Circalittoral suprabenthic coarse sand community from the western English Channel

1994 ◽  
Vol 74 (3) ◽  
pp. 543-562 ◽  
Author(s):  
Jean-Claude Dauvin ◽  
Angeles Iglesias ◽  
Jean-Claude Lorgere
Keyword(s):  
Dominant Species ◽  
Quantitative Description ◽  
Abundant Species ◽  
Coarse Sand ◽  
English Channel ◽  
The North ◽  
Four Levels ◽  
Upper Level ◽  
Similar Density ◽  
Autumn And Winter

A first quantitative description of the suprabenthic fauna in a coarse sand community from the western English Channel is provided. One hundred and twenty species of Crustacea were collected in 22 suprabenthic sledge hauls collected throughout the year (1988–1989). Mysids and Amphipods dominated the fauna, among them Anchialina agilis (Sars), Gastrosaccus spp., Apherusa spp., Eusirus longipes Boeck, and Stenothoe marina (Bate) were the dominant species. Although most dominant species showed a vertically decreasing gradient of density from the lower net to the upper level of the sledge, the most abundant species, Apherusa spp., showed similar density at all four levels. The mean density at the four levels of the sledge did not differ significantly with the distance above the sediment. Species performed nocturnal vertical migrations: the densities of mysids were higher during the day than at night; conversely, the densities of amphipods and decapods were higher at night than during the day. The density and species richness showed high seasonal variation, from low values at the end of autumn and winter to high values in summer and the beginning of autumn. The results are compared with the available data on suprabenthic communities from the North Atlantic; this highlights (1) the lack of concentration of suprabenthic fauna towards the sediment on coarse sand, and (2) the highest abundance of the suprabenthic fauna from muddy substrata.

NILAI KERJA DITINJAU DARI ETNIS BATAK TOBA PADA ANGGOTA SATUAN BRIGADE MOBILE KEPOLISIAN DAERAH SUMATERA UTARA

2019 ◽  
Vol 4 (1) ◽  
pp. 8-14
Author(s):  
Debi Angelina Br. Barus
Keyword(s):  
Work Values ◽  
Quantitative Description ◽  
The North ◽  
Work Value ◽  
Toba Batak ◽  
Relationship Of ◽  
The Relationship ◽  
North Sumatra

This study aims to determine the relationship of work values with the Batak Toba ethnic. This research was conducted at the Mobile Brigade Unit of the North Sumatra Regional Police. The subjects in this study were 45 people. This study uses a quantitative description approach. The results of the study are to find that hamoraon, hagabeon and hasangapon (3H) are in line with the principle of the work value of Brimob members. 3H is the peak achievement of individual Toba Batak ethnic work value in the mobile brigade unit of the North Sumatra regional police. Keyword: Work value, Batak Toba Etnic   Penelitian ini bertujuan untuk mengetahui hubungan nilai kerja dengan etnis Batak Toba. Penelitian ini dilakukan di Satuan Brigade Mobile Kepolisian Daerah Sumatera Utara. Subjek dalam penelitian ini adalah 45 orang. Penelitian ini menggunakan pendekatan kuantitatif deskripsi. Hasil penelitian adalah menemukan bahwa hamoraon, hagabeon dan hasangapon (3H) sejalan dengan prinsip nilai kerja pada satuan anggota Brimob. 3H merupakan puncak pencapaian dari nilai kerja individu yang beretnis Batak Toba di satuan brigade mobile kepolisian daerah Sumatera Utara. Kata Kunci: Nilai kerja, Etnis Batak Toba

scholarly journals Deep-Water Cartilaginous Fishes in the Central Mediterranean Sea: Comparison between Geographic Areas with Two Low Impact Tools for Sampling

2021 ◽  
Vol 9 (7) ◽  
pp. 686
Author(s):  
Angela Carluccio ◽  
Francesca Capezzuto ◽  
Porzia Maiorano ◽  
Letizia Sion ◽  
Gianfranco D’Onghia
Keyword(s):  
Adriatic Sea ◽  
Fish Habitat ◽  
Conservation Status ◽  
Abundant Species ◽  
Cartilaginous Fish ◽  
Fish Diversity ◽  
Ionian Sea ◽  
Central Mediterranean ◽  
The North ◽  
North Western

