessel by a lightweight, fiber optic tether in remotely operated vehicle (ROV) mode. Considering the hazardous underwater environment at the limiting depth and the hybrid operating modes, survivability has been placed on an equal level with the other design attributes of the HROV since the beginning of the project. This paper reports the survivability design elements for the HROV including basic vehicle design of integrated navigation and integrated communication, emergency recovery strategy, distributed architecture, redundant bus, dual battery package, emergency jettison system and self-repairing control system

  6. Application of underwater radon measurements in geology

    Energy Technology Data Exchange (ETDEWEB)

    Varhegyi, A.; Baranyi, I.; Gerzson, I. (Mecsek Ore Mining Enterprise, Pecs (Hungary)); Somogyi, G.; Hakl, J.; Hunyadi, I. (Magyar Tudomanyos Akademia, Debrecen (Hungary). Atommag Kutato Intezete)

    1988-01-01

    Based on the observed phenomenon of geogas migration in microbubble form from deeper regions, the authors have developed a new model for the vertical transport of radon released from deeper sources. The physical properties of the rock relating to the upflow of microbubbles below the groundwater level are considered and the radon transport parameter of rocks is introduced. The vertical distribution of radon concentration in the case of a multi-layered geological model is given and the penetration depth of underwater radon measurements is examined. Aspects of underwater radon detection by the nuclear track detector technique are analyzed. The radon transport model gives a new theoretical basis for several applications of radon measurements in geology. The advantages of underwater radon detection have already been proved in uranium exploration. Further geological applications are proposed in earthquake prediction, in volcanology, in the survey of active faults and thermal waters. (author).

  7. Modelling of the underwater disposal of uranium mine tailings in Elliot Lake

    International Nuclear Information System (INIS)

    Halbert, B.E.; Scharer, J.M.; Chakravatti, J.L.; Barnes, E.

    1982-01-01

    Underwater disposal of uranium mine tailings from the Elliot Lake area operations offers potential advantages in controlling radon gas release, emission of airborne particulate matter, and acid production from pyrites in the tailings. In addition, the proximity of the three active properties, one owned by Denison Mines Limited and two by Rio Algom Limited, to a large deep lake has spurred interest in the concept. It has been estimated that the placement of approximately 150 million tonnes of tailings from future planned production would occupy less than 20% of the lake volume. To assess the applicability of the underwater tailings disposal concept, a multi-stage study was developed in conjunction with the regulatory agencies. The most important facet identified for investigation during the first-stage investigations was an assessment of the effects of underwater disposal on water quality in the Serpent River Basin watershed. To simulate the effects of underwater disposal, a computer simulation routine was developed and integrated with a water quality model previously developed for the Basin which predicts levels of total dissolved solids, ammonia, dissolved radium-226 and pH. The underwater disposal model component reflects the effects of direct input of tailings into the hypolimnion, the chemical/biological transformation of dissolved constituents in the water column, the reactions of pyritic tailings deposited on the bottom, and the flux of dissolved constituents from the tailings into the water column. To establish site-specific values for the underwater disposal model, field and laboratory experiments were utilized to evaluate rates of pyrite and ammonia oxidation, and pH-alkalinity relationships. The results of these studies and their use in the water quality model are discussed. In addition, the results of two model run simulations are presented. (author)

  8. 77 FR 51853 - Fisheries of the Northeastern United States; Atlantic Mackerel, Squid, and Butterfish Fisheries...

    Science.gov (United States)

    2012-08-27

    ... stocks without an overfishing limit. Framework Adjustment 6 was initiated by the Mid-Atlantic Fishery... biological catch will not lead to overfishing. DATES: Effective on August 24, 2012. ADDRESSES: Copies of... overfishing limit (OFL) derived either from the stock assessment, or through the SSC ABC recommendation...

  9. The common fisheries policy of the European Union and fisheries economics

    DEFF Research Database (Denmark)

    Frost, Hans; Andersen, Peder

    2006-01-01

    with the ‘conventional’ bioeconomic theory. The purpose is to assess to what extent the lessons of the theory could be found in the Roadmap. Having in mind the complexity of the EU fisheries, the Roadmap, in particular, focuses on fleet management policy with the aim of reducing overcapacity on a community level...

  10. The safety of fishery products

    OpenAIRE

    Zugravu Gheorghe, Adrian; Turek Rahoveanu, Maria Magdalena; Turek Rahoveanu, Adrian

    2012-01-01

    The paper follows two main objectives: to understand consumers' perception and image of fishery products and to identify communication levers in order to improve the perceived image of fishery products. Orientations in terms of communication are product-focused and aim at enhancing the reputation of products, consequently with impact on product consumption. The present research is focused on the fishery products, regardless of their presentation - fresh, frozen or processed. This paper conduc...

  11. Underwater laser cutting of metallic structures

    International Nuclear Information System (INIS)

    Alfille, J.P.; Schildknecht, J.; Ramaswami, V.S.

    1993-01-01

    In the frame of an european contract, the feasibility of the underwater cutting with a CO 2 laser power is studied. The aim of this work is the dismantling metallic structures of reactors pools. The paper analyzes the general concept of the experimental device, the underwater cutting head, the experimenting vessel, examples of cuttings in dismantling situation with a 500 W CO 2 laser, and examples of cuttings with a 5 kW CO 2 laser. (author). 2 refs., 9 figs., 2 tabs

  12. Separating underwater ambient noise from flow noise recorded on stereo acoustic tags attached to marine mammals

    NARCIS (Netherlands)

    Benda-Beckmann, A.M. von; Wensveen, P.J.; Samarra, F.I.P.; Beerens, S.P.; Miller, P.J.O.

    2016-01-01

    Sound-recording acoustic tags attached to marine animals are commonly used in behavioural studies. Measuring ambient noise is of interest to efforts to understand responses of marine mammals to anthropogenic underwater sound, or to assess their communication space. Noise of water flowing around the

  13. Commercially important species associated with horse mussel (Modiolus modiolus) biogenic reefs: A priority habitat for nature conservation and fisheries benefits

    International Nuclear Information System (INIS)

    Kent, Flora E.A.; Mair, James M.; Newton, Jason; Lindenbaum, Charles; Porter, Joanne S.; Sanderson, William G.

    2017-01-01

    Horse mussel reefs (Modiolus modiolus) are biodiversity hotspots afforded protection by Marine Protected Areas (MPAs) in the NE Atlantic. In this study, horse mussel reefs, cobble habitats and sandy habitats were assessed using underwater visual census and drop-down video techniques in three UK regions. Megafauna were enumerated, differences in community composition and individual species abundances were analysed. Samples of conspicuous megafauna were also collected from horse mussel reefs in Orkney for stable isotope analysis. Communities of conspicuous megafauna were different between horse mussel habitats and other habitats throughout their range. Three commercially important species: whelks (Buccinum undatum), queen scallops (Aequipecten opercularis) and spider crabs (Maja brachydactyla) were significantly more abundant (by as much as 20 times) on horse mussel reefs than elsewhere. Isotopic analysis provided insights into their trophic relationship with the horse mussel reef. Protection of M. modiolus habitat can achieve biodiversity conservation objectives whilst benefiting fisheries also. - Highlights: • Communities of conspicuous megafauna were assessed on Modiolus modiolus reefs, sand and cobble habitats. • Tissue samples from reef fauna were subject to stable isotope analysis to investigate trophic structure. • Reef associated species included Aequipecten opercularis, Buccinum undatum and Maja brachydactyla. • Evidence of the commercial value of M. modiolus reefs in the UK.

  14. Economic effort management in multispecies fisheries: the FcubEcon model

    DEFF Research Database (Denmark)

    Hoff, Ayoe; Frost, Hans; Ulrich, Clara

    2010-01-01

    Applying single-species assessment and quotas in multispecies fisheries can lead to overfishing or quota underutilization, because advice can be conflicting when different stocks are caught within the same fishery. During the past decade, increased focus on this issue has resulted in the developm......Applying single-species assessment and quotas in multispecies fisheries can lead to overfishing or quota underutilization, because advice can be conflicting when different stocks are caught within the same fishery. During the past decade, increased focus on this issue has resulted...... optimal manner, in both effort-management and single-quota management settings.Applying single-species assessment and quotas in multispecies fisheries can lead to overfishing or quota underutilization, because advice can be conflicting when different stocks are caught within the same fishery. During...

  15. Yakima Fisheries Project. Final environmental impact statement

    International Nuclear Information System (INIS)

    1996-01-01

    BPA proposes to fund several fishery-related activities in the Yakima River Basin. These activities, known as the Yakima Fisheries Project (YFP), would be jointly managed by the State of Washington and the Yakima Indian Nation. The YFP is included in the Northwest Power Planning Council's (Council's) fish and wildlife program. The Council selected the Yakima River system for attention because fisheries resources are severely reduced from historical levels and because there is a significant potential for enhancement of these resources. BPA's proposed action is to fund (1) information gathering on the implementation of supplementation techniques and on feasibility of reintroducing coho salmon in an environment where native populations have become extinct; (2) research activities based on continuous assessment, feedback and improvement of research design and activities (open-quotes adaptive managementclose quotes); and (3) die construction, operation, and maintenance of facilities for supplementing populations of upper Yakima spring chinook salmon. Examined in addition to No Action are two alternatives for action: (1) supplementation of depressed natural populations of upper Yakima spring chinook and (2) that same supplementation plus a study to determine the feasibility of reestablishing naturally spawning population and a significant fall fishery for coho in the Yakima Basin. Alternative 2 is the preferred action. A central hatchery would be built for either alternative, as well as three sites with six raceways each for acclimation and release of spring chinook smolts. Major issues examined in the Revised Draft EIS include potential impacts of the project on genetic and ecological resources of existing fish populations, on water quality and quantity, on threatened and endangered species listed under the Endangered Species Act, and on the recreational fishery

  16. Yakima Fisheries Project : Final Environmental Impact Statement.

    Energy Technology Data Exchange (ETDEWEB)

    United States. Bonneville Power Administration; Washington (State). Dept. of Fish and Wildlife; Confederated Tribes and Bands of the Yakama Nation, Washington.

    1996-01-01

    BPA proposes to fund several fishery-related activities in the Yakima River Basin. These activities, known as the Yakima Fisheries Project (YFP), would be jointly managed by the State of Washington and the Yakima Indian Nation. The YFP is included in the Northwest Power Planning Council`s (Council`s) fish and wildlife program. The Council selected the Yakima River system for attention because fisheries resources are severely reduced from historical levels and because there is a significant potential for enhancement of these resources. BPA`s proposed action is to fund (1) information gathering on the implementation of supplementation techniques and on feasibility of reintroducing coho salmon in an environment where native populations have become extinct; (2) research activities based on continuous assessment, feedback and improvement of research design and activities ({open_quotes}adaptive management{close_quotes}); and (3) die construction, operation, and maintenance of facilities for supplementing populations of upper Yakima spring chinook salmon. Examined in addition to No Action are two alternatives for action: (1) supplementation of depressed natural populations of upper Yakima spring chinook and (2) that same supplementation plus a study to determine the feasibility of reestablishing naturally spawning population and a significant fall fishery for coho in the Yakima Basin. Alternative 2 is the preferred action. A central hatchery would be built for either alternative, as well as three sites with six raceways each for acclimation and release of spring chinook smolts. Major issues examined in the Revised Draft EIS include potential impacts of the project on genetic and ecological resources of existing fish populations, on water quality and quantity, on threatened and endangered species listed under the Endangered Species Act, and on the recreational fishery.

  17. In-air versus underwater comparison of 3D reconstruction accuracy using action sport cameras.

    Science.gov (United States)

    Bernardina, Gustavo R D; Cerveri, Pietro; Barros, Ricardo M L; Marins, João C B; Silvatti, Amanda P

    2017-01-25

    Action sport cameras (ASC) have achieved a large consensus for recreational purposes due to ongoing cost decrease, image resolution and frame rate increase, along with plug-and-play usability. Consequently, they have been recently considered for sport gesture studies and quantitative athletic performance evaluation. In this paper, we evaluated the potential of two ASCs (GoPro Hero3+) for in-air (laboratory) and underwater (swimming pool) three-dimensional (3D) motion analysis as a function of different camera setups involving the acquisition frequency, image resolution and field of view. This is motivated by the fact that in swimming, movement cycles are characterized by underwater and in-air phases what imposes the technical challenge of having a split volume configuration: an underwater measurement volume observed by underwater cameras and an in-air measurement volume observed by in-air cameras. The reconstruction of whole swimming cycles requires thus merging of simultaneous measurements acquired in both volumes. Characterizing and optimizing the instrumental errors of such a configuration makes mandatory the assessment of the instrumental errors of both volumes. In order to calibrate the camera stereo pair, black spherical markers placed on two calibration tools, used both in-air and underwater, and a two-step nonlinear optimization were exploited. The 3D reconstruction accuracy of testing markers and the repeatability of the estimated camera parameters accounted for system performance. For both environments, statistical tests were focused on the comparison of the different camera configurations. Then, each camera configuration was compared across the two environments. In all assessed resolutions, and in both environments, the reconstruction error (true distance between the two testing markers) was less than 3mm and the error related to the working volume diagonal was in the range of 1:2000 (3×1.3×1.5m 3 ) to 1:7000 (4.5×2.2×1.5m 3 ) in agreement with the

  18. Human Factors Issues When Operating Underwater Remotely Operated Vehicles and Autonomous Underwater Vehicles

    Science.gov (United States)

    2011-03-01

    etiquette (Parasuraman & Miller, 2004). Through natural and intuitive communication, Johnson et al., (2007) hope that this interface will instill greater...and etiquette in high criticality automated systems. Communications of the ACM, 47(4), 51-55. Parasuraman, R., & Riley, V. (1997). Humans and... protocols for underwater wireless communications. IEEE Communications Magazine, pp. 97-102. Quazi, A. H., & Konrad, W. L. (1982, March 1982). Underwater

  19. IVO develops a new repair technique for underwater sites. Viscous doughlike substance underwater cracks

    Energy Technology Data Exchange (ETDEWEB)

    Klingstedt, G.; Leisio, C. [ed.

    1998-07-01

    A viscous sealant is revolutionizing repair of the stone and concrete masonry of underwater dams, bridges and canals. There is now no need for expensive and time-consuming cofferdams, since a diver can extrude quick-setting mortar into underwater structures needing repair. This technique has worked well in recent years in various parts of Finland even in strongly flowing water. IVO experts are now starting to look more beyond the borders of Finland

  20. The key kinematic determinants of undulatory underwater swimming at maximal velocity.

    Science.gov (United States)

    Connaboy, Chris; Naemi, Roozbeh; Brown, Susan; Psycharakis, Stelios; McCabe, Carla; Coleman, Simon; Sanders, Ross

    2016-01-01

    The optimisation of undulatory underwater swimming is highly important in competitive swimming performance. Nineteen kinematic variables were identified from previous research undertaken to assess undulatory underwater swimming performance. The purpose of the present study was to determine which kinematic variables were key to the production of maximal undulatory underwater swimming velocity. Kinematic data at maximal undulatory underwater swimming velocity were collected from 17 skilled swimmers. A series of separate backward-elimination analysis of covariance models was produced with cycle frequency and cycle length as dependent variables (DVs) and participant as a fixed factor, as including cycle frequency and cycle length would explain 100% of the maximal swimming velocity variance. The covariates identified in the cycle-frequency and cycle-length models were used to form the saturated model for maximal swimming velocity. The final parsimonious model identified three covariates (maximal knee joint angular velocity, maximal ankle angular velocity and knee range of movement) as determinants of the variance in maximal swimming velocity (adjusted-r2 = 0.929). However, when participant was removed as a fixed factor there was a large reduction in explained variance (adjusted r2 = 0.397) and only maximal knee joint angular velocity continued to contribute significantly, highlighting its importance to the production of maximal swimming velocity. The reduction in explained variance suggests an emphasis on inter-individual differences in undulatory underwater swimming technique and/or anthropometry. Future research should examine the efficacy of other anthropometric, kinematic and coordination variables to better understand the production of maximal swimming velocity and consider the importance of individual undulatory underwater swimming techniques when interpreting the data.

  1. Harvest Strategies for an Ecosystem Approach to Fisheries Management in Western Mediterranean Demersal Fisheries

    Directory of Open Access Journals (Sweden)

    Antoni Quetglas

    2017-04-01

    Full Text Available The serious overfishing of most Mediterranean stocks demands urgent reforms of the management measures aiming to guarantee the sustainability of resources, notably when compared with the improvement observed in other European areas. The new EU Common Fisheries Policy (CFP constitutes an excellent opportunity to introduce the changes needed for such a reform. According to this CFP, all European fish stocks should be brought to a state where they can produce at MSY by 2020 at the latest. The CFP also establishes that the objective of sustainable exploitation should be achieved through multiannual plans (MAPs adopted in consultation with relevant stakeholders having fisheries management interests such as fishermen, non-governmental organizations, and policy makers. Together with the MSY and MAP approaches, the new CFP contains several other measures, directed to guarantee the ecological and socio-economic sustainability of fisheries by means of the implementation of the ecosystem approach to fisheries management (EAFM. With this new perspective, the CFP wants to avoid past failures of fisheries management based on monospecific approaches. This study is a first step toward the application of the EAFM in the Balearic Islands by means of the development of a harvest strategy with defined objectives, targets, limits, and clear management control rules aimed at optimizing socioeconomic and ecological objectives in the framework of the new CFP. Different management scenarios designed to achieve that goal were modeled for the main demersal commercial fisheries from the study area, the bottom trawl, and small-scale fisheries. The work begins with a general description of those fisheries, their main fishing grounds, and assessments of the exploitation status of the main target stocks in order to establish the current situation. Secondly, alternative management scenarios to maximize catch and profits while considering societal objectives were evaluated by

  2. Spatio-temporal declines in Philippine fisheries and its implications to coastal municipal fishers’ catch and income

    Directory of Open Access Journals (Sweden)

    Jonathan A Anticamara

    2016-03-01

    Full Text Available The problem of overexploitation in global fisheries is well-recognized. However, published assessment of fisheries spatio-temporal trends at the national scale is lacking for many high biodiversity developing countries, which is problematic since fisheries management is often implemented at the local or national levels. Here, we present the long-term spatio-temporal trends of Philippine fisheries production based on the landed national fish catch data (1980-2012 and fishers’ interviews. We found that the total Philippine fish catch volume (Metric Tons MT of most capture fisheries throughout the country has either stagnated or declined over the last three decades. The decline is even more prominent when evaluating fisheries trends at the provincial level, suggesting spatial serial depletion of the country’s fisheries. In contrast, the total Philippine fish catch value (US Dollars US$ or Philippine Pesos PHP has continued to increase over time, despite the declining fish catch volume. However, local municipal fishers are experiencing both low fish catch and income, contributing to observable poverty in many coastal communities in the Philippines. The various stakeholders of Philippine fisheries need to recognize the depleted state of Philippine fisheries, and learn from various experiences of collapsed and recovered fisheries from around the world, in order to recover the Philippines’ capture fisheries. Lessons from the literature on collapsed fisheries offer the following options for recovery: (1 regulate or reduce fisheries exploitation and other human activities impacting the fisheries to allow fisheries to rebuild or recover, (2 enforce effective networks of marine reserves, (3 engage fishers, consumers, and other stakeholders in fisheries management, (4 improve fisheries science, monitoring, and management capacities, and (5 provide alternative livelihood, skills, and improved education to fishers and their families.

  3. Underwater noise generated by offshore pile driving

    NARCIS (Netherlands)

    Tsouvalas, A.

    2015-01-01

    Anthropogenic noise emission in the marine environment has always been an environmental issue of serious concern. In particular, the noise generated during the installation of foundation piles is considered to be one of the most significant sources of underwater noise pollution. This is mainly

  4. Underwater image mosaicking and visual odometry

    Science.gov (United States)

    Sadjadi, Firooz; Tangirala, Sekhar; Sorber, Scott

    2017-05-01

    This paper summarizes the results of studies in underwater odometery using a video camera for estimating the velocity of an unmanned underwater vehicle (UUV). Underwater vehicles are usually equipped with sonar and Inertial Measurement Unit (IMU) - an integrated sensor package that combines multiple accelerometers and gyros to produce a three dimensional measurement of both specific force and angular rate with respect to an inertial reference frame for navigation. In this study, we investigate the use of odometry information obtainable from a video camera mounted on a UUV to extract vehicle velocity relative to the ocean floor. A key challenge with this process is the seemingly bland (i.e. featureless) nature of video data obtained underwater which could make conventional approaches to image-based motion estimation difficult. To address this problem, we perform image enhancement, followed by frame to frame image transformation, registration and mosaicking/stitching. With this approach the velocity components associated with the moving sensor (vehicle) are readily obtained from (i) the components of the transform matrix at each frame; (ii) information about the height of the vehicle above the seabed; and (iii) the sensor resolution. Preliminary results are presented.

  5. Efficient Modelling Methodology for Reconfigurable Underwater Robots

    DEFF Research Database (Denmark)

    Nielsen, Mikkel Cornelius; Blanke, Mogens; Schjølberg, Ingrid

    2016-01-01

    This paper considers the challenge of applying reconfigurable robots in an underwater environment. The main result presented is the development of a model for a system comprised of N, possibly heterogeneous, robots dynamically connected to each other and moving with 6 Degrees of Freedom (DOF). Th...

  6. Underwater Adhesives Retrofit Pipelines with Advanced Sensors

    Science.gov (United States)

    2015-01-01

    Houston-based Astro Technology Inc. used a partnership with Johnson Space Center to pioneer an advanced fiber-optic monitoring system for offshore oil pipelines. The company's underwater adhesives allow it to retrofit older deepwater systems in order to measure pressure, temperature, strain, and flow properties, giving energy companies crucial data in real time and significantly decreasing the risk of a catastrophe.

  7. MOSES, development of an Underwater Warfare Testbed

    NARCIS (Netherlands)

    Lentze, S.G.

    2001-01-01

    The TNO underwater warfare (UWW) research programme results in a large number of models used in operational research projects. To enhance the accessibility and re-use of these models for new projects, TNO-FEL has developed the modelling environment ‘MOSES - Maritime Operations Simulation and

  8. Human Injury Criteria for Underwater Blasts

    Science.gov (United States)

    2014-09-08

    further underscored the need for this new guideline based on injury data. Conference Name: Personal Armour Systems Symposium Conference Date...29.  Cole, R., Underwater Explosion. (Dover Publications, Inc ., New York, N.Y., 1948) 30.  Nakahara, M., Nagayama, K, Mori, Y, Japanese Journal...Abstract of the Undersea and Hyperbaric Medical Society, Inc . Annual Scientific Meeting, (1976).

  9. Impacts of underwater noise on marine vertebrates

    NARCIS (Netherlands)

    Liebschner, Alexander; Seibel, Henrike; Teilmann, Jonas; Wittekind, Dietrich; Parmentier, Eric; Dähne, Michael; Dietz, Rune; Driver, Jörg; Elk, van Cornelis; Everaarts, Eligius; Findeisen, Henning; Kristensen, Jacob; Lehnert, Kristina; Lucke, Klaus; Merck, Thomas; Müller, Sabine; Pawliczka, Iwona; Ronnenberg, Katrin; Rosenberger, Tanja; Ruser, Andreas; Tougaard, Jakob; Schuster, Max; Sundermeyer, Janne; Sveegaard, Signe; Siebert, Ursula

    2016-01-01

    The project conducts application-oriented research on impacts of underwater noise on marine vertebrates in the North and Baltic Seas. In distinct subprojects, the hearing sensitivity of harbor porpoises and gray seals as well as the acoustic tolerance limit of harbor porpoises to impulsive noise

  10. A comparison of fisheries biological reference points estimated from temperature-specific multi-species and single-species climate-enhanced stock assessment models

    Science.gov (United States)

    Holsman, Kirstin K.; Ianelli, James; Aydin, Kerim; Punt, André E.; Moffitt, Elizabeth A.

