In a series of papers dealing with changes in the distribution of intertidal animals around Britain, and especially along the English Channel, attention was drawn to some local aspects of the general warming-up of sea and air that has taken place in the last 50 years (Southward & Crisp, 1954, 1956; Crisp and Southward, 1958). In the first of these papers smoothed values of annual mean air temperature at Plymouth Hoe, and sea surface temperature of the southern Celtic Sea were given, the latter values being based on Smed (1952). The graphs showed a rise of about 1° C in the air temperature and 0·5° C in sea temperature during 50 years.

The scavenging fauna of the Patagonian slope (900–1750 m), east of the Falkland Islands was investigated using the Aberdeen University Deep Ocean Submersible (AUDOS), an autonomous baited camera vehicle designed to photograph scavenging fish and invertebrates. The AUDOS was deployed on ten occasions in Falkland waters. Nine experiments were of 10–14 h duration and baited with 800 g of squid and one experiment lasted six days, baited with a 10 kg toothfish (Dissostichus eleginoides). Analysis of photographs revealed considerable patchiness in the composition of the scavenging fauna. Hagfish (Myxine cf. fernholmi) dominated three of the shallower experiments including the 6-d experiment, arriving quickly from down-current, holding station at the bait and consuming the soft tissues first, with consumption rates of up to 200 g h−1. In the other experiments, stone crabs (Lithodidae), the blue-hake (Antimora rostrata) and amphipods were the primary consumers, but the rate of bait consumption was lower. Patagonian toothfish (D. eleginoides) were attracted to the bait at each experiment, but did not attempt to consume the bait. The patchiness in the fauna may be a result of depth, substratum and topography, but in general the rapid response of the scavenging fauna indicates that carrion is rapidly dispersed, with little impact on the local sediment community.

Gonadial, pyloric caecal and somatic indices and oocyte size-frequencies are compared over a 3-year period for the starfish Asterias rubens from an intertidal nutritionally rich site and a subtidal impoverished site from the English Channel off south-west Britain. The intertidal population showed significantly higher values for all three indices over most of the study period compared with the subtidal population, and its spawning occurred later. The somatic index of the subtidal population showed a steeper rise than the intertidal population over that part of the cycle in which the gonads were undergoing enlargement, which gives further support to the suggestion that starfishes deprived of sufficient food may give priority to maintenance of the body-wall over enlargement of either the food-storage tissues of the pyloric caeca or the gonads.

The paper deals with four species from the Clyde Area, namely: Tellina tenuis, Tellina fabula, Abra alba, and Cardium edule.

T. Tenuis.

1. The growth at one station below L.W.M. in Kames Bay is considered. This is slower than in any other part of its vertical range.

2. Heavy spat-falls were recorded in 1926 and in 1930, but, in both cases, the spat grew slowly and died off quickly at the stations below L.W.M.

3. The general rate of growth for the species from its upper to its lower limit of distribution in Kames Bay is tabulated.

INTRODUCTION

It is well known that littoral teleosts, such as Blennius pholis, are on occasions subjected to considerable and abrupt variations in the salinity of their environment. Smith (1930) constructed a tentative model of the processes involved in the osmoregulation of teleosts; quantification of the various components of the Smith model has been extensive, but little attention has been paid to the respiratory stresses undergone by teleosts in fluctuating salinities.

Three species of Gracilaria, G. foliifera (Forsk.) Børg., G. verrucosa (Huds.) Papenf., and G. bursa-pastoris (S. M. Gmel.) Silva are recognized from the British flora (Parke & Dixon, 1976). In Britain G. verrucosa is widely distributed, although not common, whereas the other two species are rare and their distribution restricted (Newton, 1931). G. foliifera was described from the Red Sea as Fucus foliifer Forsk. (Børgesen, 1932). Plants referable to this species are now reported from various parts of the world, including both the eastern and western coasts of the north Atlantic (South & Cardinal, 1970; Taylor, 1957, 1960). However, considerable variation exists within species of Gracilaria (e.g. May, 1948), thus delimitation of species is often extremely difficult. Gracilaria foliifera from Britain (Fig. 1 A) is similar morphologically to the original material of Fucus foliifer as illustrated by Børgesen (1932, fig. 1), and therefore, we have limited our consideration to G. foliifera as it occurs in Britain (also see Harvey, 1846, pl. 15). However, little information is available on G. foliifera from the British Isles, and in the present instance we have investigated the life history of this alga in culture together with preliminary results on growth in small-scale tanks with running sea water.

