scholarly journals The reactions of shoaling adult cod to a pelagic trawl: implications for commercial trawling

2012 ◽  
Vol 69 (2) ◽  
pp. 303-312 ◽  
Author(s):  
Shale Rosen ◽  
Arill Engås ◽  
Anders Fernö ◽  
Terje Jörgensen
Keyword(s):  
Fuel Economy ◽  
Packing Density ◽  
Atlantic Cod ◽  
Average Rate ◽  
Lower Half ◽  
North Coast ◽  
Marine Science ◽  
Improve Fuel Economy ◽  
The North ◽  
Commercial Harvest

Abstract Rosen, S., Engås, A., Fernö, A., and Jörgensen, T. 2012. The reactions of shoaling adult cod to a pelagic trawl: implications for commercial trawling. – ICES Journal of Marine Science, 69: 303–312. The reactions of shoaling adult Atlantic cod to a pelagic trawl were measured during fishing off the north coast of Norway. Cod remaining in the trawl track dived at rates as fast as 0.35 m s−1 following vessel passage and swam away from the vessel, in the direction of the approaching trawl, at an average rate of 0.6 m s−1. They did not attempt to swim ahead of the trawl as documented previously, but passed into the lower half of the trawl entrance and swam slowly in the direction of trawling at a rate of 0.2–0.5 m s−1 as the trawl's greater speed through water carried them deeper into the trawl. Shoals compressed vertically once inside the trawl, suggesting that packing density increased at least fourfold. Fish remained in the lower part of the trawl as they moved through its tapered section towards the codend, with little to no clearance above the bottom panel, but significant clearance beneath the top panel. Catches were sufficient to support commercial harvest, and the behaviour observed suggests that changes in trawl design and fishing strategy might improve fuel economy and species selectivity.

Spatial and temporal microsatellite variation in spawning Atlantic cod, Gadus morhua, around Iceland

2013 ◽  
Vol 70 (8) ◽  
pp. 1151-1158 ◽  
Author(s):  
Guðni Magnús Eiríksson ◽  
Einar Árnason
Keyword(s):  
Allele Frequency ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
Genetic Difference ◽  
North Coast ◽  
The South ◽  
Microsatellite Variation ◽  
The North ◽  
Significant Difference ◽  
The Difference

The present study suggests that the observed genetic difference between Atlantic cod, Gadus morhua, off the south and the north coast of Iceland may be caused by natural selection affecting genetic variation at a microsatellite loci (Gmo34). When disregarding this locus from the analysis, no genetic difference was observed between northern and southern Iceland. The methods applied here were very sensitive, and differences as small as FST = 0.0005 are unlikely to go unnoticed. The difference between cod off the south and the north coast of Iceland is thus likely to be smaller than that. Such a small difference is negligible and is not likely to have any biological meaning. Genetic drift was detected by allele frequency comparison among different cohorts (FST = 0.0007, P = 0.0209). A small but significant difference was observed among allele frequency for cod grouped by depth at the south coast of Iceland (FST = 0.0017, P = 0.0002). This difference is very subtle and needs to be interpreted with caution.

scholarly journals The Surface Velocity of The Yakataga Glacier Alaska

1957 ◽  
Vol 3 (22) ◽  
pp. 125-130 ◽  
Author(s):  
Don J. Miller
Keyword(s):  
Average Rate ◽  
Gulf Of Alaska ◽  
Rock Fall ◽  
Aerial Photographs ◽  
Surface Velocity ◽  
North Coast ◽  
Time Interval ◽  
Main Trunk ◽  
The North ◽  
Photogrammetric Measurement

