Norges fiskerihøgskole: Nye registreringer
Viser treff 1041-1060 av 1751
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Size selection of Nephrops norvegicus (L.) in commercial creel fishery in the Mediterranean Sea
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-12-23)In the Mediterranean Sea <i>Nephrops</i> (<i>Nephrops norvegicus</i>) is predominantly caught with bottom trawls, but it is also harvested with creels. While the size selection of <i>Nephrops</i> in bottom trawls is well documented, there is no previous information on creel size selection for this species. Therefore, sea trials were carried out to assess the selective properties of commercial creels ... -
Comparison of fishing efficiency between biodegradable PBSAT gillnets and conventional nylon (PA) gillnets
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-01-19)Gillnets made of a new biodegradable resin (polybutylene succinate co-adipate-co-terephthalate (PBSAT) were tested under commercial fishing conditions to compare their fishing performance with that of conventional nylon (PA) nets. The relative catch efficiency between the two gillnet 15 types was evaluated over the entire winter fishing season for cod (<i>Gadus morhua</i>) in northern Norway. The ... -
Size selectivity and length-dependent escape behaviour of haddock in a sorting device combining a grid and a square mesh panel
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-10-04)Size selectivity of a new sorting section combining a sorting grid and a square mesh panel was tested for haddock (Melanogrammus aeglefinus) in the Barents Sea demersal trawl fishery. Sampling data for a wide size range enabled investigating the selection process for this species in detail, both for the grid and the square mesh panel. Contrary to earlier studies modelling size selectivity for grids ... -
A case of vertebral coalescence and lateral line deformity in Hypophthalamichthys nobilis (Richardson, 1844) obtained from aquaculture activity in Iran
(Journal article; Tidsskriftartikkel, 2011-10-31)Vertebral coalescence and malformation in the lateral line are reported in a specimen of cultured cyprinid fish <i>Hypophthalamichthys nobilis </i>. Severe vertebral fusion was observed and described. Lateral line showed unusual undulation in the trunk region. Genetic and epigenetic causes may be implicated in these anomalies. -
Hundreds of species observations and four ascomycetes new to Norway during a mycology field course
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018)During a mycology field course in Drøbak 29th August – 2nd September 2011 several interesting and some new taxa to Norway were found. Species not previously recorded in Norway include <i>Tatraea dumbirensis, Corollospora maritima, Nectriopsis candicans</i> and <i>Ombrophila juniperinella</i>. A list of 413 taxa, including records of three threatened species, is given and the ecology and distribution ... -
Fishing efficiency of biodegradable PBSAT gillnets and conventional nylon gillnets used in Norwegian cod (Gadus morhua) and saithe (Pollachius virens) fisheries
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-09-10)Fishing trials were carried out to compare the relative fishing efficiency of gillnets made of a new biodegradable resin (polybutylene succinate co-adipate-co-terephthalate, PBSAT) with conventional (nylon) nets. The fishing trials covered two consecutive fishing seasons (2016 and 2017) for cod (<i>Gadus morhua</i>) and saithe (<i>Pollachius virens</i>) in northern Norway. Results generally showed ... -
Policy context as a factor of bias in the valuation of environmental goods – a dual-process theories perspective
(Journal article; Tidsskriftartikkel, 2018-03-13)When ecosystem services value estimates are applied in the economic assessment of environmental policies, high accuracy of these estimates is required. One of the directions in the scientific discussion on biases in stated preference (SP) valuation surveys builds on dual-process theories of judgment. The paper contributes to this literature by presenting an experiment where two types of judgment ... -
Opportunity Cost of Environmental Conservation in the Presence of Externalities: Application to the Farmed and Wild Salmon Trade-Off in Norway
(Journal article; Tidsskriftartikkel, 2018-08-17)Estimation of the opportunity cost is necessary for the economic assessment of environmental conservation policies. This paper considers the case where an environmental good is negatively affected in the process of the production of marketable goods. In the presence of externalities, conservation implies the undertaking of abatement measures by polluters. A relevant measure of opportunity cost in ... -
The demands they are a-changin'
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-03-15)Smooth operators such as time trends are often applied to deal with unidentified demand shifters. However, if unknown factors affect demand irregularly, a time trend fails to capture the variation. We present an index approach for estimating irregular demand shifts, decomposing total demand shifts into predicted and unexplained effects. This allows separating demand shifts caused by known factors ... -
Paralithocins, Antimicrobial Peptides with Unusual Disulfide Connectivity from the Red King Crab, Paralithodes camtschaticus
(Journal article; Tidsskriftartikkel, 2018-01-17)As part of an ongoing exploration of marine invertebrates as a source of new antimicrobial peptides, hemocyte extracts from the red king crab, <i>Paralithodes camtschaticus</i>, were studied. Three cationic cysteine (Cys)-rich peptides, named paralithocins 1–3, were isolated by bioassay-guided purification, and their amino acid sequences determined by Edman degradation and expressed sequences tag ... -
Using Machine Learning to Uncover Latent Research Topics in Fishery Models
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-01-16)Modeling has become the most commonly used method in fisheries science, with numerous types of models and approaches available today. The large variety of models and the overwhelming amount of scientific literature published yearly can make it difficult to effectively access and use the output of fisheries modeling publications. In particular, the underlying topic of an article cannot always be ... -
Could green artificial light reduce bycatch during Barents Sea Deep-water shrimp trawling?