The spatial heterogeneity of epifauna on a Modiolus modiolus reef off north-west Wales was investigated using divers. The community associated with these horse mussels was similar to that described previously from Loch Creran and the north basin of Strangford Lough. Some differences in epifauna may be attributable to the less sheltered nature of the site. Modiolus modiolus numbers and the associated epifaunal community were significantly different between ridge and trough sub-habitats. Troughs can be considered ‘reduced’ ridge communities whereas ridges have high densities of horse mussels and certain sessile taxa were correlated with their abundance. Modiolus modiolus aggregation as a competitive response to the feeding environment, enhanced food availability on ridges and sediment deposition amongst mussel clumps may start to explain the undulating bed-form. Patchiness in community composition and periodic cover by ophuroids has implications when considering the monitoring of the horse mussel community. Stratified, in situ recording of the highly populated ridges could improve the statistical sensitivity of monitoring horse mussel reefs whilst simultaneously focusing on the more sensitive indicators of fishing threats.

This study tested the hypothesis that predator odours alter behavioural responses of hermit crabs to other chemical stimuli. Stimuli that cause alarm and shell-related behaviour (hermit crab haemolymph and two gastropod flesh extracts), and stimuli that did not cause shell-related behaviour (sea-water and predator haemolymph) were used. Individual hermit crab responses to stimuli were observed in ambient sea-water and predator odour. In the absence of predator odour, hermit crab haemolymph and gastropod flesh extracts stimulated shell grasping behaviour. Locomotion was the major response to sea-water and stone crab haemolymph. Crabs behaved consistently when repeatedly exposed to a particular stimulus. In general, addition of predator odour to mixtures, resulted in decreased shell grasping and increased locomotion. Shell fit was a poor predictor of behaviour for the size range of crabs tested. Hermit crabs respond to, and discriminate, a variety of complex odour mixtures.

The space–time dynamic of phytoplankton diversity and succession was investigated during the wane of a Phaeocystis globosa spring bloom in four distinct hydrological sub-systems of the eastern English Channel. Nutrients, chlorophyll-a concentrations, and phytoplankton composition, standing stocks, size spectra and diversity were monitored during three key periods in 2003: late spring, early summer and summer. Two consecutive diatom assemblages were observed, respectively dominated by: (i) small colonial species (<100 μm; Melosira sp., Diploneis sp. and Navicula transitans) in April; and (ii) large fine-walled cells (>200 μm; Guinardia striata and Rhizosolenia imbricata) in May and July. This shift in diatom composition appeared to be related to the potentially limitating silicic acid in early summer. Specific phytoplankton assemblages identified in distinct water masses have evolved from a mature/senescent community towards a relatively homogeneous aestival structure of dominant species that might have been triggered by the wane of the P. globosa bloom. Our results also identified a strong heterogeneity in the distribution of secondary species between distinct water masses during the summer period, suggesting that the magnitude of the observed patterns was intrinsically related to the hydrological properties prevailing in each sub-system. The identification of distinct temporal patterns in phytoplankton species diversity and succession following the wane of a spring bloom at relatively small spatial scales (i.e. <10 km) is discussed in the framework of P. globosa blooms in particular and phytoplankton blooms in general and is suggested to have potentially strong consequences on food web dynamics and the carbon cycle in coastal ecosystems.

Adult Nassarius reticulatus were exposed for two to three months to dissolved tributyltin (TBT), dibutyltin (DBT), triphenyltin (TPT) and diphenyltin (DPT) chlorides and to copper sulphate (CuSO4) in order to study the effectiveness of these compounds to induce imposex (penis and vas deferens development). The dialkyltins and copper did not promote imposex under exposure to 500 ng Sn l−1 and 500 ng Cu l−1. However, dissolved nominal concentrations varying between 100 and 500 ng Sn l−1 of TBT or TPT induced imposex in, respectively, 22 to 43% and 24 to 44% of the females. The testosterone titres of females increased significantly after two months' exposure to 250 ng Sn l−1 of TPT and TBT and the same happened to males exposed to 100 and 250 ng TPT-Sn l−1 and to 250 ng TBT-Sn l−1.

A description is given of characters which allow the larval stages of Balanus balanoides, B. crenatus and Verruca stroemia to be identified rapidly.

It is emphasized that the characters used in this method of identification are only valid for these three species inter se, further work on similar lines for other species may reveal difficulties not apparent in the present scheme.

Measuring the impact of anthropogenic factors on marine mammals is critical to the conservation of these species. Recently, the effect of personal watercraft on marine mammal behaviour and well-being has become a topic of increasing concern. The purpose of this study was to examine the immediate effects of high-speed personal watercraft on Atlantic bottlenose dolphin (Tursiops truncatus) behaviour. Opportunistic surveys were conducted from a research vessel in the Mississippi Sound (30º13′22.6″N 89º01′36.5″W) from September 2003 through to August 2005. The passing of a high-speed personal watercraft significantly increased dolphin dive duration, dolphin group cohesion and dolphin breathing synchrony. Additionally, in 47% of the encounters a dolphin group's behaviour changed within one minute of the presence of a high-speed personal watercraft. The most notable changes were an increase in dolphin travelling behaviour and a decrease in feeding behaviour following the boat's presence. The results demonstrated an immediate, short-term change in dolphin behaviour, suggesting that an increase in the frequency of high-speed personal watercraft in this area could produce long-term detrimental effects. Research on the long-term effects of boat traffic on marine mammals is clearly needed to assess and hopefully mediate any potential long-term effects.