    2016-12-01

    Multi-species statistical catch at age models (MSCAA) can quantify interacting effects of climate and fisheries harvest on species populations, and evaluate management trade-offs for fisheries that target several species in a food web. We modified an existing MSCAA model to include temperature-specific growth and predation rates and applied the modified model to three fish species, walleye pollock (Gadus chalcogrammus), Pacific cod (Gadus macrocephalus) and arrowtooth flounder (Atheresthes stomias), from the eastern Bering Sea (USA). We fit the model to data from 1979 through 2012, with and without trophic interactions and temperature effects, and use projections to derive single- and multi-species biological reference points (BRP and MBRP, respectively) for fisheries management. The multi-species model achieved a higher over-all goodness of fit to the data (i.e. lower negative log-likelihood) for pollock and Pacific cod. Variability from water temperature typically resulted in 5-15% changes in spawning, survey, and total biomasses, but did not strongly impact recruitment estimates or mortality. Despite this, inclusion of temperature in projections did have a strong effect on BRPs, including recommended yield, which were higher in single-species models for Pacific cod and arrowtooth flounder that included temperature compared to the same models without temperature effects. While the temperature-driven multi-species model resulted in higher yield MBPRs for arrowtooth flounder than the same model without temperature, we did not observe the same patterns in multi-species models for pollock and Pacific cod, where variability between harvest scenarios and predation greatly exceeded temperature-driven variability in yield MBRPs. Annual predation on juvenile pollock (primarily cannibalism) in the multi-species model was 2-5 times the annual harvest of adult fish in the system, thus predation represents a strong control on population dynamics that exceeds temperature

  11. Communication and cooperation in underwater acoustic networks

    Science.gov (United States)

    Yerramalli, Srinivas

    In this thesis, we present a study of several problems related to underwater point to point communications and network formation. We explore techniques to improve the achievable data rate on a point to point link using better physical layer techniques and then study sensor cooperation which improves the throughput and reliability in an underwater network. Robust point-to-point communications in underwater networks has become increasingly critical in several military and civilian applications related to underwater communications. We present several physical layer signaling and detection techniques tailored to the underwater channel model to improve the reliability of data detection. First, a simplified underwater channel model in which the time scale distortion on each path is assumed to be the same (single scale channel model in contrast to a more general multi scale model). A novel technique, which exploits the nature of OFDM signaling and the time scale distortion, called Partial FFT Demodulation is derived. It is observed that this new technique has some unique interference suppression properties and performs better than traditional equalizers in several scenarios of interest. Next, we consider the multi scale model for the underwater channel and assume that single scale processing is performed at the receiver. We then derive optimized front end pre-processing techniques to reduce the interference caused during single scale processing of signals transmitted on a multi-scale channel. We then propose an improvised channel estimation technique using dictionary optimization methods for compressive sensing and show that significant performance gains can be obtained using this technique. In the next part of this thesis, we consider the problem of sensor node cooperation among rational nodes whose objective is to improve their individual data rates. We first consider the problem of transmitter cooperation in a multiple access channel and investigate the stability of

  12. Projected impacts of climate change on marine fish and fisheries

    DEFF Research Database (Denmark)

    Hollowed, Anne B.; Barange, Manuel; Beamish, Richard J.

    2013-01-01

    This paper reviews current literature on the projected effects of climate change on marine fish and shellfish, their fisheries, and fishery-dependent communities throughout the northern hemisphere. The review addresses the following issues: (i) expected impacts on ecosystem productivity and habitat......) implications for food security and associated changes; and (v) uncertainty and modelling skill assessment. Climate change will impact fish and shellfish, their fisheries, and fishery-dependent communities through a complex suite of linked processes. Integrated interdisciplinary research teams are forming...... in many regions to project these complex responses. National and international marine research organizations serve a key role in the coordination and integration of research to accelerate the production of projections of the effects of climate change on marine ecosystems and to move towards a future where...

  13. Fisheries management under nutrient influence

    DEFF Research Database (Denmark)

    Hammarlund, Cecilia; Nielsen, Max; Waldo, Staffan

    2018-01-01

    A fisheries management model that identifies the economic optimal management of fisheries under the influence of nutrients is presented. The model starts from the idea that growth in fish biomass increases with increasing availability of nutrients owing to higher food availability up to a peak...

  14. Fisheries Information Network in Indonesia.

    Science.gov (United States)

    Balachandran, Sarojini

    During the early 1980s the Indonesian government made a policy decision to develop fisheries as an important sector of the national economy. In doing so, it recognized the need for the collection and dissemination of fisheries research information not only for the scientists themselves, but also for the ultimate transfer of technology through…

  15. The added value of participatory modelling in fisheries management – what has been learnt?

    DEFF Research Database (Denmark)

    Röckmann, C.; Ulrich, Clara; Dreyer, M.

    2012-01-01

    Holders) invited fisheries stakeholders to participate in the process of framing the management problem, and to give input and evaluate the scientific models that are used to provide fisheries management advice. JAKFISH investigated various tools to assess and communicate uncertainty around fish stock assessments...

  16. A Social Wellbeing in Fisheries Tool (SWIFT to Help Improve Fisheries Performance

    Directory of Open Access Journals (Sweden)

    Tracy Van Holt

    2016-07-01

    Full Text Available We report on a rapid and practical method to assess social dimensions of performance in small-scale and industrial fisheries globally (Social Wellbeing in Fisheries Tool (SWIFT. SWIFT incorporates aspects of security (fairness and stability of earnings, benefits of employment to local fishing communities, worker protection, and personal safety and health in communities associated with fisheries; flexibility (including opportunity for economic advancement; and the fishery’s social viability (including whether the fishery is recruiting new harvesters and diverse age classes of workers, whether women’s participation and leadership in global production networks are on an upward trajectory.. We build on resilience research by conceptualizing wellbeing in terms of security, flexibility, and viability, and assessing wellbeing at individual, community, and system levels. SWIFT makes social performance measures more broadly accessible to global production networks, incorporates an everyday understanding of wellbeing for people involved in the seafood industry, and helps put social sustainability into measurable terms that are relevant for businesses.

  17. Integrating stochastic age-structured population dynamics into complex fisheries economic models for management evaluations: the North Sea saithe fishery as a case study

    NARCIS (Netherlands)

    Simons, S.L.; Bartelings, H.; Hamon, K.G.; Kempf, A.J.; Doring, R.; Temming, A.

    2014-01-01

    There is growing interest in bioeconomic models as tools for understanding pathways of fishery behaviour in order to assess the impact of alternative policies on natural resources. A model system is presented that combines stochastic age-structured population dynamics with complex fisheries

  18. Underwater Photosynthesis of Submerged Plants – Recent Advances and Methods

    Science.gov (United States)

    Pedersen, Ole; Colmer, Timothy D.; Sand-Jensen, Kaj

    2013-01-01

    We describe the general background and the recent advances in research on underwater photosynthesis of leaf segments, whole communities, and plant dominated aquatic ecosystems and present contemporary methods tailor made to quantify photosynthesis and carbon fixation under water. The majority of studies of aquatic photosynthesis have been carried out with detached leaves or thalli and this selectiveness influences the perception of the regulation of aquatic photosynthesis. We thus recommend assessing the influence of inorganic carbon and temperature on natural aquatic communities of variable density in addition to studying detached leaves in the scenarios of rising CO2 and temperature. Moreover, a growing number of researchers are interested in tolerance of terrestrial plants during flooding as torrential rains sometimes result in overland floods that inundate terrestrial plants. We propose to undertake studies to elucidate the importance of leaf acclimation of terrestrial plants to facilitate gas exchange and light utilization under water as these acclimations influence underwater photosynthesis as well as internal aeration of plant tissues during submergence. PMID:23734154

  19. A Survey on Intermediation Architectures for Underwater Robotics

    Directory of Open Access Journals (Sweden)

    Xin Li

    2016-02-01

    Full Text Available Currently, there is a plethora of solutions regarding interconnectivity and interoperability for networked robots so that they will fulfill their purposes in a coordinated manner. In addition to that, middleware architectures are becoming increasingly popular due to the advantages that they are capable of guaranteeing (hardware abstraction, information homogenization, easy access for the applications above, etc.. However, there are still scarce contributions regarding the global state of the art in intermediation architectures for underwater robotics. As far as the area of robotics is concerned, this is a major issue that must be tackled in order to get a holistic view of the existing proposals. This challenge is addressed in this paper by studying the most compelling pieces of work for this kind of software development in the current literature. The studied works have been assessed according to their most prominent features and capabilities. Furthermore, by studying the individual pieces of work and classifying them several common weaknesses have been revealed and are highlighted. This provides a starting ground for the development of a middleware architecture for underwater robotics capable of dealing with these issues.

  20. Stability analysis of hybrid-driven underwater glider

    Science.gov (United States)

    Niu, Wen-dong; Wang, Shu-xin; Wang, Yan-hui; Song, Yang; Zhu, Ya-qiang

    2017-10-01

    Hybrid-driven underwater glider is a new type of unmanned underwater vehicle, which combines the advantages of autonomous underwater vehicles and traditional underwater gliders. The autonomous underwater vehicles have good maneuverability and can travel with a high speed, while the traditional underwater gliders are highlighted by low power consumption, long voyage, long endurance and good stealth characteristics. The hybrid-driven underwater gliders can realize variable motion profiles by their own buoyancy-driven and propeller propulsion systems. Stability of the mechanical system determines the performance of the system. In this paper, the Petrel-II hybrid-driven underwater glider developed by Tianjin University is selected as the research object and the stability of hybrid-driven underwater glider unitedly controlled by buoyancy and propeller has been targeted and evidenced. The dimensionless equations of the hybrid-driven underwater glider are obtained when the propeller is working. Then, the steady speed and steady glide path angle under steady-state motion have also been achieved. The steady-state operating conditions can be calculated when the hybrid-driven underwater glider reaches the desired steady-state motion. And the steadystate operating conditions are relatively conservative at the lower bound of the velocity range compared with the range of the velocity derived from the method of the composite Lyapunov function. By calculating the hydrodynamic coefficients of the Petrel-II hybrid-driven underwater glider, the simulation analysis has been conducted. In addition, the results of the field trials conducted in the South China Sea and the Danjiangkou Reservoir of China have been presented to illustrate the validity of the analysis and simulation, and to show the feasibility of the method of the composite Lyapunov function which verifies the stability of the Petrel-II hybrid-driven underwater glider.

  1. A climatology of the California Current System from a network of underwater gliders

    Science.gov (United States)

    Rudnick, Daniel L.; Zaba, Katherine D.; Todd, Robert E.; Davis, Russ E.

    2017-05-01

    Autonomous underwater gliders offer the possibility of sustained observation of the coastal ocean. Since 2006 Spray underwater gliders in the California Underwater Glider Network (CUGN) have surveyed along California Cooperative Oceanic Fisheries Investigations (CalCOFI) lines 66.7, 80.0, and 90.0, constituting the world's longest sustained glider network, to our knowledge. In this network, gliders dive between the surface and 500 m, completing a cycle in 3 h and covering 3 km in that time. Sections extend 350-500 km offshore and take 2-3 weeks to occupy. Measured variables include pressure, temperature, salinity, and depth-average velocity. The CUGN has amassed over 10,000 glider-days, covering over 210,000 km with over 95,000 dives. These data are used to produce a climatology whose products are for each variable a mean field, an annual cycle, and the anomaly from the annual cycle. The analysis includes a weighted least-squares fit to derive the mean and annual cycle, and an objective map to produce the anomaly. The final results are variables on rectangular grids in depth, distance offshore, and time. The mean fields are finely resolved sections across the main flows in the California Current System, including the poleward California Undercurrent and the equatorward California Current. The annual cycle shows a phase change from the surface to the thermocline, reflecting the effects of air/sea fluxes at the surface and upwelling in the thermocline. The interannual anomalies are examined with an emphasis on climate events of the last ten years including the 2009-2010 El Niño, the 2010-2011 La Niña, the warm anomaly of 2014-2015, and the 2015-2016 El Niño.

  2. 78 FR 50347 - Fisheries Off West Coast States; Modifications of the West Coast Commercial Salmon Fisheries...

    Science.gov (United States)

    2013-08-19

    ... Commercial Salmon Fisheries; Inseason Actions 6 Through 11 AGENCY: National Marine Fisheries Service (NMFS... salmon fisheries. These inseason actions modified the commercial fisheries in the area from the U.S...: Background In the 2013 annual management measures for ocean salmon fisheries (78 FR 25865, May 3, 2013), NMFS...

  3. 78 FR 30780 - Fisheries Off West Coast States; Modifications of the West Coast Commercial Salmon Fisheries...

    Science.gov (United States)

    2013-05-23

    ... Commercial Salmon Fisheries; Inseason Action 3 AGENCY: National Marine Fisheries Service (NMFS), National... in the ocean salmon fisheries. This inseason action modified the commercial fisheries in the area... ocean salmon fisheries (78 FR 25865, May 3, 2013), NMFS announced the commercial and recreational...

  4. 78 FR 35153 - Fisheries Off West Coast States; Modifications of the West Coast Commercial Salmon Fisheries...

    Science.gov (United States)

    2013-06-12

    ... Commercial Salmon Fisheries; Inseason Actions 4 and 5 AGENCY: National Marine Fisheries Service (NMFS... inseason actions in the ocean salmon fisheries. These inseason actions modified the commercial fisheries in...: Background In the 2013 annual management measures for ocean salmon fisheries (78 FR 25865, May 3, 2013), NMFS...

  5. Assessment of human health hazards associated with the dietary exposure to organic and inorganic contaminants through the consumption of fishery products in Spain

    Energy Technology Data Exchange (ETDEWEB)

    Rodríguez-Hernández, Ángel; Camacho, María; Henríquez-Hernández, Luis A.; Boada, Luis D.; Ruiz-Suárez, Norberto; Valerón, Pilar F.; Almeida González, Maira [Toxicology Unit, Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Plaza Dr. Pasteur s/n, 35016 Las Palmas de Gran Canaria (Spain); Instituto Canario de Investigación del Cáncer (ICIC), Plaza Dr. Pasteur s/n, 35016 Las Palmas de Gran Canaria (Spain); Spanish Biomedical Research Centre in Physiopathology of Obesity and Nutrition (CIBERObn), Plaza Dr. Pasteur s/n, 35016 Las Palmas de Gran Canaria (Spain); Zaccaroni, Annalisa [Large Pelagic Vertebrate Group, Veterinary Faculty, University of Bologna, Viale Vespucci 2, Cesenatico (FC) 47042 (Italy); Zumbado, Manuel [Toxicology Unit, Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Plaza Dr. Pasteur s/n, 35016 Las Palmas de Gran Canaria (Spain); Instituto Canario de Investigación del Cáncer (ICIC), Plaza Dr. Pasteur s/n, 35016 Las Palmas de Gran Canaria (Spain); Spanish Biomedical Research Centre in Physiopathology of Obesity and Nutrition (CIBERObn), Plaza Dr. Pasteur s/n, 35016 Las Palmas de Gran Canaria (Spain); and others

    2016-07-01

    In this work we have evaluated the potential carcinogenic and acutely toxic risks associated to the exposure to highly prevalent organic and inorganic contaminants through the consumption of fishery products by the Spanish population. The concentrations of 8 organochlorine pesticides (OCPs), 18 polychlorinated biphenils (PCBs), 7 polycyclic aromatic hydrocarbons (expressed as benzo[a]pyrene toxic equivalents (B[a]P{sub eq})), and three inorganic toxic elements [arsenic (As), cadmium (Cd), and mercury (Hg)] were determined in 93 samples of the most consumed species of white fish, blue fish, cephalopods and seafood species, which were acquired directly in markets and supermarkets in the Canary Islands, Spain. The chemical concentration data were combined with the pattern of consumption of these foodstuffs in order to calculate the daily intake of these contaminants, and on this basis the risk quotients for carcinogenicity and acute toxicity were determined for Spanish adults and children. Our results showed that the daily intake of OCPs, PCBs and B[a]P{sub eq,} which is associated to blue fish consumption was the highest within the fish group. The estimated intake of pollutants can be considered low or very low for the individual contaminants, when compared to reference values, except in the case of HCB and As. All the estimated intakes were below the reported Tolerable Daily Intakes. Considering the additive effects of multiple contaminants, the risk of acute toxic effects can also be considered as low or very low. However, our results reflect that the current consumption of white fish in adults and children, and also the blue fish in the case of adults, poses a moderate carcinogenic risk to Spanish consumers, mainly related to their concentrations of As. The conclusions of this research may be useful for the design of appropriate risk communication campaigns. - Highlights: • The daily intake of persistent pollutants through fish consumption is estimated

  6. Assessment of human health hazards associated with the dietary exposure to organic and inorganic contaminants through the consumption of fishery products in Spain

    International Nuclear Information System (INIS)

    Rodríguez-Hernández, Ángel; Camacho, María; Henríquez-Hernández, Luis A.; Boada, Luis D.; Ruiz-Suárez, Norberto; Valerón, Pilar F.; Almeida González, Maira; Zaccaroni, Annalisa; Zumbado, Manuel

    2016-01-01

    In this work we have evaluated the potential carcinogenic and acutely toxic risks associated to the exposure to highly prevalent organic and inorganic contaminants through the consumption of fishery products by the Spanish population. The concentrations of 8 organochlorine pesticides (OCPs), 18 polychlorinated biphenils (PCBs), 7 polycyclic aromatic hydrocarbons (expressed as benzo[a]pyrene toxic equivalents (B[a]P_e_q)), and three inorganic toxic elements [arsenic (As), cadmium (Cd), and mercury (Hg)] were determined in 93 samples of the most consumed species of white fish, blue fish, cephalopods and seafood species, which were acquired directly in markets and supermarkets in the Canary Islands, Spain. The chemical concentration data were combined with the pattern of consumption of these foodstuffs in order to calculate the daily intake of these contaminants, and on this basis the risk quotients for carcinogenicity and acute toxicity were determined for Spanish adults and children. Our results showed that the daily intake of OCPs, PCBs and B[a]P_e_q_, which is associated to blue fish consumption was the highest within the fish group. The estimated intake of pollutants can be considered low or very low for the individual contaminants, when compared to reference values, except in the case of HCB and As. All the estimated intakes were below the reported Tolerable Daily Intakes. Considering the additive effects of multiple contaminants, the risk of acute toxic effects can also be considered as low or very low. However, our results reflect that the current consumption of white fish in adults and children, and also the blue fish in the case of adults, poses a moderate carcinogenic risk to Spanish consumers, mainly related to their concentrations of As. The conclusions of this research may be useful for the design of appropriate risk communication campaigns. - Highlights: • The daily intake of persistent pollutants through fish consumption is estimated • Dietary

  7. Marine biodiversity and fishery sustainability.

    Science.gov (United States)

    Shao, Kwang-Tsao

    2009-01-01

    Marine fish is one of the most important sources of animal protein for human use, especially in developing countries with coastlines. Marine fishery is also an important industry in many countries. Fifty years ago, many people believed that the ocean was so vast and so resilient that there was no way the marine environment could be changed, nor could marine fishery resources be depleted. Half a century later, we all agree that the depletion of fishery resources is happening mainly due to anthropogenic factors such as overfishing, habitat destruction, pollution, invasive species introduction, and climate change. Since overfishing can cause chain reactions that decrease marine biodiversity drastically, there will be no seafood left after 40 years if we take no action. The most effective ways to reverse this downward trend and restore fishery resources are to promote fishery conservation, establish marine-protected areas, adopt ecosystem-based management, and implement a "precautionary principle." Additionally, enhancing public awareness of marine conservation, which includes eco-labeling, fishery ban or enclosure, slow fishing, and MPA (marine protected areas) enforcement is important and effective. In this paper, we use Taiwan as an example to discuss the problems facing marine biodiversity and sustainable fisheries.

  8. The contribution of lakes to global inland fisheries harvest

    Science.gov (United States)

    Deines, Andrew M.; Bunnell, David B.; Rogers, Mark W.; Bennion, David; Woelmer, Whitney; Sayers, Michael J.; Grimm, Amanda G.; Shuchman, Robert A.; Raymer, Zachary B.; Brooks, Colin N.; Mychek-Londer, Justin G.; Taylor, William W.; Beard, Douglas

    2017-01-01

    Freshwater ecosystems provide numerous services for communities worldwide, including irrigation, hydropower, and municipal water; however, the services provided by inland fisheries – nourishment, employment, and recreational opportunities – are often comparatively undervalued. We provide an independent estimate of global lake harvest to improve biological and socioeconomic assessments of inland fisheries. On the basis of satellite-derived estimates of chlorophyll concentration from 80,012 globally distributed lakes, lake-specific fishing effort based on human population, and output from a Bayesian hierarchical model, we estimated that the global lake fishery harvest in the year 2011 was 8.4 million tons (mt). Our calculations excluded harvests from highly productive rivers, wetlands, and very small lakes; therefore, the true cumulative global fishery harvest from all freshwater sources likely exceeded 11 mt as reported by the Food and Agriculture Organization of the United Nations (FAO). This putative underestimate by the FAO could diminish the perceived importance of inland fisheries and perpetuate decisions that adversely affect these fisheries and millions of people.

  9. Fisheries regulatory regimes and resilience to climate change.

    Science.gov (United States)

    Ojea, Elena; Pearlman, Isaac; Gaines, Steven D; Lester, Sarah E

    2017-05-01

    Climate change is already producing ecological, social, and economic impacts on fisheries, and these effects are expected to increase in frequency and magnitude in the future. Fisheries governance and regulations can alter socio-ecological resilience to climate change impacts via harvest control rules and incentives driving fisher behavior, yet there are no syntheses or conceptual frameworks for examining how institutions and their regulatory approaches can alter fisheries resilience to climate change. We identify nine key climate resilience criteria for fisheries socio-ecological systems (SES), defining resilience as the ability of the coupled system of interacting social and ecological components (i.e., the SES) to absorb change while avoiding transformation into a different undesirable state. We then evaluate the capacity of four fisheries regulatory systems that vary in their degree of property rights, including open access, limited entry, and two types of rights-based management, to increase or inhibit resilience. Our exploratory assessment of evidence in the literature suggests that these regulatory regimes vary widely in their ability to promote resilient fisheries, with rights-based approaches appearing to offer more resilience benefits in many cases, but detailed characteristics of the regulatory instruments are fundamental.

  10. Towed Optical Assessment Device (TOAD) Data to Support Benthic Habitat Mapping since 2001

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Optical validation data were collected using a Tethered Optical Assessment Device (TOAD), an underwater sled equipped with an underwater digital video camera and...

