A5072256881- Marine and fisheries research
- Underwater Acoustics Research
- Fish Ecology and Management Studies
- Direction-of-Arrival Estimation Techniques
- Marine Bivalve and Aquaculture Studies
- Indoor and Outdoor Localization Technologies
- Marine animal studies overview
- Satellite Image Processing and Photogrammetry
- Food Industry and Aquatic Biology
- Geological Modeling and Analysis
- 3D Modeling in Geospatial Applications
- Forecasting Techniques and Applications
- Water Quality and Resources Studies
- Identification and Quantification in Food
Norwegian Institute of Marine Research
2015-2024
Acoustics (Norway)
2020-2021
Multi-beam sonar is commonly used in purse seine fishing to visually evaluate school size and biomass. However, quantitative analyses of the across-beam dimensions may provide more accurate estimates volumes. These help fishers improve their fish biomass prior setting a set; assist scientists accurately assess distributions abundances pelagic schooling fishes. Fish-school volumes are evaluated using data from simulated Simrad SX90 sonar. The accuracy dependent on number ensonifying beams,...
Abstract Density-dependent growth, which might influence the effects of fisheries on a population, is often ignored when management strategies are evaluated, mainly due to lack appropriate models readily available be implemented. To improve this, we investigated if somatic growth in Norwegian spring-spawning herring (Clupea harengus) depends cohort density using formulation von Bertalanffy function cohorts from 1921 2014 and found significant negative correlation between estimated asymptotic...
Abstract The influence of density-dependent effects on fish maturity is rarely considered when evaluating different harvest strategies, nor formulating short-term catch advice. In cases where these are included, the spawning stock size commonly used as density variable. However, this approach inadequate for a juvenile and mature individuals have limited interaction. such instances, using abundance recruits cohort variable more appropriate alternative. study, we Norwegian spring-spawning...
Abstract Pelagic fishes are a major source of protein and unsaturated fatty acids, robust management is critical to avoid overfishing. Fisheries often supported by indices from scientific acoustic-trawl surveys, where vertically aligned echo sounders trawl samples used provide an estimate abundance. Survey biases may be introduced when fish located near the sea surface or if they survey vessel. Horizontally scanning acoustic equipment, such as fish-detection sonars, have been proposed method...
Abstract Economic profitability and responsible fisheries are objectives of fishermen managers. In purse seine fisheries, an accurate biomass estimate the targeted school is crucial to accomplish this. For this study, omnidirectional sonar was used individual Norwegian spring spawning herring (Clupea harengus) Atlantic mackerel (Scomber scombrus). A sampling design based on professional skipper’s experience provided detailed information dimensions acoustic backscattering. Using calibrated...
The equivalent beam angle is a key parameter in echo integration, where it assumed that targets are uniformly distributed within the sampling volume of transducer beam. For horizontally oriented sonar, this assumption violated if vertical distribution fish non-uniform throughout sample, potentially causing substantial bias estimates abundance or biomass. This paper investigates magnitude using observations and simulated data, each case limited geographical area estimated.
Two methods for measuring the angular position of a reference target when observed with horizontally transmitting, multi-beam fishery sonar are described. The theory behind realizations both Split-Beam (SB) algorithm and an Interpolated Neighbouring Beam (INB) is described cylindrical transducer array. algorithms were implemented on simulated real data collected during field calibrations. estimated precision was ±0.2 to ±0.25°, within central part beam. reduced targets large inclination...