Abstract The Yakataga Glacier occupies a steep-walled valley in the Robinson Mountains on the north coast of the Gulf of Alaska. The main trunk of the glacier descends from 1130 to 150 m. in a distance of 21 km. A rock fall at the head of the glacier formed a moraine of distinctive shape which advanced at an average rate of 114 m./yr. from 1938 to 1954. The surface velocity of the glacier at fifteen stations below the firn line was calculated from the displacement of the rock-fall moraine and other less conspicuous features that are shown in two sets of vertical aerial photographs, taken in 1948 and 1954. For this time interval the average surface velocity along the medial line of the glacier ranged from a maximum of about 90 m./yr. at a station 14 km. above the terminus to zero at a station 2.3 km. above the terminus. The technique of photogrammetric measurement of surface velocity by using natural features on the surface of a glacier has wide application in Alaska, where many glaciers have been rephotographed from the air after intervals of a few years to as many as thirty years.

scholarly journals Morphological and molecular identification of Cryptocotyle lingua metacercariae isolated from Atlantic cod (Gadus morhua) from Danish seas and whiting (Merlangius merlangus) from the English Channel

2021 ◽  
Author(s):  
Maureen Duflot ◽  
Mélanie Gay ◽  
Graziella Midelet ◽  
Per Walter Kania ◽  
Kurt Buchmann
Keyword(s):  
Phylogenetic Trees ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
Black Spot ◽  
Morphological Data ◽  
North Coast ◽  
English Channel ◽  
The North ◽  
Superficial Muscle ◽  
Merlangius Merlangus

AbstractTrematode larvae (metacercariae) causing black spot disease occur frequently in gills, fins, skin and the superficial muscle layers of marine fish. Species within the genus Cryptocotyle Lühe, 1899 are frequently associated with this disease. Descriptions of the metacercarial stage are relatively limited and none has hitherto been reported from fish from the English Channel. The present study reports the morphological and molecular identifications of encysted black spot-inducing parasites from whiting (Merlangius merlangus) and Atlantic cod (Gadus morhua) caught respectively from the north coast of France (English Channel) and from Danish sea waters. Metacercariae were characterised morphologically based on microscopic observations and molecularly using Sanger sequencing of fragments of the mitochondrial cox1 gene and rDNA ITS region. Morphological data were compared with available data in the literature. Phylogenetic trees including reference sequences were built to confirm morphological and molecular identifications. This survey constitutes the first description of C. lingua metacercariae in the English Channel ecosystems.

scholarly journals The Surface Velocity of The Yakataga Glacier Alaska

1957 ◽  
Vol 3 (22) ◽  
pp. 125-130 ◽  
Author(s):  
Don J. Miller
Keyword(s):  
Average Rate ◽  
Gulf Of Alaska ◽  
Rock Fall ◽  
Aerial Photographs ◽  
Surface Velocity ◽  
North Coast ◽  
Time Interval ◽  
Main Trunk ◽  
The North ◽  
Photogrammetric Measurement

AbstractThe Yakataga Glacier occupies a steep-walled valley in the Robinson Mountains on the north coast of the Gulf of Alaska. The main trunk of the glacier descends from 1130 to 150 m. in a distance of 21 km. A rock fall at the head of the glacier formed a moraine of distinctive shape which advanced at an average rate of 114 m./yr. from 1938 to 1954. The surface velocity of the glacier at fifteen stations below the firn line was calculated from the displacement of the rock-fall moraine and other less conspicuous features that are shown in two sets of vertical aerial photographs, taken in 1948 and 1954. For this time interval the average surface velocity along the medial line of the glacier ranged from a maximum of about 90 m./yr. at a station 14 km. above the terminus to zero at a station 2.3 km. above the terminus. The technique of photogrammetric measurement of surface velocity by using natural features on the surface of a glacier has wide application in Alaska, where many glaciers have been rephotographed from the air after intervals of a few years to as many as thirty years.

