Shingle Bank Research Articles

Biological Flora of Britain and Ireland: Silene uniflora‡

Abstract This account presents information on all aspects of the biology of Silene uniflora Roth (S. maritima With., S. vulgaris Garcke subsp. maritima (With.) Á. & D. Löve), Sea Campion, that are relevant to understanding its ecological characteristics and behaviour. The main topics are presented within the standard framework of the Biological Flora of Britain and Ireland: distribution, habitat, communities, responses to biotic factors, responses to environment, structure and physiology, phenology, floral and seed characters, herbivores and disease, history and conservation. Silene uniflora is a mat‐like perennial herb that in Britain and Ireland is primarily distributed in coastal habitats, notably on sea cliffs and shingle banks but also at the drift line and rarely on sand; it also has populations on mountains and heavy metal mine waste tips. All of these substrates tend to be oligotrophic, loose‐textured and freely draining, and often with adverse ion concentrations. It is found in suitable habitats around much of the Atlantic and Baltic coasts of Europe. Its breeding system is gynodioecious and gynomonoecious (some individuals bearing female flowers only, some bearing hermaphrodite flowers only and others with both types of flower). The proportions of the three types of individual vary considerably between populations, but hermaphrodite flowers tend to predominate. The showy, white, nectar‐producing flowers are produced continuously over the entire summer and are pollinated mainly by long‐tongued Hymenoptera and night‐flying moths but autogamous selfing is also frequent. Silene uniflora and its close relative S. vulgaris were the subject of a classic, decadal study involving genetical and transplant experiments that was seminal in the development of ‘experimental taxonomy’. More recently, attention has focused on the rapid evolution of Zn‐tolerant populations of S. uniflora growing on mine spoil and contaminated river gravels. It has also become a model organism for the study of sexually transmitted, castrating fungal diseases in plants (notably of the genus Microbotryum).

Geomorphic development of an unvegetated shingle cay on the Ximen Reef in the southern South China Sea

Unvegetated shingle cay (USC) is a type of coral island typically located in the southern South China Sea (SCS). Currently, there is a lack of detailed understanding of its development process and dynamic mechanism. The geomorphic development of a representative USC at the Ximen Reef in the southern SCS was examined through a field survey and high-resolution imagery analysis. The USC consisted of shingle sediments composed of coral skeletal clastics. It exhibited a composite geomorphic structure with shingle ridges and a central depression. From 2000 to 2020, the USC showed highly dynamic changes such as an increase in fully emerged area, morphological variations, and southeastward migrations. The USC development model has four main stages: 1) a shingle bank representing the embryonic foundation of the USC, 2) a mound-shaped shingle cay representing the early growth of the USC, 3) a single shingle ridge-depression representing the formation of the composite structure, and 4) a multiple shingle ridges-depression representing the adjustment of the geomorphic structure. The USC has undergone all development stages multiple times over the past two decades. The centripetal refracted wave convergence, which is controlled by the elliptical reef shape, is the key dynamic factor influencing the USC development. Monsoons and tropic cyclones play a joint role in the morphological variations in the USC during the past two decades. The short-term development of the USC at the Ximen Reef helps us understand the long-term evolution of the USCs in the southern SCS under past and future climate changes.

Planimetric and volumetric changes of reef islands in response to wave conditions

AbstractReef islands are morphologically dynamic features located on atolls and platform reefs that are very sensitive to wave‐induced processes on different timescales. The planform morphological evolution of reef islands is widely described; however, the mechanisms of the volumetric variations in response to wave energy are still poorly documented. To assess their multitemporal vertical and horizontal mobility, we performed a series of synchronous measurements of the volumetric changes and incident wave energies at two reef islands and a shingle bank at the Rocas Atoll in the South Atlantic Ocean. The results show the differences in the magnitudes and locations of the sediment mobility between the reef islands. Whereas one island remained stable on all timescales, with only small volumetric changes concentrated at its extremities, the other island (Farol Island) showed high mobility, especially during the energetic northern swell season. The gross volumetric change reached 10.03 × 103 m3 (5% of the total island volume) on a daily timescale; however, on a seasonal scale, the gross erosion was compensated by the gross accretion, indicating a cyclical seasonal pattern. Moreover, the observed volumetric changes induced by the waves on both daily and seasonal timescales did not result in large shoreline displacements. However, long‐term oceanward erosion and substantial lagoonward accretion were observed at Farol Island on a decadal scale, resulting in a pronounced change in its planform morphology. This appears to be promoted by at least three sediment transport pathways induced by waves at the atoll, including sediment adjustment between the reef islands. Our results show that reef islands on the same atoll can have very distinct morphological behaviors on daily, seasonal and decadal scales in response to the same boundary conditions. Copyright © 2017 John Wiley & Sons, Ltd.