  11. Hydrodynamic Coefficients Identification and Experimental Investigation for an Underwater Vehicle

    Directory of Open Access Journals (Sweden)

    Shaorong XIE

    2014-02-01

    Full Text Available Hydrodynamic coefficients are the foundation of unmanned underwater vehicles modeling and controller design. In order to reduce identification complexity and acquire necessary hydrodynamic coefficients for controllers design, the motion of the unmanned underwater vehicle was separated into vertical motion and horizontal motion models. Hydrodynamic coefficients were regarded as mapping parameters from input forces and moments to output velocities and acceleration of the unmanned underwater vehicle. The motion models of the unmanned underwater vehicle were nonlinear and Genetic Algorithm was adopted to identify those hydrodynamic coefficients. To verify the identification quality, velocities and acceleration of the unmanned underwater vehicle was measured using inertial sensor under the same conditions as Genetic Algorithm identification. Curves similarity between measured velocities and acceleration and those identified by Genetic Algorithm were used as optimizing standard. It is found that the curves similarity were high and identified hydrodynamic coefficients of the unmanned underwater vehicle satisfied the measured motion states well.

  12. Delay Tolerance in Underwater Wireless Communications: A Routing Perspective

    Directory of Open Access Journals (Sweden)

    Safdar Hussain Bouk

    2016-01-01

    Full Text Available Similar to terrestrial networks, underwater wireless networks (UWNs also aid several critical tasks including coastal surveillance, underwater pollution detection, and other maritime applications. Currently, once underwater sensor nodes are deployed at different levels of the sea, it is nearly impossible or very expensive to reconfigure the hardware, for example, battery. Taking this issue into account, considerable amount of research has been carried out to ensure minimum energy costs and reliable communication between underwater nodes and base stations. As a result, several different network protocols were proposed for UWN, including MAC, PHY, transport, and routing. Recently, a new paradigm was introduced claiming that the intermittent nature of acoustic channel and signal resulted in designing delay tolerant routing schemes for the UWN, known as an underwater delay tolerant network. In this paper, we provide a comprehensive survey of underwater routing protocols with emphasis on the limitations, challenges, and future open issues in the context of delay tolerant network routing.

  13. Efficient Weibull channel model for salinity induced turbulent underwater wireless optical communications

    KAUST Repository

    Oubei, Hassan M.; Zedini, Emna; Elafandy, Rami T.; Kammoun, Abla; Ng, Tien Khee; Alouini, Mohamed-Slim; Ooi, Boon S.

    2017-01-01

    Recent advances in underwater wireless optical communications necessitate a better understanding of the underwater channel. We propose the Weibull model to characterize the fading of salinity induced turbulent underwater wireless optical channels

  14. Underwater videography and photography in Gulf of Kachchh. Sponsored by Gujarat Ecological Society, Vadodara, Gujarat

    Digital Repository Service at National Institute of Oceanography (India)

    Marine Archaeology Centre (MAC) has been carrying out underwater explorations and excavations of ancient ports and sunken shipwrecks to preserve underwater cultural heritage. MAC has the infrastructure facility to carry out underwater investigations...

  15. Underwater laser beam welding of Alloy 690

    International Nuclear Information System (INIS)

    Hino, Takehisa; Tamura, Masataka; Kono, Wataru; Kawano, Shohei; Yoda, Masaki

    2009-01-01

    Stress Corrosion Clacking (SCC) has been reported at Alloy 600 welds between nozzles and safe-end in Pressurized Water Reactor (PWR) plant. Alloy 690, which has higher chromium content than Alloy 600, has been applied for cladding on Alloy 600 welds for repairing damaged SCC area. Toshiba has developed Underwater Laser Beam Welding technique. This method can be conducted without draining, so that the repairing period and the radiation exposure during the repair can be dramatically decreased. In some old PWRs, high-sulfur stainless steel is used as the materials for this section. It has a high susceptibility of weld cracks. Therefore, the optimum welding condition of Alloy 690 on the high-sulfur stainless steel was investigated with our Underwater Laser Beam Welding unit. Good cladding layer, without any crack, porosity or lack of fusion, could be obtained. (author)

  16. Cymbal and BB underwater transducers and arrays

    Energy Technology Data Exchange (ETDEWEB)

    Newnham, R.E.; Zhang, J.; Alkoy, S.; Meyer, R.; Hughes, W.J.; Hladky-Hennion, A.C.; Cochran, J.; Markley, D. [Materials Research Laboratory, Penn State University, University Park, PA 16802 (United States)

    2002-09-01

    The cymbal is a miniaturized class V flextensional transducer that was developed for use as a shallow water sound projector and receiver. Single elements are characterized by high Q, low efficiency, and medium power output capability. Its low cost and thin profile allow the transducer to be assembled into large flexible arrays. Efforts were made to model both single elements and arrays using the ATILA code and the integral equation formulation (EQI).Millimeter size microprobe hydrophones (BBs) have been designed and fabricated from miniature piezoelectric hollow ceramic spheres for underwater applications such as mapping acoustic fields of projectors, and flow noise sensors for complex underwater structures. Green spheres are prepared from soft lead zirconate titanate powders using a coaxial nozzle slurry process. A compact hydrophone with a radially-poled sphere is investigated using inside and outside electrodes. Characterization of these hydrophones is done through measurement of hydrostatic piezoelectric charge coefficients, free field voltage sensitivities and directivity beam patterns. (orig.)

  17. Involving stakeholders in the commissioning and implementation of fishery science projects: experiences from the U.K. Fisheries Science Partnership.

    Science.gov (United States)

    Armstrong, M J; Payne, A I L; Deas, B; Catchpole, T L

    2013-10-01

    Following from similar initiatives worldwide, the U.K.'s Fisheries Science Partnership (FSP) was established in 2003 to provide the fishing industry with opportunities to propose and participate in scientific studies in collaboration with fishery scientists. Key concepts were that most of the available funding would support industry participation, that industry, not scientists, would come up with the ideas for projects, and that commercial fishing vessels and fishing methods would be used to address specific concerns of the fishing industry in a scientifically controlled manner. Nearly 100 projects had been commissioned by March 2012, covering annual time-series surveys of stocks subject to traditional assessment, and ad hoc projects on, e.g. gear selectivity, discard survival, tagging and migration and fishery development. The extent to which the results of the projects have been used by stakeholders, fishery scientists and fishery managers at a national and E.U. level is evaluated, along with the degree of industry interest and involvement, and reasons are identified for successes or failures in the uptake of the results into management and policy. Finally, the question is posed whether the programme has been successful in improving the engagement of the fishing community in the science-management process and in fostering communication and greater trust between fishers, scientists and managers. © 2013 Crown Copyright. © 2013 The Fisheries Society of the British Isles.

  18. Biological impacts of oil pollution: fisheries

    International Nuclear Information System (INIS)

    1997-01-01

    Fisheries and aquaculture may be affected following oil spills. This report describes the direct effects on the species themselves, and indirect effects through impacts on their habitats. The impact on fishing gear and aquaculture facilities is also considered. Information is included on the basic ecology of the species concerned, and on fishing and aquaculture methods. Response to spills is discussed and reference is made to case history examples. (author) ntial information for the assessment of pipeline defects from the comprehensive review report cited above. (2) Summarise current practice and capability for defect inspection during and after laying: material properties pertaining to defect assessment in ageing, new and future lines: an

  19. Equipment and appliances for underwater operations. Pt. 2

    International Nuclear Information System (INIS)

    Krueger, P.

    1976-01-01

    The 6/75 edition of 'mt' reported on the 'ARGE underwater appliances' and the study on 'design development of appliances and equipment for underwater use' in a brief summary. One of these designs, the 'unmanned DSWS underwater appliance' was described in detail. The present article describes three further design developments mentioned in the above study and which are based on unmanned appliances connected to the mother-ship. These designs were developed by Preussag-Meerestechnik. (orig.) [de

  20. On the sustainability of inland fisheries: Finding a future for the forgotten

    Science.gov (United States)

    Cooke, Steven J.; Allison, Edward H.; Beard, Douglas; Arlinghaus, Robert; Arthington, Angela; Bartley, Devin; Cowx, Ian G.; Fuentevilla, Carlos; Léonard, Nancy J.; Lorenzen, Kai; Lynch, Abigail; Nguyen, Vivian M.; Youn, So-Jung; Tayor, William W.; Welcomme, Robin

    2016-01-01

    At present, inland fisheries are not often a national or regional governance priority and as a result, inland capture fisheries are undervalued and largely overlooked. As such they are threatened in both developing and developed countries. Indeed, due to lack of reliable data, inland fisheries have never been part of any high profile global fisheries assessment and are notably absent from the Sustainable Development Goals. The general public and policy makers are largely ignorant of the plight of freshwater ecosystems and the fish they support, as well as the ecosystem services generated by inland fisheries. This ignorance is particularly salient given that the current emphasis on the food-water-energy nexus often fails to include the important role that inland fish and fisheries play in food security and supporting livelihoods in low-income food deficit countries. Developing countries in Africa and Asia produce about 11 million tonnes of inland fish annually, 90 % of the global total. The role of inland fisheries goes beyond just kilocalories; fish provide important micronutrients and essentially fatty acids. In some regions, inland recreational fisheries are important, generating much wealth and supporting livelihoods. The following three key recommendations are necessary for action if inland fisheries are to become a part of the food-water-energy discussion: invest in improved valuation and assessment methods, build better methods to effectively govern inland fisheries (requires capacity building and incentives), and develop approaches to managing waters across sectors and scales. Moreover, if inland fisheries are recognized as important to food security, livelihoods, and human well-being, they can be more easily incorporated in regional, national, and global policies and agreements on water issues. Through these approaches, inland fisheries can be better evaluated and be more fully recognized in broader water resource and aquatic ecosystem planning and decision

  1. Marine Ecological Footprint of Italian Mediterranean Fisheries

    Directory of Open Access Journals (Sweden)

    Federica de Leo

    2014-10-01

    Full Text Available The capacity of marine and coastal ecosystems to sustain seafood production and consumption is seldom accounted for and is not included in the signals that guide economic development. In this article, we review estimates of marine and coastal areas aimed at sustaining catches for seafood consumption. The aim of this paper is the assessment of the interactions between the environment, intended as a set of ecological subsystems in natural equilibrium, including the marine ecosystem, and the process of fisheries systems. In particular we analyze fisheries in Italy, which is the third biggest economy and the greatest consumer of seafood in the Eurozone, conducting an in-depth analysis of the Marine Ecological Footprint (MEF that evaluates the marine ecosystem area exploited by human populations to supply seafood and other marine products and services. The positioning of Italian fisheries shows a level of sustainability next to the threshold value. The analysis in the present study highlights the importance of absolute indicators in providing rough estimates about human dependence on ecological systems and recognizes the importance of those indicators, such as the Marine Footprint (expressed in % of Primary Production Required/Primary Production, in ensuring a high level of precision and accuracy in quantifying human activity impact on the environment.

  2. Marine fisheries monitoring programmes in South Africa

    Directory of Open Access Journals (Sweden)

    M. Mayekiso

    2010-01-01

    Full Text Available South Africa was an early leader in multidisciplinary studies of marine resources, particularly with the Benguela Ecology Programme in the 1980s and 1990s and catch records are available for some species dating back more than a century. Resources data have focused on trends in catches, fishing effort and changes in distribution and abundance of harvested resources, which often account for a major part of the structure and functioning of marine ecosystems. Data have been collected by means of fishery-dependent and fishery-independent survey techniques appropriate to each particular stock and analysed using traditional single species stock assessment techniques. The data are complemented by comprehensive information on the environment and top predators and have been analysed using trophodynamic models such as Ecopath with Ecosim. Future approaches include a shift to an ecosystem approach to fisheries monitoring and management, in an attempt to reconcile utilisation and biodiversity conservation objectives. Despite these scientific achievements, the single species approach to the management of most resources still persists, with only limited interactions between competing species or predators and prey being formally taken into account when modelling the stock dynamics and providing management advice to the authorities.

  3. MEDITERRANEAN: Underwater neutrinos get off the ground

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    Now funded is the initial stage of NESTOR, an imaginative new programme for a dedicated underwater neutrino astroparticle physics laboratory. Located in the international waters off the southernmost corner of continental Europe near the town of Pylos in S.W. Greece, NESTOR (NEutrinos from Supernovae and TeV sources Ocean Range) recalls the wise king of Pylos who counselled the Greeks during the Trojan war, an excellent tradition for new scientific goals of detecting neutrinos

  4. Inspecting the inside of underwater hull

    Science.gov (United States)

    Valkovic, Vladivoj; Sudac, Davorin

    2009-05-01

    In order to demonstrate the possibility of identifying the material within ship's underwater hull, sunken ships and other objects on the sea floor tests with the 14 MeV sealed tube neutron generator incorporated inside a small submarine submerged in the test basin filled with sea water have been performed. Results obtained for inspection of diesel fuel and explosive presence behind single and double hull constructions are presented.

  5. Underwater bipedal locomotion by octopuses in disguise.

    Science.gov (United States)

    Huffard, Christine L; Boneka, Farnis; Full, Robert J

    2005-03-25

    Here we report bipedal movement with a hydrostatic skeleton. Two species of octopus walk on two alternating arms using a rolling gait and appear to use the remaining six arms for camouflage. Octopus marginatus resembles a coconut, and Octopus (Abdopus) aculeatus, a clump of floating algae. Using underwater video, we analyzed the kinematics of their strides. Each arm was on the sand for more than half of the stride, qualifying this behavior as a form of walking.

  6. Role of Confined Water in Underwater Adhesion

    Science.gov (United States)

    Dhinojwala, Ali

    Surface bound water is a strong deterrent for forming strong bonds between two surfaces underwater and expelling that bound water is important for strong adhesion. I will discuss examples of different strategies used by geckos, spiders, and mussels to handle this last layer of bound water. Recent results using infrared-visible sum frequency generation spectroscopy to probe the structure of this bound water will be discussed. National Science Foundation.

  7. 75 FR 9158 - Atlantic Coastal Fisheries Cooperative Management Act Provisions; Coastal Sharks Fishery

    Science.gov (United States)

    2010-03-01

    ... Coastal Fisheries Cooperative Management Act Provisions; Coastal Sharks Fishery AGENCY: National Marine... Commission's Interstate Fishery Management Plan (ISFMP) for Coastal Sharks. Subsequently, the Commission... New Jersey failed to carry out its responsibilities under the Coastal Sharks ISFMP, and if the...

  8. Study on underwater plasma arc cutting technology

    International Nuclear Information System (INIS)

    Yada, Toshio; Nakamura, Uhachiro; Tomidokoro, Sakae; Fukuzawa, Mitsuo

    1980-01-01

    The zirconium alloy tube of the impile creep test facility had been subjected to inner pressure in the Japan Material Testing Reactor (JMTR) environment. In the near future, it will be necessary to dismantle the facility and to take out the tube for such examinations as irradiation effects on material properties. In order to establish the dismantling technology for the radioactive facility, a study on underwater plasma arc cutting has been carried out since 1977. Primarily, optimum underwater cutting sequence and conditions were studied in details for developing the remote control handling and the cutting system. Further, the amounts of particles suspended in water as well as those contained in bubbled gas were quantitatively analyzed for developing a safe removal system for contaminants which were produced by cutting the radioactive material. As a result of this study, it has been concluded that the underwater plasma arc cutting method is generally suitable and effective for dismantling such radioactive material as the impile creep test facility of the JMTR. (author)

  9. Underwater Acoustic Target Tracking: A Review

    Science.gov (United States)

    Han, Ying; Fan, Liying

    2018-01-01

    Advances in acoustic technology and instrumentation now make it possible to explore marine resources. As a significant component of ocean exploration, underwater acoustic target tracking has aroused wide attention both in military and civil fields. Due to the complexity of the marine environment, numerous techniques have been proposed to obtain better tracking performance. In this paper, we survey over 100 papers ranging from innovative papers to the state-of-the-art in this field to present underwater tracking technologies. Not only the related knowledge of acoustic tracking instrument and tracking progress is clarified in detail, but also a novel taxonomy method is proposed. In this paper, algorithms for underwater acoustic target tracking are classified based on the methods used as: (1) instrument-assisted methods; (2) mode-based methods; (3) tracking optimization methods. These algorithms are compared and analyzed in the aspect of dimensions, numbers, and maneuvering of the tracking target, which is different from other survey papers. Meanwhile, challenges, countermeasures, and lessons learned are illustrated in this paper. PMID:29301318

  10. Underwater detection by using ultrasonic sensor

    Science.gov (United States)

    Bakar, S. A. A.; Ong, N. R.; Aziz, M. H. A.; Alcain, J. B.; Haimi, W. M. W. N.; Sauli, Z.

    2017-09-01

    This paper described the low cost implementation of hardware and software in developing the system of ultrasonic which can visualize the feedback of sound in the form of measured distance through mobile phone and monitoring the frequency of detection by using real time graph of Java application. A single waterproof transducer of JSN-SR04T had been used to determine the distance of an object based on operation of the classic pulse echo detection method underwater. In this experiment, the system was tested by placing the housing which consisted of Arduino UNO, Bluetooth module of HC-06, ultrasonic sensor and LEDs at the top of the box and the transducer was immersed in the water. The system which had been tested for detection in vertical form was found to be capable of reporting through the use of colored LEDs as indicator to the relative proximity of object distance underwater form the sensor. As a conclusion, the system can detect the presence of an object underwater within the range of ultrasonic sensor and display the measured distance onto the mobile phone and the real time graph had been successfully generated.

  11. Afocal viewport optics for underwater imaging

    Science.gov (United States)

    Slater, Dan

    2014-09-01

    A conventional camera can be adapted for underwater use by enclosing it in a sealed waterproof pressure housing with a viewport. The viewport, as an optical interface between water and air needs to consider both the camera and water optical characteristics while also providing a high pressure water seal. Limited hydrospace visibility drives a need for wide angle viewports. Practical optical interfaces between seawater and air vary from simple flat plate windows to complex water contact lenses. This paper first provides a brief overview of the physical and optical properties of the ocean environment along with suitable optical materials. This is followed by a discussion of the characteristics of various afocal underwater viewport types including flat windows, domes and the Ivanoff corrector lens, a derivative of a Galilean wide angle camera adapter. Several new and interesting optical designs derived from the Ivanoff corrector lens are presented including a pair of very compact afocal viewport lenses that are compatible with both in water and in air environments and an afocal underwater hyper-hemispherical fisheye lens.

  12. Modeling and Control of Underwater Robotic Systems

    Energy Technology Data Exchange (ETDEWEB)

    Schjoelberg, I:

    1996-12-31

    This doctoral thesis describes modeling and control of underwater vehicle-manipulator systems. The thesis also presents a model and a control scheme for a system consisting of a surface vessel connected to an underwater robotic system by means of a slender marine structure. The equations of motion of the underwater vehicle and manipulator are described and the system kinematics and properties presented. Feedback linearization technique is applied to the system and evaluated through a simulation study. Passivity-based controllers for vehicle and manipulator control are presented. Stability of the closed loop system is proved and simulation results are given. The equation of motion for lateral motion of a cable/riser system connected to a surface vessel at the top end and to a thruster at the bottom end is described and stability analysis and simulations are presented. The equations of motion in 3 degrees of freedom of the cable/riser, surface vessel and robotic system are given. Stability analysis of the total system with PD-controllers is presented. 47 refs., 32 figs., 7 tabs.

  13. Environmental effects on underwater optical transmission

    Science.gov (United States)

    Chu, Peter C.; Breshears, Brian F.; Cullen, Alexander J.; Hammerer, Ross F.; Martinez, Ramon P.; Phung, Thai Q.; Margolina, Tetyana; Fan, Chenwu

    2017-05-01

    Optical communication/detection systems have potential to get around some limitations of current acoustic communications and detection systems especially increased fleet and port security in noisy littoral waters. Identification of environmental effects on underwater optical transmission is the key to the success of using optics for underwater communication and detection. This paper is to answer the question "What are the transfer and correlation functions that relate measurements of hydrographic to optical parameters?" Hydrographic and optical data have been collected from the Naval Oceanographic Office survey ships with the High Intake Defined Excitation (HIDEX) photometer and sea gliders with optical back scattering sensor in various Navy interested areas such as the Arabian Gulf, Gulf of Oman, east Asian marginal seas, and Adriatic Sea. The data include temperature, salinity, bioluminescence, chlorophyll-a fluorescence, transmissivity at two different wavelengths (TRed at 670 nm, TBlue at 490 nm), and back scattering coefficient (bRed at 700 nm, bBlue at 470 nm). Transfer and correlation functions between the hydrographic and optical parameters are obtained. Bioluminescence and fluorescence maxima, transmissivity minimum with their corresponding depths, red and blue laser beam peak attenuation coefficients are identified from the optical profiles. Evident correlations are found between the ocean mixed layer depth and the blue and red laser beam peak attenuation coefficients, bioluminescence and fluorescence maxima in the Adriatic Sea, Arabian Gulf, Gulf of Oman, and Philippine Sea. Based on the observational data, an effective algorithm is recommended for solving the radiative transfer equation (RTE) for predicting underwater laser radiance.

  14. Automatic stabilization of underwater robots in the time manipulation operations

    International Nuclear Information System (INIS)

    Filaretov, V.F.; Koval, E.V.

    1994-01-01

    When carrying out underwater technical works by means of an underwater vehicles having a manipulator it is desirable to perform manipulation operations in the regime of the underwater vehicle hovering above the object without durable and complicated operations up its rigid fixation. Underwater vehicle stabilization is achieved by compensation all the effects on the vehicle caused by the operating manipulator in water medium. This automatic stabilization is formed due to input of the required control signals into corresponding vehicle propellers proportional to calculated components of the generalized forces and moments. The propellers should form stops reacting against effects

  15. Underwater hearing in the great cormorant (Phalacrocorax carbo sinensis)

    DEFF Research Database (Denmark)

    Hansen, Kirstin Anderson; Larsen, Ole Næsbye; Wahlberg, Magnus

    2016-01-01

    The underwater hearing threshold of a great cormorant (Phalacrocroax carbo sinensis) was measured at 2 kHz using psychophysical methods. Previous in-air and underwater testing suggests that cormorants have rather poor in-air hearing compared to other birds of similar size (Johansen, 2016). Prelim......The underwater hearing threshold of a great cormorant (Phalacrocroax carbo sinensis) was measured at 2 kHz using psychophysical methods. Previous in-air and underwater testing suggests that cormorants have rather poor in-air hearing compared to other birds of similar size (Johansen, 2016...

  16. Contour Tracking Control for the REMUS Autonomous Underwater Vehicle

    National Research Council Canada - National Science Library

    Van Reet, Alan R

    2005-01-01

    In the interest of enhancing the capabilities of autonomous underwater vehicles used in US Naval Operations, controlling vehicle position to follow depth contours presents exciting potential for navigation...

  17. Autopilot Using Differential Thrust for ARIES Autonomous Underwater Vehicle

    National Research Council Canada - National Science Library

    Sarton, Christopher

    2003-01-01

    .... Unfortunately, communication antennas must point to specific satellites in this system and thus underwater vehicles must steer a specific course on the surface during the communication process...

  18. Research on Operational Aspects of Large Autonomous Underwater Glider Fleets

    National Research Council Canada - National Science Library

    Fratantoni, David M

    2007-01-01

    This program supported research on the operational and management issues stemming from application of large fleets of autonomous underwater gliders to oceanographic research and rapid environmental...

  19. Hoffman etal 2016 Fisheries Data

    Data.gov (United States)

    U.S. Environmental Protection Agency — Fish collection data associated with the data analysis presented in Hoffman et al. 2016. Fisheries 41(1):26-37, DOI: 10.1080/03632415.2015.1114926. This dataset is...

  20. Morocco - Small-Scale Fisheries

    Data.gov (United States)

    Millennium Challenge Corporation — The final performance evaluation roadmap for the Small-Scale Fisheries Project (PPA-MCC) is developed using a grid constructed around indicators relating to Project...

