scholarly journals NAFO Research Vessel Stock-by-Stock Surveys Summary 2000-2010

2013 ◽  
Vol 45 ◽  
pp. 1-91 ◽  
Author(s):  
N A F O Secretariat
Keyword(s):  
Research Vessel

scholarly journals Gadoid dynamics: differing perceptions when contrasting stock vs. population trends and its implications to management

2014 ◽  
Vol 71 (6) ◽  
pp. 1433-1442 ◽  
Author(s):  
Steven J. Holmes ◽  
Colin P. Millar ◽  
Robert J. Fryer ◽  
Peter J. Wright
Keyword(s):  
North Sea ◽  
Stock Assessment ◽  
Research Vessel ◽  
Vital Rates ◽  
The North ◽  
Depth Contour ◽  
Spawning Stock ◽  
Population Structures ◽  
The North Sea ◽  
Local Pressures

Recent research suggests that ICES stock definitions for cod, haddock, and whiting of “west of Scotland” and “North Sea”, do not reflect underlying population structures. As population responses to different vital rates and local pressures would be expected to lead to asynchrony in dynamics, we examined trends in local spawning-stock biomass (SSB) among putative subpopulations of the three species. Delineation of subpopulation boundaries around spawning time was made based on genetic, tagging, and otolith microchemistry studies together with density distributions of species based on research vessel survey data. Subpopulation specific indices of SSB were derived using numbers-at-age and maturity observations from the same research vessel data and asynchrony was assessed by fitting a smoother to log SSB for each subpopulation and testing whether the smooths were parallel. Results for cod support the hypothesis of distinct inshore and larger offshore subpopulations and for whiting for northern and southern North Sea subpopulations with a boundary associated with the 50 m depth contour. In haddock, no difference in SSB trends between the North Sea and west of Scotland was found. For cod and whiting, subpopulation SSB trends differed substantially within current stock assessment units, implying reported stock-based SSB time-series have masked underlying subpopulation trends.

Seabird and dolphin associations: do seabirds benefit from feeding in association with dusky dolphins in Patagonia?

2013 ◽  
Vol 94 (6) ◽  
pp. 1147-1153 ◽  
Author(s):  
Mariana Degrati ◽  
Silvana L. Dans ◽  
Griselda V. Garaffo ◽  
Enrique A. Crespo
Keyword(s):  
Foraging Strategy ◽  
Research Vessel ◽  
Feeding Strategies ◽  
Seabird Species ◽  
Magellanic Penguins ◽  
Dusky Dolphins ◽  
Dusky Dolphin ◽  
Mixed Groups

The objective of this study was to describe associations between several species of seabirds and dusky dolphins. We investigated during what dolphin activities seabirds were most commonly associated, and the size of flock in relation to the number of dolphins in a group. Since both seabirds and dolphins may display different feeding strategies, we also investigated if benefits differed among seabird species. Data were collected in Golfo Nuevo (42°20′S65°00′W) on-board a research vessel between 2001 and 2008. A total of 224 mixed groups of seabirds were encountered during this study. The seabird–dolphin associations were mainly observed during dusky dolphin surface feeding. Shearwaters and kelp gulls were mainly observed in flocks that were associated with dolphins, while Magellanic penguins and cormorants were mainly observed without dolphins. Seabirds may be conditioned to the foraging strategy of dolphins, since birds are associated with dolphins only during dolphin surface feeding. This association probably helped seabirds to find prey, but there were no obvious benefits to dolphins.

scholarly journals Accurate mobile remote sensing of XCO<sub>2</sub> and XCH<sub>4</sub> latitudinal transects from aboard a research vessel

2015 ◽  
Vol 8 (12) ◽  
pp. 5023-5038 ◽  
Author(s):  
F. Klappenbach ◽  
M. Bertleff ◽  
J. Kostinek ◽  
F. Hase ◽  
T. Blumenstock ◽  
...  
Keyword(s):  
Absorption Spectrometry ◽  
Total Carbon ◽  
Research Vessel ◽  
Weather Forecasts ◽  
Technical Developments ◽  
Solar Tracker ◽  
Network Instrument ◽  
Monitoring Service ◽  
Gosat Satellite ◽  
Better Than

