Hydrographic measurements were made on RRS ‘Charles Darwin’ Cruise CD97 of the structure of a Subtropical Ring called STORM discovered south-west of the Azores in October 1995 which moved westward along a latitude near 32·5°N. The results showed an elliptical ring structure with a ratio of minor to major axis of 0·6. The external Ring structure extended across a scale of ~400 km in an east-west direction along the major axis of the structure. The internal structure showed isotherms (isopycnals) that were domed upwards by ~200 m. The swirl transport in the Ring was 44 Sv with a negligible barotropic component and the cyclonic flow extended throughout the water column from the surface (maximum ~50cms-1, at a radial distance of ~100km) with reduced intensity to the sea-floor ~4km depth where the flow was effectively zero. The surface currents and dynamic height data showed that the STORM centre was associated with a ~38cm lowering of sea level. The ERS-1 and ERS-2 altimeter surface signature of STORM revealed a similar structure (~42cm sea level depression) but with a larger scale of influence ~500 km. The remote sensing surface elevation structure derived from altimetry also maps (~-600X) changes in the deeper ocean temperature structure and transport (1 cm change equivalent ~ 1 Sv) in the general region. A ~500 d record from a current meter mooring deployed in the region showed three STORM signatures, each separated by a mean of ~180 days. In June 1996, HMS ‘Hecla’ crossed the North Atlantic at a latitude near 33°N and found three STORM temperature signatures.

The soft-sediment marine benthos is well-known to be patchily distributed. To test whether this could be caused by individual epifaunal movement, spatial and temporal variation in numbers of adult mudsnails, Hydrobia ulvae, were analysed within an area of 40 m2 on an intertidal mudflat over periods of 4 or 6 d on three occasions, two of spring tides and one of neap. Significant spatial variation was always present, and significant temporal variation occurred during the spring tides. There was no variation dependent on the numbers of replicate samples taken from each station. Furthermore, movement of large, individually marked winkles, Littorina saxatilis, in the same habitat was measured and shown to be significantly directional over three series of spring tides, although the mean angle of movement varied widely between the different tidal series; storm-induced movement was particularly large. Such directional movement could account for the temporal and spatial variation seen in H. ulvae. Distances moved by winkles under permanently submerged conditions, however, did not display any directional component. Estimates of the population density and dispersion of potentially mobile or movable, intertidal epibenthos obtained on a series of individual, widely spaced days must therefore be treated with caution, however much replicated on any given occasion.

The macrofauna of the benthic boundary layer (macrozooplankton and suprabenthos) was studied at six stations in May–June 1993 in the English Channel over sediments ranging from medium sand to pebble. The fauna collected consisted of 227 taxa in 30 suprabenthic sledge hauls. Numerically, the macrozooplankton was dominated by euphausids, chaetognaths, the holoplanktonic amphipod Apherusa spp. and fish larvae, and the suprabenthos by mysids (Anchialina agilis, Gastrosaccus spp.), amphipods (Stenothoe marina) and cumaceans at both medium sand stations. Suprabenthos species richness and diversity were significantly higher at western stations, in contrast to the pattern for macrozooplankton. The density of macrozooplankton was significantly higher, and suprabenthos significantly lower, at the western stations. The biomass of macrozooplankton was similar at the six stations, except in the middle of the Dover Strait which had a low biomass. The biomass of the suprabenthos was highest in the eastern part of the Channel. Two main assemblages were distinguished in relation to planktonic production and sediment composition: three western stations with two subgroups (stations 1 and 3 along the coasts of Brittany and station 2 off Plymouth); and the eastern stations also with two subgroups (station 4 in the Bay of Seine and stations 5 and 6 in the Dover Strait). For the macrozooplankton, two types of trophic structures could be distinguished: stations 1 and 4 where suspension-feeders dominated and the other stations (2, 3, 5 and 6) where carnivorous plankton feeders, omnivorous and scavengers predominate. For the suprabenthos, the plankton feeding, omnivorous and carnivorous trophic guilds dominated each station.