  1. Exploring optimal fishing scenarios for the multispecies artisanal fisheries of Eritrea using a trophic model

    NARCIS (Netherlands)

    Tsehaye, I.W.; Nagelkerke, L.A.J.

    2008-01-01

    This study represents the first attempt to assess the potential for fisheries in the artisanal Red Sea reef fisheries of Eritrea in an ecosystem context. We used an Ecopath with Ecosim model to integrate known aspects of the ecosystem and its inhabitants into a single framework, with the aim to gain

  2. 77 FR 4282 - Gulf of Mexico Fishery Management Council; Public Meeting

    Science.gov (United States)

    2012-01-27

    ... meeting. SUMMARY: The Gulf of Mexico Fishery Management Council will convene a meeting of the Shrimp Stock... Laboratory, 4700 Avenue U, Galveston, TX 77551-5997. Council address: Gulf of Mexico Fishery Management... Management Council; telephone: (813) 348-1630. SUPPLEMENTARY INFORMATION: The Shrimp Stock Assessment Review...

  3. Judgement and Knowledge in Fisheries Involving Stakeholders. JAKFISH D1.5 Final Report

    DEFF Research Database (Denmark)

    Pastoors, Martin; Ulrich, Clara; Wilson, Douglas Clyde

    . In four different case studies, the JAKFISH project invited fisheries stakeholders to participate in the process of framing the management problem, and to give input and evaluate the scientific models that are used to provide fisheries management advice. JAKFISH investigated various tools to assess...

  4. 76 FR 65155 - Fisheries Off West Coast States; Highly Migratory Species Fisheries; Swordfish Retention Limits

    Science.gov (United States)

    2011-10-20

    ...; Swordfish Retention Limits AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and... consistent with regulations implementing the Western Pacific Fishery Management Council's Pacific Pelagics...

  5. Action Sport Cameras as an Instrument to Perform a 3D Underwater Motion Analysis.

    Science.gov (United States)

    Bernardina, Gustavo R D; Cerveri, Pietro; Barros, Ricardo M L; Marins, João C B; Silvatti, Amanda P

    2016-01-01

    Action sport cameras (ASC) are currently adopted mainly for entertainment purposes but their uninterrupted technical improvements, in correspondence of cost decreases, are going to disclose them for three-dimensional (3D) motion analysis in sport gesture study and athletic performance evaluation quantitatively. Extending this technology to sport analysis however still requires a methodologic step-forward to making ASC a metric system, encompassing ad-hoc camera setup, image processing, feature tracking, calibration and 3D reconstruction. Despite traditional laboratory analysis, such requirements become an issue when coping with both indoor and outdoor motion acquisitions of athletes. In swimming analysis for example, the camera setup and the calibration protocol are particularly demanding since land and underwater cameras are mandatory. In particular, the underwater camera calibration can be an issue affecting the reconstruction accuracy. In this paper, the aim is to evaluate the feasibility of ASC for 3D underwater analysis by focusing on camera setup and data acquisition protocols. Two GoPro Hero3+ Black (frequency: 60Hz; image resolutions: 1280×720/1920×1080 pixels) were located underwater into a swimming pool, surveying a working volume of about 6m3. A two-step custom calibration procedure, consisting in the acquisition of one static triad and one moving wand, carrying nine and one spherical passive markers, respectively, was implemented. After assessing camera parameters, a rigid bar, carrying two markers at known distance, was acquired in several positions within the working volume. The average error upon the reconstructed inter-marker distances was less than 2.5mm (1280×720) and 1.5mm (1920×1080). The results of this study demonstrate that the calibration of underwater ASC is feasible enabling quantitative kinematic measurements with accuracy comparable to traditional motion capture systems.

  6. Action Sport Cameras as an Instrument to Perform a 3D Underwater Motion Analysis.

    Directory of Open Access Journals (Sweden)

    Gustavo R D Bernardina

    Full Text Available Action sport cameras (ASC are currently adopted mainly for entertainment purposes but their uninterrupted technical improvements, in correspondence of cost decreases, are going to disclose them for three-dimensional (3D motion analysis in sport gesture study and athletic performance evaluation quantitatively. Extending this technology to sport analysis however still requires a methodologic step-forward to making ASC a metric system, encompassing ad-hoc camera setup, image processing, feature tracking, calibration and 3D reconstruction. Despite traditional laboratory analysis, such requirements become an issue when coping with both indoor and outdoor motion acquisitions of athletes. In swimming analysis for example, the camera setup and the calibration protocol are particularly demanding since land and underwater cameras are mandatory. In particular, the underwater camera calibration can be an issue affecting the reconstruction accuracy. In this paper, the aim is to evaluate the feasibility of ASC for 3D underwater analysis by focusing on camera setup and data acquisition protocols. Two GoPro Hero3+ Black (frequency: 60Hz; image resolutions: 1280×720/1920×1080 pixels were located underwater into a swimming pool, surveying a working volume of about 6m3. A two-step custom calibration procedure, consisting in the acquisition of one static triad and one moving wand, carrying nine and one spherical passive markers, respectively, was implemented. After assessing camera parameters, a rigid bar, carrying two markers at known distance, was acquired in several positions within the working volume. The average error upon the reconstructed inter-marker distances was less than 2.5mm (1280×720 and 1.5mm (1920×1080. The results of this study demonstrate that the calibration of underwater ASC is feasible enabling quantitative kinematic measurements with accuracy comparable to traditional motion capture systems.

  7. Reservoir area of influence and implications for fisheries management

    Science.gov (United States)

    Martin, Dustin R.; Chizinski, Christopher J.; Pope, Kevin L.

    2015-01-01

    Understanding the spatial area that a reservoir draws anglers from, defined as the reservoir's area of influence, and the potential overlap of that area of influence between reservoirs is important for fishery managers. Our objective was to define the area of influence for reservoirs of the Salt Valley regional fishery in southeastern Nebraska using kernel density estimation. We used angler survey data obtained from in-person interviews at 17 reservoirs during 2009–2012. The area of influence, defined by the 95% kernel density, for reservoirs within the Salt Valley regional fishery varied, indicating that anglers use reservoirs differently across the regional fishery. Areas of influence reveal angler preferences in a regional context, indicating preferred reservoirs with a greater area of influence. Further, differences in areas of influences across time and among reservoirs can be used as an assessment following management changes on an individual reservoir or within a regional fishery. Kernel density estimation provided a clear method for creating spatial maps of areas of influence and provided a two-dimensional view of angler travel, as opposed to the traditional mean travel distance assessment.

  8. Comparative Resilience in Five North Pacific Regional Salmon Fisheries

    Directory of Open Access Journals (Sweden)

    Xanthippe Augerot

    2010-06-01

    Full Text Available Over the past century, regional fisheries for Pacific salmon (Oncorhynchus spp. have been managed primarily for their provisioning function, not for ecological support and cultural significance. We examine the resilience of the regional salmon fisheries of Japan, the Russian Far East, Alaska, British Columbia, and Washington-Oregon-California (WOC in terms of their provisioning function. Using the three dimensions of the adaptive cycle - capital, connectedness, and resilience - we infer the resilience of the five fisheries based on a qualitative assessment of capital accumulation and connectedness at the regional scale. In our assessment, we evaluate natural capital and connectedness and constructed capital and connectedness. The Russian Far East fishery is the most resilient, followed by Alaska, British Columbia, Japan, and WOC. Adaptive capacity in the fisheries is contingent upon high levels of natural capital and connectedness and moderate levels of constructed capital and connectedness. Cross-scale interactions and global market demand are significant factors in reduced resilience. Greater attention to ecological functioning and cultural signification has the potential to increase resilience in Pacific salmon ecosystems.

  9. Repairs on underwater spent fuel transfer buggy and review of other underwater facilities of Cirus rod cutting building

    International Nuclear Information System (INIS)

    Rao, D.V.H.; Ganeshan, P.; Khadilkar, M.G.

    1994-01-01

    Cirus rod cutting building is a pool of water in concrete unlined bays. This houses several equipment required for processing of spent fuel and other experimental assemblies. These have been in use for over three decades. Recently the fuel transfer buggy had a major breakdown and the repair involved elaborate planning preparation and special methods to ensure safe working condition and to minimise manrem consumption. This also provided an opportunity to assess the condition of other underwater components in radiation environment which were hitherto inaccessible. This paper highlights the repair work carried on buggy and also the effect of ageing on some of the equipment vis a vis the possibility of their life extension. (author). 7 figs

  10. 78 FR 64200 - Caribbean Fishery Management Council; Public Meetings

    Science.gov (United States)

    2013-10-28

    ... Caribbean Fishery Management Council's (Council) Scientific and Statistical Committee (SSC) will hold... Fishery Management Council; Public Meetings AGENCY: National Marine Fisheries Service (NMFS), National... held at the Caribbean Fishery Management Council Headquarters, located at 270 Mu[ntilde]oz Rivera...

  11. 76 FR 55363 - Pacific Fishery Management Council; Public Meeting

    Science.gov (United States)

    2011-09-07

    ... Pacific Fishery Management Council's (Pacific Council) Groundfish Management Team (GMT) [[Page 55364... Fishery Management Council; Public Meeting AGENCY: National Marine Fisheries Service (NMFS), National...; telephone: (206) 526-6150. Council address: Pacific Fishery Management Council, 7700 NE Ambassador Place...

  12. 75 FR 33245 - Pacific Fishery Management Council; Public Meeting

    Science.gov (United States)

    2010-06-11

    ... Pacific Fishery Management Council's (Council) Groundfish Management Team (GMT) will hold a working... Fishery Management Council; Public Meeting AGENCY: National Marine Fisheries Service (NMFS), National... be held at the Pacific Fishery Management Council office, Large Conference Room, 7700 NE Ambassador...

  13. 78 FR 77658 - Pacific Fishery Management Council; Public Meeting

    Science.gov (United States)

    2013-12-24

    ... Pacific Fishery Management Council's (Pacific Council) Highly Migratory Species Management Team (HMSMT... Fishery Management Council; Public Meeting AGENCY: National Marine Fisheries Service (NMFS), National.... Potential changes to management measures for the west coast drift gillnet fishery. 2. Developments to...

  14. 77 FR 75614 - Pacific Fishery Management Council; Public Meeting

    Science.gov (United States)

    2012-12-21

    ... Pacific Fishery Management Council's (Pacific Council) Highly Migratory Species Management Team (HMSMT... Fishery Management Council; Public Meeting AGENCY: National Marine Fisheries Service (NMFS), National.... Council address: Pacific Fishery Management Council, 7700 NE. Ambassador Place, Suite 101, Portland, OR...

  15. 75 FR 49890 - Pacific Fishery Management Council; Public Meeting

    Science.gov (United States)

    2010-08-16

    ... Pacific Fishery Management Council's (Pacific Council) Coastal Pelagic Species Management Team (CPSMT) and... Fishery Management Council; Public Meeting AGENCY: National Marine Fisheries Service (NMFS), National... will be available at the following location: Pacific Fishery Management Council, Small Conference Room...

  16. 75 FR 80470 - Pacific Fishery Management Council; Public Meeting

    Science.gov (United States)

    2010-12-22

    ... Pacific Fishery Management Council's (Council) Groundfish Management Team (GMT) will hold a working... Fishery Management Council; Public Meeting AGENCY: National Marine Fisheries Service (NMFS), National.... Council address: Pacific Fishery Management Council, 7700 NE. Ambassador Place, Suite 101, Portland, OR...

  17. Identification of a putative man-made object from an underwater crash site using CAD model superimposition.

    Science.gov (United States)

    Vincelli, Jay; Calakli, Fatih; Stone, Michael; Forrester, Graham; Mellon, Timothy; Jarrell, John

    2018-04-01

    In order to identify an object in video, a comparison with an exemplar object is typically needed. In this paper, we discuss the methodology used to identify an object detected in underwater video that was recorded during an investigation into Amelia Earhart's purported crash site. A computer aided design (CAD) model of the suspected aircraft component was created based on measurements made from orthogonally rectified images of a reference aircraft, and validated against historical photographs of the subject aircraft prior to the crash. The CAD model was then superimposed on the underwater video, and specific features on the object were geometrically compared between the CAD model and the video. This geometrical comparison was used to assess the goodness of fit between the purported object and the object identified in the underwater video. Copyright © 2018 Elsevier B.V. All rights reserved.

  18. WODA technical guidance on underwater sound from dredging

    NARCIS (Netherlands)

    Thomsen, F.; Borsani, F.; Clarke, D.; Jong, C. de; Wit, P. de; Goethals, F.; Holtkamp, M.; Martin, E.S.; Spadaro, P.; Raalte, G. van; Victor, G.Y.V.; Jensen, A.

    2016-01-01

    The World Organization of Dredging Associations (WODA) has identified underwater sound as an environmental issue that needs further consideration. A WODA Expert Group on Underwater Sound (WEGUS) prepared a guidance paper in 2013 on dredging sound, including a summary of potential impacts on aquatic

  19. Evaluating the SCC resistance of underwater welds in sodium tetrathionate

    International Nuclear Information System (INIS)

    White, R.A.; Angeliu, T.M.

    1997-01-01

    The susceptibility of welds to stress corrosion cracking (SCC) is enhanced by the surface residual tensile stresses generated by the typical welding process. However, underwater plasma transferred arc (PTA) welding has been shown to produce compressive surface residual stresses, an encouraging result if repairs of cracked boiling water reactor (BWR) components are to be made without further endangering them to SCC. This program was designed to verify that underwater PTA welds are resistant to SCC and to determine if underwater PTA welding could mitigate SCC in potentially susceptible welds. This was achieved by exposing various welds on solution annealed (SA) and SA + thermally sensitized 304 stainless steel at 25 C in a solution of 1.5 gm/liter of sodium sulfide added to 0.05M sodium tetrathionate, titrated to a pH of 1.25 with H 2 SO 4 . The autogeneous welds were produced using gas tungsten arc (GTA) and plasma transferred arc (PTA) welding under atmospheric conditions, and PTA welding underwater. After 1 hour of sodium tetrathionate exposure, GTA and air PTA welds exhibited SCC while the underwater PTA weld heat affected zones were more resistant. Underwater PTA welds bisecting a GTA weld eliminated the cracking in the GTA weld heat affected zone under certain conditions. The lack of IG cracking in the region influenced by the underwater PTA weld is consistent with the measurement of compressive surface residual stresses inherent to the underwater welding process

  20. Remarks on the observability of single beacon underwater navigation

    DEFF Research Database (Denmark)

    Jouffroy, Jerome; Ross, Andrew

    This paper contributes a simple and intuitive result in the analysis of underwater navigation using a single ranging beacon. This analysis should help with the design of small and lightweight underwater vehicles by reducing the amount of instrumentation required for accurate navigation. The concept...

  1. Underwater laser cladding and seal welding for INCONEL 52

    International Nuclear Information System (INIS)

    Tamura, Masataka; Kouno, Wataru; Makino, Yoshinobu; Kawano, Shohei; Yoda, Masaki

    2007-01-01

    Recently, stress corrosion cracking (SCC) has been observed at aged components of nuclear power plants under water environment and high exposure of radiation. Toshiba has been developing both an underwater laser welding directly onto surface of the aged components as maintenance and repair techniques. This paper reports underwater laser cladding and seal welding for INCONEL 52. (author)

  2. Underwater methods for study of salmonids in the Intermountain West

    Science.gov (United States)

    Russell F. Thurow

    1994-01-01

    This guide describes underwater methods using snorkeling gear to study fish populations in flowing waters of the Intermountain West. It outlines procedures for estimating salmonid abundance and habitat use and provides criteria for identifying and estimating the size of fish underwater.

  3. The WODA guidance paper on underwater sound from dredging (abstract)

    NARCIS (Netherlands)

    Thomsen, F.; Borsani, F.; Clarke, D.; Jong, C.A.F. de; Witt, P. de; Holtkamp, M.; Goethals, F.; San Martin, E.; Spadaro, P.; Raalte, G. van; Jensen, A.

    2013-01-01

    The World Organisation of Dredging Associations (WODA) has identified underwater sound as an environmental issue that needs further consideration. A WODA Expert Group on Underwater Sound (WEGUS) was established to provide a guidance paper on dredging sound, impact on aquatic biota and advice on

  4. Constrained Multi-Body Dynamics for Modular Underwater Robots — Theory and Experiments

    DEFF Research Database (Denmark)

    Nielsen, Mikkel Cornelius; Eidsvik, Ole Alexander; Blanke, Mogens

    2018-01-01

    This paper investigates the problem of modelling a system of interconnected underwater robots with highly coupled dynamics. The objective is to develop a mathematical description of the system that captures its most significant dynamics. The proposed modelling method is based on active constraint...... on a BlueROV vehicle to determine the model parameters. The applicability of the modelling approach is assessed by comparing experimental data to simulations of an equivalent model synthesised using the proposed theory....

  5. Low-cost small action cameras in stereo generates accurate underwater measurements of fish

    OpenAIRE

    Letessier, T. B.; Juhel, Jean-Baptiste; Vigliola, Laurent; Meeuwig, J. J.

    2015-01-01

    Small action cameras have received interest for use in underwater videography because of their low-cost, standardised housing, widespread availability and small size. Here, we assess the capacity of GoPro action cameras to provide accurate stereo-measurements of fish in comparison to the Sony handheld cameras that have traditionally been used for this purpose. Standardised stereo-GoPro and Sony systems were employed to capture measurements of known-length targets in a pool to explore the infl...

  6. Validation of Passive Sampling Devices for Monitoring of Munitions Constituents in Underwater Environments

    Science.gov (United States)

    2017-09-01

    and explosives of concern (MEC) corroding, breaching, and leaking MC into the water column (Darrach, Chutjian, and Plett, 1998; GMI, 2007; Lewis et...underwater UWMM have the potential to corrode, breach, and leak munitions constituents (MCs) such as 2,4,6-trinitrotoluene (TNT) and hexahydro-1,3,5...Wang et al., 2013), a number of challenges prevent accurate assessment of environmental exposure using traditional water , sediment, and tissue

  7. Optimization of an Intelligent Controller for an Unmanned Underwater Vehicle

    Directory of Open Access Journals (Sweden)

    M. Fauzi Nor Shah

    2011-08-01

    Full Text Available Underwater environment poses a difficult challenge for autonomous underwater navigation. A standard problem of underwater vehicles is to maintain it position at a certain depth in order to perform desired operations. An effective controller is required for this purpose and hence the design of a depth controller for an unmanned underwater vehicle is described in this paper. The control algorithm is simulated by using the marine guidance navigation and control simulator. The project shows a radial basis function metamodel can be used to tune the scaling factors of a fuzzy logic controller. By using offline optimization approach, a comparison between genetic algorithm and metamodeling has been done to minimize the integral square error between the set point and the measured depth of the underwater vehicle. The results showed that it is possible to obtain a reasonably good error using metamodeling approach in much a shorter time compared to the genetic algorithm approach.

  8. A man-made object detection for underwater TV

    Science.gov (United States)

    Cheng, Binbin; Wang, Wenwu; Chen, Yao

    2018-03-01

    It is a great challenging task to complete an automatic search of objects underwater. Usually the forward looking sonar is used to find the target, and then the initial identification of the target is completed by the side-scan sonar, and finally the confirmation of the target is accomplished by underwater TV. This paper presents an efficient method for automatic extraction of man-made sensitive targets in underwater TV. Firstly, the image of underwater TV is simplified with taking full advantage of the prior knowledge of the target and the background; then template matching technology is used for target detection; finally the target is confirmed by extracting parallel lines on the target contour. The algorithm is formulated for real-time execution on limited-memory commercial-of-the-shelf platforms and is capable of detection objects in underwater TV.

  9. Evaluating fishery rehabilitation under uncertainty: A bioeconomic analysis of quota management for the Green Bay yellow perch fishery

    Science.gov (United States)

    Johnson, B.L.; Milliman, S.R.; Bishop, R.C.; Kitchell, J.F.

    1992-01-01

    The fishery for yellow perch Perca flavescens in Green Bay, Lake Michigan, is currently operating under a rehabilitation plan based on a commercial harvest quota. We developed a bioeconomic computer model that included links between population density and growth, recruitment, and fishing effort for this fishery. Random variability was included in the stock-recruitment relation and in a simulated population assessment. We used the model in an adaptive management framework to evaluate the effects of the rehabilitation plan on both commercial and sport fisheries and to search for ways to improve the plan. Results indicate that the current quota policy is a member of a set of policies that would meet most management goals and increase total value of the fishery. Sensitivity analyses indicate that this conclusion is robust over a wide range of biological conditions. We predict that commercial fishers will lose money relative to the baseline condition, but they may receive other benefits from the elimination of the common-property nature of the fishery. The prospect exists for managing variability in harvest and stock size and for maximizing economic returns in the fishery, but more information is required, primarily on sportfishing effort dynamics and angler preferences. Stock-recruitment relations, density dependence of growth, and dynamics of sportfishing effort are the primary sources of uncertainty limiting the precision of our predictions. The current quota policy is about as good as other policies at reducing this uncertainty and appears, overall, to be one of the best choices for this fishery. The analytical techniques used in this study were primarily simple, heuristic approaches that could be easily transferred to other studies.

  10. Leakage warning system for flexible underwater pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Moeller, E; Bernstein, L

    1985-08-01

    Underwater pipelines for unloading oil tankers, e.g. in 30 km distance from the harbour site, are required to be flexible and require supervision. This is done by implementation of oil sensitive sensors between the inner rubber tube and the following impregnated textile layer. The generated sensor signals, influenced by leak oil, have to be wireless transmitted from 150 meters under water to the supervisory station at the coast. Sensor configurations are described, to derive the point of the leakage from the topologized warning signals.

  11. Underwater Sound Propagation from Marine Pile Driving.

    Science.gov (United States)

    Reyff, James A

    2016-01-01

    Pile driving occurs in a variety of nearshore environments that typically have very shallow-water depths. The propagation of pile-driving sound in water is complex, where sound is directly radiated from the pile as well as through the ground substrate. Piles driven in the ground near water bodies can produce considerable underwater sound energy. This paper presents examples of sound propagation through shallow-water environments. Some of these examples illustrate the substantial variation in sound amplitude over time that can be critical to understand when computing an acoustic-based safety zone for aquatic species.

  12. Underwater photography - A visual survey method

    Digital Repository Service at National Institute of Oceanography (India)

    Sharma, R.

    Content-Type text/plain; charset=UTF-8 173 Underwater photography - A visual survey method Rahul Sharma National Institute of Oceanography, Dona Paula, Goa-403004 rsharma@nio.org Introduction “Photography as a means of observing...-sea photographs were those made by Maurice Ewing and his co-workers during cruises on Atlantis in 1940-48. Their subject was the seafloor and their method of clicking was to trigger the camera mechanically when its mounting struck bottom. This is the only...

  13. Water waves generated by underwater explosion

    CERN Document Server

    Mehaute, Bernard Le

    1996-01-01

    This is the first book on explosion-generated water waves. It presents the theoretical foundations and experimental results of the generation and propagation of impulsively generated waves resulting from underwater explosions. Many of the theories and concepts presented herein are applicable to other types of water waves, in particular, tsunamis and waves generated by the fall of a meteorite. Linear and nonlinear theories, as well as experimental calibrations, are presented for cases of deep and shallow water explosions. Propagation of transient waves on dissipative, nonuniform bathymetries to

  14. Radon dynamics in underwater thermal radon therapy

    International Nuclear Information System (INIS)

    Lettner, H.; Hofmann, W.; Winkler, R.; Rolle, R.; Foisner, W.