On the presence of Long-billed Plovers Charadrius placidus in Rupa, Arunachal Pradesh in the summer months

The Long-billed Plover Charadrius placidus is a medium sized wader with a black breast band and brown cheeks. According to Grewal et al. (2002) C. Placidus is a rare winter visitor to the northern rivers and the Gujarat coast of India.Charadrius placidus has been observed in Rupa, in West Kameng District of Arunachal Pradesh not only in winters but throughout the year for a period of two years. In June-July 2010 three separate individuals were observed inhabiting the shingle banks of the river in Rupa and feeding in their typical solitary and unobtrusive fashion. This could mean that there is a breeding population of the long-billed plover Charadrius placidus in and around Rupa in West Kameng district of Arunachal Pradesh.

Assessment of ecosystem function following marine aggregate dredging

A number of indices designed to assess ecosystem function were applied to an existing benthic macrofaunal dataset collected following recent marine aggregate extraction activity at the Hastings Shingle Bank (UK). The objective of the study was to assess the use of these different functional metrics, some incorporating biological traits analysis, to investigate the rate of recovery in ecosystem function after dredging impact. All of the indices tested behaved in a broadly similar fashion following the aggregate extraction event, although some suggested faster rates of functional recovery than others. All indicated that the disturbed area of seabed was capable of full recovery given enough time. It is considered that this outcome may be because the physical nature of the seabed was unlikely to have been permanently altered by dredging for aggregate by the method used. This is not always the case following aggregate extraction and depends on the dredging protocol used (e.g., sediment screening). The indices tested (some applied for the first time to benthic macrofaunal data) were considered to be complementary to traditional environmental assessment metrics and each might be used under different circumstances.

Recovery of the seabed following marine aggregate dredging on the Hastings Shingle Bank off the southeast coast of England

The aim of this study was to investigate the effect of dredging intensity on the physical and biological recovery times of the seabed following marine aggregate dredging. Two areas of seabed, previously subject to, respectively, relatively high and lower levels of dredging intensity, were identified on the Hastings Shingle Bank. Two reference areas were also selected for comparative purposes. All four sites were monitored annually over the period 2001–2004, using a combination of acoustic, video and grab sampling techniques. Since the site was last dredged in 1996, this was intended to provide a sequence of data 5–8 years after cessation of dredging. However, an unexpected resumption of dredging within the high intensity site, during 2002 and 2003, allowed an additional assessment of the immediate effects and aftermath of renewed dredging at the seabed. The early stages of recovery could then be assessed after dredging ceased in 2003. Results from both dredged sites provide a useful insight into the early and latter stages of physical and biological recovery. A comparison of recent and historic dredge track features provided evidence of track erosion. However, tracks were still visible 8 years after the cessation of dredging. Within the high dredging intensity site, recolonisation was relatively rapid after the cessation of dredging in 2003. Rather than indicating a full recovery, we suggest that this initial ‘colonization community’ may enter a transition phase before eventually reaching equilibrium. This hypothesis is supported by results from the low intensity site, where biological recovery was judged to have taken 7 years. Further monitoring is needed in order to test this. An alternative explanation is that the rapid recovery may be explained by the settlement of large numbers of Sabellaria spinulosa. As the resumption of dredging within the high intensity site limited our assessment of longer-term recovery it is not yet possible to assume that a 7-year biological recovery period will be applicable to other, more intensively dredged areas at this or more distant locations.

Hedera helix L.

