Differences in the swimming behaviour of the amphipod Corophium volutator from different populations

1990 ◽  
Vol 70 (1) ◽  
pp. 143-148 ◽  
Author(s):  
R.G. Hughes ◽  
I. M. Horsfall
Keyword(s):  
East Coast ◽  
High Water ◽  
Flood Tide ◽  
Swimming Behaviour ◽  
Corophium Volutator ◽  
East Anglia ◽  
Laboratory Conditions ◽  
Different Populations ◽  
Autumn And Winter

The swimming behaviour of Corophium volutator from Wales and East Anglia was investigated to establish whether differences apparent from two previous studies are real or artefacts of the different techniques used. Swimming C. volutator were caught in a Welsh estuary in the summer, but only rarely in the autumn and winter, and in both daylight and darkness. In simulated tidal conditions in the laboratory C. volutator from two sites in East Anglia never swam, while those from Wales swam whenever the substratum was immersed, in daylight and darkness, mostly on the ebb tide and in winter. The unnatural swimming in winter may have been stimulated by laboratory conditions, but the East Anglian amphipods were not so affected. The tidal swimming rhythm is different to east coast C. volutator which only swim at night. This difference may be related to the time of spring tides, when most swimming occurs. In Wales high water of spring tides may occur only in daylight in summer and nocturnal swimming may not be possible. The ebb tide swimming by C. volutator in Wales contrasts with the flood and ebb swimming of east coast amphipods and may reflect differences in their habitats. The former were collected close to the sea while the latter were 15 km up a narrow estuary and may represent a sub-population of amphipods with a disposition to swim early (on the flood tide) enabling them to colonise upstream habitats.

XII.—A Survey of Clyde Plankton

1926 ◽  
Vol 45 (2) ◽  
pp. 117-141 ◽  
Author(s):  
Sheina M. Marshall
Keyword(s):  
High Water ◽  
Flood Tide ◽  
Sea Floor

The tow-nettings on which this survey is based were taken mostly from Keppel Pier. The tide as a rule runs down the channel strongly for several hours after high water, and the current is sufficiently strong to hold out the tow-nets more or less horizontal. Owing to some peculiarity in the configuration of the sea-floor at Keppel, the downward current is much the stronger and often begins an hour or several hours before high water. The flood-tide is never strong enough nor constant enough to hold out a tow-net for any length of time, and so most of the observations are based on tow-nettings taken on the ebb. Tow-nettings were taken almost every day and the tow-nets were usually left out for an hour.

scholarly journals Effects of spinosad and abamectin on different populations of rice weevil Sitophilus oryzae (L.) in treated wheat grain

2011 ◽  
Vol 26 (4) ◽  
pp. 377-384 ◽  
Author(s):  
Goran Andric ◽  
Petar Kljajic ◽  
Marijana Prazic-Golic
Keyword(s):  
Sitophilus Oryzae ◽  
Rice Weevil ◽  
Wheat Grain ◽  
Progeny Production ◽  
Laboratory Conditions ◽  
Parental Exposure ◽  
Application Rates ◽  
Efficient Control ◽  
Different Populations ◽  
Natural Insecticides