    1998-01-01

    At a facility for underwater thermal radon therapy in Bad Hofgastein, experiments were carried out with the aim of establishing radon in the air exhaled by the treated patients and of radon decay products on the skin of the patients. The time course of radon concentration in the exhaled air shows a maximum a few minutes after entering the bath, then the Rn concentration remains constant over the remaining time spent in the bath. Taking into account several simplifying assumptions, the average dose to the epidermis from radon daughters is about 50 μGy. (A.K.)

  15. Underwater Activities in the Soviet Union

    Science.gov (United States)

    1975-03-01

    morska , no. 12, 1967, 558-559. Eighty hours under the ice. Poseidon, no. 10 (70), 1967, inside front cover, 433-438, and 465. Fisera, M. A tent, a...Schiffbautechnik, no. 10, 1968. 568-574. 222. Kullnski, J. Meduza-2 underwater base for divers. Technika i gospodarka morska , no. 1, 1969, 44-46. 223...Technika i gospodarka morska , no. 4, 1973, 225-226. Baras, J., S. A. Guljar, and J. N. Kiklewitsch. The Ikhtiandr experiments. Poseidon, no. 4(136

  16. Hydraulic lifter for an underwater drilling rig

    Energy Technology Data Exchange (ETDEWEB)

    Garan' ko, Yu L

    1981-01-15

    A hydraulic lifter is suggested for an underwater drilling rig. It includes a base, hydraulic cylinders for lifting the drilling pipes connected to the clamp holder and hydraulic distributor. In order to simplify the design of the device, the base is made with a hollow chamber connected to the rod cavities and through the hydraulic distributor to the cavities of the hydraulic cylinders for lifting the drilling pipes. The hydraulic distributor is connected to the hydrosphere through the supply valve with control in time or by remote control. The base is equipped with reverse valves whose outlets are on the support surface of the base.

  17. Forecast of Remote Underwater Sensing Technology.

    Science.gov (United States)

    1980-07-01

    Ndgrt o oth NIA ye ’ Suite 709NrtFaothMAO5i Arligton VA 2202Attn: Dave Ho0soci, Chief Enginee~r Attn : Jay W. -arford, Manlager, (617) 563-59)17 (703...0,1305 Attn: Dr. A. Zielinski , Asst. Professor Attn: C. R. B. Lister Faculty of Engineering and (20t) 325-5497 Applied Science (709) 753-1200 Lockheed...157. Zielinski , A.; Barbour, L.; "Swept Carrier Acoustic Underwater Communica- tions," IEEE/MTS Oceans 󈨒, Washington, DC, Sept. 6-8, 1978. 158

  18. Working underwater: deepwater drilling support by ROV

    Energy Technology Data Exchange (ETDEWEB)

    1958-01-01

    Experience with the drill ships Discoverer Seven Seas and Penrod 78 explains some of the problems associated with the use of remotely operated vehicles (ROVs) for underwater operations. Support services are a bigger problem than depth. The author describes developments, such as the new guidewire methods, side launch A-frame davit, and top hat stabilizing frame. All parts of the ROV system must be of heavy duty design, and operative skill is of paramount importance. The major requirements for deep water ROVs are reliability, fail-safe redundancy, cage deployment, compact size, adequate power, and capacity for heavy intervention work. 8 figures.

  19. Determining spherical lens correction for astronaut training underwater.

    Science.gov (United States)

    Porter, Jason; Gibson, C Robert; Strauss, Samuel

    2011-09-01

    To develop a model that will accurately predict the distance spherical lens correction needed to be worn by National Aeronautics and Space Administration astronauts while training underwater. The replica space suit's helmet contains curved visors that induce refractive power when submersed in water. Anterior surface powers and thicknesses were measured for the helmet's protective and inside visors. The impact of each visor on the helmet's refractive power in water was analyzed using thick lens calculations and Zemax optical design software. Using geometrical optics approximations, a model was developed to determine the optimal distance spherical power needed to be worn underwater based on the helmet's total induced spherical power underwater and the astronaut's manifest spectacle plane correction in air. The validity of the model was tested using data from both eyes of 10 astronauts who trained underwater. The helmet's visors induced a total power of -2.737 D when placed underwater. The required underwater spherical correction (FW) was linearly related to the spectacle plane spherical correction in air (FAir): FW = FAir + 2.356 D. The mean magnitude of the difference between the actual correction worn underwater and the calculated underwater correction was 0.20 ± 0.11 D. The actual and calculated values were highly correlated (r = 0.971) with 70% of eyes having a difference in magnitude of astronauts. The model accurately predicts the actual values worn underwater and can be applied (more generally) to determine a suitable spectacle lens correction to be worn behind other types of masks when submerged underwater.

  20. Underwater welding using remote controlled robots. Development of remote underwater welding technology with a high power YAG laser

    International Nuclear Information System (INIS)

    Miwa, Yasuhiro; Sato, Syuuichi; Kojima, Toshio; Owaki, Katsura; Hirose, Naoya

    2002-01-01

    As components in nuclear power plant have been periodically carried out their inspection and repair to keep their integrity, on radioactive liquid wastes storage facility, because of difficulty on their inspection by human beings, some are remained without inspection, and even when capable of inspection, conversion from human works to remote operations is desired from a viewpoint of their operation efficiency upgrading. For response to these needs, some developments on a technology capable of carrying out inspection of their inside at underwater environment and repairing welding with YAG laser by means of remote operation, have been performed. Remote underwater inspection and repair technology is a combination technology of already applied underwater mobile technique (underwater inspection robot) with underwater YAG laser welding technique which is recently at actual using level. Therefore, this technology is composed of an inspection robot and a repair welding robot. And, testing results using the underwater inspection robot and welding test results using the underwater repair welding robot, were enough preferable to obtain forecasting applicable to actual apparatuses. This technology is especially effective for inspection and repair of inside of nuclear fuel cycle apparatuses and relatively high dose apparatuses, and can be thought to be applicable also to large capacity tanks, tanks dealing with harmful matters, underwater structures, and so on, in general industries. (G.K.)

  1. 75 FR 44938 - Atlantic Coastal Fisheries Cooperative Management Act Provisions; Atlantic Coastal Shark Fishery

    Science.gov (United States)

    2010-07-30

    ... Coastal Fisheries Cooperative Management Act Provisions; Atlantic Coastal Shark Fishery AGENCY: National... moratorium on fishing for Atlantic coastal sharks in the State waters of New Jersey. NMFS canceled the... Fisheries Commission's (Commission) Interstate Fishery Management Plan for Atlantic Coastal Sharks (Coastal...

  2. KB WOT Fisheries 2018: maintaining excellence and innovation in fisheries research

    NARCIS (Netherlands)

    Damme, van C.J.G.; Verver, S.W.

    2017-01-01

    The KB WOT Fisheries programme is developed to maintain and develop expertise needed to carry out the Dutch statutory obligations in fisheries monitoring and advice. The KB WOT Fisheries programme developed for 2018 reflects the scientific and management needs of the WOT fisheries programme. The

  3. 78 FR 26523 - Fisheries of the Northeastern United States; Atlantic Bluefish Fishery; 2013 and 2014 Atlantic...

    Science.gov (United States)

    2013-05-07

    .... 130104009-3416-02] RIN 0648-XC432 Fisheries of the Northeastern United States; Atlantic Bluefish Fishery; 2013 and 2014 Atlantic Bluefish Specifications AGENCY: National Marine Fisheries Service (NMFS... final specifications for the 2013 and 2014 Atlantic bluefish fishery, including annual catch limits...

  4. 77 FR 25100 - Fisheries of the Northeastern United States; Atlantic Bluefish Fishery; 2012 Atlantic Bluefish...

    Science.gov (United States)

    2012-04-27

    .... 120201086-2418-02] RIN 0648-XA904 Fisheries of the Northeastern United States; Atlantic Bluefish Fishery; 2012 Atlantic Bluefish Specifications AGENCY: National Marine Fisheries Service (NMFS), National... specifications for the 2012 Atlantic bluefish fishery, including an annual catch limit, total allowable landings...

  5. 77 FR 8776 - Fisheries of the Northeastern United States; Atlantic Bluefish Fishery; 2012 Atlantic Bluefish...

    Science.gov (United States)

    2012-02-15

    .... 120201086-2085-01] RIN 0648-XA904 Fisheries of the Northeastern United States; Atlantic Bluefish Fishery; 2012 Atlantic Bluefish Specifications AGENCY: National Marine Fisheries Service (NMFS), National... comments. SUMMARY: NMFS proposes specifications for the 2012 Atlantic bluefish fishery, including an annual...

  6. 77 FR 58051 - Fisheries of the Northeastern United States; Bluefish Fishery; Commercial Quota Harvested for the...

    Science.gov (United States)

    2012-09-19

    .... 120201086-2418-02] RIN 0648-XC236 Fisheries of the Northeastern United States; Bluefish Fishery; Commercial...: NMFS announces that the 2012 bluefish commercial quota allocated to the Commonwealth of Massachusetts has been harvested. Vessels issued a commercial Federal fisheries permit for the bluefish fishery may...

  7. 78 FR 11809 - Fisheries of the Northeastern United States; Atlantic Bluefish Fishery; 2013-2014 Atlantic...

    Science.gov (United States)

    2013-02-20

    .... 130104009-3099-01] RIN 0648-XC432 Fisheries of the Northeastern United States; Atlantic Bluefish Fishery; 2013-2014 Atlantic Bluefish Specifications AGENCY: National Marine Fisheries Service (NMFS), National... comments. SUMMARY: NMFS proposes specifications for the 2013 and 2014 Atlantic bluefish fishery, including...

  8. 77 FR 51709 - International Fisheries; Western and Central Pacific Fisheries for Highly Migratory Species...

    Science.gov (United States)

    2012-08-27

    ... Migratory Species; Bigeye Tuna Catch Limit in Longline Fisheries for 2012 AGENCY: National Marine Fisheries... Fisheries of the Western Pacific Region (Pelagics FEP) developed by the Western Pacific Fishery Management... Pelagics FEP. Section 113(a) further directs the Secretary of Commerce, for the purposes of annual...

  9. Magnuson-Stevens Fishery Conservation Act

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Magnuson-Stevens Fishery Conservation and Management Act (MSA) is the primary law governing marine fisheries management in U.S. federal waters. It has since been...

  10. Fisheries issues: trade and access to resources

    National Research Council Canada - National Science Library

    1989-01-01

    .... A sequel to the 1985 overview report on Problems of Trade in Fishery Products, this volume provides a country by country survey of measures, policies and practices affecting imports and exports of fishery products...

  11. Market-Based Fisheries Management

    DEFF Research Database (Denmark)

    Høst, Jeppe Engset

    a timely, critical insight into the social, cultural and economic aspects and consequences of market-based fisheries management. The privatization of fish quotas in Denmark represents one of the most far-reaching and comprehensive privatization schemes of its kind and has been widely promoted as a market......-based system with innovative social safeguards. This work critically examines this privatization of fish resources, combining quantitative and qualitative material to provide new understanding of fish quotas and their social value. Scholars with an interest in privatization and the socio-economic aspects...... of fisheries, and those working with NGOs, fishers and fisheries, and concerned with political conflicts will all value the research presented here....

  12. A review of orange roughy Hoplostethus atlanticus fisheries ...

    African Journals Online (AJOL)

    ... catch rate until a survey series has been established. Keywords: age determination, aggregations, assessment, biology, diet, distribution, fisheries, genetics, habitat, Hoplostethus atlanticus, lipids, Namibia, orange roughy, reproduction, review, stock structure, surveys. African Journal of Marine Science 2001, 23: 181–203 ...

  13. Benefits and organization of cooperative research for fisheries management

    NARCIS (Netherlands)

    Johnson, T.R.; Densen, van W.L.T.

    2007-01-01

    Drawing on research in the northeastern USA and northwestern Europe, a description is given of how cooperative research is organized and a statement made of how involving fishers in research can contribute to better fisheries management. The focus is on improving stock assessments through the

  14. The Traceability and Safety of Fishery Products

    OpenAIRE

    Gheorghe Adrian ZUGRAVU; Ionica SOARE

    2012-01-01

    The paper follows two main objectives: to understand consumers’ perception of safety trasability and quality of fishery products and to identify communication levers in order to improve the perceived image of fishery products. The present research is focused on the fishery products, regardless of their presentation – fresh, frozen or processed. This paper conducted a questionnaire survey of Romanian consumers’ perception toward fishery products. The empirical study with brands indicated that ...

  15. CROATIAN FISHERY IN 2003 YEAR

    Directory of Open Access Journals (Sweden)

    Irena Jahutka

    2004-12-01

    Full Text Available This work deals with the analysis and sublimation of all the relevant informations regarding fisheries in Republic of Croatia. This means that there were processed data about freshwater fisheries (farming of freshwater fish and other aquatic organisms, commercial and sports fisheries, marine fisheries (mariculture, commercial fisheries, small–scale fisheries and processing of fish products, import and export of fish and fish products as well as the financial subventions regarding fisheries. The farming of freshwater fish in 2003 is marked by the decrease of production comparing to the past 5 years. Carp is furthermore the most dominant fish species in freshwater fish farming, but it’s percentage is decreasing, and the percentage of the trout is increasing over the years. In addition to the decrease of production, the areas of production are decreasing as well, and now they are the smallest in the past decade — 6,281.97 ha. In 2003 the amount of used food is also decreased, but the amount of used fertilizers and lime is increased, that means it is the biggest in the past decade. This is caused by the bad climate conditions during the summer. Marine fisheries farming (mariculture in 2003 is in a slightly better position then the freshwater fish farming. The production of white fish species, which was reached before few years, is not changing — 2,510 tons, also the farming of oysters is stagnating, but in the past few years the farming of mussels and tuna fish is increasing. The total marine fish catch is 29,102 tons and it is performed over 34,000 km2, comparing to the 2002 it is increased by almost 49.24%. Additional to the increase of the total catch the number of commercial fishermen and fishing vessels is also increased. The number of fisherman which fish for their own consumption without the right to sell fish, that means the small–scale fishermen in 2003 is 13,500. The production of fish and fish products in 2003 is 19,000 tons

  16. Increased competition for aquaculture from fisheries

    DEFF Research Database (Denmark)

    Jensen, Frank; Nielsen, Max; Nielsen, Rasmus

    2014-01-01

    ; and supplies from aquaculture have grown continuously. In this paper, the impact of improved fisheries management on aquaculture growth is studied assuming perfect substitution between farmed and wild fish. We find that improved fisheries management, ceteris paribus, reduces the growth potential of global...... aquaculture in markets where wild fisheries constitute a large share of total supply....

  17. Is the Dutch shrimp fishery sustainable?

    NARCIS (Netherlands)

    Welleman, H.C.; Daan, N.

    2001-01-01

    The fishery of the brown shrimp (Crangon crangon LINNEAUS 1758) is a widespread human activity in the coastal zone. Yet management of this fishery has never been implemented. The question is raised whether an uncontrolled fishery is sustainable or the conceivable ecological stress results in

  18. Achieving maximum sustainable yield in mixed fisheries

    NARCIS (Netherlands)

    Ulrich, Clara; Vermard, Youen; Dolder, Paul J.; Brunel, Thomas; Jardim, Ernesto; Holmes, Steven J.; Kempf, Alexander; Mortensen, Lars O.; Poos, Jan Jaap; Rindorf, Anna

    2017-01-01

    Achieving single species maximum sustainable yield (MSY) in complex and dynamic fisheries targeting multiple species (mixed fisheries) is challenging because achieving the objective for one species may mean missing the objective for another. The North Sea mixed fisheries are a representative example

  19. Trust and new modes of fisheries governance

    NARCIS (Netherlands)

    Vos, de B.I.

    2011-01-01

    It is a commonplace today that many of the world’s commercial fisheries are in a state of crisis. As a response to the state of fisheries management, a large array of governance innovations has been deployed over the past two decades in many fisheries industries worldwide. In these new

  20. Underwater sediment-contact radiation survey method

    International Nuclear Information System (INIS)

    Lee, D.R.; St. Aubin, M.; Welch, S.J.

    1991-01-01

    The authors are striving to produce a practical system for mapping lateral distributions in gamma activity on submerged sediments. This is in response to the need for quality control and interpretation of data obtainable by sediment sampling and analyses near nuclear utilities. A prototype gamma probe has been constructed and tested. The prototype is essentially a background survey meter packaged in a 53-cm-long x 5.4-cm-diam waterproof vehicle. This usage-shaped vehicle is connected to a cable for towing in contact with bottom sediments of lakes, rivers, and coastal waters. This vehicle, or sediment probe as it is called, was initially developed for measuring sediment electrical conductances, a parameter that can be used to locate underwater areas of groundwater and contaminant upwelling. During towing, the probe does not roll or twist around its longitudinal axis by more than 10 deg, so that sensors, which have been fixed within the vehicle, can be oriented to look up, down, or sideways. In over 450 lin-km of underwater survey, only a single sediment probe has been irretrievably snagged on sunken rocks or other debris. Work in the Ottawa River near the Chalk River Laboratories has shown good agreement among point measurements of river sediment with continuous measurements using the moving probe

  1. Underwater inspection training in intense radiation field

    International Nuclear Information System (INIS)

    Taniguchi, Ryoichi

    2017-01-01

    Osaka Prefecture University has a large dose cobalt 60 gamma ray source of about 2 PBq, and is engaged in technological training and human resource development. It is assumed that the decommissioning underwater operation of Fukushima Daiichi Nuclear Power Station would be the focus. The university aims at acquisition of the basic of underwater inspection work under radiation environment that is useful for the above purpose, radiation measurement under water, basic training in image measurement, and aims as well to evaluate the damage of imaging equipment due to radiation, and master practical knowledge for the use of inspection equipment under a large dose. In particular, it is valuable to train in the observation of Cherenkov light emitted from a large dose cobalt radiation source in water using a high sensitivity camera. The measurement of radiation dose distribution in water had difficulty in remote measurement due to water shielding effect. Although it took much time before, the method using high sensitivity camera is easy to sequentially perform two-dimensional measurement, and its utility value is large. Its effect on the dose distribution measurement of irregularly shaped sources is great. The contents of training includes the following: radiation source imaging in water, use of a laser rangefinder in water, dose distribution measurement in water and Cherenkov light measurement, judgment of equipment damage due to irradiation, weak radiation measurement, and measurement and decontamination of surface contamination. (A.O.)

  2. Underwater noise from a wave energy converter

    DEFF Research Database (Denmark)

    Tougaard, Jakob

    A recent addition to the anthropogenic sources of underwater noise is offshore wave energy converters. Underwater noise was recorded from the Wavestar wave energy converter located at Hastholm, Denmark (57°7.73´N, 8°37.23´E). The Wavestar is a full-scale test and demonstration converter...... in full operation and start and stop of the converter. Median broad band (10 Hz – 20 kHz) sound pressure level (Leq) was 123 dB re. 1 Pa, irrespective of status of the wave energy converter (stopped, running or starting/stopping). The most pronounced peak in the third-octave spectrum was in the 160 Hz...... significant noise above ambient could be detected above the 250 Hz band. The absolute increase in noise above ambient was very small. L50 third-octave levels in the four bands with the converter running were thus only 1-2 dB above ambient L50 levels. The noise recorded 25 m from the wave energy converter...

  3. Hybrid Underwater Vehicle: ARV Design and Development

    Directory of Open Access Journals (Sweden)

    Zhigang DENG

    2014-02-01

    Full Text Available The development of SMU-I, a new autonomous & remotely-operated vehicle (ARV is described. Since it has both the characteristics of autonomous underwater vehicle (AUV and remote operated underwater vehicle (ROV, it is able to achieve precision fix station operation and manual timely intervention. In the paper the initial design of basic components, such as vehicle, propulsion, batteries etc. and the control design of motion are introduced and analyzed. ROV’s conventional cable is replaced by a fiber optic cable, which makes it available for high-bandwidth real-time video, data telemetry and high-quality teleoperation. Furthermore, with the aid of the manual real-time remote operation and ranging sonar, it also resolves the AUV’s conflicting issue, which can absolutely adapt the actual complex sea environment and satisfy the unknown mission need. The whole battery system is designed as two-battery banks, whose voltages and temperatures are monitored through CAN (controller area network bus to avoid battery fire and explosion. A fuzzy-PID controller is designed for its motion control, including depth control and direction control. The controller synthesizes the advantage of fuzzy control and PID control, utilizes the fuzzy rules to on-line tune the parameters of PID controller, and achieves a better control effect. Experiment results demonstrate to show the effectiveness of the test-bed.

  4. An explanatory model of underwater adaptation

    Directory of Open Access Journals (Sweden)

    Joaquín Colodro

    Full Text Available The underwater environment is an extreme environment that requires a process of human adaptation with specific psychophysiological demands to ensure survival and productive activity. From the standpoint of existing models of intelligence, personality and performance, in this explanatory study we have analyzed the contribution of individual differences in explaining the adaptation of military personnel in a stressful environment. Structural equation analysis was employed to verify a model representing the direct effects of psychological variables on individual adaptation to an adverse environment, and we have been able to confirm, during basic military diving courses, the structural relationships among these variables and their ability to predict a third of the variance of a criterion that has been studied very little to date. In this way, we have confirmed in a sample of professionals (N = 575 the direct relationship of emotional adjustment, conscientiousness and general mental ability with underwater adaptation, as well as the inverse relationship of emotional reactivity. These constructs are the psychological basis for working under water, contributing to an improved adaptation to this environment and promoting risk prevention and safety in diving activities.

  5. Modelling cavitating flow around underwater missiles

    Directory of Open Access Journals (Sweden)

    Fabien Petitpas

    2011-12-01

    Full Text Available The diffuse interface model of Saurel et al. (2008 is used for the computation of compressible cavitating flows around underwater missiles. Such systems use gas injection and natural cavitation to reduce drag effects. Consequently material interfaces appear separating liquid and gas. These interfaces may have a really complex dynamics such that only a few formulations are able to predict their evolution. Contrarily to front tracking or interface reconstruction method the interfaces are computed as diffused numerical zones, that are captured in a routinely manner, as is done usually with gas dynamics solvers for shocks and contact discontinuity. With the present approach, a single set of partial differential equations is solved everywhere, with a single numerical scheme. This leads to very efficient solvers. The algorithm derived in Saurel et al. (2009 is used to compute cavitation pockets around solid bodies. It is first validated against experiments done in cavitation tunnel at CNU. Then it is used to compute flows around high speed underwater systems (Shkval-like missile. Performance data are then computed showing method ability to predict forces acting on the system.

  6. 3D DOCUMENTATION OF ARCHEOLOGICAL REMAINS IN THE UNDERWATER PARK OF BAIAE

    Directory of Open Access Journals (Sweden)

    F. Bruno

    2015-04-01

    Full Text Available This paper presents some experimentations, which have been conducted in the submerged archeological Park of Baiae, aimed to identify the problems related to the underwater 3D documentation process. The first test has been addressed to verify if a dense stereo mapping technique, usually employed in terrestrial and aerial applications, might be employed in critical underwater conditions by assessing the influence of different factors on the results. In the second test, the accuracy of the 3D model obtained through this technique has been evaluated. The third test deals with the geo-localization of the 3D models, conducted by merging the optical and acoustic data, through a multi-resolution bathymetric map of the site as a reference.

