East Coast Of England Research Articles

Estimating Probabilities of Extreme Sea-Levels

A key problem in the design of sea defences is the estimation of quantiles of the distribution of annual maximum hourly sea‐levels. Traditional statistical analyses fail to exploit the considerable knowledge of the astronomical tidal component of the sea; consequently the corresponding results are highly site specific. Using results from extreme value theory an ad hoc method developed by oceanographers to overcome this problem is revised. The method is illustrated with data from three sites on the east coast of England which exhibit widely differing characteristics.

A review of medical airlifts by a search and rescue squadron on the east coast of England over 18 years.

This paper reviews the medical workload of a Royal Air Force Search and Rescue squadron on the East Coast of England over a period of 18 years and their association with the principal receiving hospitals in that area. It illustrates the effects of improvements in road networks on the workload of the squadron and contrasts the use of military helicopters with established U.K. civilian helicopter schemes.

Size composition and pot selectivity in the lobster (Homarus gammarus (L.)) and crab (Cancer pagurus L.) fisheries on the east coast of England

Size composition and pot selectivity in the lobster (Homarus gammarus (L.)) and crab (Cancer pagurus L.) fisheries on the east coast of England

The Bathside Bay story

In this article the author considers whether an opportunity to develop harbour facilities at a strategically located site in Harwich Harbour on the east coast of England may have been missed in the 1960s and 1970s. The complications of divided ownership and powers to develop the site are explained; and successive attempts to obtain Government approval for harbour development under section 9 of the Harbours Act 1964 (since repealed) are described. The effective operation of that control in this case, influenced at one stage by political considerations, is questioned.

Movements of Eiders Somateria mollissima on the east coast of Britain

Movement patterns, sex differences in natal dispersal and breeding dispersal, and interchange of birds between colonies were studied in the population of Eiders Somateria mollissima breeding on the east coast of Britain. First‐winter Eiders reared at the Sands of Forvie, Grampian, remain at or close to the colony, while most adults move about 100 km south to winter on the Firths of Forth and Tay. A proportion of the Forvie population is sedentary. Eiders which breed in Northumberland either move north to winter on the Tay and Forth estuaries or remain close to their breeding areas. Eiders breeding in Fife are sedentary. Recoveries of British‐ringed Eiders in Scandinavia indicate that some British‐born males join the Baltic breeding population, probably by pairing with Scandinavian females wintering in Britain. There is extensive natal dispersal of males from Forvie, with more than twice as many Forvie‐bred females as males returning to the colony to breed. The breeding dispersal of males is also twice that of females. Dispersal of males from the relatively sedentary Forvie wintering population is less than that from the breeding population. Previous work suggested that at Forvie sedentary birds nesting close to the estuary were genetically isolated from migratory ones nesting along the coast. This situation is less clear cut than had been supposed previously, with many migrants nesting close to the estuary. It is unlikely that the genetic differences between females nesting in different parts of the Forvie colony will remain stable in the long term, due to the natal and breeding dispersal of males.

Interstitial marine rhizopods (Protozoa) from littoral sands on the East Coast of England

The detailed structure and morphology of the shells of foraminifera and marine testate amoebae found interstitially in littoral sands have been studied by light- and scanning electron microscopy. Species are described within the known taxa. A comparison of shell architecture shows similarities in construction between those shells made from defined plates with those made from agglutinate particles, but lack of biological information prevents suggestions on possible phylogenetic connections. The testacean genus Lagenidiopsis Golemansky, 1974 is transferred to the foraminifera. Empty Tintinnid loricae may possibly be confused with empty testate shells.

Abundances of autotrophic and heterotrophic nanoplankton and the size distribution of microbial biomass in the southwestern North Sea in October 1986

Nanoplankton numbers ranged from 0.9 to 5.0 × 10 3 cells · ml −1 in coastal waters off the east coast of England in October 1986. On average, 80% of nanoplankton ranged in size from 2 to 4 μm equivalent spherical diameter (ESD). Autotrophic nanoplankton accounted for 20–80% (mean of 55%) of total nanoplankton. The nanoplankton were dominated by unidentified, small autotrophic and heterotrophic flagellates and monads which accounted for ≈ 84% of nanoplankton numbers. Identified groups included diatoms (6% of total nanoplankton numbers), cryptomonads (8% of nanoplankton numbers), dinoflagellates (2% of nanoplankton numbers), and choanoflagellates (0.6% of nanoplankton numbers). About equal biovolumes and biomasses of organisms were found in nanoplankton (2–20-μm ESD) and microplankton (20–200-μm ESD) size classes.