The prosobranchiate gastropods are divided into three orders, the Archaeogastropoda, the Mesogastropoda and the Stenoglossa. In the first of these groups the gonad is connected with the right kidney by a duct which is developed from the ovary, and the sex cells escape to the posterior end of the mantle cavity through the right ureter. The eggs are usually shed singly into the sea where fertilization occurs. In the Mesogastropoda and Stenoglossa the right kidney is not developed and the ovarian duct leads to a short and narrow section of the genital duct which is typically ciliated, and may communicate with the pericardium by a gonopericardial duct and passes anteriorly to a long glandular tract running forwards to the mouth of the mantle cavity. This glandular section is incipient in the archaeogastropod Calliostoma zizyphinum. It is probably formed, as Thiele (1935) suggests, by an ectodermal intucking and will be referred to as the pallial oviduct, for it lies anterior to the opening of the original right kidney, and must be derived from the ectoderm of the mantle (Bourne, 1908; Giese, 1915). The short duct which links it with the ovarian duct will be termed the renal oviduct: in Paludina (=Viviparus), in which its development has been investigated (Drummond, 1903), it is formed from the vestige of the right kidney, and even in the highly specialized Stenoglossa it retains the connexion with the pericardium which is characteristic of the right and left kidneys of the archaeogastropods. Similarly, in the male system of the Mesogastropoda and Stenoglossa there can be distinguished a testis duct, which is connected to the posterior end of the mantle cavity by a renal vas deferens, and this in turn is followed by a pallial vas deferens.

Due to postglacial isostatic uplift many stratified lakes, at different stages of isolation, are located along the shores of the White Sea. In five lakes, located near the White Sea Biological Station of Moscow State University, salinity, temperature, pH, concentration of dissolved oxygen, redox potential, and illuminance were measured. Distribution of microorganisms and spectral properties of water layers were also studied. All the lakes had a narrow bright coloured layer in the redox zone caused by mass development of phototropic microorganisms. Light absorption and fluorescence spectra indicated algae containing chlorophyll a predominate in the red water layers while the colouration of green and brown layers is caused by green sulphur bacteria with bacteriochlorophylls d and e. Sunlight is completely absorbed in the redox zone because of the high density of algae and/or bacteria, resulting in aphotic conditions below. Coloured layers act as a specific biotope for special communities of microorganisms. Eukaryotes identified by the 18S rRNA gene included different species of mixotrophic algae and ciliates resistant to anoxia. The water layer colour and spectral characteristics (i.e. light absorption and fluorescence) of water in the redox zone can be considered indicators of the stage of lake isolation from the sea, with the red colour caused by cryptophyte alga Rhodomonas sp. bloom found in earlier stages and brown and green colours caused by green sulphur bacteria in later stages.

Two sabellariid polychaetes, Sabellaria alveolata from European waters and Phragmatopoma californica from the west coast of North America, are known from previous work to have larvae that settle and metamorphose preferentially on the cemented sand tubes of conspecific adults. The naturally occurring inducers of larval metamorphosis were recently isolated and identified for P. californica. In the present study, larval behaviour of S. alveolata and P. californica was compared in reciprocal laboratory settlement assays. For both species, metamorphosis occurred to a greater extent on conspecific tube sand than on control sand or on heterospecific tube sand. Extraction of the tube sand of S. alveolata with organic solvents diminished its capacity to induce metamorphosis pi conspecific larvae, but this capacity was not transferred to the extracts, as was the case for P. californica. The substance responsible for the enhanced metamorphosis of S. alveolata on conspecific tube sand remains unknown. The free fatty acid (FFA) inducers of larval metamorphosis of P. californica either inhibited, or had no effect on, metamorphosis of S. alveolata. Both species responded abnormally upon exposure to unnaturally high concentrations of certain (particularly polyenoic) FFAs. Abnormal larval responses of S. alveolata, however, did not incorporate behavioural components of normal metamorphosis, as were observed for P. californica. FFAs were isolated from the natural tube sand of S. alveolata at less than one-tenth the concentration found in the natural tube sand of P. californica. The differences between the two species provide further evidence that a very specific mechanism is responsible for the perception of FFAs by the larvae of P. californica.