  7. Design and Experimental Validation of a USBL Underwater Acoustic Positioning System.

    Science.gov (United States)

    Reis, Joel; Morgado, Marco; Batista, Pedro; Oliveira, Paulo; Silvestre, Carlos

    2016-09-14

    This paper presents the steps for developing a low-cost POrtableNavigation Tool for Underwater Scenarios (PONTUS) to be used as a localization device for subsea targets. PONTUS consists of an integrated ultra-short baseline acoustic positioning system aided by an inertial navigation system. Built on a practical design, it can be mounted on an underwater robotic vehicle or be operated by a scuba diver. It also features a graphical user interface that provides information on the tracking of the designated target, in addition to some details on the physical properties inside PONTUS. A full disclosure of the architecture of the tool is first presented, followed by thorough technical descriptions of the hardware components ensemble and the software development process. A series of experiments was carried out to validate the developed prototype, and the results are presented herein, which allow assessing its overall performance.

  8. Design and Experimental Validation of a USBL Underwater Acoustic Positioning System

    Directory of Open Access Journals (Sweden)

    Joel Reis

    2016-09-01

    Full Text Available This paper presents the steps for developing a low-cost POrtableNavigation Tool for Underwater Scenarios (PONTUS to be used as a localization device for subsea targets. PONTUS consists of an integrated ultra-short baseline acoustic positioning system aided by an inertial navigation system. Built on a practical design, it can be mounted on an underwater robotic vehicle or be operated by a scuba diver. It also features a graphical user interface that provides information on the tracking of the designated target, in addition to some details on the physical properties inside PONTUS. A full disclosure of the architecture of the tool is first presented, followed by thorough technical descriptions of the hardware components ensemble and the software development process. A series of experiments was carried out to validate the developed prototype, and the results are presented herein, which allow assessing its overall performance.

  9. Accuracy of Positioning Autonomous Biomimetic Underwater Vehicle Using Additional Measurement of Distances

    Directory of Open Access Journals (Sweden)

    Naus Krzysztof

    2016-12-01

    Full Text Available The article describes a study of problem of estimating the position coordinates of Autonomous Biomimetic Underwater Vehicle (ABUV using two methods: dead reckoning (DR and extended Kalman filter (EKF. In the first part of the paper, navigation system of ABUV is described and scientific problem with underwater positioning is formulated. The main part describes a way of estimating the position coordinates using DR and EKF and a numerical experiment involving motion of ABUV along the predetermined test distance. The final part of the paper contains a comparative statistical analysis of the results, carried out for assessing the accuracy of estimation of the position coordinates using DR and EKF methods. It presents the generalized conclusions from the research and the problems relating to the proper placement of the components of the system measuring distances.

  10. 77 FR 68723 - Fisheries of the Northeastern United States; Summer Flounder, Scup, and Black Sea Bass Fisheries...

    Science.gov (United States)

    2012-11-16

    ... flounder, scup, black sea bass, longfin squid, butterfish, and Atlantic bluefish fisheries. If the total... of butterfish; and 715,830 lb of bluefish. For 2014, projects may collectively be awarded up to 587... Atlantic bluefish, and assessment-quality data for weakfish, Atlantic croaker, spot, several skate and ray...

  11. 75 FR 70192 - Fisheries of the Northeastern United States; Summer Flounder, Scup, and Black Sea Bass Fisheries...

    Science.gov (United States)

    2010-11-17

    ... squid, butterfish, and Atlantic bluefish fisheries. If the total amount of RSA is not awarded, NMFS will...; 727,527 lb (330 mt) of Loligo squid; 818,790 lb (371 mt) of bluefish; and 33,069 lb (15 mt) of... stock assessment data for summer flounder, scup, black sea bass, Loligo squid, butterfish, bluefish...

  12. Evaluation of Underwater Adhesives and Friction Coatings for In Situ Attachment of Fiber Optic Sensor System for Subsea Applications

    Science.gov (United States)

    Tang, Henry H.; Le, Suy Q.; Orndoff, Evelyne S.; Smith, Frederick D.; Tapia, Alma S.; Brower, David V.

    2012-01-01

    Integrity and performance monitoring of subsea pipelines and structures provides critical information for managing offshore oil and gas production operation and preventing environmentally damaging and costly catastrophic failure. Currently pipeline monitoring devices require ground assembly and installation prior to the underwater deployment of the pipeline. A monitoring device that could be installed in situ on the operating underwater structures could enhance the productivity and improve the safety of current offshore operation. Through a Space Act Agreement (SAA) between the National Aeronautics and Space Administration (NASA) Johnson Space Center (JSC) and Astro Technology, Inc. (ATI), JSC provides technical expertise and testing facilities to support the development of fiber optic sensor technologies by ATI. This paper details the first collaboration effort between NASA JSC and ATI in evaluating underwater applicable adhesives and friction coatings for attaching fiber optic sensor system to subsea pipeline. A market survey was conducted to examine different commercial ]off ]the ]shelf (COTS) underwater adhesive systems and to select adhesive candidates for testing and evaluation. Four COTS epoxy based underwater adhesives were selected and evaluated. The adhesives were applied and cured in simulated seawater conditions and then evaluated for application characteristics and adhesive strength. The adhesive that demonstrated the best underwater application characteristics and highest adhesive strength were identified for further evaluation in developing an attachment system that could be deployed in the harsh subsea environment. Various friction coatings were also tested in this study to measure their shear strengths for a mechanical clamping design concept for attaching fiber optic sensor system. A COTS carbide alloy coating was found to increase the shear strength of metal to metal clamping interface by up to 46 percent. This study provides valuable data for

  13. Global fishery development patterns are driven by profit but not trophic level.

    Science.gov (United States)

    Sethi, Suresh A; Branch, Trevor A; Watson, Reg

    2010-07-06

    Successful ocean management needs to consider not only fishing impacts but drivers of harvest. Consolidating post-1950 global catch and economic data, we assess which attributes of fisheries are good indicators for fishery development. Surprisingly, year of development and economic value are not correlated with fishery trophic levels. Instead, patterns emerge of profit-driven fishing for attributes related to costs and revenues. Post-1950 fisheries initially developed on shallow ranging species with large catch, high price, and big body size, and then expanded to less desirable species. Revenues expected from developed fisheries declined 95% from 1951 to 1999, and few high catch or valuable fishing opportunities remain. These results highlight the importance of economic attributes of species as leading indicators for harvest-related impacts in ocean ecosystems.

  14. Underwater cladding with laser beam and plasma arc welding

    International Nuclear Information System (INIS)

    White, R.A.; Fusaro, R.; Jones, M.G.; Solomon, H.D.; Milian-Rodriguez, R.R.

    1997-01-01

    Two welding processes, plasma arc (transferred arc) (PTA) and laser beam, were investigated to apply cladding to austenitic stainless steels and Inconel 600. These processes have long been used to apply cladding layers , but the novel feature being reported here is that these cladding layers were applied underwater, with a water pressure equivalent to 24 m (80 ft). Being able to apply the cladding underwater is very important for many applications, including the construction of off-shore oil platforms and the repair of nuclear reactors. In the latter case, being able to weld underwater eliminates the need for draining the reactor and removing the fuel. Welding underwater in reactors presents numerous challenges, but the ability to weld without having to drain the reactor and remove the fuel provides a huge cost savings. Welding underwater in reactors must be done remotely, but because of the radioactive corrosion products and neutron activation of the steels, remote welding would also be required even if the reactor is drained and the fuel removed. In fact, without the shielding of the water, the remote welding required if the reactor is drained might be even more difficult than that required with underwater welds. Furthermore, as shall be shown, the underwater welds that the authors have made were of high quality and exhibit compressive rather than tensile residual stresses

  15. Underwater fiber-wireless communication with a passive front end

    Science.gov (United States)

    Xu, Jing; Sun, Bin; Lyu, Weichao; Kong, Meiwei; Sarwar, Rohail; Han, Jun; Zhang, Wei; Deng, Ning

    2017-11-01

    We propose and experimentally demonstrate a novel concept on underwater fiber-wireless (Fi-Wi) communication system with a fully passive wireless front end. A low-cost step-index (SI) plastic optical fiber (POF) together with a passive collimating lens at the front end composes the underwater Fi-Wi architecture. We have achieved a 1.71-Gb/s transmission at a mean BER of 4.97 × 10-3 (1.30 × 10-3 when using power loading) over a 50-m SI-POF and 2-m underwater wireless channel using orthogonal frequency division multiplexing (OFDM). Although the wireless part is very short, it actually plays a crucial role in practical underwater implementation, especially in deep sea. Compared with the wired solution (e.g. using a 52-m POF cable without the UWOC part), the proposed underwater Fi-Wi scheme can save optical wet-mate connectors that are sophisticated, very expensive and difficult to install in deep ocean. By combining high-capacity robust POF with the mobility and ubiquity of underwater wireless optical communication (UWOC), the proposed underwater Fi-Wi technology will find wide application in ocean exploration.

  16. Intelligent Navigation for a Solar Powered Unmanned Underwater Vehicle

    Directory of Open Access Journals (Sweden)

    Francisco García-Córdova

    2013-04-01

    Full Text Available In this paper, an intelligent navigation system for an unmanned underwater vehicle powered by renewable energy and designed for shadow water inspection in missions of a long duration is proposed. The system is composed of an underwater vehicle, which tows a surface vehicle. The surface vehicle is a small boat with photovoltaic panels, a methanol fuel cell and communication equipment, which provides energy and communication to the underwater vehicle. The underwater vehicle has sensors to monitor the underwater environment such as sidescan sonar and a video camera in a flexible configuration and sensors to measure the physical and chemical parameters of water quality on predefined paths for long distances. The underwater vehicle implements a biologically inspired neural architecture for autonomous intelligent navigation. Navigation is carried out by integrating a kinematic adaptive neuro-controller for trajectory tracking and an obstacle avoidance adaptive neuro- controller. The autonomous underwater vehicle is capable of operating during long periods of observation and monitoring. This autonomous vehicle is a good tool for observing large areas of sea, since it operates for long periods of time due to the contribution of renewable energy. It correlates all sensor data for time and geodetic position. This vehicle has been used for monitoring the Mar Menor lagoon.

  17. The influence of underwater turbulence on optical phase measurements

    Science.gov (United States)

    Redding, Brandon; Davis, Allen; Kirkendall, Clay; Dandridge, Anthony

    2016-05-01

    Emerging underwater optical imaging and sensing applications rely on phase-sensitive detection to provide added functionality and improved sensitivity. However, underwater turbulence introduces spatio-temporal variations in the refractive index of water which can degrade the performance of these systems. Although the influence of turbulence on traditional, non-interferometric imaging has been investigated, its influence on the optical phase remains poorly understood. Nonetheless, a thorough understanding of the spatio-temporal dynamics of the optical phase of light passing through underwater turbulence are crucial to the design of phase-sensitive imaging and sensing systems. To address this concern, we combined underwater imaging with high speed holography to provide a calibrated characterization of the effects of turbulence on the optical phase. By measuring the modulation transfer function of an underwater imaging system, we were able to calibrate varying levels of optical turbulence intensity using the Simple Underwater Imaging Model (SUIM). We then used high speed holography to measure the temporal dynamics of the optical phase of light passing through varying levels of turbulence. Using this method, we measured the variance in the amplitude and phase of the beam, the temporal correlation of the optical phase, and recorded the turbulence induced phase noise as a function of frequency. By bench marking the effects of varying levels of turbulence on the optical phase, this work provides a basis to evaluate the real-world potential of emerging underwater interferometric sensing modalities.

  18. Underwater television camera for monitoring inner side of pressure vessel

    International Nuclear Information System (INIS)

    Takayama, Kazuhiko.

    1997-01-01

    An underwater television support device equipped with a rotatable and vertically movable underwater television camera and an underwater television camera controlling device for monitoring images of the inside of the reactor core photographed by the underwater television camera to control the position of the underwater television camera and the underwater light are disposed on an upper lattice plate of a reactor pressure vessel. Both of them are electrically connected with each other by way of a cable to rapidly observe the inside of the reactor core by the underwater television camera. The reproducibility is extremely satisfactory by efficiently concentrating the position of the camera and image information upon inspection and observation. As a result, the steps for periodical inspection can be reduced to shorten the days for the periodical inspection. Since there is no requirement to withdraw fuel assemblies over a wide reactor core region, and the device can be used with the fuel assemblies being left as they are in the reactor, it is suitable for inspection of detectors for nuclear instrumentation. (N.H.)

  19. Untying the Mediterranean Gordian Knot: A Twenty First Century Challenge for Fisheries Management

    Directory of Open Access Journals (Sweden)

    Ilaria Vielmini

    2017-06-01

    Full Text Available Management of fisheries in the Mediterranean basin has often been described as a unique and complex challenge, due to their multi-specificity, the diversity of gear-types, and the number of nations involved. This perspective has gone hand-in-hand for decades with a lack of strong political will from decision-makers, who have been unwilling to put Mediterranean fisheries management high on their agendas. Over time, exploitation rates of demersal stocks have increased and in 2016, 97% of shared stocks assessed in the Mediterranean were reported to be overfished. An alarm bell about the chronic overfishing of Mediterranean fish stocks was rung by European policy makers in 2015, exactly 20 years after the Code of Conduct for Responsible Fisheries adopted by the Food and Agriculture Organization mandated that states should ensure the sustainable use of fishery resources. In this perspective, we: (i review the context of fisheries management in the Mediterranean; (ii identify the potential factors that may have hindered management and; (iii discuss how the reformed European Union Common Fisheries Policy and the binding commitments laid down in its text may lead to knock-on effects for fisheries management in the international Mediterranean context, if properly implemented. In this line, we also present the example of demersal fisheries management in the Strait of Sicily, which may represent a starting point for science-based management in the Mediterranean.

  20. 77 FR 62217 - Gulf of Mexico Fishery Management Council; Public Meetings

    Science.gov (United States)

    2012-10-12

    ... 33607. FOR FURTHER INFORMATION CONTACT: Dr. Stephen Bortone, Executive Director, Gulf of Mexico Fishery... Snapper Benchmark Assessment; review any additional comments from the Scientific and Statistical Committee and from the Socioeconomic Scientific and Statistical Committee; and discuss Exempted Fishing Permits...

  1. Fishery potential along the Indian coastal waters between Porbandar and Ratnagiri

    Digital Repository Service at National Institute of Oceanography (India)

    Gajbhiye, S.N.; Mehta, P.; Mustafa, S.; Nair, V.R.

    As part of the ongoing marine pollution monitoring programme the coastal stretch between Porbandar and Ratnagiri was considered to assess the fishery potential. Regular experimental trawling was done off Porbandar, Veraval, Diu, Hazira, Daman...

  2. Small-scale fisheries in Greenlandic planning

    DEFF Research Database (Denmark)

    Jacobsen, Rikke Becker

    2013-01-01

    This article analyses an ongoing planning process in Greenlandic fisheries governance aiming to reform the coastal Greenland halibut fishery. It examines the way certain truths about this fishery and the need for reform are produced up to and in the final policy document ‘regulation concerning...... could also be understood as primarily a problem to a certain ‘governmentality’ mode of governance. Whereas some fishery studies document how governmentality modes of governance in fisheries succeeds in transforming subjectivities, this study offers a view into the process that might go before successful...

  3. The Traceability and Safety of Fishery Products

    Directory of Open Access Journals (Sweden)

    Gheorghe Adrian ZUGRAVU

    2012-12-01

    Full Text Available The paper follows two main objectives: to understand consumers’ perception of safety trasability and quality of fishery products and to identify communication levers in order to improve the perceived image of fishery products. The present research is focused on the fishery products, regardless of their presentation – fresh, frozen or processed. This paper conducted a questionnaire survey of Romanian consumers’ perception toward fishery products. The empirical study with brands indicated that consumers are different awareness to domestic and foreign safety fish products. National fishery products got more attention from the consumers.

  4. Autonomous docking control of visual-servo type underwater vehicle system aiming at underwater automatic charging

    International Nuclear Information System (INIS)

    Yanou, Akira; Ohnishi, Shota; Ishiyama, Shintaro; Minami, Mamoru

    2015-01-01

    A visual-servo type remotely operated vehicle (ROV) system with binocular wide-angle lens was developed to survey submarine resources, decontaminate radiation from mud in dam lake and so on. This paper explores the experiments on regulator performance and underwater docking of the robot system utilizing Genetic Algorithm (GA) for real-time recognition of the robot's relative position and posture through 3D marker. The visual servoing performances have been verified as follows; (1) The stability performances of the proposed regulator system have been evaluated by exerting abrupt distrubane force while the ROV is controlled by visual servoing. (2) The proposed system can track time-variant desired target position in x-axis (front-back direction of the robot). (3) The underwater docking can be completed by switching visual servoing and docking modes based on the error threshold, and by giving time-varying desired target position and orientation to the controller as a desired pose. (author)

  5. Fish welfare in capture fisheries

    NARCIS (Netherlands)

    Veldhuizen, L.J.L.; Berentsen, P.B.M.; Boer, de I.J.M.; Vis, van de J.W.; Bokkers, E.A.M.

    2018-01-01

    Concerns about the welfare of production animals have extended from farm animals to fish, but an overview of the impact of especially capture fisheries on fish welfare is lacking. This review provides a synthesis of 85 articles, which demonstrates that research interest in fish welfare in capture

  6. Invertebrates and Plants :: NOAA Fisheries

    Science.gov (United States)

    Invertebrates & Plants Species of Concern Threatened & Endangered Health & Stranding Marine Mammals Chart Partnerships Fisheries Home » Protected Resources » Species Invertebrates and Plants White Marine Sanctuary Mollusks, corals, and brachiopods are three groups of marine invertebrates. To view ESA

  7. Managing Small-scale Fisheries

    International Development Research Centre (IDRC) Digital Library (Canada)

    But the story of this particular book really started in 1997 with Robin's paper in the Canadian Journal of Fisheries and Aquatic Sciences. ..... Some drying, smoking, salting; primarily human consumption. Little or ...... The World Wide Web provides access to a variety of resources that would be otherwise ...... Smith, I.R. 1979.

  8. Solving complex fisheries management problems

    DEFF Research Database (Denmark)

    Petter Johnsen, Jahn; Eliasen, Søren Qvist

    2011-01-01

    A crucial issue for the new EU common fisheries policy is how to solve the discard problem. Through a study of the institutional set up and the arrangements for solving the discard problem in Denmark, the Faroe Islands, Iceland and Norway, the article identifies the discard problem as related...

  9. Summary of the guideline on underwater laser beam repair welding

    International Nuclear Information System (INIS)

    Ichikawa, Hiroya; Yoda, Masaki; Motora, Yuichi

    2013-01-01

    It is known that stress corrosion cracking (SCC) might occur at the weld of a reactor pressure vessel or core internals. Underwater laser beam clad welding for mitigation of SCC has been already established and the guideline 'Underwater laser beam clad welding' was published. Moreover, the guideline 'Seal welding' was also published as a repair method for SCC. In addition to these guidelines, the guideline 'Underwater laser beam repair welding' was newly published in November, 2012 for the repair welding after completely removing a SCC crack occurred in weld or base metal. This paper introduces the summary of this guideline. (author)

  10. A Secure Communication Suite for Underwater Acoustic Sensor Networks

    Directory of Open Access Journals (Sweden)

    Angelica Lo Duca

    2012-11-01

    Full Text Available In this paper we describe a security suite for Underwater Acoustic Sensor Networks comprising both fixed and mobile nodes. The security suite is composed of a secure routing protocol and a set of cryptographic primitives aimed at protecting the confidentiality and the integrity of underwater communication while taking into account the unique characteristics and constraints of the acoustic channel. By means of experiments and simulations based on real data, we show that the suite is suitable for an underwater networking environment as it introduces limited, and sometimes negligible, communication and power consumption overhead.

  11. Application of YAG laser processing in underwater welding and cutting

    Energy Technology Data Exchange (ETDEWEB)

    Ohwaki, Katsura; Morita, Ichiro; Kojima, Toshio; Sato, Shuichi [Ishikawajima-Harima Heavy Industries Co. Ltd., Tokyo (Japan)

    2002-09-01

    The high-power YAG laser is a new fabrication tool. The laser torch is easy to combine with complex with complex mechanics because of beam delivery through optical fiber. A direct underwater laser welding technology has been developed and applied to the preservation, maintenance and removal of nuclear power plants. For subdividing or removing operations for retirement of plants, the laser cutting properties were confirmed to allow a maximum cutting thickness of 80 mm. For repairing inner surface of stainless steel tanks, an underwater laser welding system using a remote-controlled robot was developed and the high quality of underwater laser welding was confirmed. (author)

  12. WODA Technical Guidance on Underwater Sound from Dredging.

    Science.gov (United States)

    Thomsen, Frank; Borsani, Fabrizio; Clarke, Douglas; de Jong, Christ; de Wit, Pim; Goethals, Fredrik; Holtkamp, Martine; Martin, Elena San; Spadaro, Philip; van Raalte, Gerard; Victor, George Yesu Vedha; Jensen, Anders

    2016-01-01

    The World Organization of Dredging Associations (WODA) has identified underwater sound as an environmental issue that needs further consideration. A WODA Expert Group on Underwater Sound (WEGUS) prepared a guidance paper in 2013 on dredging sound, including a summary of potential impacts on aquatic biota and advice on underwater sound monitoring procedures. The paper follows a risk-based approach and provides guidance for standardization of acoustic terminology and methods for data collection and analysis. Furthermore, the literature on dredging-related sounds and the effects of dredging sounds on marine life is surveyed and guidance on the management of dredging-related sound risks is provided.

  13. Development of underwater laser cladding and underwater laser seal welding techniques for reactor components

    International Nuclear Information System (INIS)

    Hino, Takehisa; Tamura, Masataka; Tanaka, Yoshimi; Kouno, Wataru; Makino, Yoshinobu; Kawano, Shohei; Matsunaga, Keiji

    2009-01-01

    Stress corrosion cracking (SCC) has been reported at the aged components in many nuclear power plants. Toshiba has been developing the underwater laser welding. This welding technique can be conducted without draining the water in the reactor vessel. It is beneficial for workers not to exposure the radiation. The welding speed can be attaining twice as fast as that of Gas Tungsten Arc Welding (GTAW). The susceptibility of SCC can also be lower than the Alloy 600 base metal. (author)

  14. Forecasting the Seasonal Timing of Maine's Lobster Fishery

    Directory of Open Access Journals (Sweden)

    Katherine E. Mills

    2017-11-01

    Full Text Available The fishery for American lobster is currently the highest-valued commercial fishery in the United States, worth over US$620 million in dockside value in 2015. During a marine heat wave in 2012, the fishery was disrupted by the early warming of spring ocean temperatures and subsequent influx of lobster landings. This situation resulted in a price collapse, as the supply chain was not prepared for the early and abundant landings of lobsters. Motivated by this series of events, we have developed a forecast of when the Maine (USA lobster fishery will shift into its high volume summer landings period. The forecast uses a regression approach to relate spring ocean temperatures derived from four NERACOOS buoys along the coast of Maine to the start day of the high landings period of the fishery. Tested against conditions in past years, the forecast is able to predict the start day to within 1 week of the actual start, and the forecast can be issued 3–4 months prior to the onset of the high-landings period, providing valuable lead-time for the fishery and its associated supply chain to prepare for the upcoming season. Forecast results are conveyed in a probabilistic manner and are updated weekly over a 6-week forecasting period so that users can assess the certainty and consistency of the forecast and factor the uncertainty into their use of the information in a given year. By focusing on the timing of events, this type of seasonal forecast provides climate-relevant information to users at time scales that are meaningful for operational decisions. As climate change alters seasonal phenology and reduces the reliability of past experience as a guide for future expectations, this type of forecast can enable fishing industry participants to better adjust to and prepare for operating in the context of climate change.