Spatial variations of mean sea level of the North Sea off the east coast of Britain

Low frequency currents and bottom pressures off the east coast of Britain and sea levels from coastal stations, collected during May and June 1981, are used to investigate the spatial gradient of the mean sea level. The summer time was chosen for the experiment so that the relatively calm conditions would allow an accurate measurement of the mean sea level slope for comparison with the slope as determined by the traditional methods of geodetic levelling on land. Effects of the wind stress and pressure gradients on the mean sea level and on the balance of the equations of momentum are also considered. However, as hoped, weather was relatively calm during these months and its influence on the sea level was negligible. Low frequency changes in sea level at different sites were strongly correlated, as were both wind and atmospheric pressure. Principal component analysis showed that more than 88% of the variance of all the time series of each of these variables can be accounted for by the first empirical mode. However, low frequency currents at different sites are only weakly correlated and the first empirical mode cannot account for more than 30% of the total variance. The Coriolis, pressure gradient and bottom friction terms of the momentum equations are significantly correlated. Though the variance of the bottom-friction term is very small, there is a strong correlation between it and the Coriolis term, in both the longshore and offshore momentum equation. For low frequency variations, at least a five-fold increase in the coefficient of bottom friction is required to obtain the best balance for both equations of momentum, but it is difficult to justify such a large increase. There is no evidence to support the view that there is north-south slope of mean sea level as suggested by the geodetic levelling.

Bacterial sulphate reduction in sediments of a european salt marsh: Acid-volatile and tin-reducible products

The products of 35S-sulphate reduction by sedimentary bacteria were measured at two sites in a salt marsh on the east coast of England. Non-acid-volatile products were measured, after acid-volatile sulphide was removed, by their reduction to sulphide by digestion with tin. The proportion of the sulphate reduced to tin-reducible products varied between 25% in a salt marsh pan and 61% in creek sediment, over a 0–25 cm depth profile. There were also variations with depth at each site in the proportions of sulphate reduced to tin-reducible products. Further examination revealed differences in the proportions of sulphate which were reduced to free sulphide, acid-volatile sulphide, sulphur or pyrite at the two sites. The data suggest that previous work which did not measure non-acid-volatile products underestimated sulphate reduction rates by three-fold in the creek site, but by only one third in the pan.

A photographic study of seabird attendance at Moray Firth colonies outside the breeding season

Daytime attendance of Guillemots, Razorbills, Kittiwakes and Fulmars at colonies in east Caithness was monitored by time-lapse photography over the winters of 1982/83, 1983/84 and 1984185. Fulmars frequented the colonies over a large part of each non-breeding period but were absent for extended spells in mid-winter. Guillemot visits were infrequent and usually involved relatively small numbers. They became more frequent in February in 1984 and 1985, but not in 1983, the year of a large wreck of auks on the east coast of Britain. Razorbills and Kittiwakes were absent throughout autumn and winter and re-appeared in late February or early March. The low level of winter attendance by auks, which contrasts with reports from colonies elsewhere, was probably because few adults wintered within easy reach of the Caithness colonies.

Comparisons of the physical and optical properties of atmospheric aerosol from airborne and surface measurements on the east coast of England

Results are presented of a three-day joint surface and aircraft experiment during July 1984 measuring aerosol properties at a coastal site in Lincolnshire. Scattering and absorption coefficients were measured and are in good agreement with coefficients modelled by Mie theory using measured size spectra. The dependence of aerosol size and concentration on relative humidity and altitude is also considered.

The Impact of Tributyl Tin (TBT) Antifouling Paints on Molluscan Fisheries

Laboratory and field experiments carried out during 1982–84 confirmed that some UK estuaries contained sufficient organotin compounds to cause reduced meat yields and shell thickening in the Pacific oyster, Crassostrea gigas. Historically the European flat oyster, Ostrea edulis, has been the basis of an important fishery on the east coast of England but the population has recently declined to an all-time low. Laboratory experiments have been carried out to compare larval survival, growth of spat and the development of gametes in adult O. edulis, and the growth of spat of four other bivalve species in the presence and absence of organotin toxins. The results from these experiments are discussed in relation to the concentrations of organotin compounds in samples of water and oyster tissues, from several sites in the UK, and the reproductive behaviour of adult oysters from natural stocks in the Crouch/Roach estuary system. The data strongly suggest that TBT is at least a contributory factor and probably a major cause of the failure in recent years of O. edulis to reproduce naturally in the Crouch Estuary. The UK Government has proposed legislation to control and reduce organotin emissions into the marine environment and this is briefly outlined.

