The colonization of microscopic organisms, commonly called a biofilm, was examined on fibreglass panels situated intertidally at Quibray Bay of Botany Bay in New South Wales, Australia. Panels were examined by incident light microscopy, measuring percentage cover, and by a computer image analysis technique, measuring optical density. Optical density was positively correlated with and was therefore a reliable estimate of total percentage cover of the biofilm. Optical density has not been used before in this application and, although some drawbacks are discussed, it is a much more efficient sampling method than microscopic examination of panels.

The feeding ecology of the Brazilian silverside, Atherinella brasiliensis, in a sub-tropical estuary of Brazil was investigated through the gut analysis of 1431 individuals. We described dietary composition and analysed seasonal, estuarine habitat, and body size variations in the diet; trophic level; feeding diversity; and gut fullness indices. Results reveal that A. brasiliensis is a typical, generalistic and opportunistic predator that makes use of a wide array of prey types (at least 89 different types), with zooplankton (mainly calanoids), diatoms, terrestrial insects, and plant detritus making up the bulk of the overall diet. The exotic calanoid Temora turbinata ranked as the primary prey. A wide feeding diversity (mean H′ = 2.26), low trophic level (mean TROPH = 2.57), and high gut replenishment were persistent across seasons and habitats. Diet composition varied largely and significantly with respect to habitat, season, and body size. A closer assessment showed that habitat and season had a stronger effect on diet than fish size.

Thirteen carefully prepared drogued buoy assemblies have been deployed in the eastern subtropical North Atlantic giving ~20 buoy years of Lagrangian data at a depth of 200 m. The buoy results together with hydrography have revealed the structure of the eastward flowing Azores Current (AC). The main jet had a transport of 26 Sv (near 28°W) with compensating counterflows in March 1992. Jet and counterflows were readily seen in the ADCP current structure and evident in the upper layer temperature (salinity) structure on an isopycnal surface. Buoys and hydrography showed that the adjacent westward flowing counterflows resulted in recirculation both north (anticlockwise circulation) and south (clockwise circulation) of the AC - the Subtropical Recirculations. South-south-west flow (3 cm s−1) occurred in the central region of study west of the Canary Islands. The long-term movement measured in the south or northern North Equatorial Current region was 3·5 cm s−1 west-south-west. The mean south displacement per year of the buoys was 2·2° of latitude to the south and most of this displacement occurred in the first half of the year (February-August). The maximum westward displacement rate occurred six months later in October and November. The Subtropical Front/Azores Current region was identified as a zone of increased levels of kinetic energy (>100 cm2s−2) at a latitude near 34°N at the 200 m level, stretching for >2000 km, and as a marked horizontal winter sea surface temperature contrast at a latitude near 36°N. Winter mixing created an outcropping region of water with density in the range 26–4<σ0<26·6 kg m−3 along the Subtropical Front near 34°N with a maximum vertical extent of 200 m.

Pressure waves moving across the sand beds at 3 m depth at Le Racou caused circulation of water in the unconsolidated sand layer. The pattern of circulation apparently depended on the depth of the unconsolidated layer and the form of the sand ripples. The rate of flow was determined by the height of the surface waves and the permeability of the deposit. The physical properties of the sands at the crests and in the troughs of the ripples were in part determined by the organic component which in turn would have been governed largely by the patterns and flow rates of the interstitial currents supplying organic material and nutrients to the sand. Differences in the physical properties of the sediment at the crest and in the trough of a ripple due to the organic component were such as would have affected substantially the prevalence of Branchiostoma lanceolatum and harpacticoid copepods. Sand properties dependent on the organic component would clearly be subject to change in accordance with the prevailing weather conditions and hence the supply of organic material. The role of irrigated sands in the removal of organic material from shallow seas is discussed.

The Scaphopoda or tusk-shells are the smallest and most uniform class of molluscs. They burrow in sand of medium to coarse shelly grade, and specialize on a diet of hard-shelled microbenthos, particularly Foraminifera. Dentalium entalis L. is the commonest West European species, and may become locally dominant. Le Danois (1948) has described a ‘Dentalietum’ in deeper water sandy ground at about 100 fathoms in the southern Celtic Sea. Stephen (1933) discusses the distribution of D. entalis in the northern North Sea, where it is largely restricted to the ‘Offshore zone’, the southern limit being marked by the 60 m line. Low salinity is probably responsible for its absence from the southern North Sea; and in general it seems limited more by hydrographic conditions than by the relative abundance of foraminiferan food. For example, in Stephen's Thyasira+ Foraminifera Zone, it is no more than sparsely present. Holme (1953) finds Dentalium entalis rare or absent near Plymouth, though it was relatively common at the Eddystone Grounds at the end of last century (Allen, 1899). It has today receded to the mouth of the Channel, in coarse deposits resulting from fairly strong scour, and Holme suspects it to be one of the list of species sensitive to recent hydrographic changes in the area.