Araliaceae, Schefflereae. Climbing, sometimes reaching 30 m, or prostrate and creeping, forming extensive carpets. Woody stems up to 25 cm diameter, young twigs pubescent with stellate to peltate hairs, and densely furnished with adventitious roots. Leaves petiolate, simple, alternate, exstipulate, coriaceous, glabrous, evergreen; those of climbing or creeping stems 4–10 ( − 25) cm, palmately lobed with 3–5 triangular, entire lobes; leaves of flowering stems 6–10 cm, entire, ovate or rhombic. Leaves shining, dark green above, often with pale veins, paler green below; may become pale green/ yellow in late summer, and upper surface sometimes tinged with purple in winter. Flowers actinomorphic, c. 20 in terminal globose umbels, which may be arranged into panicles. Sepals 5, very small, deltate. Petals 5( − 6), yellowish-green, 3–4 mm, triangular-ovate, somewhat hooded at apex; free. Flowers hermaphrodite, stamens 5; ovary inferior, 5-celled, styles joined into a column. Nectar secreted by a domed disk surrounding the styles. Peduncle, pedicels and receptacle stellate-tomentose; pedicels not jointed. Fruit a berry, bluishor greenishblack (rarely yellow or white), globose, 6–8 mm. Pulp purple, seeds 1–5, c . 35 mg dry mass, rugose, whitish; embryo small, endosperm ruminate. There is considerable disagreement over the taxonomy of the ivies ( Hedera spp.), with the number of European species being cited as between one and six. Three subspecies of Hedera helix L. (hereafter ‘ivy’) are recognized in Fl. Eur.: ssp. helix , ssp. poetarum and ssp. canariensis . ‘ Hedera hibernica ’ (‘Irish ivy’) is recognized only as a horticultural form that is somewhat intermediate between H. helix ssp. helix and ssp. canariensis . Stace (1997) places ssp. canariensis with H. algeriensis Hibberd, and recognizes ‘ H. hibernica ’ as a subspecies of H. helix – ssp. hibernica (G. Kirchn.) D.C. McClint, along with ssp. helix (the common British ivy) and the yellow-fruited garden-escape ssp. poetarum Nyman, from the Mediterranean. Recent molecular data suggest that ssp. helix and ssp. hibernica may represent distinct species, with ssp. helix being the (diploid) maternal parent of the tetraploid ssp. hibernica (Ackerfield & Wen 2003). They are distinguishable by their cpDNA phylogeny, by their trichome morphology and by aspects of their ecology (McAllister 1981; McAllister & Rutherford 1990; Ackerfield & Wen 2002, 2003; Grivet & Petit 2002). Throughout this account Irish ivy will be treated as ssp. hibernica of H. helix , as in much of the older literature the subspecies concerned have not been distinguished. Hundreds of cultivars of H. helix and its subspecies are recognized in the horticultural trade.

Mapping seabed biotopes at Hastings Shingle Bank, eastern English Channel. Part 1. Assessment using sidescan sonar

A multi-technique approach was used to map the spatial distribution of seabed biotopes (i.e. physical habitats and their associated benthic assemblages) in the vicinity of Hastings Shingle Bank in the eastern English Channel, part of which is licensed for the extraction of marine aggregates for the construction industry. An area of seabed, approximately 12×4 km in size, was surveyed using a high-resolution sidescan sonar system, and a mosaic of the output was produced, covering 100% of the survey area. The area was then divided into acoustically distinct regions based on the sidescan sonar data, and the benthic communities and sediment types within each of the regions were ground-truthed using a Hamon grab fitted with a video camera, and using a heavy duty 2-m beam trawl. Additional information concerning the seabed was obtained through the application of video and photographic techniques. Sediments within the survey area ranged from cobbles and coarse gravels on the Shingle Bank, to various grades of sands to the north and south. Analysis of faunal data revealed the presence of statistically distinct biological assemblages within each acoustic region. Using all available data, four discrete biotopes were identified and their spatial distribution mapped across the survey area.