  15. Yakima Fisheries Project : Revised Draft Environmental Impact Statement.

    Energy Technology Data Exchange (ETDEWEB)

    United States. Bonneville Power Administration.

    1995-05-01

    BPA proposes to fund several fishery-related activities in the Yakima River Basin. The Yakima Fisheries Project (YFP), included in the Northwest Power Planning Council`s fish and wildlife program, would be jointly managed by the State of Washington and the Yakima Indian Nation. Fisheries resources in the Yakima River are severely reduced from historical levels and there is a significant potential for enhancement of these resources. BPA`s proposed action is to fund (1) information gathering on the implementation of supplementation techniques and on feasibility of reintroducing coho salmon in an environment where native populations have become extinct; (2) research activities based on continuous assessment, feedback and improvement of research design and activities ({open_quotes}adaptive management{close_quotes}); and (3) the construction, operation, and maintenance of facilities for supplementing populations of upper Yakima spring chinook salmon. The project has been considerably revised from the original proposal described in the first draft EIS. Examined in addition to No Action (which would leave present anadromous fisheries resources unchanged in the, Basin) are two alternatives for action: (1) supplementation of depressed natural populations of upper Yakima spring chinook and (2) that same supplementation plus a study to determine the feasibility of re-establishing (via stock imported from another basin) naturally spawning population and a significant fall fishery for coho in the Yakima Basin. Alternative 2 has been identified as the preferred action. Major issues examined in the Revised Draft EIS include potential impacts of the project on genetic and ecological resources of existing fish populations, on water quality and quantity, on threatened and endangered species listed under the Endangered Species Act, and on the recreational fishery.

  16. Energy Consumption and Greenhouse Gas Emission of Korean Offshore Fisheries

    Science.gov (United States)

    Lee, Jihoon; Kim, Taeho; Ellingsen, Harald; Hognes, Erik Skontorp; Hwang, Bokyu

    2018-06-01

    This paper presents the energy and greenhouse gas (GHG) emission assessments of Korean offshore fisheries. The consumption of energy by fisheries is a significant concern because of its attendant environmental effect, as well as the cost of the fuel consumed in fishing industry. With the global attention of reducing GHG emission and increasing energy efficiency of fuel, the seafood industry needs to further understand its energy use and reduce its GHG emission. In the present study, the amount of energy consumed and the GHG emission of Korean offshore fisheries in a period from 2009 to 2013 were examined. Offshore fisheries accounted for 24% of Korean production in 2013 and 60% of fuel consumption related GHG emission. Whereas the total GHG emission intensity of this sector improved slightly between 2009 and 2012; as such emission decreased by approximately 1.9%, which increased again in 2013. The average amount of total GHG emission in this five years period was 1.78 × 106 tons of carbon dioxide equivalent/year (t CO2 eq. y-1). Active fishing gear was found to consume 20% more fuel than passive gear. However, the production from passive gear was 28%, lower than 72% from active gear. The reason for this is that less abundant stationary resources are harvested using passive gear. Furthermore, the consumption of fuel was significantly influenced by the fishing method. Implementation and development of new fishing technologies and methods are important for improving energy efficiency and reducing the climate impact on fisheries. To realize these purposes, the fishery management system needs to be established by centralizing on energy efficiency and climate effect.

  17. Task Allocation and Path Planning for Collaborative Autonomous Underwater Vehicles Operating through an Underwater Acoustic Network

    Directory of Open Access Journals (Sweden)

    Yueyue Deng

    2013-01-01

    Full Text Available Dynamic and unstructured multiple cooperative autonomous underwater vehicle (AUV missions are highly complex operations, and task allocation and path planning are made significantly more challenging under realistic underwater acoustic communication constraints. This paper presents a solution for the task allocation and path planning for multiple AUVs under marginal acoustic communication conditions: a location-aided task allocation framework (LAAF algorithm for multitarget task assignment and the grid-based multiobjective optimal programming (GMOOP mathematical model for finding an optimal vehicle command decision given a set of objectives and constraints. Both the LAAF and GMOOP algorithms are well suited in poor acoustic network condition and dynamic environment. Our research is based on an existing mobile ad hoc network underwater acoustic simulator and blind flooding routing protocol. Simulation results demonstrate that the location-aided auction strategy performs significantly better than the well-accepted auction algorithm developed by Bertsekas in terms of task-allocation time and network bandwidth consumption. We also demonstrate that the GMOOP path-planning technique provides an efficient method for executing multiobjective tasks by cooperative agents with limited communication capabilities. This is in contrast to existing multiobjective action selection methods that are limited to networks where constant, reliable communication is assumed to be available.

  18. The NESTOR underwater neutrino telescope project

    Energy Technology Data Exchange (ETDEWEB)

    Rapidis, Petros A. [Institute of Nuclear Physics, National Center for Scientific Research ' Demokritos' , Athens 15310 (Greece)], E-mail: rapidis@inp.demokritos.gr

    2009-04-11

    The NESTOR collaboration is continuing its efforts towards deploying an underwater neutrino telescope. Further site studies (e.g. water light transmission measurements, sedimentation rates, etc.) are being carried out within the context of characterizing a site that may host the proposed KM3NeT infrastructure. In addition, following the successful deployment of a single floor of a NESTOR tower in 2003, five floors are now in the final stages of preparation. The use of these five floors in a form of a truncated tower together with four autonomous strings to be located some 300 m away from the tower is being contemplated. This arrangement, named NuBE (for Neutrino Burst Experiment), that may allow the detection neutrinos in coincidence with Gamma Ray Bursts, will be described.

  19. Transducers and arrays for underwater sound

    CERN Document Server

    Butler, John L

    2016-01-01

    This improved and updated second edition covers the theory, development, and design of electro-acoustic transducers for underwater applications. This highly regarded text discusses the basics of piezoelectric and magnetostrictive transducers that are currently being used as well as promising new designs. It presents the basic acoustics as well as the specific acoustics data needed in transducer design and evaluation. A broad range of designs of projectors and hydrophones are described in detail along with methods of modeling, evaluation, and measurement. Analysis of projector and hydrophone transducer arrays, including the effects of mutual radiation impedance and numerical models for elements and arrays, are also covered. The book includes new advances in transducer design and transducer materials and has been completely reorganized to be suitable for use as a textbook, as well as a reference or handbook. The new edition contains updates to the first edition, end-of-chapter exercises, and solutions to select...

  20. Collision Detection for Underwater ROV Manipulator Systems

    Directory of Open Access Journals (Sweden)

    Satja Sivčev

    2018-04-01

    Full Text Available Work-class ROVs equipped with robotic manipulators are extensively used for subsea intervention operations. Manipulators are teleoperated by human pilots relying on visual feedback from the worksite. Operating in a remote environment, with limited pilot perception and poor visibility, manipulator collisions which may cause significant damage are likely to happen. This paper presents a real-time collision detection algorithm for marine robotic manipulation. The proposed collision detection mechanism is developed, integrated into a commercial ROV manipulator control system, and successfully evaluated in simulations and experimental setup using a real industry standard underwater manipulator. The presented collision sensing solution has a potential to be a useful pilot assisting tool that can reduce the task load, operational time, and costs of subsea inspection, repair, and maintenance operations.

  1. The NESTOR underwater neutrino telescope project

    International Nuclear Information System (INIS)

    Rapidis, Petros A.

    2009-01-01

    The NESTOR collaboration is continuing its efforts towards deploying an underwater neutrino telescope. Further site studies (e.g. water light transmission measurements, sedimentation rates, etc.) are being carried out within the context of characterizing a site that may host the proposed KM3NeT infrastructure. In addition, following the successful deployment of a single floor of a NESTOR tower in 2003, five floors are now in the final stages of preparation. The use of these five floors in a form of a truncated tower together with four autonomous strings to be located some 300 m away from the tower is being contemplated. This arrangement, named NuBE (for Neutrino Burst Experiment), that may allow the detection neutrinos in coincidence with Gamma Ray Bursts, will be described.

  2. Silent Localization of Underwater Sensors Using Magnetometers

    Directory of Open Access Journals (Sweden)

    Jonas Callmer

    2010-01-01

    Full Text Available Sensor localization is a central problem for sensor networks. If the sensor positions are uncertain, the target tracking ability of the sensor network is reduced. Sensor localization in underwater environments is traditionally addressed using acoustic range measurements involving known anchor or surface nodes. We explore the usage of triaxial magnetometers and a friendly vessel with known magnetic dipole to silently localize the sensors. The ferromagnetic field created by the dipole is measured by the magnetometers and is used to localize the sensors. The trajectory of the vessel and the sensor positions are estimated simultaneously using an Extended Kalman Filter (EKF. Simulations show that the sensors can be accurately positioned using magnetometers.

  3. Indications and complications of tube thoracostomy with improvised underwater seal bottles

    Directory of Open Access Journals (Sweden)

    Sunday A Edaigbini

    2014-01-01

    Full Text Available Background: Tube thoracostomy is a lifesaving and frequently performed procedure in hospitals where the expertise and necessary tools are available. Where the ideal drainage receptacle is unavailable, the underwater seal device can be improvised with bottled water plastic can especially in emergency situations. Aims and Objectives: To determine the frequencies of the various indications and complications of tube thoracostomy with improvised underwater seal. Materials and Methods: A cross-sectional study with a structured proforma was used for assessment over a 3-year period (May 2010-April 2013. The proforma was filled at the time of the procedure by the performing surgeon and patients were followed up with serial chest X-rays until certified cured. A 1.5 L bottled water container was used as the underwater seal receptacle. The data was analysed with SPSS 15 software program. Results: A total of 167 patients were managed. There were 106 (63.5% males and 61 (36.5% females. The mean age was 34.85 ± 16.72 with a range of 1-80 years. The most frequent indication was for malignant/paramalignant effusion, 46 (27.5%. Others were trauma, 44 (26.3%, Parapneumonic effusion, 20 (12%, postthoracotomy 14 (8.4%, empyema thoracis 12 (7.2%, heart disease and tuberculous effusion 11 (6.6% each, pneumothorax 8 (4.8% and misdiagnosis 1 (0.6%. A hundred and one (60.5% of the procedures were performed by registrars, 41 (24.6% by consultants, house officers 15 (9% and senior registrars 10 (6%. The overall complication rate was 16.8% with the more frequent complications been empyema (5.6% and pneumothorax (3.6%. The average duration of tube placement was 13.02 ± 12.362 days and range of 1-110 days. Conclusion : Tube thoracostomy can be a relatively safe procedure with acceptable complication rates even with improvised underwater seal drainage bottles.

  4. Underwater colorectal EMR: remodeling endoscopic mucosal resection.

    Science.gov (United States)

    Curcio, Gabriele; Granata, Antonino; Ligresti, Dario; Tarantino, Ilaria; Barresi, Luca; Liotta, Rosa; Traina, Mario

    2015-05-01

    Underwater EMR (UEMR) has been reported as a new technique for the removal of large sessile colorectal polyps without need for submucosal injection. To evaluate (1) outcomes of UEMR, (2) whether UEMR can be easily performed by an endoscopist skilled in traditional EMR without specific dedicated training in UEMR, and (3) whether EUS is required before UEMR. Prospective, observational study. Single, tertiary-care referral center. Underwater EMR. Complete resection and adverse events. A total of 72 consecutive patients underwent UEMR of 81 sessile colorectal polyps. EUS was performed before UEMR in 9 cases (11.1%) with a suspicious mucosal/vascular pattern. The mean polyp size was 18.7 mm (range 10-50 mm); the mean UEMR time was 11.8 minutes. Fifty-five polyps (68%) were removed en bloc, and 26 (32%) were removed with a piecemeal technique. Histopathology consisted of tubular adenomas (25.9%), tubulovillous adenomas (5%), adenomas with high-grade dysplasia (42%), serrated polyps (4.9%), carcinoma in situ (13.6%), and hyperplastic polyps (8.6%). Surveillance colonoscopy was scheduled at 3 months. Complete resection was successful in all patients. No adverse events or recurrence was recorded in any of the patients. Limited follow-up; single-center, uncontrolled study. Interventional endoscopists skilled in conventional EMR performed UEMR without specific dedicated training. EUS may not be required for lesions with no invasive features on high-definition narrow-band imaging. UEMR appears to be an effective and safe alternative to traditional EMR and could eventually improve the way in which we can effectively and safely treat colorectal lesions. Copyright © 2015 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.

  5. Morphing hull implementation for unmanned underwater vehicles

    Science.gov (United States)

    Miller, Timothy F.; Gandhi, Farhan; Rufino, Russell J.

    2013-11-01

    There has been much interest and work in the area of morphing aircraft since the 1980s. Morphing could also potentially benefit unmanned underwater vehicles (UUVs). The current paper envisions a UUV with an interior pressure hull and a variable diameter outer flexible hull with fuel stored in the annulus between, and presents a mechanism to realize diameter change of the outer hull. The outer hull diameter of UUVs designed for very long endurance/range could be progressively reduced as fuel was consumed, thereby reducing drag and further increasing endurance and range capability. Diameter morphing could also be advantageous for compact storage of UUVs. A prototype is fabricated to represent an axial section of such a morphing diameter UUV. Diameter change is achieved using eight morphing trusses arranged equidistant around the circumference of the representative interior rigid hull. Each morphing truss has a lower rail (attached to the rigid hull) and an upper rail with V-linkages between, at either ends of the rail. Horizontal motion of the feet of the V-linkages (sliding in the lower rail) results in vertical motion of the upper rail which in turn produces diameter change of the outer hull. For the prototype built and tested, a 63% increase in outer diameter from 12.75″ to 20.75″ was achieved. The introduction of a stretched latex representative flexible skin around the outer rails increased actuation force requirement and led to a propensity for the wheel-in-track sliders in the morphing truss to bind. It is anticipated that this could be overcome with higher precision manufacturing. In addition to symmetric actuation of the morphing trusses resulting in diameter change, the paper also shows that with asymmetric actuation the hull cross-section shape can be changed (for example, from a circular section for underwater operation to a V-section for surface operations).

  6. Morphing hull implementation for unmanned underwater vehicles

    International Nuclear Information System (INIS)

    Miller, Timothy F; Gandhi, Farhan; Rufino, Russell J

    2013-01-01

    There has been much interest and work in the area of morphing aircraft since the 1980s. Morphing could also potentially benefit unmanned underwater vehicles (UUVs). The current paper envisions a UUV with an interior pressure hull and a variable diameter outer flexible hull with fuel stored in the annulus between, and presents a mechanism to realize diameter change of the outer hull. The outer hull diameter of UUVs designed for very long endurance/range could be progressively reduced as fuel was consumed, thereby reducing drag and further increasing endurance and range capability. Diameter morphing could also be advantageous for compact storage of UUVs. A prototype is fabricated to represent an axial section of such a morphing diameter UUV. Diameter change is achieved using eight morphing trusses arranged equidistant around the circumference of the representative interior rigid hull. Each morphing truss has a lower rail (attached to the rigid hull) and an upper rail with V-linkages between, at either ends of the rail. Horizontal motion of the feet of the V-linkages (sliding in the lower rail) results in vertical motion of the upper rail which in turn produces diameter change of the outer hull. For the prototype built and tested, a 63% increase in outer diameter from 12.75″ to 20.75″ was achieved. The introduction of a stretched latex representative flexible skin around the outer rails increased actuation force requirement and led to a propensity for the wheel-in-track sliders in the morphing truss to bind. It is anticipated that this could be overcome with higher precision manufacturing. In addition to symmetric actuation of the morphing trusses resulting in diameter change, the paper also shows that with asymmetric actuation the hull cross-section shape can be changed (for example, from a circular section for underwater operation to a V-section for surface operations). (paper)

  7. Lake Roosevelt Fisheries Monitoring Progam; Thyroid-Induced Chemical Imprinting in Early Life Stages and Assessment of Smoltification in Kokanee Salmon Implications for Operating Lake Roosevelt Kokanee Salmon Hatcheries; 1993 Supplement Report.

    Energy Technology Data Exchange (ETDEWEB)

    Tilson, Mary Beth; Galloway, Heather; Scholz, Allan T. (Eastern Washington University, Upper Columbia United Tribes Fisheries Research Center, Cheney, WA)

    1994-06-01

    In 1991, two hatcheries were built to provide a kokanee salmon and rainbow trout fishery for Lake Roosevelt as partial mitigation for the loss of anadromous salmon and steelhead caused by construction of Grand Coulee Dam. The Sherman Creek Hatchery, located on a tributary of Lake Roosevelt to provide an egg collection and imprinting site, is small with limited rearing capability. The second hatchery was located on the Spokane Indian Reservation because of a spring water source that supplied cold, pure water for incubating and rearing eggs.`The Spokane Tribal Hatchery thus serves as the production facility. Fish reared there are released into Sherman Creek and other tributary streams as 7-9 month old fry. However, to date, returns of adult fish to release sites has been poor. If hatchery reared kokanee imprint to the hatchery water at egg or swim up stages before 3 months of age, they may not be imprinting as 7-9 month old fry at the time of stocking. In addition, if these fish undergo a smolt phase in the reservoir when they are 1.5 years old, they could migrate below Grand Coulee Dam and out of the Lake Roosevelt system. In the present investigation, which is part of the Lake Roosevelt monitoring program to assess hatchery effectiveness, kokanee salmon were tested to determine if they experienced thyroxine-induced chemical imprinting and smoltification similar to anadromous salmonids. Determination of the critical period for olfactory imprinting was determined by exposing kokanee to different synthetic chemicals (morpholine or phenethyl alcohol) at different life stages, and then measuring the ability to discriminate the chemicals as sexually mature adults. Whole body thyroxine content and blood plasma thyroxine concentration was measured to determine if peak thyroid activity coincided with imprinting or other morphological, physiological or behavioral transitions associated with smoltification.

  8. Review of potential impacts to sea turtles from underwater explosive removal of offshore structures

    International Nuclear Information System (INIS)

    Viada, Stephen T.; Hammer, Richard M.; Racca, Roberto; Hannay, David; Thompson, M. John; Balcom, Brian J.; Phillips, Neal W.

    2008-01-01

    The purpose of this study was to collect and synthesize existing information relevant to the explosive removal of offshore structures (EROS) in aquatic environments. Data sources were organized and summarized by topic - explosive removal methods, physics of underwater explosions, sea turtle resources, documented impacts to sea turtles, and mitigation of effects. Information was gathered via electronic database searches and literature source review. Bulk explosive charges are the most commonly used technique in EROS. While the physical principles of underwater detonations and the propagation of pressure and acoustic waves are well understood, there are significant gaps in the application of this knowledge. Impacts to sea turtles from explosive removal operations may range from non-injurious effects (e.g. acoustic annoyance; mild tactile detection or physical discomfort) to varying levels of injury (i.e. non-lethal and lethal injuries). Very little information exists regarding the impacts of underwater explosions on sea turtles. Effects of explosions on turtles often must be inferred from documented effects to other vertebrates with lungs or other gas-containing organs, such as mammals and most fishes. However, a cautious approach should be used when determining impacts to sea turtles based on extrapolations from other vertebrates. The discovery of beached sea turtles and bottlenose dolphins following an explosive platform removal event in 1986 prompted the initiation of formal consultation between the U.S. Department of the Interior, Minerals Management Service (MMS) and the National Marine Fisheries Service (NMFS), authorized through the Endangered Species Act Section 7, to determine a mechanism to minimize potential impacts to listed species. The initial consultation resulted in a requirement for oil and gas companies to obtain a permit (through separate consultations on a case-by-case basis) prior to using explosives in Federal waters. Because many offshore

  9. Event localization in underwater wireless sensor networks using Monitoring Courses

    KAUST Repository

    Debont, Matthew John Robert; Jamshaid, Kamran; Shihada, Basem; Ho, Pin-Han

    2012-01-01

    We propose m-courses (Monitoring Courses), a novel solution to localize events in an underwater wireless sensor network. These networks consists of surface gateways and relay nodes. GPS can localize the position of surface gateways which can

  10. UTOFIA: an underwater time-of-flight image acquisition system

    Science.gov (United States)

    Driewer, Adrian; Abrosimov, Igor; Alexander, Jonathan; Benger, Marc; O'Farrell, Marion; Haugholt, Karl Henrik; Softley, Chris; Thielemann, Jens T.; Thorstensen, Jostein; Yates, Chris

    2017-10-01

    In this article the development of a newly designed Time-of-Flight (ToF) image sensor for underwater applications is described. The sensor is developed as part of the project UTOFIA (underwater time-of-flight image acquisition) funded by the EU within the Horizon 2020 framework. This project aims to develop a camera based on range gating that extends the visible range compared to conventional cameras by a factor of 2 to 3 and delivers real-time range information by means of a 3D video stream. The principle of underwater range gating as well as the concept of the image sensor are presented. Based on measurements on a test image sensor a pixel structure that suits best to the requirements has been selected. Within an extensive characterization underwater the capability of distance measurements in turbid environments is demonstrated.

  11. Digital sonar design in underwater acoustics principles and applications

    CERN Document Server

    Li, Qihu

    2012-01-01

    "Digital Sonar Design in Underwater Acoustics Principles and Applications" provides comprehensive and up-to-date coverage of research on sonar design, including the basic theory and techniques of digital signal processing, basic concept of information theory, ocean acoustics, underwater acoustic signal propagation theory, and underwater signal processing theory. This book discusses the general design procedure and approaches to implementation, the design method, system simulation theory and techniques, sonar tests in the laboratory, lake and sea, and practical validation criteria and methods for digital sonar design. It is intended for researchers in the fields of underwater signal processing and sonar design, and also for navy officers and ocean explorers. Qihu Li is a professor at the Institute of Acoustics, Chinese Academy of Sciences, and an academician of the Chinese Academy of Sciences.

  12. Trade-off Analysis of Underwater Acoustic Sensor Networks

    Science.gov (United States)

    Tuna, G.; Das, R.

    2017-09-01

    In the last couple of decades, Underwater Acoustic Sensor Networks (UASNs) were started to be used for various commercial and non-commercial purposes. However, in underwater environments, there are some specific inherent constraints, such as high bit error rate, variable and large propagation delay, limited bandwidth capacity, and short-range communications, which severely degrade the performance of UASNs and limit the lifetime of underwater sensor nodes as well. Therefore, proving reliability of UASN applications poses a challenge. In this study, we try to balance energy consumption of underwater acoustic sensor networks and minimize end-to-end delay using an efficient node placement strategy. Our simulation results reveal that if the number of hops is reduced, energy consumption can be reduced. However, this increases end-to-end delay. Hence, application-specific requirements must be taken into consideration when determining a strategy for node deployment.

  13. Localization of Energy Harvesting Empowered Underwater Optical Wireless Sensor Networks

    KAUST Repository

    Saeed, Nasir; Celik, Abdulkadir; Al-Naffouri, Tareq Y.; Alouini, Mohamed-Slim

    2017-01-01

    with insufficient battery, harvest the energy and starts communicating once it has sufficient energy storage. Network localization is carried out by measuring the RSSs of active nodes, which are modeled based on the underwater optical communication channel

  14. Wireless Underwater Monitoring Systems Based on Energy Harvestings

    Directory of Open Access Journals (Sweden)

    Sea-Hee HWANGBO

    2013-01-01

    Full Text Available One of the important research fields for aquatic exploitation and conservation is underwater wireless sensor network. Since limited energy source for underwater nodes and devices is a main open problem, in this paper, we propose wireless underwater monitoring systems powered by energy harvester which resolves the energy constraint. The target system generates renewable energy from energy harvester and shares the energy with underwater sensor nodes. For the realization of the system, key components to be investigated are discriminated as follows: acoustic modem, actuator, smart battery charge controller, energy harvester and wireless power transfer module. By developing acoustic modem, actuator and smart battery charge controller and utilizing off-the-shelf energy harvester and wireless power transfer module, we design and implement a prototype of the system. Also, we verify the feasibility of concept of target system by conducting indoor and outdoor experiments.