MBAH HENDRO KUSUMO BIN SYECH AHMAD MUTAMAKKIN: JEJAK SYIAR ISLAM DI WILAYAH PATI

EMPIRISMA ◽  
2008 ◽  
Vol 27 (2) ◽  
Author(s):  
Fathimatuz Zahra Dan Abdul Azis
Keyword(s):  
Central Region ◽  
Marital Relationship ◽  
Southern Region ◽  
North Coast ◽  
The North ◽  
Trace Back ◽  
Northern Regions ◽  
The One

Pati is a region on the north coast, according to the hypothesis of the researcher, the region is divided into three categories. The northern regions are more religious, the central is more plural, while the southern region is in the middle. In the central region there are many relics of tombs believed to be the those of the Muslim proselytizers in the area of Pati. The one that attracts the researcher is a tomb in the Gambiran area, where there are five local Muslim saints buried, one of them belons to mbah Hendro Kusumo, the son of Syech Ahmad Mutamakkin. This article attempts to trace back the spreading of Islam in Pati based on the existence of thetomb of Mbah Hendro Kusumo. It wants to answer question of whethere the existence of his tomb is due to his studying there or marital relationship, and how it relates to the spreading of Islam.Keywords: Mbah Hendro Kusumo, Traces of Islamic Dakwah, Islam

4 The Tyara Site

1968 ◽  
Vol 22 ◽  
pp. 44-79 ◽  
Author(s):  
William E. Taylor
Keyword(s):  
Sandy Beach ◽  
North Coast ◽  
National Museum ◽  
The West ◽  
Rock Outcrops ◽  
Small Boat ◽  
The North

The Tyara site, KkFb-7 in the National Museum catalogue and site file, faces the north coast of the Ungava mainland and rests on the west shore of Sugluk Island (Fig. 1). That island stands about five hundred yards from the mainland and from Sugluk Inlet, one of the few good harbors on that coast. This handsome little island, about one and one-half miles long and as wide, consists of rounded, rugged, hardrock hills that shelter well-vegetated, generally flat-floored valleys. The valleys often contain marshy patches. The shore, of variable incline, is quite jagged, a result of abrupt rock outcrops projecting seaward from brief stretches of sandy beach. The shore facing the mainland is, therefore, quite convenient for small boat use. Dark grey gneisses seem to predominate, although they are often cut by dykes and veins of lighter material, notably quartz. The dense, green valley and hillside vegetation includes willows, mosses, grasses, lichens, and a pleasant profusion of arctic wild flowers (Polunin 1948, Pt. III). I was told at Sugluk that at the head of the inlet, willows, growing in protected situations, reach the thickness of a man's wrist.

Seed production and seedling emergence of Giant Parramatta grass on the north coast of New South Wales

1996 ◽  
Vol 36 (3) ◽  
pp. 299 ◽  
Author(s):  
TS Andrews ◽  
RDB Whalley ◽  
CE Jones
Keyword(s):  
Seed Production ◽  
Seed Bank ◽  
New South ◽  
New South Wales ◽  
Seed Banks ◽  
North Coast ◽  
The North ◽  
South Wales ◽  
Seed Fall ◽  
The Impact

Inputs and losses from Giant Parramatta grass [GPG, Sporobolus indicus (L.) R. Br. var. major (Buse) Baaijens] soil seed banks were quantified on the North Coast of New South Wales. Monthly potential seed production and actual seed fall was estimated at Valla during 1991-92. Total potential production was >668 000 seeds/m2 for the season, while seed fall was >146000 seeds/m2. Seed fall >10000 seeds/m2.month was recorded from January until May, with further seed falls recorded in June and July. The impact of seed production on seed banks was assessed by estimating seed banks in the seed production quadrats before and after seed fall. Seed banks in 4 of the 6 sites decreased in year 2, although seed numbers at 1 damp site increased markedly. Defoliation from mid-December until February, April or June prevented seed production, reducing seed banks by 34% over 7 months. Seed banks in undefoliated plots increased by 3300 seeds/m2, although seed fall was estimated at >114 000 seeds/m2. Emergence of GPG seedlings from artificially established and naturally occurring, persistent seed banks was recorded for 3 years from bare and vegetated treatment plots. Sown seeds showed high levels of innate dormancy and only 4% of seeds emerged when sown immediately after collection. Longer storage of seeds after collection resulted in more seedlings emerging. Estimates of persistent seed banks ranged from 1650 to about 21260 seeds/m2. Most seedlings emerged in spring or autumn and this was correlated with rainfall but not with ambient temperatures. Rates of seed bank decline in both bare and vegetated treatment plots was estimated by fitting exponential decay curves to seed bank estimates. Assuming no further seed inputs, it was estimated that it would take about 3 and 5 years, respectively, for seed banks to decline to 150 seeds/m2 in bare and vegetated treatments.