For the living material used in this study I am greatly indebted to Mr N. A. Holme, who collected it in deeper water in the Celtic Sea on a 1953 cruise of the R.R.S. ‘Discovery II’. With it were collected Chlamys opercularis, Caryophyllia and in places Astropecten irregularis; there were also many of the tusk-shaped serpulid tube worm Ditrupa arietina which as I found can impose a neat deception on the uncritical hunter for scaphopods.

This study employed a suite of three biomonitors to investigate trace metal pollution in the Thames estuary, a region of significant clean-up of contaminants and the cumulative return of fauna and flora over the last two decades. The biomonitors chosen are the brown seaweed Fucus vesiculosus (bladder wrack), the barnacle Balanus improvisus and the talitrid amphipod crustacean Orchestia gammarellus, in order to obtain data on the bioavailabilities of Zn, Cu, Cd, Pb, Fe, Ag and Mn in the Thames estuary in 2001, as a basis for future comparisons as pollution is further reduced in the Thames. Accumulated metal concentrations in these organisms represent integrated records of the total bioavailabilities of the metals to that organism at that location over a previous time period, and comparisons of accumulated concentrations in a biomonitor between sites are indeed comparisons of the recent contaminant bioavailabilities to that biomonitor. All three biomonitors showed geographical differences in trace metal bioavailabilities along the Thames estuary. There was general agreement in the conclusions to be drawn from each of the three species used. Raised bioavailabilities of zinc, cadmium, lead, iron and manganese are present, particularly in the middle region of the Thames investigated, downstream of the effluent discharges of the sewage works at Beckton and Crossness.

The eggs of Purpura are laid in vase-shaped capsules, attached in clusters to the rocks. Spawning takes place throughout the year, but chiefly in the winter and spring (Pelseneer, 1935; Moore, 1938; Colton, 1916). It is said to take more than an hour to produce one capsule, and 24 hr to produce ten (Pelseneer, 1935, p. 508), and the number of capsules laid at one time is said to average fifteen, and to range from six to thirty-one (Pelseneer, 1935, p. 490). Cooke (1895, p. 124) states that a single Purpura produces as many as 245 capsules. The capsules contain a large number of yolky eggs, the estimates of the numbers of these per capsule varying from three hundred to a thousand (Colton, 1916; Pelseneer, 1935, p. 527). Most of these ova are unfertilized and serve as food for the few embryos which develop: five to forty according to Pelseneer (1935, p. 481), ten to twelve according to Colton (1916). The time of development is about 4 months (Pelseneer 1935, p. 527). The capsules are laid in crevices in the rocks, or sometimes under stones, but at the same tidal level as that inhabited by the adults. The young, when hatched, are generally supposed to retreat into cracks in the rocks, presumably at the same level, and Colton states that they feed there on small Mytilus.

An improved underwater photographic apparatus has been used to take further series of photographs of the sea bottom near Plymouth. The photographs in the present series are each ¼ m.2 in area instead of 1 m.2, and at this scale definition is much better.

Photographs of the bottom in the Rame Mud area showed ripple marks but no living epifaunal animals. In an area south of the Rame Mud, on a muddy sand and gravel bottom and in a similar area 6 miles south of Looe, dense populations of the brittle-star, Ophiothrix fragilis were photographed. In the area south of Looe this type of population (density more than 100 individuals per m.2) ha s been photographed on three different occasions in 1950–1. In a similar but still denser Ophiothrix population found ¾ mile north-west of Eddystone, there were about 340 individuals per m.2, and this aggregation was apparently of long standing, since exceptionally large dredge hauls of Ophiothrix were taken there in the last decade of the nineteenth century. It is suggested that the food supply for these populations, in the form of suspended material, is brought to them largely by the tidal streams and that the crowded beds are in localities where this is likely to happen.

Previous studies with the marine gastropod Littorina littorea have shown that cadmium is concentrated in the digestive gland and that cytosolic metallothionein-like proteins sequester a large proportion of the accumulated burden. In the current investigation, an electron microscope cryo-preparation method and X-ray microanalysis have revealed that some cadmium, in association with sulphur, is localised in the region of the limiting membrane of the mineralised granules which detoxify certain metals as an insoluble phosphate salt. It appears, therefore, that there could be interaction between the sulphur and phosphate systems for binding metals within the basophil cells of the digestive epithelium.