Mapping seabed biotopes at two spatial scales in the eastern English Channel. Part 2. Comparison of two acoustic ground discrimination systems

Spatial surveys of marine benthic habitats and biota based on the interpretation of acoustic data were carried out at two sites in the eastern English Channel each representing different scales of geographic area and intensity of survey. A small area (4×12 km) crossing the Hastings Shingle Bank was surveyed at a relatively high intensity (track spacing 400 m) and was nested within a larger area between Hastings and Dungeness (12×40 km), which was surveyed at a lower intensity (track spacing 2 km). Surveys were conducted with two acoustic ground discrimination systems (AGDS), RoxAnn and QTC-VIEW and the primary purpose of the investigation was to compare the performance of the two AGDS using a common approach to analysis of the different data outputs (E1 and E2 for RoxAnn and the Q eigenvectors from QTC-VIEW). Exploratory data analysis using variography indicated that interpolation between tracks was justified for the smaller site to create a complete coverage, but was limited to the creation of a digital image of the track data for the larger area. Grab and video sample data were available for supervised classification of the AGDS data and interpreted sidescan images for comparison with unsupervised classification. Both AGDS gave similar outputs, although RoxAnn consistently gave slightly better levels of performance than QTC-VIEW as measured using error matrices. Although the investigation was not designed to compare the performance of AGDS and sidescan, the outputs from AGDS were similar to the visual interpretation of the sidescan sonar data. It was concluded that despite the inherent limitations of AGDS, they may be suitable for providing distribution maps at a broad scale that can give a context for the interpretation of finer scale survey of smaller, nested areas.

Physical and biological impact of marine aggregate extraction along the French coast of the Eastern English Channel: short- and long-term post-dredging restoration

Sediment and associated macrofauna of an industrial extraction site off Dieppe have been monitored during a 10-year period. The original heterogeneous substrate of the shingle bank, characterized by gravels and coarse sands, was progressively dominated by fine sands deposited in dredging tracks. The maximum impact on benthic macrofauna was a reduction by 80% for species richness and 90% for both abundance and biomass. The structure of the community changed from one of coarse sands with Branchiostoma lanceolatum to one of fine sands with Ophelia borealis, Nephtys cirrosa, and Spiophanes bombyx, with local dominance of the opportunistic, sessile Pomatoceros triqueter on bare shingles. Impact of overflowing sands on benthic macrofauna in the surrounding deposition area proved equally large as in the dredged area. Early stages of recolonization were studied from 1995 to 1997 after cessation of dredging. Species richness has been fully restored after 16 months, while densities and biomass were still 40% and 25%, respectively, lower than in reference stations after 28 months. Nevertheless, community structure differed from the initial one corresponding to the new type of sediment. Impact within and around the dredging site was classified according to three levels. Exploration of a former experimental site (CNEXO) dredged in the 1970s provided an example of long-term restoration.

Koeleria macrantha (Ledeb.) Schultes (K. alpigena Domin, K. cristata (L.) Pers. pro parte, K. gracilis Pers., K. albescens auct. non DC.)

<i>Koeleria macrantha</i> (Ledeb.) Schultes (<i>K. alpigena</i> Domin, <i>K. cristata</i> (L.) Pers. pro parte, <i>K. gracilis</i> Pers., <i>K. albescens</i> auct. non DC.)

A comparison of realised niche relations of species in New Zealand and Britain.

Many plant species prominent in the native vegetation of the dry shingle banks at Dungeness (Britain) are also prominent as exotics in the dry Upper Clutha catchment (New Zealand). To examine the realised niche relations of these species, vegetation was sampled in the two areas. Inverse classification and ordination were used to determine the relative beta niches of the species in the two areas. There was little agreement; it seems that the exotic species in the Upper Clutha were pre-adapted to different niches from those in their native range.

CHARACTERISTICS OF SHINGLE BEACHES WITH REFERENCE TO CHRISTCHURCH BAY, S. ENGLAND

The rapid recession of the shingle bank of Hurst Beach (up to 3.5m/yr) makes it an excellent natural laboratory for the study of the factors which influence the stability of shingle beaches. Studies have included: the significance of long period, high energy, swell waves - the classification and quantification of overwash processes - run-up and seepage characteristics - the effect of settlement of the underlying strata - and the implications for practices in shingle nourishment. The studies have revealed the distinctive character of shingle beaches as compared with the more fully researched sand beaches. More detailed research on shingle beaches is justified particularly in relation to (i) the run-up characteristics including its interaction with swash cusps and (ii) the influence of the subsidiary sand fraction on the beach characteristics.