Baited lander represents a low impact technique, an alternative to the traditional trawl sampling for collecting data on fish diversity and abundance, especially for threatened species such as Chondrichthyes living in sensitive habitats. In this study, distribution and abundance of cartilaginous fish were compared between two geographic areas, the southern Adriatic Sea and the north-western Ionian Sea, with two low impact sampling gears, an experimental bottom longline and a baited lander. Species diversity was evaluated by applying ecological indices and difference in mean abundances were tested using multivariate analysis. A total of 13 species of cartilaginous fish were collected. Significant differences in the assemblage recorded in the same area using different sampling tools were detected and no significant differences were detected among different areas explored with the same method. Using longline, the most abundant species collected in both areas was Galeus melastomus, while using lander, the most observed species were Dalatias licha in the southern Adriatic Sea and Hexanchus griseus in the north-western Ionian Sea. According to IUCN classification, of the 13 species collected, 2 are near threatened and 5 are threatened. A better governance of sensitive habitats coinciding with the essential fish habitat for these species would ensure them a better conservation status.

Further Investigation upon the Water Movements in the English Channel. Drift-Bottle Experiments in the Summers of 1927, 1928 and 1929, with Critical Notes on Drift-Bottle Experiments in General.

1930 ◽  
Vol 17 (1) ◽  
pp. 241-275 ◽  
Author(s):  
J. N. Carruthers
Keyword(s):  
Wind Speed ◽  
North Sea ◽  
English Channel ◽  
The North ◽  
Different Types ◽  
The North Sea ◽  
The Common ◽  
Relationship Of ◽  
Great Simplicity ◽  
Simple Surface

In July–August of three different years common surface-floating bottles were set adrift at International Station E2 (49° 27' N.—4° 42' W.). With them, various types of drag-fitted bottles were also put out. The journeys accomplished are discussed, and the striking differences as between year and year in the case of the common surface floaters, and as between the different types in the same year, are commented upon in the light of the prevailing winds. An inter-relationship of great simplicity is deduced between wind speed and the rate of travel of simple surface floating bottles up-Channel and across the North Sea from the results of experiments carried out in four different summers.

Temperature, Salinity and Plankton in the Eastern North Atlantic and Coastal Waters of Britain, 1957.: I. The Characterisation and Distribution of Surface Waters

1963 ◽  
Vol 20 (3) ◽  
pp. 789-826 ◽  
Author(s):  
B. McK. Bary
Keyword(s):  
North Sea ◽  
North Atlantic ◽  
Coastal Waters ◽  
Water Bodies ◽  
English Channel ◽  
Oceanic Water ◽  
Climatic Fluctuations ◽  
The North ◽  
The North Sea ◽  
Eastern North Atlantic

Monthly temperature-salinity diagrams for 1957 have demonstrated that three surface oceanic "water bodies" were consistently present in the eastern North Atlantic; two are regarded as modified North Atlantic Central water which give rise to the third by mixing. As well in the oceanic areas, large and small, high or low salinity patches of water were common. Effects of seasonal climatic fluctuations differed in the several oceanic water bodies. In coastal waters, differences in properties and in seasonal and annual cycles of the properties distinguish the waters from the North Sea, English Channel and the western entrance to the Channel.The geographic distributions of the oceanic waters are consistent with "northern" and "southern" water bodies mixing to form a "transitional" water. Within this distribution there are short-term changes in boundaries and long-term (seasonal) changes in size of the water bodies.Water in the western approaches to the English Channel appeared to be influenced chiefly by the mixed, oceanic transitional water; oceanic influences in the North Sea appear to have been from northern and transitional waters.

Determinacy of fecundity in sole (Solea solea) from the Bristol Channel

1990 ◽  
Vol 70 (4) ◽  
pp. 803-813 ◽  
Author(s):  
J. W. Horwood ◽  
M. Greer Walker
Keyword(s):  
Bay Of Biscay ◽  
English Channel ◽  
Potential Fecundity ◽  
Frequency Distributions ◽  
The North ◽  
Size Frequency ◽  
Solea Solea ◽  
The North Sea ◽  
The Common ◽  
Common Sole

Ovaries of the common sole (Solea solea (Linnaeus)) were collected prior to, or at the beginning of, spawning from the spawning grounds in the Bristol Channel. Size frequency distributions of oocytes over 100 μm are presented. They clearly show a break in the size frequency distributions, at about 170 μm, indicating that the production of new oocytes to be spawned that season had ceased. It indicates that the sole is a determinate spawner and that, at least for this population, an annual potential fecundity can be measured. Estimated annual fecundity at length of Bristol Channel sole is calculated, and values are compared with those found for sole from the North Sea, eastern English Channel and the Bay of Biscay.