Factors affecting the isotopic composition of daily rainfall at Driby, Lincolnshire

AbstractTo further the understanding of the relationships between past climatic conditions and the hydrogen and oxygen isotope composition of old groundwaters, a study of the relationship between the composition of daily rainfall and meteorological parameters at a single site was made. The composition of daily rainfall was found to be extremely variable, with little seasonal dependence, and with no clear relationship to daily mean air temperature. This is typical of a maritime climate, although the site studied is located on the east coast of England. The most important control on composition is the origin of the precipitating air mass, whether Atlantic or Continental. The possibility of investigating past climates is discussed.

Flandrian sea‐level changes in the Fenland. I: The geographical setting and evidence of relative sea‐level changes

AbstractThe Flandrian sediments of the Fenland record the infilling of the Wash embayment on the east coast of England, UK. Since at least 6500 BP changes in sea level have been a major control on the rate and pattern of sediment accumulation. New data are presented from the area which together with published information allow the reconstruction of palaeoenvironments from 6500 to 2500 BP. The major environmental changes involved alternations between freshwater fen and intertidal marine sedimentation. Each episode was characterised by transitional changes as vegetation and sediment zones shifted over large areas. Marine/brackish sediments are found up to 45 km inland of the present coast. Radiocarbon dated sea‐level index points, with relevant stratigraphic and micropalaeontological data, ranging from 6415 BP at −8.17m OD to 2595 BP at +1.45m OD, are described.

Some buried Tertiary dykes of Britain and surrounding waters deduced by magnetic modelling and seismic reflection methods

Dykes of Tertiary age have been identified by modelling offshore marine and aeromagnetic data and onshore aeromagnetic data. Dykes have been found in the North Sea off NE England, and in the Irish Sea. Published aeromagnetic maps have also been used to locate non-outcropping Tertiary dykes in the Scottish Borders. Many of the offshore anomalies are caused by multiple dykes that cannot be separately resolved. All dykes retain the dominant NW-SE trend of the known Tertiary dykes although this trend approaches E-W near the east coast of England. Under the North Sea the trend swings back and becomes increasingly southerly trending. The dykes may be the result of NW-SE compressional or NE-SW tensional stress with deep crustal weaknesses causing changes in trend.

Further Analysis of Individual Spacing within Aggregations of the Anemone, Actinia Equina

We have recently assessed phenotypic and genotypic diversity within an aggregation of the intertidal beadlet anemone, Actinia equina L., located at Burniston in N. Yorkshire, on the east coast of Britain (Quicke & Brace, 1983). The study was undertaken in order to provide information relating to the role of intraspecific aggression (Bonnin, 1964; Brace & Pavey, 1978; Brace, Pavey & Quicke, 1979) in modifying the spacing of individuals. Limited work on the genus Actinia (A. tenebrosa Farquhar) has already indicated that whilst genetically dissimilar anemones display aggression towards one another, auto-genotypic aggression is minimal (Ayre, 1982), as is also the case for the clonal anemone, Anthopleura elegantissima (Brandt) (Francis, 1973a,b,1976). We therefore anticipated that aggressive interactions would promote auto-genotypic clustering, initiated by the local settlement of the asexually produced, brooded young (Carter & Thorp, 1979; Gashout & Ormond, 1979; Orr, Thorpe & Carter, 1982), and that correspondingly, genetic diversity within aggregations of anemones would be low.