Abstract. A portable Fourier transform spectrometer (FTS), model EM27/SUN, was deployed onboard the research vessel Polarstern to measure the column-average dry air mole fractions of carbon dioxide (XCO2) and methane (XCH4) by means of direct sunlight absorption spectrometry. We report on technical developments as well as data calibration and reduction measures required to achieve the targeted accuracy of fractions of a percent in retrieved XCO2 and XCH4 while operating the instrument under field conditions onboard the moving platform during a 6-week cruise on the Atlantic from Cape Town (South Africa, 34° S, 18° E; 5 March 2014) to Bremerhaven (Germany, 54° N, 19° E; 14 April 2014). We demonstrate that our solar tracker typically achieved a tracking precision of better than 0.05° toward the center of the sun throughout the ship cruise which facilitates accurate XCO2 and XCH4 retrievals even under harsh ambient wind conditions. We define several quality filters that screen spectra, e.g., when the field of view was partially obstructed by ship structures or when the lines-of-sight crossed the ship exhaust plume. The measurements in clean oceanic air, can be used to characterize a spurious air-mass dependency. After the campaign, deployment of the spectrometer alongside the TCCON (Total Carbon Column Observing Network) instrument at Karlsruhe, Germany, allowed for determining a calibration factor that makes the entire campaign record traceable to World Meteorological Organization (WMO) standards. Comparisons to observations of the GOSAT satellite and concentration fields modeled by the European Centre for Medium-Range Weather Forecasts (ECMWF) Copernicus Atmosphere Monitoring Service (CAMS) demonstrate that the observational setup is well suited to provide validation opportunities above the ocean and along interhemispheric transects.

scholarly journals Stratus 16 Sixteenth Setting of the Stratus Ocean Reference Station Cruise on Board RV Ronald H. Brown May 5 - 20, 2017 Rodman, Panama - Arica, Chile

2021 ◽  
Author(s):  
Sebastien P. Bigorre ◽  
Robert A. Weller ◽  
Byron Blomquist ◽  
Benjamin Pietro ◽  
Emerson Hasbrouck ◽  
...  
Keyword(s):  
Reference Station ◽  
Research Vessel ◽  
Northern Chile ◽  
Ocean Temperature ◽  
Argo Floats ◽  
Stratus Clouds ◽  
In Situ Calibration ◽  
Observation Program ◽  
Surface Drifters

The Ocean Reference Station at 20°S, 85°W under the stratus clouds west of northern Chile is being maintained to provide ongoing climate-quality records of surface meteorology, air-sea fluxes of heat, freshwater, and momentum, and of upper ocean temperature, salinity, and velocity variability. The Stratus Ocean Reference Station (ORS Stratus) is supported by the National Oceanic and Atmospheric Administration’s (NOAA) Climate Observation Program. It is recovered and redeployed annually, with past cruises that have come between October and May. This cruise was conducted on the NOAA research vessel Ronald H. Brown. During the 2017 cruise on the Ronald H. Brown to the ORS Stratus site, the primary activities were the recovery of the previous (Stratus 15) WHOI surface mooring, deployment of the new Stratus 16 WHOI surface mooring, in-situ calibration of the buoy meteorological sensors by comparison with instrumentation installed on the ship, CTD casts near the moorings. Surface drifters and ARGO floats were also launched along the track.

scholarly journals GNSS-Acoustic Observations of Seafloor Crustal Deformation Using a Wave Glider

2021 ◽  
Vol 9 ◽  
Author(s):  
Takeshi Iinuma ◽  
Motoyuki Kido ◽  
Yusaku Ohta ◽  
Tatsuya Fukuda ◽  
Fumiaki Tomita ◽  
...  
Keyword(s):  
Data Acquisition ◽  
Crustal Deformation ◽  
Satellite Communication ◽  
Satellite System ◽  
Japan Trench ◽  
Research Vessel ◽  
Solar Panels ◽  
Wave Glider ◽  
Human Costs ◽  
Global Navigation Satellite

Crustal deformation of the seafloor is difficult to observe solely using global navigation satellite system (GNSS). The GNSS-acoustic (GNSS-A) technique was developed to observe seafloor crustal deformation, and it has produced a steady series of successful observations with remarkable results related to crustal deformation associated with huge earthquakes around the Japanese Islands. However, utilizing GNSS-A incurs very large financial and human costs as it requires the use of a research vessel as a surface platform and has a limited observation frequency, which is less than once a year at seafloor stations along the Japan Trench. To conduct frequent observations, an automatic GNSS-A data acquisition system was developed that operates via an unmanned surface vehicle (wave glider). The first observations using this system were performed at a seafloor station off Aomori Prefecture in July 2019. The wave glider was equipped with two GNSS antennas, an acoustic transducer, a microelectromechanical system gyroscope, and associated control and logging units. Data acquisition and autonomous activation of the seafloor stations were successfully executed by controlling the power supply to the payload via satellite communication with the wave glider. The glider rarely strayed off the configured course and the solar panels generated sufficient power to perform the observations although the weather was mostly cloudy. The GNSS-A data processing results show that the position of the station was determined with the same accuracy and precision as in previous observations performed using a research vessel.

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