Spurious Grid-Scale Precipitation in the North American Regional Reanalysis

2007 ◽  
Vol 135 (6) ◽  
pp. 2168-2184 ◽  
Author(s):  
Gregory L. West ◽  
W. James Steenburgh ◽  
William Y. Y. Cheng
Keyword(s):  
North American ◽  
Prediction Models ◽  
Weather Prediction ◽  
Regional Climate ◽  
Potential Temperature ◽  
Climate Data ◽  
The North ◽  
North American Regional Reanalysis ◽  
Upper Level ◽  
Regional Reanalysis

Abstract Spurious grid-scale precipitation (SGSP) occurs in many mesoscale numerical weather prediction models when the simulated atmosphere becomes convectively unstable and the convective parameterization fails to relieve the instability. Case studies presented in this paper illustrate that SGSP events are also found in the North American Regional Reanalysis (NARR) and are accompanied by excessive maxima in grid-scale precipitation, vertical velocity, moisture variables (e.g., relative humidity and precipitable water), mid- and upper-level equivalent potential temperature, and mid- and upper-level absolute vorticity. SGSP events in environments favorable for high-based convection can also feature low-level cold pools and sea level pressure maxima. Prior to 2003, retrospectively generated NARR analyses feature an average of approximately 370 SGSP events annually. Beginning in 2003, however, NARR analyses are generated in near–real time by the Regional Climate Data Assimilation System (R-CDAS), which is identical to the retrospective NARR analysis system except for the input precipitation and ice cover datasets. Analyses produced by the R-CDAS feature a substantially larger number of SGSP events with more than 4000 occurring in the original 2003 analyses. An oceanic precipitation data processing error, which resulted in a reprocessing of NARR analyses from 2003 to 2005, only partially explains this increase since the reprocessed analyses still produce approximately 2000 SGSP events annually. These results suggest that many NARR SGSP events are not produced by shortcomings in the underlying Eta Model, but by the specification of anomalous latent heating when there is a strong mismatch between modeled and assimilated precipitation. NARR users should ensure that they are using the reprocessed NARR analyses from 2003 to 2005 and consider the possible influence of SGSP on their findings, particularly after the transition to the R-CDAS.

Seasonality in a taxocoenosis of molluscs from soft bottoms in the Bay of Cádiz (southern Spain)

2001 ◽  
Vol 81 (6) ◽  
pp. 903-912 ◽  
Author(s):  
Jose L. Rueda ◽  
Manuel Fernández-Casado ◽  
Carmen Salas ◽  
Serge Gofas
Keyword(s):  
Species Richness ◽  
Correspondence Analysis ◽  
Dominant Species ◽  
Southern Spain ◽  
Soft Bottom ◽  
Soft Bottoms ◽  
High Species Richness ◽  
Bay Of Cadiz ◽  
Bay Of Cádiz ◽  
Autumn And Winter

The macrofauna of molluscs associated with soft bottoms in the Bay of Cádiz (southern Spain) was studied monthly from February 1994 to January 1996. The number of species (63) is high for a soft bottom and is related to environmental characteristics (growth of macrophytes) and the biogeographical setting of the studied area. Corbula gibba (∼90%) was the dominant species in this taxocoenosis together with the gastropod Nassarius pygmaeus and the bivalves Pandora inaequivalvis, Parvicardium exiguum and Macoma melo. The most frequent species during the two years was also the bivalve Corbula gibba (100%) followed by the gastropods Nassarius pygmaeus, Tricolia tenuis, Rissoa membranacea and the bivalve Macoma melo. Total abundance of the taxocoenosis in both years reached higher values in spring. The dynamics of the ecological indices such as diversity or evenness, and the species richness showed a similar pattern in both years, with low values of diversity and evenness together with high species richness in spring and summer months and the reverse in autumn and winter. The qualitative correspondence analysis of monthly samples shows an ordination related to seasonality in both studied years, however the values of Jaccard's coefficient do not indicate significant boundaries among the monthly samples. The quantitative correspondence analysis shows an ordination and grouping of samples related to the biology of species, particularly with the recruitment of C. gibba, the dominant species. The existence of similar trends in the structure of the taxocoenoses over both years, and the seasonality highlighted by the qualitative correspondence analysis, seems to indicate a certain stability of the ecosystem.