In laboratory conditions (25?1.C and 60?5% r.h.) effects of natural insecticides spinosad and abamectin on five S. oryzae populations (laboratory, Sid, Gornji Milanovac, Zabari and Novi Pazar) were investigated. Both insecticides for all tested populations were applied to untreated wheat grain at following rates 0.25, 0.5, 1.0 and 2.0 mg AI/kg, subsequently 25 adults were added in each plastic vessels (V=200 cm3) containing 50 g of treated wheat, in four replicates, for each population tested. Mortality of weevils was determined after 2-, 7- and 14-days, and the effect on progeny production was determined 8-weeks from parental exposure. Efficacy of spinosad and abamectin after 2-days of weevil exposure for all tested populations and all application rates was <15%. After 7-days of exposure, the efficacy was ?95% for weevils from Zabari, in wheat treated with 2 mg/kg of spinosad and abamectin, and for weevils from Gornji Milanovac, only in wheat treated with 2 mg/kg of spinosad. After 14-days of exposure the efficacy ?95% was found for laboratory weevils and weevils from Zabari and Gornji Milanovac, in wheat treated with 1 and 2 mg/kg of spinosad, and for S. oryzae from Novi Pazar and Sid, in wheat treated with 2 mg/kg of spinosad. At the same time for all tested populations abamectin at rates of 0.5, 1.0 and 2.0 mg/kg was 94-100% efficien t. No insecticide achieved total (100%) progeny reduction in tested populations of S. oryzae, while high progeny reduction (?95%) was found only in weevils which were in contact with wheat treated with 1 and 2 mg/kg of abamectin. The results showed that for highly efficient control of different populations of S. oryzae in wheat grain, ?2 mg/kg of abamectin, and, particularly, spinosad should be applied.

Climatic conditions over the estuary and Firth of Forth, Scotland

1987 ◽  
Vol 93 (3-4) ◽  
pp. 245-258
Author(s):  
S. J. Harrison
Keyword(s):  
East Coast ◽  
High Water ◽  
Surface Interactions ◽  
Climatic Conditions ◽  
Heat Fluxes ◽  
Spatial And Temporal Scales ◽  
Surface Heat Fluxes ◽  
Air Movement ◽  
Tidal Water ◽  
Firth Of Forth

SynopsisThe pattern of climatic variation over estuaries and their environs is, to a considerable extent, controlled by aspect, slope and elevation in addition to orientation of the major relief features with respect to the movement of principal weather systems. Data from the few climatological stations within the immediate vicinity of the estuary and Firth of Forth demonstrate the essentially maritime nature of climate, and indicate also that there is a dominantly west–east gradient of change in most climatological variables. Below the high water mark the movement of water in tidal ebb and flow and river inflow modify atmosphere–surface interactions over relatively short spatial and temporal scales. Observations from a fixed instrument tower on Skinflats in the middle estuary and from Inchkeith Lighthouse indicate that tidal water movements exert varying degrees of control over sub-surface heat fluxes, air movement in the atmospheric boundary layer and the inland penetration of coastal weather systems such as the typical east coast haar.

scholarly journals Quaternary River Diversions in the London Basin and the Eastern English Channel

2007 ◽  
Vol 51 (3) ◽  
pp. 337-346 ◽  
Author(s):  
D. R. Bridgland ◽  
P. L. Gibbard
Keyword(s):  
North Sea ◽  
East Coast ◽  
Middle Pleistocene ◽  
North Coast ◽  
English Channel ◽  
East Anglia ◽  
The North ◽  
Course Changes ◽  
The North Sea ◽  
The Last Glacial

ABSTRACT The principal river of the London basin, the Thames, has experienced a number of course changes during the Quaternary. Some, at least, of these are known to result directly from glaciation. In the early Quaternary the river flowed to the north of London across East Anglia to the north coast of Norfolk. By the early Middle Pleistocene it had changed its course to flow eastwards near the Suffolk - Essex border into the southern North Sea. The Thames valley to the north of London was blocked by ice during the Anglian/Elsterian glaciation, causing a series of glacial lakes to form. Overflow of these lakes brought the river into its modern valley through London. It is thought that this valley already existed by the Anglian in the form of a tributary of the north-flowing River Medway, which joined the old Thames valley near Clacton. Also during the Anglian/Elsterian glaciation. British and continental ice masses are thought to have joined in the northern part of the North Sea basin, causing a large lake to form between the east coast of England and the Netherlands. It is widely believed that the overflow from this lake caused the first breach in the Weald-Artois Ridge, bringing about the formation of the Strait of Dover. Prior to the glaciation the Thames, in common with rivers from the continent (including the Rhine and Meuse), flowed into the North Sea Basin. It seems that, after the lake overflow, these rivers together drained southwards into the English Channel. Whether this southern drainage route was adopted during all later periods of low sea level remains to be determined, but it seems certain that this was the case during the last glacial.