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-03-31)The Nordmøre grid is widely used in shrimp trawls to reduce the bycatch of fish species. However, small-sized fish species and juveniles still pass through the grid and enter the codend, along with the targeted shrimp. This bycatch of small fish has a negative impact on the ecosystem due to increased fish mortality, and leads to additional sorting work onboard. Some small-sized fish that enter the ... -
3-Chloro-N′-(2-hydroxybenzylidene) benzohydrazide: An LSD1-Selective Inhibitor and Iron-Chelating Agent for Anticancer Therapy
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-09-07)Despite the discovery and development of novel therapies, cancer is still a leading cause of death worldwide. In order to grow, tumor cells require large quantities of nutrients involved in metabolic processes, and an increase in iron levels is known to contribute to cancer proliferation. Iron plays an important role in the active site of a number of proteins involved in energy metabolism, DNA ... -
The effect of Nordmøre grid length and angle on codend entry of bycatch fish species and shrimp catches
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-06-18)The Nordmøre grid is regarded as an efficient bycatch reducing device and is used in various shrimp trawl fisheries globally. However, in some shrimp fisheries bycatch remains a problem that seriously impacts commercial trawl activities. This study tested and compared the performance of two versions of the Nordmøre grid in the Northeast Arctic Deepwater Shrimp (Pandalus borealis) fishery; a standard ... -
Investigating fish behavioural responses to LED lights in trawls and potential applications for bycatch reduction in the Nephrops-directed fishery
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-04-18)Light-emitting diodes (LEDs) have been tested in trawl fisheries to reduce the bycatch of unwanted species through behavioural stimulation. Previous studies used LED lights to either highlight escaping routes or increase the contact rate with square-mesh panels. However, phototactic responses (moving towards or away from light sources) to LED lights could also be exploited to separate species during ... -
CREELSELECT—A method for determining the optimal creel mesh: Case study on Norway lobster (Nephrops norvegicus) fishery in the Mediterranean Sea
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-03-31)In the laboratory, we investigated which sizes of <i>Nephrops</i> (<i>Nephrops norvegicus</i>) could pass through the meshes of different size and shape to establish a predictive model for the creels size selectivity. Predictions agreed well with the results from experimental fishing, demonstrating the reliability of this simple method. <i>Nephrops</i> minimum target size is 20 mm carapace length ... -
The efficiency of sieve-panels for bycatch separation in Nephrops trawls
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-11-11)This study investigated the efficiency of a sieve‐panel concept, intended to separate bycatch species from <i>Nephrops</i> (Norway lobster) in a trawl gear via mechanical and behavioural means. Four different designs of varying panel mesh size or inclination were tested in experimental fishing. For each design, the length‐dependent sieving efficiency, defined as the fraction of <i>Nephrops</i> or ... -
Size selection of cod (Gadus morhua) and haddock (Melanogrammus aeglefinus) in the Northeast Atlantic bottom trawl fishery with a newly developed double steel grid system
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-02-06)In recent years, Norwegian fishermen have reported problems with fish accumulation in front of the mandatory sorting grids (Sort-X, Sort-V, and Flexigrid). These problems are associated with high fish entry rates and low water flow through the grid sections. In this study, we replaced the lifting panel in the original design of a sorting grid section (Sort-V) by another steel grid (“lower grid”) in ... -
Simulated trawling: Exhaustive swimming followed by extreme crowding as contributing reasons to variable fillet quality in trawl-caught Atlantic cod (Gadus morhua)
(Journal article; Tidsskriftartikkel, 2018-07-19)Trawl-caught Atlantic cod (<i>Gadus morhua</i>) often yield high variable fillet quality potentially related to capture stress. To investigate mechanisms involved in causing variable quality, commercial-sized (size 3.5±0.9 kg) Atlantic cod were swum to exhaustion in a large swim tunnel and exposed to extreme crowding (736±50 kg m3) for 0, 1 or 3 hours in an experimental cod-end. Further, fish were ... -
Social-ecological timelines to explore human adaptation to coastal change
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-12-19)Through the construction of a socio-ecological timeline for the Porsanger fjord ecosystem, this article illustrates the different ways in which environmental and social–ecological changes have influenced the adaptations of rural households in coastal Sami communities in Finnmark, north Norway. The main finding is that, although environmental change in the form of seal invasions and dwindling ...