Spisula subtruncata is a shallow-burrowing member of the Mactridae which inhabits silty sand. Adaptations to such conditions include long frontal cilia on the gills (Atkins), and the presence of a siphonal membrane with associated mantle folds over-arching a waste canal, as postulated by Kellogg for allied species.

The mantle edges are free ventrally, but are normally closely applied except for a short distance at the base of the inhalant siphon, an effective fourth pallial aperture being so formed. Through this opening material from the waste canal is ejected.

Lutraria lutraria is a deep-burrowing species belonging to the same family. The general resemblance to Mya arenaria is due to convergence. Cleansing currents resemble those of Spisula subtruncata and there is a similar waste canal, but the siphonal membrane and the long frontal cilia associated with a silty environment are absent.

Orientated navigational behaviour in Talitrus saltator (Montagu) was studied throughout the diel cycle. Amphipods released at the centre of a circular arena without an artificial horizon on the periphery showed random escape directions at all times of day. In the presence of an artificial light/dark boundary the escape direction was random at night but was towards the boundary by day. The onset of significantly orientated navigation occurred just before the time of dawn and persisted in a typically circadian manner for 7 days in amphipods kept in continuous darkness.

The phase of the circadian rhythm could be reset in altered light/dark cycles. Phase changes were directly proportional to imposed L:D phases over the range —4 to + 12 h, except that shifts from —2 to +2 h induced no phase change in the orientation rhythm. The endogenous pattern of change of orientated navigation is discussed in relation to the nocturnal endogenous locomotor activity rhythm of Talitrus and its diel pattern of foraging and burrowing behaviour on sandy beaches.

The growth of the Ficopomatus enigmaticus reefs was measured throughout a coastal lagoon at different temporal and spatial scales (over 24 years, annually and monthly throughout the coastal lagoon). The results show that reef cover increased in the last 24 years, and many neighbouring reefs have coalesced into large platforms. Growth rate varies spatially and temporally. Small reefs grow faster than large ones. Ficopomatus enigmaticus polychaetes living in higher salinity areas show a lower biomass than those living in brackish water areas, and the same pattern was observed for the inter-ring distance measured on the tubes. The results also show that important environmental variables, including salinity, nutrient availability and environmental energy (measured as current speed and depth) may be the most important factors affecting the growth and spread of the reefs.

A total of 11 polydorid species of the family Spionidae were extracted from non-calcareous substrata from Japan. The polydorids were: one Polydora sp., Polydora cornuta; three Dipolydora spp., Dipolydora quadrilobata, D. cardalia, D. socialis; one Carazziella sp., Carazziella spongilla; one Boccardiella sp., Boccardiella hamata; two Boccardia spp., Boccardia perata, B. proboscidea; three Pseudopolydora spp., Pseudopolydora cf. kempi, P. antennata, P. paucibranchiata. All inhabited mud deposits including mud in crevices of calcareous substrata, sponge and sandstone rocks, and were never found in self-excavated burrows in calcareous substrata. This study attempts to summarize and discuss the taxonomic, morphological, and behavioural characteristics of these non-boring species inhabiting Japanese waters and to compare them with the previously known boring species. The 11 non-boring species belonged to six genera. Thus their taxonomic and morphological variability was higher than those of boring species, which belonged only to three genera. A generic overview suggests that some genera contain many species capable of boring and others contain many species incapable of boring. Branchial blood vessels were thick and conspicuous in non-boring species. Moreover, they showed high crawling activity and a strong, vigorous palp movement. These observations suggest a possible link between boring activity and the morphology and behaviour in polydorids. In addition, Polydora cornuta, Dipolydora quadrilobata, D. cardalia, D. socialis, Boccardia perata and Pseudopolydora cf. kempi are new to Japan.

Although sponges constitute the dominant animal group in marine caves globally, few studies have investigated quantitatively their diversity patterns in this habitat. Regarding Mediterranean marine caves, data describing the structure and diversity gradients of sponge assemblages are available for the north-western basin, while information for the eastern Mediterranean is almost inexistent. In this study, the sponge assemblages in two Aegean marine caves (eastern Mediterranean Sea) with different topography were examined using a non-destructive method. In each cave, three quadrats (25 × 25 cm) were photographed at 5 m intervals, along three transects: one along the ceiling and two along the opposite walls. Per cent coverage for each sponge species was calculated using advanced image processing software. Our analyses revealed a rich sponge assemblage, which consisted of 50 species assigned to eight growth forms. Resemblance analysis for the surveyed caves revealed two major groups of samples corresponding to the shadowy outer and the darker internal cave sectors. However, differences in species composition as well as divergent spatial patterns of species richness, Shannon–Wiener diversity and morphological diversity were found not only between the caves but also between different transects within each cave. Sponge morphological diversity presented significant positive correlation with species richness and Shannon–Wiener diversity in both caves, suggesting that it could possibly be used as a surrogate measure for describing sponge diversity gradients in Mediterranean caves. Cave topography was found to have a significant effect on the observed diversity patterns and assemblage structure, highlighting the high level of individuality in these unique habitats.