Computing near coastal tidal dynamics from observations and a numerical model

A two-dimensional vertically integrated model of the North Sea is used to compute the distribution of M 2 and M 4 tidal elevations and currents over the region. Comparison of computed and observed elevations and currents in the area shows that the model can accurately reproduce the M 2 tide in the North Sea, although there are difficulties with the M 4 tide particularly in the northern North Sea. Comparison between model and a large number of observations collected in a shallow water region off the east coast of England, revealed that the model can accurately reproduce the tides even in near coastal regions, where model resolution problems can occur. Comparisons of computed and observed M 2 tidal energy fluxes in this region, show that model and observations agree to within the order of 10% (the error associated with the necessary interpolation of the observations in order to compute the energy flux). The problem of computing energy dissipation in the area by subtracting the energy fluxes into and out of the region is shown to be ill-conditioned in that the energy dissipation in the area is comparable to the error in the energy flux. Consequently for the sea region considered here it is not meaningful to compare this energy budget with energy dissipation due to bottom friction. Energy dissipation for the whole of the North Sea is computed using the numerical model and the geographical distribution of dissipation due to bottom friction is given for the M 2 tide.

The Effectiveness of Ship Routing off North West Europe

Traffic separation was first introduced on a voluntary basis in the Dover Strait in September 1967, just over fifteen years ago. Compliance with the IMO provisions relating to traffic separation schemes has been mandatory for all ships during the last five years and for some ships for as much as ten years. It may therefore be appropriate to assess the effectiveness of routing off North West Europe by comparing collision statistics for five-year periods since 1957.The results given in the following tables apply only to collisions involving trading vessels of over 100 g.r.t. under way and not engaged in any special activities. Collisions in harbours, rivers and congested port approaches where special circumstances apply are not included. The figures quoted for the Dover Strait have been checked against the results obtained by the National Maritime Institute but are based on different criteria, and there may be some discrepancies.The area covered is the coastal region from the south-western approaches to the Ushant TSS to the approaches to the Elbe including all parts of the English Channel and the Dover Strait, but not including waters off the East Coast of England which are well clear of the traffic separation schemes and deep-water routes.The numbers of collisions are based almost entirely on Lloyd's Weekly Casualty Reports. Information relating to encounter situations is based on voyage data supplemented wherever possible by information received from additional sources relating to the actual courses steered by each vessel. It is not claimed that the figures constitute a precise record but they should provide a good indication of changes in the incidence of collision off North West Europe.

Phenotypic and genotypic spacing within an aggregation of the anemone, Actinia equina

Enzyme and colour phenotypes were determined within a single mid-shore aggregation (n = 106) of the anemone, Actinia equina L. on the east coast of Britain. On the basis of allelic variation at four enzyme loci, a large number (n ≃ 30) of genotypes were distinguished of which only three consisted often or more anemones. Little evidence was found of obvious genotypic clustering, a result which was unexpected since this species broods young which are genetically identical with their parents, and which are potentially available for local (within site) colonization. We propose that the unexpectedly high level of genetic variability encountered at this site, can be explained by the following factors: (1) site and anemone longevities are probably measurable in tens of years, (2) distances travelled by anemones during their lifetime may be considerable, thus resulting in extensive inter-digitation of clones over time, and (3) the reproductive strategy of A. equina incorporates sexual reproduction with a planktonic dispersal phase.Nearest-neighbour analyses applied to the distribution of phenotypes within this aggregation revealed several examples of auto-phenotypic under-dispersion. These results, together with (1) departure from Hardy–Weinberg equilibrium at a hexokinase locus, (2) evidence of linkage disequilibrium between hexokinase and malate dehydrogenase alleles, and (3) linkage between alleles at both these loci with a colour phenotype (grey pedal disc), all indicate that the genetic composition of this group of anemones had been strongly influenced by founder effects followed by clonal reproduction.A comparative analysis of the size distributions of the various phenotypes and genotypes yielded few conclusions relating either to colonization history or to differential selection; reasons are given to account for this failure.

The effect of an offshore bank in attenuating waves

Waverider buoys were installed in approximately 16 m of water offshore of the Size-well-Dunwich Bank off the East Coast of England and in approximately 11 m of water inshore of it. Minimum water depth over the bank was approximately 4.5 m at mid-tide level. Simultaneous records were obtained for substantial periods between November 1978 and May 1979. These show negligible attenuation for small waves, but as the offshore waveheight increased, the inshore waveheight tended to saturate at an H s of about 3 m. The form of the relationship between inshore and offshore waveheight is predicted theoretically assuming that high individual waves which cross the bank are limited by breaking. The theoretical curve agrees well with the measured data. The measured saturation level corresponds to a wave breaking when its height is approximately 0.5 the water depth, which is considerably lower than the usual engineering criterion. However, some published tank results also appear to show the same low value.