VII.—Recent Marine Clays At Kuchavelli, Ceylon

1905 ◽  
Vol 2 (11) ◽  
pp. 508-509 ◽  
Author(s):  
Ananda K. Coomaraswamy
Keyword(s):  
East Coast ◽  
High Water ◽  
The Other ◽  
High Water Mark ◽  
The Right ◽  
Marine Clays

Kuchavelli is twenty-two miles north of Trincomalee on the JV. east coast of Ceylon. Two miles south of Kuchavelli is the mouth of the Salape aru. On the right bank of this river, near the mouth, raised beach, consisting of shelly sandstone, is exposed. The sandstone is often full of marine shells, and there are also thick growths of oysters attached to upstanding masses of rock. The bed is from 6inches to 2 feet in thickness, and is exposed about 1 foot above high-water mark, and stretches down the sloping bank between tide-marks. This is the ordinary raised beach of Ceylon, a deposit usuallyoccurring at or below high-water mark, and now being continually eroded at numerous points on the coast of Ceylon where it is exposed (e.g. Bentota). This deposit will not now be further spoken of.The Salape aru is really the name of the estuary of several rivers; proceeding up the river inland, the Matti aru is reached, a shallow river with alluvial banks eight or ten feet above the water on either side. Extensive sandbanks are found on one side or the other of the river, alternating on the meanders with places where erosion is in progress. These banks are covered with marine shells, the large flat Placunas being most common. There are also found clayey nodules including marine shells, crabs, and it is said sometimes tortoises and fishes. The crabs are collected for use as medicine, being powdered and mixed with milk or water as a specific for diabetes.

Growth of Corophium volutator Under Laboratory Conditions

2007 ◽  
Vol 54 (3) ◽  
pp. 440-446 ◽  
Author(s):  
Belinda J. Kater ◽  
Johan G. Jol ◽  
Mathijs G. D. Smit
Keyword(s):  
Corophium Volutator ◽  
Laboratory Conditions

scholarly journals Investigation of Changes in Beach Morphology due to Coastal Armoring

2021 ◽  
Vol 11 (1) ◽  
pp. 65
Author(s):  
C. Anandan ◽  
C. Senthil Kumar
Keyword(s):  
East Coast ◽  
Morphological Changes ◽  
High Water ◽  
Satellite Monitoring ◽  
Swash Zone ◽  
Residential Areas ◽  
Sedimentation Pattern ◽  
East Coast Of India ◽  
Beach Morphology ◽  
The Impact

The Tsunami, which struck the east coast of India on 26th December 2004, caused huge damage to life, property and environment. Beyond the heavy toll on human lives, it had caused an enormous environmental impact. Kalpakkam located in the south east coast of India is one of the areas affected by the tsunami. At some locations along the coast around Kalpakkam, morphological changes, vegetation loss and fatality were reported. Later, a slew of remedial measures were initiated at Kalpakkam in 2006 and construction of coastal armoring in the form of Tsunami Protection Wall (TPW) of 3.2 km length was one of them. A study was undertaken to assess the impact of this TPW on the surroundings based on periodic measurements of High Water Line (HWL) before and after construction of the wall. Also beach profiles were made at selected locations to observe seasonal changes in sedimentation pattern (i.e. accretion and erosion). As the residential area at Kalpakkam is located between fishing hamlets at northern and southern side, it is necessary to understand the impact of TPW, if any, in the surrounding area and on the fishing hamlets. Towards this assessment, high resolution satellite data such as Quickbird and IKONOS were employed (for the years 2002, 2003, 2009 and 2011) to measure the HWL. In addition, monthly beach profiles were carried out to measure the sedimentation pattern at selected transects with the help of N3 Precision Level survey instrument for the year 2009. The detailed investigations and analysis revealed no significant impact on the beach morphology and sedimentation patterns due to the construction of TPW, within the residential areas as well as at fishing hamlets. The average variations in the position of HWL along the coast was 4.6m and sedimentation changes were in the range of &asymp; 0.5m in the berm of backshore region and &asymp; 1.7m in the swash zone of the foreshore region all along the study area. No adverse effect is observed and the variations observed are similar to that in an unarmored control beach. The study provides the confidence that multi-dated satellite monitoring together with the profiling of beach would suffice the need for understanding the changes in the beach morphology due to the construction of beach armoring.