Observations on behaviour and foraging of the Ibisbill Ibidorhyncha struthersii in Nepal

In March and April 1984, I studied the territorial, courtship and foraging behaviour of Ibisbills Ibidorhyncha struthersii, mainly on Langtang Khola in Nepal. On their river‐bed breeding grounds, Ibisbills were territorial, rival birds meeting on shingle banks and performing prolonged circling displays. Aquatic invertebrates, especially stoneflies, mayflies and caddisflies, were the main prey, but fish and riparian invertebrates were taken also. When the water temperature was below 5oC, invertebrates were inactive and hidden beneath submerged stones, where the birds probed for them. When the water temperature was above 5oC, many invertebrates drifted in the water and Ibisbills switched to pecking at them from preferred feeding stations. Riparian foraging involved probing beneath stones on shingle banks and probing into soil. Foraging responses to changes in prey behaviour were similar to those of the Black Stilt Himantopus novaezealandiae on New Zealand river‐beds.

The Effect of Grazing by a Chrysomelid Beetle, Gastrophysa Viridula, on Growth and Survival of Rumex Crispus on a Shingle Bank

(1) Previous work had suggested that the absence of Rumex crispus on a shingle bank may be a result of grazing by a chrysomelid beetle, Gastrophysa viridula. (2) Sixty R. crispus plants were grown from seed in the glasshouse and planted in a regular grid on the shingle, interspersed with Rumex obtusifolius, an alternative food plant for G. viridula. (3) Thirty R. crispus were kept free of G. viridula grazing by removal of the beetle by hand. Dispersal of G. viridula from the R. obtusifolius was permitted on the other thirty R. crispus plants. (4) Gastrophysa viridula may have up to three generations in a year on the shingle. The experimental plants of R. crispus were harvested at the end of each G. viridula generation and shoot and root dry weights were measured. (5) In 1978 there was a significant reduction in both shoot and root dry weights of R. crispus when grazed by G. viridula compared with ungrazed controls. In 1980, shoot and root dry weights were significantly reduced at the end of the first generation of the beetle but reductions in the weight of grazed plants after the second generation were not significant. (6) None of the R. crispus plants was killed by grazing. (7) During the winter and spring following grazing by G. viridula, the experimental R. crispus plants were flooded. Survival of previously grazed plants was found to be approximately one-third that of plants previously protected from grazing. The reduction in rooting volume due to grazing appeared to be the main cause. (8) The virtual absence of R. crispus on the shingle bank is attributed to the combined effects of grazing by G. viridula and flooding. Neither factor would by itself eliminate R. crispus. The presence of the beetle in sufficient numbers depends on the availability of R. obtusifolius as an alternative food.

Predation and Piracy by Gulls at a Ternery in Maine

THE current increase in the numbers of large gulls, exemplified by the population of Herring Gulls in New England which is doubling every 12 to 15 years (Kadlec and Drury, 1968), has engendered much concern and speculation about its consequences for other seabirds. The general conclusion is that terns, in particular, suffer heavily from predation and competition for nesting sites (for example, Gross, 1954; Drury, 1965; Howard, 1968). Arctic and Common Terns (Sterna paradisaea and S. hirundo) are probably unaffected in the nonbreeding season by changing gull populations. Thus the interactions between terns and gulls observable at breeding colonies can be a realistic indicator of the changing fortunes of the terns in the face of predation of eggs and young, competition for nesting sites and cleptoparasitism (seizing food gathered by another, which can be considered a special form of food competition). This paper considers predation of tern chicks by Herring and Great Black-backed Gulls (Larus argentatus and L. marinus) and stealing of fish by Laughing Gulls (Larus atricilla) at a colony of Arctic and Common Terns on the island of Petit Manan, Maine. These observations were made from 17 June to 13 July 1968 during th'e course of other studies on the island. It would, of course, be unwise to attribute every reduction in the numbers of breeding terns to the gulls, especially in view of the accumulation of persistent biocides in the oceans (Risebrough et al., 1967), a potential hazard not limited to the breeding season. Nevertheless, it will be shown that a substantial number of chicks are now lost to the large gulls and that fish-stealing is likely to be significant when the terns find fishing difficult. Petit Manan (44?22' N, 67?52' W) is a small, low, treeless island 4 km SE of the point of the same name in southwestern Washington County, Maine. It lies between two outer islands with large colonies of Arctic Terns (Matinicus Rock, 104 km SW and Machias Seal Island, New Brunswick, 64 km E by N), but is closer to the mainland than either of these. The island is approximately rectangular 300 X 250 m, predominantly grassy, with exposed rocks along the north and east shores and a large shingle bank along the southern and western edges. A small part at the southeastern edge of the island that rises to 6 m above mean sea level is the site of the tall lighthouse tower and the five associated buildings are nearby. Terns nested all over the island except where disturbed by the activities