scholarly journals The Potential of GRASP/GARRLiC Retrievals for Dust Aerosol Model Evaluation: Case Study during the PreTECT Campaign

2021 ◽  
Vol 13 (5) ◽  
pp. 873
Author(s):  
Dimitra Konsta ◽  
Alexandra Tsekeri ◽  
Stavros Solomos ◽  
Nikolaos Siomos ◽  
Anna Gialitaki ◽  
...  
Keyword(s):  
Model Evaluation ◽  
Dust Concentration ◽  
Saharan Dust ◽  
North Coast ◽  
Concentration Profiles ◽  
Future Studies ◽  
Aerosol Model ◽  
The North ◽  
Sun Photometer

We use the Generalized Retrieval of Aerosol Surface Properties algorithm (GRASP) to compare with dust concentration profiles derived from the NMME-DREAM model for a specific dust episode. The GRASP algorithm provides the possibility of deriving columnar and vertically-resolved aerosol properties from a combination of lidar and sun-photometer observations. Herein, we apply GRASP for analysis of a Saharan dust outburst observed during the “PREparatory: does dust TriboElectrification affect our ClimaTe” campaign (PreTECT) that took place at the North coast of Crete, at the Finokalia ACTRIS station. GRASP provides column-averaged and vertically resolved microphysical and optical properties of the particles. The retrieved dust concentration profiles are compared with modeled concentration profiles derived from the NMME-DREAM dust model. To strengthen the results, we use dust concentration profiles from the POlarization-LIdar PHOtometer Networking method (POLIPHON). A strong underestimation of the maximum dust concentration is observed from the NMME-DREAM model. The reported differences between the retrievals and the model indicate a high potential of the GRASP algorithm for future studies of dust model evaluation.

scholarly journals Thinner Sea Ice Contribution to the Remarkable Polynya Formation North of Greenland in August 2018

2021 ◽  
Author(s):  
Xiaoyi Shen ◽  
Chang-Qing Ke ◽  
Bin Cheng ◽  
Wentao Xia ◽  
Mengmeng Li ◽  
...  
Keyword(s):  
Sea Ice ◽  
Ice Cover ◽  
Reanalysis Data ◽  
Mean Value ◽  
Ocean Model ◽  
North Coast ◽  
Average Value ◽  
The North ◽  
Wind Sea ◽  
The One

AbstractIn August 2018, a remarkable polynya was observed off the north coast of Greenland, a perennial ice zone where thick sea ice cover persists. In order to investigate the formation process of this polynya, satellite observations, a coupled ice-ocean model, ocean profiling data, and atmosphere reanalysis data were applied. We found that the thinnest sea ice cover in August since 1978 (mean value of 1.1 m, compared to the average value of 2.8 m during 1978–2017) and the modest southerly wind caused by a positive North Atlantic Oscillation (mean value of 0.82, compared to the climatological value of −0.02) were responsible for the formation and maintenance of this polynya. The opening mechanism of this polynya differs from the one formed in February 2018 in the same area caused by persistent anomalously high wind. Sea ice drift patterns have become more responsive to the atmospheric forcing due to thinning of sea ice cover in this region.

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