Effect of extremely severe winters on under-ice phytoplankton development in a mesotrophic lake (Eastern Poland)

2014 ◽  
Vol 43 (2) ◽  
Author(s):  
Władysława Wojciechowska ◽  
Tomasz Lenard
Keyword(s):  
Water Column ◽  
Dominant Species ◽  
Biomass Concentration ◽  
Thermal Conditions ◽  
Ice Cover ◽  
Abundant Species ◽  
Blue Green Algae ◽  
Cyanobacteria And Algae ◽  
Taxonomic Groups ◽  
The Vertical Distribution

AbstractThe research was carried out in a mesotrophic and dimictic lake during winters with ice cover. In the last forty years, the development of phytoplankton was analyzed in five extreme winter seasons. The studies of phytoplankton characteristics in the water column took into account values of biomass, concentration of chlorophyll-a and species composition, including dominant species. Differences in the vertical distribution of flagellate and non-flagellate species belonging to cyanobacteria and algae were analyzed in the gradient of light and thermal conditions. The phytoplankton biomass was low and vertically differentiated, with the lowest values at the deeper part of the water column. Flagellate species from the group of Cryptophyceae, Chrysophyceae and Dinophyceae were most abundant. Species biodiversity was low but every winter the dominant species represented different taxonomic groups. In some periods, larger non-motile phytoplankton species from green or blue-green algae dominated. The research proved that the development of phytoplankton under the ice cover was limited mainly by light and, to a lesser extent, by temperature.

scholarly journals Barotropic Regeneration of Upper-Level Synoptic Disturbances in Different Configurations of the Zonal Weather Regime

2008 ◽  
Vol 65 (10) ◽  
pp. 3159-3178 ◽  
Author(s):  
Gwendal Rivière
Keyword(s):  
Large Scale ◽  
Deformation Field ◽  
Regeneration Process ◽  
Barotropic Model ◽  
Weather Regime ◽  
The North ◽  
The Difference ◽  
Upper Level ◽  
Composite Maps ◽  
Large Scale Flow

Barotropic dynamics of upper-tropospheric midlatitude disturbances evolving in different configurations of the zonal weather regime (i.e., in different zonal-like large-scale flows) were studied using observational analyses and barotropic model experiments. The contraction stage of upper-level disturbances that follows their elongation stage leads to an increase of eddy kinetic energy that is called the barotropic regeneration process in this text. This barotropic mechanism is studied through notions of barotropic critical regions (BtCRs) and effective deformation that have been introduced in a previous paper. The effective deformation field is equal to the difference between the square of the large-scale deformation magnitude and the square of the large-scale vorticity. Regions where the effective deformation is positive correspond to regions where the large-scale flow tends to strongly stretch synoptic disturbances. A BtCR is an area separating two large-scale regions of positive effective deformation, one located upstream and on the south side of the jet and the other downstream and on the north side. Such a region presents a discontinuity in the orientation of the dilatation axes and is a potential area where the barotropic regeneration process may occur. Winter days presenting a zonal weather regime in the 40-yr ECMWF Re-Analysis dataset are decomposed, via a partitioning algorithm, into different configurations of the effective deformation field at 300 hPa. A six-cluster partition is obtained. Composite maps of the barotropic generation rate for each cluster exhibit a succession of negative and positive values on both sides of the BtCRs. It confirms statistically that the barotropic regeneration mechanism occurs preferentially about BtCRs. Numerical experiments using a forced barotropic model on the sphere are performed. Each experiment consists of adding a synoptic-scale perturbation to one of the zonal-like jet configurations found in observations, which is kept fixed with time. The combined effects of the effective deformation and nonlinearities are shown to be crucial to reproduce the barotropic regeneration process about BtCRs.

1.—The Competitors and the Result

1906 ◽  
Vol 10 (40) ◽  
pp. 50-51
Keyword(s):  
Great Britain ◽  
North Sea ◽  
English Channel ◽  
Long Distance ◽  
The North ◽  
The North Sea ◽  
The Way

No fewer than seven nations tried to win the Gordon Bennett Cup in the race which started from the Tuileries Gardens, in Paris, on September 30th. But the wind was in an unfavourable direction for the accomplishment of a long distance record. To some, the English Channel barred the way, to some, the North Sea.The cup offered for the greatest distance covered has been accorded to the American aeronaut, Mr. Frank P. Lahm, who descended 15 miles north of Scarborough.It will be seen in another part of this Journal that in December next, Members of the Aëronautical Society of Great Britain will hear an account of the Gordon-Bennett race from Colonel J. E. Capper, who took part in the race, having accompanied Mr. Rolls in the “ Britannia.” In this account, therefore, it will suffice to merely tabulate the competitors and results.

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