The functional morphology of the veliger, pediveliger, and early post-larva of Venus striatula is described. Settlement takes place at a length of 220- 240 /u, and is marked by the rapid loss of the velum, functioning of the byssus gland, and commencement of secretion of the post-larval shell (dissoconch). With the exception of the loss of the velum, the changes which occur at metamorphosis take place relatively slowly. The significance to phylogeny of the mode of development of certain organs in the post-larva is discussed. It is concluded that the form of many of the organs in development, especially of those organs concerned in producing a respiratory and feeding current, are juvenile adaptations, resulting in the early functional re-adjustment of the free-swimming larval habit to a bottom-living habit, but having little or no phylogenetic significance.

Attention was first drawn by Wilson (1932) to the large copepod fauna which can be found in an ordinary sandy beach. In his introduction he describes his method of collecting these copepods (p. 7) and in the course of the paper describes a number of new genera and species thus obtained.

Sand-dwelling animals, particularly Crustacea and worms (excluding sessile forms), are usually regarded as burrowers, since in their migrations they displace the particles of their environment. The fauna opened up by Wilson's discovery is of a quite different type. In contrast to true sand-burrowing animals, these copepods do not displace the particles of the sand through which they move but crawl over the surface of the grains, which, by capillarity, always hold more or less water, even high up on the beach at low tide. Such copepods, together with nematodes, rotifers, protozoa and other animals sufficiently small, may be regarded as part of an “interstitial” fauna.

The effect of short-term (5 days) exposure to CO2-acidified seawater (year 2100 predicted values, ocean pH = 7.6) on key aspects of the function of the intertidal common limpet Patella vulgata (Gastropoda: Patellidae) was investigated. Changes in extracellular acid–base balance were almost completely compensated by an increase in bicarbonate ions. A concomitant increase in haemolymph Ca2+ and visible shell dissolution implicated passive shell dissolution as the bicarbonate source. Analysis of the radula using SEM revealed that individuals from the hypercapnic treatment showed an increase in the number of damaged teeth and the extent to which such teeth were damaged compared with controls. As radula teeth are composed mainly of chitin, acid dissolution seems unlikely, and so the proximate cause of damage is unknown. There was no hypercapnia-related change in metabolism (O2 uptake) or feeding rate, also discounting the possibility that teeth damage was a result of a CO2-related increase in grazing. We conclude that although the limpet appears to have the physiological capacity to maintain its extracellular acid–base balance, metabolism and feeding rate over a 5 days exposure to acidified seawater, radular damage somehow incurred during this time could still compromise feeding in the longer term, in turn decreasing the top-down ecosystem control that P. vulgata exerts over rocky shore environments.

Sea water collected at Station E1, surface, between June 1948, and November 1949, contained suspended matter from 2·77 to 0·45 g./m.3 (or parts per million) dried and ignited. A few determinations of insoluble organic matter gave 1·77 to 1·15 parts per million dry weight at 100° C. The ignited residue contained from 55 to 17% silica, 28 to 3 of ferric oxide, 20 to under 1 of alumina and 70 (or excluding one high value 29) to 9 calcium carbonate. There was nothing in the records for temperature or salinity to suggest that the water mass had changed during the period of sampling.

The analyses reveal an unsuspectedly large amount of iron, compared with that found in solution. The ignited residue is rich in silicate, judging from the silica alumina ratio, but it is quite doubtful whether the additional supply of silicate available for diatoms is at all adequate to balance their requirements calculated on a phosphate utilization basis. It seems more probable that a considerable amount of the phosphate is available for non-siliceous phytoplankton.

A new species of Chrysochromulina with an unusual type of cocoon-like scaly covering has been described with the light microscope. The morphology and arrangement of the scales has been elucidated with the electron microscope. Salient features are the presence of four different types of scale (large and small plates and large and small spines) in characteristic positions in or on the case, the small plates having the normal two layers characteristic of primitive scales in this group, the other three types being specialized modifications of this. Some developmental and evolutionary consequences of the morphological observations are discussed. A preliminary observation on the thickness of micro-fibrils composing the base-plates of spined scales is given.