The Capricorn Reef Complex, Great Barrier Reef, Australia

ABSTRACT The Capricorn Reef Complex at the southern end of the Great Barrier Reef lies near the southern limit of the tropics and appears to be in a region that is climatically just adequate for reef growth. The reefs are found on the marginal shelves of the region and grow in a zone 25 or more miles wide. The outer reefs of the Capricorn Reef Complex are located approximately 5 miles shoreward from the shelf edge. Physiographically the complex consists of a gently undulating marine plain 15-30 fathoms deep from which individual reefal mounds rise. The upper surfaces of the reefal mounds (Reef Tops and Reefal Shoals) which are found in the shallow water, high-energy zone form slightly more than 5 percent of the study area. In contrast. the moderate- to low-energy inter-reef zones (Inter-Reef Plains, Inter-Reef Channels, Outer Shelf, and Continental Slope) constitute about 85 percent of the region. Between these extremes is an intermediate zone (Fore-Reef Slopes) which surrounds each reefal unit and grades from the shallow water high-energy zone to the deeper water, low-energy zone. The individual reefs of the Capricorn Group lie in distinct lines. It is suggested that these reefs grew on pre-reef ridges which could be sedimentary structures such as tidal-current ridges, river levees, offshore bars, or barrier islands formed during the Pleistocene low stand of sea level. The elongate shape of the individual reefs is thought to he a result of tidal currents. In detail the distinct shape of each reef is probably the result of wind, waves, biological activity, storms, and reef to reef encroachment. Skeletal material from five organisms form the bulk of the sediments in the complex, but the distribution and ecology of these organisms is poorly known. In general, coral is found growing most abundantly from low tide level to approximately 50 feet in depth on the Fore-Reef Slopes. Encrusting coralline algae creates a smooth pavement on many of the Algal Rims and also encrusts large detritus on the Reef Flats and Fore-Reef Slopes. Halimeda plants live throughout the area, but appear to be a little more abundant in protected places on the reefs and Reefal Shoals. Forams live in the shelter of coral and shingle banks on the Reef Tops, Reefal Shoals, and on the Inner Shallow Shelf to the west of the reef complex. Molluscs are found most abundantly on the sandy part of the Reef Fl t, under niggerheads on the Algal Rims, and throughout the inter-reef areas.

Gunsight Trials at Orfordness in 1916–17

Near the coast of Suffolk at a spot a little to the north of Harwich lies the village of Orford. There, from close to the ancient castle, Quay Street runs eastwards until it ends abruptly at the river, beyond which is the aerodrome and the stone and shingle banks stretching to Orfordness point and the sea. It was here in the winter of 1916–17 at the Aircraft Armament and Gunnery Experimental Establishment, that a handful of Boffins and pilots carried out a programme of research and development of gunsights and bombsights.

THE LIFE HISTORY AND ECOLOGY OF THE LITTORAL CENTIPEDE STRIGAMIA (=SCOLIOPLANES) MARITIMA (LEACH)*

The work here reported is of an investigation into the ecology and life history of a shore dwelling geophilomorph centipede Strigamia maritima (Leach). A method of determining the age of individuals and hence the life history, is described. By analysis of monthly samples it is shown that for the purposes of insemination, egg laying and moulting, individuals migrate from their feeding grounds, which are frequently covered by the tide, to a shingle bank where more terrestrial conditions prevail. The egg‐laying period is more restricted than in terrestrial species and takes place in May and June when spring tides are at their smallest amplitude and there is consequently least danger of the eggs being immersed. When animals in the feeding zone are covered by the tide they migrate out of this zone up into the shingle bank. It is concluded that the species is able to maintain itself in the intertidal zone only by virtue of the fact that non‐saline conditions prevail at the top of the beach for much of the year. Information on the prey, predators and parasites of S. maritima is given.

On the Postglacial Deposits of Western Lancashire and Cheshire

On the Postglacial Deposits of Western Lancashire and Cheshire