the evolutionary radiation of the family syngnathidae was accompanied by a diversification of structures involved in male parental care whose anatomical variations may signal differences in reproductive strategies, with increasing egg protection possibly affecting female investment in offspring or larvae quality at the end of the embryonic development phase. an analysis of egg numbers showed significant differences between syngnathids with and without marsupium, suggesting that the brood pouch, besides increasing protection to the male and its eggs, also introduced the ability to carry an additional number of offspring per pregnancy, from one or more females. curiously, even though larvae sizes do not significantly differ between the considered brooding structures (controlling for male length), seahorse larvae were smaller than expected, given the large volume of the pear-shaped eggs. these observations suggest that the sealed seahorse pouch, although allowing the transport of a great number of offspring and capable of multiple consecutive pregnancies, may impose serious functional constraints, namely those related with oxygenation of the developing larvae, thus explaining the increased egg surface together with the presence of specific salinity control mechanisms inside the marsupium.

current concerns about the population levels of the basking shark (cetorhinus maximus) in the north-east atlantic have prompted a need to understand population distribution, habitat preference and centres of abundance. in this study, spatial distribution maps derived from satellite-tag geolocations, boat surveys and public sightings data were compared. the broad distribution patterns revealed by these different methods are similar, but there are considerable differences in density distributions. surface sightings data show high densities, or ‘hotspots’ in the hebridean sea, clyde sea, irish sea and close inshore around devon and cornwall. tag geolocations, in contrast, identified two areas where individuals spent considerable time outside the distributions indicated by surveys and public sightings: the celtic sea and western approaches of the english channel. the reason for this disparity and its implications for population estimates for the species are discussed.

Nine hundred and fifty-four bass were tagged, mainly by anglers, in the river estuaries and off the coasts of Cornwall, Devonshire, Dorset and Hampshire, England, in 1970 and 1971. To date 59 bass have been recaptured, 86 % by anglers, 12 % by commercial fishermen and 2 % by research vessels. Forty-seven bass were recaptured within 16 km of their release point. Of the 12 bass recaptured at a greater distance, four were taken within 90 days and had moved by an average of 1.4 km/day. From the tag returns and the length distributions of the bass tagged by areas it is concluded that bass form permanent populations in estuaries until they are 2–3 years old, when they move offshore, eventually becoming very mobile as evidenced by the long-distance movements observed.

Heteroxenia fuscescens is a common zooxanthellate soft coral on the shallow reefs of the Gulf of Eilat, northern Red Sea. Its main nutritional sources are the uptake of dissolved organic material (DOM) and carbon fixation by its symbiotic algae (zooxanthellae). Recent studies have indicated that although colonies of H. fuscescens release planulae all year round, their fecundity was subject to seasonal changes. In this study the monthly per cent of ash, lipid, protein and carbohydrate in the coral tissue over a three year period was determined. It was found that the tissues of colonies of H. fuscescens contained a monthly per cent mean of 8.8±4 ash (without sclerites), 11±3.5 lipid, 19.2±6.4 protein, and 0.6±0.01 carbohydrate (N=36). This study is the first to present such values based on long term investigation of the biochemical profile of a coral, thus enabling an examination of temporal variability in biochemical composition among seasons and successive years. The results indicated seasonal fluctuations in lipid and protein content, while variation in the biochemical composition among years was expressed only in the protein content. The mean energetic content of H. fuscescens was relatively high at 23.3±1.2 kJ g−1 dry weight (DW). A significant difference in the energetic content of H. fuscescens was found among seasons. It is suggested that the increase in nutrient levels following the annual mixing event at the Gulf of Eilat and the raised light levels led to high energetic content during summer, which may reflect the increase in the number of embryos and developing planulae in H. fuscescens colonies. Furthermore, it is suggested that in the Gulf of Eilat seasonal fluctuations in the abiotic features of the water may have an impact on the biochemical composition and energetic content of the studied species.

The eunicid polychaete Marphysa sanguinea was until recently believed to be a cosmopolitan species, with a distribution ranging from the south-west coast of England to the Pacific coast of America, and New Zealand and Australia in the western Pacific. However, there are many morphological and ecological inter-population differences that render the definitive identification of these numerous populations difficult. The recent designation of a neotype, together with a more detailed morphological description of specimens from the type locality in south-west England, has allowed the concept that M. sanguinea represents a series of cryptic species, to be investigated by examining populations of species previously referred to as Marphysa sanguinea. A new species Marphysa mullawa was described from Moreton Bay Queensland, Australia. In this paper we describe a new species from the western Cape of South Africa which has previously been referred to as ‘Marphysa sanguinea’, using an integrative approach combining morphological data, RAPD-PCR analysis and a study of the sperm ultra-structure. The South African species is a popular bait animal for local sea anglers and is heavily exploited throughout the western Cape. The RAPD-PCR analysis also demonstrates that populations referred to as ‘Marphysa sanguinea’ from other geographical locations studied have distinct genetic pools, providing further evidence that Marphysa sanguinea is not a cosmopolitan species and consists of a suite of cryptic species.