  15. Underwater target positioning with a single acoustic sensor

    Digital Repository Service at National Institute of Oceanography (India)

    David, M-S; Pascoal, A.M.; Joaquin, A.

    The availability of reliable underwater positioning systems to localize one or more vehicles simultaneously based on information received on-board a support ship or an autonomous surface vessel is key to the operation of some classes of AUVs...

  16. Filming Underwater in 3d Respecting Stereographic Rules

    Science.gov (United States)

    Rinaldi, R.; Hordosch, H.

    2015-04-01

    After an experimental phase of many years, 3D filming is now effective and successful. Improvements are still possible, but the film industry achieved memorable success on 3D movie's box offices due to the overall quality of its products. Special environments such as space ("Gravity") and the underwater realm look perfect to be reproduced in 3D. "Filming in space" was possible in "Gravity" using special effects and computer graphic. The underwater realm is still difficult to be handled. Underwater filming in 3D was not that easy and effective as filming in 2D, since not long ago. After almost 3 years of research, a French, Austrian and Italian team realized a perfect tool to film underwater, in 3D, without any constrains. This allows filmmakers to bring the audience deep inside an environment where they most probably will never have the chance to be.

  17. FILMING UNDERWATER IN 3D RESPECTING STEREOGRAPHIC RULES

    Directory of Open Access Journals (Sweden)

    R. Rinaldi

    2015-04-01

    Full Text Available After an experimental phase of many years, 3D filming is now effective and successful. Improvements are still possible, but the film industry achieved memorable success on 3D movie’s box offices due to the overall quality of its products. Special environments such as space ("Gravity" and the underwater realm look perfect to be reproduced in 3D. "Filming in space" was possible in "Gravity" using special effects and computer graphic. The underwater realm is still difficult to be handled. Underwater filming in 3D was not that easy and effective as filming in 2D, since not long ago. After almost 3 years of research, a French, Austrian and Italian team realized a perfect tool to film underwater, in 3D, without any constrains. This allows filmmakers to bring the audience deep inside an environment where they most probably will never have the chance to be.

  18. Multi-layer protective armour for underwater shock wave mitigation

    Directory of Open Access Journals (Sweden)

    Ahmed Hawass

    2015-12-01

    The strain gauge data and displacement sensors results showed that the multi-layer plates have higher level of underwater shock wave mitigation than the triple aluminum plates with strain and deflection of nearly 50%.

  19. Euclidean reconstruction of natural underwater scenes using optic imagery sequence

    Science.gov (United States)

    Hu, Han

    The development of maritime applications require monitoring, studying and preserving of detailed and close observation on the underwater seafloor and objects. Stereo vision offers advanced technologies to build 3D models from 2D still overlapping optic images in a relatively inexpensive way. However, while image stereo matching is a necessary step in 3D reconstruction procedure, even the most robust dense matching techniques are not guaranteed to work for underwater images due to the challenging aquatic environment. In this thesis, in addition to a detailed introduction and research on the key components of building 3D models from optic images, a robust modified quasi-dense matching algorithm based on correspondence propagation and adaptive least square matching for underwater images is proposed and applied to some typical underwater image datasets. The experiments demonstrate the robustness and good performance of the proposed matching approach.

  20. Object detection from images obtained through underwater turbulence medium

    Science.gov (United States)

    Furhad, Md. Hasan; Tahtali, Murat; Lambert, Andrew

    2017-09-01

    Imaging through underwater experiences severe distortions due to random fluctuations of temperature and salinity in water, which produces underwater turbulence through diffraction limited blur. Lights reflecting from objects perturb and attenuate contrast, making the recognition of objects of interest difficult. Thus, the information available for detecting underwater objects of interest becomes a challenging task as they have inherent confusion among the background, foreground and other image properties. In this paper, a saliency-based approach is proposed to detect the objects acquired through an underwater turbulent medium. This approach has drawn attention among a wide range of computer vision applications, such as image retrieval, artificial intelligence, neuro-imaging and object detection. The image is first processed through a deblurring filter. Next, a saliency technique is used on the image for object detection. In this step, a saliency map that highlights the target regions is generated and then a graph-based model is proposed to extract these target regions for object detection.

  1. Economic Valuation of European Commercial Fisheries under Good Environmental Status

    DEFF Research Database (Denmark)

    Goulding, Ian; Hutniczak, Barbara; Münch, Angela

    2012-01-01

    This paper focuses on assessing the economic impact of achieving Good Environmental Status in the EU’s commercial capture fisheries, being one of the descriptors listed under the MSFD in terms of landed value using 2010 prices. The approach adopted is to assess the values of landings under...... different environmental scenarios, and use the differences between them to highlight the economic impacts of each....

  2. A review of techniques for the identification and measurement of fish in underwater stereo-video image sequences

    Science.gov (United States)

    Shortis, Mark R.; Ravanbakskh, Mehdi; Shaifat, Faisal; Harvey, Euan S.; Mian, Ajmal; Seager, James W.; Culverhouse, Philip F.; Cline, Danelle E.; Edgington, Duane R.

    2013-04-01

    Underwater stereo-video measurement systems are used widely for counting and measuring fish in aquaculture, fisheries and conservation management. To determine population counts, spatial or temporal frequencies, and age or weight distributions, snout to fork length measurements are captured from the video sequences, most commonly using a point and click process by a human operator. Current research aims to automate the measurement and counting task in order to improve the efficiency of the process and expand the use of stereo-video systems within marine science. A fully automated process will require the detection and identification of candidates for measurement, followed by the snout to fork length measurement, as well as the counting and tracking of fish. This paper presents a review of the techniques used for the detection, identification, measurement, counting and tracking of fish in underwater stereo-video image sequences, including consideration of the changing body shape. The review will analyse the most commonly used approaches, leading to an evaluation of the techniques most likely to be a general solution to the complete process of detection, identification, measurement, counting and tracking.

  3. TurtleCam: A “Smart” Autonomous Underwater Vehicle for Investigating Behaviors and Habitats of Sea Turtles

    Directory of Open Access Journals (Sweden)

    Kara L. Dodge

    2018-03-01

    Full Text Available Sea turtles inhabiting coastal environments routinely encounter anthropogenic hazards, including fisheries, vessel traffic, pollution, dredging, and drilling. To support mitigation of potential threats, it is important to understand fine-scale sea turtle behaviors in a variety of habitats. Recent advancements in autonomous underwater vehicles (AUVs now make it possible to directly observe and study the subsurface behaviors and habitats of marine megafauna, including sea turtles. Here, we describe a “smart” AUV capability developed to study free-swimming marine animals, and demonstrate the utility of this technology in a pilot study investigating the behaviors and habitat of leatherback turtles (Dermochelys coriacea. We used a Remote Environmental Monitoring UnitS (REMUS-100 AUV, designated “TurtleCam,” that was modified to locate, follow and film tagged turtles for up to 8 h while simultaneously collecting environmental data. The TurtleCam system consists of a 100-m depth rated vehicle outfitted with a circular Ultra-Short BaseLine receiver array for omni-directional tracking of a tagged animal via a custom transponder tag that we attached to the turtle with two suction cups. The AUV collects video with six high-definition cameras (five mounted in the vehicle nose and one mounted aft and we added a camera to the animal-borne transponder tag to record behavior from the turtle's perspective. Since behavior is likely a response to habitat factors, we collected concurrent in situ oceanographic data (bathymetry, temperature, salinity, chlorophyll-a, turbidity, currents along the turtle's track. We tested the TurtleCam system during 2016 and 2017 in a densely populated coastal region off Cape Cod, Massachusetts, USA, where foraging leatherbacks overlap with fixed fishing gear and concentrated commercial and recreational vessel traffic. Here we present example data from one leatherback turtle to demonstrate the utility of TurtleCam. The

  4. Multi-layer protective armour for underwater shock wave mitigation

    OpenAIRE

    Ahmed Hawass; Hosam Mostafa; Ahmed Elbeih

    2015-01-01

    The effect of underwater shock wave on different target plates has been studied. An underwater shock wave generator (shock tube) was used to study the interactions between water and different constructed targets which act as shock wave mitigation. Target plates, composed of sandwich of two aluminum sheets with rubber and foam in between, were prepared and studied. For comparison, the target plates composed of triple aluminum sheets were tested. The study includes the testing of the selected p...

  5. FILMING UNDERWATER IN 3D RESPECTING STEREOGRAPHIC RULES

    OpenAIRE

    R. Rinaldi; H. Hordosch

    2015-01-01

    After an experimental phase of many years, 3D filming is now effective and successful. Improvements are still possible, but the film industry achieved memorable success on 3D movie’s box offices due to the overall quality of its products. Special environments such as space ("Gravity") and the underwater realm look perfect to be reproduced in 3D. "Filming in space" was possible in "Gravity" using special effects and computer graphic. The underwater realm is still difficult to be handled. Under...

  6. Remote Underwater Characterization System - Innovative Technology Summary Report

    International Nuclear Information System (INIS)

    Willis, Walter David

    1999-01-01

    Characterization and inspection of water-cooled and moderated nuclear reactors and fuel storage pools requires equipment capable of operating underwater. Similarly, the deactivation and decommissioning of older nuclear facilities often requires the facility owner to accurately characterize underwater structures and equipment which may have been sitting idle for years. The underwater characterization equipment is often required to operate at depths exceeding 20 ft (6.1 m) and in relatively confined or congested spaces. The typical baseline approach has been the use of radiation detectors and underwater cameras mounted on long poles, or stationary cameras with pan and tilt features mounted on the sides of the underwater facility. There is a perceived need for an inexpensive, more mobile method of performing close-up inspection and radiation measurements in confined spaces underwater. The Remote Underwater Characterization System (RUCS) is a small, remotely operated submersible vehicle intended to serve multiple purposes in underwater nuclear operations. It is based on the commercially-available ''Scallop'' vehicle, but has been modified by Department of Energy's Robotics Technology Development Program to add auto-depth control, and vehicle orientation and depth monitoring at the operator control panel. The RUCS is designed to provide visual and gamma radiation characterization, even in confined or limited access areas. It was demonstrated in August 1998 at Idaho National Engineering and environmental Laboratory (INEEL) as part of the INEEL Large Scale Demonstration and Deployment Project. During the demonstration it was compared in a ''head-to-head'' fashion with the baseline characterization technology. This paper summarizes the results of the demonstration and lessons learned; comparing and contrasting both technologies in the areas of cost, visual characterization, radiological characterization, and overall operations

  7. Strong tracking adaptive Kalman filters for underwater vehicle dead reckoning

    Institute of Scientific and Technical Information of China (English)

    XIAO Kun; FANG Shao-ji; PANG Yong-jie

    2007-01-01

    To improve underwater vehicle dead reckoning, a developed strong tracking adaptive kalman filter is proposed. The filter is improved with an additional adaptive factor and an estimator of measurement noise covariance. Since the magnitude of fading factor is changed adaptively, the tracking ability of the filter is still enhanced in low velocity condition of underwater vehicles. The results of simulation tests prove the presented filter effective.

  8. On the Performance of the Underwater Acoustic Sensor Networks

    Science.gov (United States)

    2015-05-01

    performance of UWSN. 5.1 Hardware and Software Details 5.1.1 Equipment Our experimental model consisted of an indoor swimming pool , two pairs...UWSN has many constraints mainly due to limited capacity, propagation loss, as well as power limitation since in underwater environment solar energy ...since in underwater environment solar energy cannot be used to recharge batteries. In our approach, we estimate the number of operating receivers

  9. The Theseus Autonomous Underwater Vehicle: A Canadian Success Story

    Science.gov (United States)

    1997-04-01

    P502414.PDF [Page: 1 of 9] P502414.PDF [Page: 2 of 9] P502414.PDF [Page: 3 of 9] The Theseus Autonomous Underwater Vehicle A Canadian Success Story...autonomous underwater vehicle, named Theseus , for laying optical fiber cables in ice- covered waters. In trials and missions conducted in 1996, this...stations. An acoustic telemetry system enables communication with Theseus from surface stations, and an optical telemetry system is used for system

  10. Monterey Bay ambient noise profiles using underwater gliders

    OpenAIRE

    Chandrayadula, Tarun K.; Miller, Chris W.; Joseph, John

    2013-01-01

    The article of record as published may be found at http://dx.doi.org/10.1121/1.4799131 In 2012, during two separate week-long deployments, underwater gliders outfitted with external hydrophones profiled the upper 100-200 m of the Monterey Bay. The environment contained various noises made by marine mammals, ships, winds, and earthquakes. Unlike hydrophone receivers moored to a fixed location, moving gliders measure noise variability across a wide terrain. However, underwater mobile s...

  11. Deep Learning Methods for Underwater Target Feature Extraction and Recognition

    Directory of Open Access Journals (Sweden)

    Gang Hu

    2018-01-01

    Full Text Available The classification and recognition technology of underwater acoustic signal were always an important research content in the field of underwater acoustic signal processing. Currently, wavelet transform, Hilbert-Huang transform, and Mel frequency cepstral coefficients are used as a method of underwater acoustic signal feature extraction. In this paper, a method for feature extraction and identification of underwater noise data based on CNN and ELM is proposed. An automatic feature extraction method of underwater acoustic signals is proposed using depth convolution network. An underwater target recognition classifier is based on extreme learning machine. Although convolution neural networks can execute both feature extraction and classification, their function mainly relies on a full connection layer, which is trained by gradient descent-based; the generalization ability is limited and suboptimal, so an extreme learning machine (ELM was used in classification stage. Firstly, CNN learns deep and robust features, followed by the removing of the fully connected layers. Then ELM fed with the CNN features is used as the classifier to conduct an excellent classification. Experiments on the actual data set of civil ships obtained 93.04% recognition rate; compared to the traditional Mel frequency cepstral coefficients and Hilbert-Huang feature, recognition rate greatly improved.

  12. Optimal Node Placement in Underwater Acoustic Sensor Network

    KAUST Repository

    Felemban, Muhamad

    2011-10-01

    Almost 70% of planet Earth is covered by water. A large percentage of underwater environment is unexplored. In the past two decades, there has been an increase in the interest of exploring and monitoring underwater life among scientists and in industry. Underwater operations are extremely difficult due to the lack of cheap and efficient means. Recently, Wireless Sensor Networks have been introduced in underwater environment applications. However, underwater communication via acoustic waves is subject to several performance limitations, which makes the relevant research issues very different from those on land. In this thesis, we investigate node placement for building an initial Underwater Wireless Sensor Network infrastructure. Firstly, we formulated the problem into a nonlinear mathematic program with objectives of minimizing the total transmission loss under a given number of sensor nodes and targeted volume. We conducted experiments to verify the proposed formulation, which is solved using Matlab optimization tool. We represented each node with a truncated octahedron to fill out the 3D space. The truncated octahedrons are tiled in the 3D space with each node in the center where locations of the nodes are given using 3D coordinates. Results are supported using ns-3 simulator. Results from simulation are consistent with the obtained results from mathematical model with less than 10% error.

  13. Cardiovascular response during submaximal underwater treadmill exercise in stroke patients.

    Science.gov (United States)

    Yoo, Jeehyun; Lim, Kil-Byung; Lee, Hong-Jae; Kwon, Yong-Geol

    2014-10-01

    To evaluate the cardiovascular response during head-out water immersion, underwater treadmill gait, and land treadmill gait in stroke patients. Ten stroke patients were recruited for underwater and land treadmill gait sessions. Each session was 40 minutes long; 5 minutes for standing rest on land, 5 minutes for standing rest in water or on treadmill, 20 minutes for treadmill walking in water or on land, 5 minutes for standing rest in water or on treadmill, and 5 minutes for standing rest on land. Blood pressure (BP) and heart rate (HR) were measured during each session. In order to estimate the cardiovascular workload and myocardial oxygen demand, the rate pressure product (RPP) value was calculated by multiplying systolic BP (SBP) by HR. SBP, DBP, mean BP (mBP), and RPP decreased significantly after water immersion, but HR was unchanged. During underwater and land treadmill gait, SBP, mBP, DBP, RPP, and HR increased. However, the mean maximum increases in BP, HR and RPP of underwater treadmill walking were significantly lower than that of land treadmill walking. Stroke patients showed different cardiovascular responses during water immersion and underwater gait as opposed to standing and treadmill-walking on land. Water immersion and aquatic treadmill gait may reduce the workload of the cardiovascular system. This study suggested that underwater treadmill may be a safe and useful option for cardiovascular fitness and early ambulation in stroke rehabilitation.

  14. Cooperation between scientists, NGOs and industry in support of sustainable fisheries: the South African hake Merluccius spp. trawl fishery experience.

    Science.gov (United States)

    Field, J G; Attwood, C G; Jarre, A; Sink, K; Atkinson, L J; Petersen, S

    2013-10-01

    This paper examines the increasingly close interaction between natural and social scientists, non-governmental organizations (NGO) and industry, in pursuit of responsible ecosystem-based management of fisheries. South Africa has committed to implementing an ecosystem approach to fisheries management. Management advice stems from multi-stakeholder representation on government-led scientific and management working groups. In the hake Merluccius capensis and Merluccius paradoxus fishery, the primary management measure is an annual total allowable catch (TAC), the level of which is calculated using a management procedure (MP) that is revised approximately every 4 years. Revision of the MP is a consultative process involving most stakeholders, and is based on simulation modelling of projected probable scenarios of resource and fishery dynamics under various management options. NGOs, such as the Worldwide Fund for Nature in South Africa (WWF-SA), have played an important role in influencing consumers, the fishing industry and government to develop responsible fishing practices that minimize damage to marine ecosystems. Cooperation between industry, government and scientists has helped to improve sustainability and facilitated the meeting of market-based incentives for more responsible fisheries. Research includes ecosystem modelling, spatial analysis and ecosystem risk assessment with increasing research focus on social and economic aspects of the fishery. A four-year cooperative experiment to quantify the effect of trawling on benthic community structure is being planned. The food requirements of top predators still need to be included in the TAC-setting formulae and more social and economic research is needed. This paper also demonstrates how NGO initiatives such as Marine Stewardship Council certification and the Southern African Sustainable Seafood Initiative, a traffic light system of classifying seafood for consumers, have contributed to responsible fishing

  15. Management of complex fisheries

    DEFF Research Database (Denmark)

    Frost, Hans Staby; Andersen, Peder; Hoff, Ayoe

    2013-01-01

    , including taking into account the response of the fishermen to implemented management measures. To demonstrate the use of complex management models this paper assesses a number of second best management schemes against a first rank optimum (FRO), an ideal individual transferable quotas (ITQ) system...

  16. Technological development in fisheries management

    DEFF Research Database (Denmark)

    Eigaard, Ole Ritzau; Marchal, Paul; Gislason, Henrik

    2014-01-01

    Many marine fish stocks are overexploited and considerable overcapacity exists in fishing fleets worldwide. One of the reasons for the imbalance between resource availability and fishing capacity is technological development, which continuously increases the efficiency of the vessels—a mechanism...... referred to as “technological creep.” We review how the introduction of new and more efficient electronic equipment, gear design, engines, deck equipment, and catch-handling procedures influences the capture efficiency (catchability) of commercial fishing vessels. On average, we estimate that catchability...... increases by 3.2% per year due to technological developments, an increase often ignored in fisheries management. The documentation and quantification of technological creep improves the basis for successfully integrating the effects of technological development (and catchability changes) in fisheries...

  17. Feasibility of underwater welding of highly irradiated in-vessel components of boiling-water reactors: A literature review

    International Nuclear Information System (INIS)

    Lund, A.L.

    1997-11-01

    In February 1997, the U.S. Nuclear Regulatory Commission (NRC), Office of Nuclear Regulatory Research (RES), initiated a literature review to assess the state of underwater welding technology. In particular, the objective of this literature review was to evaluate the viability of underwater welding in-vessel components of boiling water reactor (BWR) in-vessel components, especially those components fabricated from stainless steels that are subjected to high neutron fluences. This assessment was requested because of the recent increased level of activity in the commercial nuclear industry to address generic issues concerning the reactor vessel and internals, especially those issues related to repair options. This literature review revealed a preponderance of general information about underwater welding technology, as a result of the active research in this field sponsored by the U.S. Navy and offshore oil and gas industry concerns. However, the literature search yielded only a limited amount of information about underwater welding of components in low-fluence areas of BWR in-vessel environments, and no information at all concerning underwater welding experiences in high-fluence environments. Research reported by the staff of the U.S. Department of Energy (DOE) Savannah River Site and researchers from the DOE fusion reactor program proved more fruitful. This research documented relevant experience concerning welding of stainless steel materials in air environments exposed to high neutron fluences. It also addressed problems with welding highly irradiated materials, and primarily attributed those problems to helium-induced cracking in the material. (Helium is produced from the neutron irradiation of boron, an impurity, and nickel.) The researchers found that the amount of helium-induced cracking could be controlled, or even eliminated, by reducing the heat input into the weld and applying a compressive stress perpendicular to the weld path

  18. Yakima fisheries project. Revised draft environmental impact statement

    International Nuclear Information System (INIS)

    1995-05-01

    BPA proposes to fund several fishery-related activities in the Yakima River Basin. These activities, known as the Yakima Fisheries Project (YFP), would be jointly managed by the State of Washington and the Yakima Indian Nation. The YFP is included in the Northwest Power Planning Council's (Council's) fish and wildlife program. The Council selected the Yakima River system for attention because fisheries resources are severely reduced from historical levels and because there is a significant potential for enhancement of these resources. BPA's proposed action is to fund (1) information gathering on the implementation of supplementation techniques and on feasibility of reintroducing coho salmon in an environment where native populations have become extinct; (2) research activities based on continuous assessment, feedback and improvement of research design and activities (adaptive management); and (3) the construction, operation, and maintenance of facilities for supplementing populations of upper Yakima spring chinook salmon. Major issues examined in the Revised Draft EIS include potential impacts of the project on genetic and ecological resources of existing fish populations, on water quality and quantity, on threatened and endangered species listed under the Endangered Species Act, and on the recreational fishery. Only minor differences in environmental consequences were found between Alternatives 1 and 2. Potentially high impacts on wild, native, and non-target fish populations under both alternatives would be mitigated through careful adherence to the adaptive management process outlined in the EIS

  19. 76 FR 57945 - Fisheries Off West Coast States; West Coast Salmon Fisheries; Notice of Availability for...

    Science.gov (United States)

    2011-09-19

    ... Reauthorization Act (MSRA). These guidelines are intended to prevent and end overfishing and rebuild fisheries through implementation of status determination criteria, overfishing limits, annual catch limits, and... end overfishing and rebuild fisheries. In particular, the revised guidelines provide guidance on...

  20. 78 FR 3848 - Fisheries Off West Coast States; Pacific Coast Groundfish Fishery; Trawl Rationalization Program...

    Science.gov (United States)

    2013-01-17

    ... Rationalization Program; Emergency Rule Extension AGENCY: National Marine Fisheries Service (NMFS), National... Coast Groundfish Fishery Trawl Rationalization Program (program) regulations. This emergency rule... trawl rationalization program. Background on this rule was provided in the proposed rule, published on...