scholarly journals Changes in the distribution and abundance of Carex ericetorum in Britain since the 1970s

2020 ◽  
Vol 2 (2) ◽  
Author(s):  
Kevin Walker ◽  
Peter Stroh
Keyword(s):  
Nitrogen Deposition ◽  
Agricultural Intensification ◽  
Vegetation Management ◽  
Calcareous Grassland ◽  
Festuca Ovina ◽  
East Anglia ◽  
Limestone Grassland ◽  
Population Sizes ◽  
Winter Grazing ◽  
Autumn And Winter

British populations of Carex ericetorum Poll. (Rare Spring Sedge) were visited between 2008 and 2015 to assess size, habitats, associated vegetation, management, threats and changes in abundance since the 1970s. C. ericetorum was relocated at 40 of the 64 sites visited, mainly in northwest England (24 sites) and East Anglia (nine sites); most populations that couldn’t be relocated were in southern and eastern England. Population sizes were usually small (<100 individuals) and had remained relatively stable or had increased in size since the 1970s. In southern and eastern England, C. ericetorum was restricted to species-rich calcareous grassland overlying chalk or limestone dominated by Festuca ovina and Bromopsis erecta. In northwest England, it was confined to limestone grassland dominated by Sesleria caerulea. Ideal management for C. ericetorum comprised autumn and winter grazing to maintain a short sward (<6 cm), although it had persisted in the absence of grazing where the growth of dominants was restricted by exposure and/or soil infertility. The main threat to its survival is now a lack of grazing leading to increased competition with tall grasses, although agricultural intensification had caused losses in the lowlands. Nitrogen deposition is also likely to have compounded these threats on some sites. Its survival on many sites will require the maintenance or reinstatement of grazing.

The Fosse

1924 ◽  
Vol 14 (1-2) ◽  
pp. 252-256 ◽  
Author(s):  
R. G. Collingwood
Keyword(s):  
West Coast ◽  
East Coast ◽  
Nodal Point ◽  
Relative Importance ◽  
East Anglia ◽  
North West ◽  
North East ◽  
The North ◽  
Railway System ◽  
Cross Country

The main lines of communication, in any given country, alter very little from age to age. They are dictated by geography; the vicissitudes of economic and political history may affect their relative importance and alter the details of their lay-out, but nothing except the cessation of traffic can fundamentally change them. This is strikingly exemplified in the relation between the Roman roads of England and its modern railway-system. The main Roman roads are laid out with such accurate attention to geographical facts, that the railway engineers of the nineteenth century were unconsciously forced to imitate their choice of track. In both cases, London is the hub of the system, and main lines radiate to the Channel ports, the Solent, the Exe, the Bristol Channel, the north-west coast, the north-east coast, and East Anglia. In both cases, again, there are certain “cross-country” lines—one from Cheshire to the Usk, one from the Tyne to the Solway, others through the passes of the Pennines. In short, a map of main Roman roads superimposed upon one of main railway-lines shows a very close general agreement, modified by such details as the substitution of Liverpool for Chester as the chief port of the north-west, and the substitution of Reading for Silchester or Shrewsbury for Wroxeter as a nodal point.

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