The metazoan meiobenthos was investigated in an Antarctic coastal sediment (Factory Cove, Signy Island, Antarctica). The fine sands contained much higher abundances compared to major sublittoral sediments worldwide. Classified second after Narrangansett Bay (North Atlantic) they reached numbers of 13 × 106 ind m-2. The meiofauna was highly abundant in the surface layers, but densities decreased sharply below 2 cm. Vertical profiles mirrored steep gradients of microbiota, chloropigments and organic matter and were coincident with chemical stratification. Spatial patchiness manifested especially in the surface layer. Nematodes dominated (up to 90%), and Aponema, Chromctdorita, Diplolaimella, Daptonema, Microlaimus and Neochromadora constituted almost the entire community. Overall, the nematode fauna showed a strong similarity with fine sand communities elsewhere. The dominant trophic strategies were epistrarum and non-selective deposit feeding, but the applied classification for feeding guild structure of the nematodes of Factory Cove is discussed. High standing stock, low diversity and shallow depth distribution may have occurred because of the high nutritive (chlorophyll exceeded lOOOmgm-2 and constituted almost 50% of the organic pool) and reductive character of the benthic environment. These observations must have originated from the substantial input of fresh organic matter from phytoplankton and microphytobenthic production, typical for an Antarctic coastal ecosystem during the austral summer.

Spatial analysis, laboratory experiments and field observations in the intertidal zone of La Ranee Estuary (northern coast of Brittany, France) of the infaunal polychaete Perinereis cultrifera indicate that the distribution and the abundance of this species appear to be related to the availability of cobbles. Individuals build U-shaped galleries with a surface gutter network protected by a cobble which acts as a roof. The study of spatio-temporal evolution of P. cultrifera burrows showed experimentally that density is important in space-sharing modalities within the sediment. Effects of increased density lead to modifications in the shape and size of the burrows. The absence of connections between burrows, as observed in ‘sandwich aquaria’ and in resin casts, suggest that the gallery is defended against intruders. The study of the distance between individuals in the laboratory did not reveal a regular distribution pattern. These results probably mean that the area around the burrow opening is not defended and, therefore, does not constitute a territory. Perinereis cultrifera is probably competing for burrow space while food may be shared. Territoriality is certainly the main factor involved in the organization and the spatial arrangements of individuals within a population.

Tigriopus californicus uses several appendages and processes in the collection and manipulation of food. Their structure and function appear to enable the species to utilize the variety of food materials found in splashpools, including: detritus and organic floes; superficial material on particles; faecal pellets; protists; diatoms; and small crustaceans. From light and scanning electron microscopy and video, the labrum and labium appear to be adapted for biting soft and hard food materials and holding food for trituration by the mandibles. From energy dispersive X-ray spectra, the gnathobase of the mandible is suggested to be sclerotized but not calcified or silicified. It has an array of bilobate and multilobate teeth, clusters of spinous processes, and a heavy, spine-bearing process to move food into the oesophagus. There is also a flange which articulates in a groove in the labrum which appears to provide a guide for the gnathobase as it moves vertically.

The study describes the seasonal density and age structure for splashpool metapopulations of Tigriopus californicus (Copepoda: Harpacticoida). Natural populations were highly variable, ranging from 217 ± 401·7 ind 1−1 in winter (mean ± SE) to 835 ± 1750·6 ind 1−1 in summer, with some populations approaching 20,000 ind 1−1 in all seasons except winter. Male-to-female ratio ranged from 1·36 in spring and summer to 1·84 in autumn, and reproduction was observed throughout the year. Nauplii abundance averaged 28 + 7·4 ind 11, a value much lower than expected for in situ copepod populations and possibly due to behavioural processes such as cannibalism and inhibition of egg deposition. The densest assemblages of splashpool microcrustacea were almost entirely T. californicus, principally mature adults and including clasped male-female pairs and ovigerous females. A simple population growth model is presented, along with parameters for calculating the instantaneous rate of increase, birth, and death in the absence of disturbance.

The reproductive cycle of the pedunculate barnacle Pollicipes pollicipes from two intertidal levels (mid and low) at Cabo de Sines, south-west coast of Portugal has been described. Pollicipes pollicipes larger than 12.5 mm (rostrocarinal distance, RC) are simultaneous hermaphrodites. Minimum size for maturity of the female gonad was 12.5 mm (RC) whilst sperm production is achieved at a smaller size (10 mm). The breeding season was from April to September. Reproductive activity was similar at both tidal levels and was significantly correlated with seawater temperature. Brooding activity was most pronounced in late spring and summer when seawater temperature ranged from 18 to 21°C. Throughout the year, sperm was stored in the seminal vesicles, although the testes regressed from October–December. The female gonad was resting in October–January and active during March–September. During resting, only a few empty ovarioles were observed. At the beginning and in the middle of the reproductive season (March to August), the ovary was completely disrupted after fertilization and ovary recovery occurred simultaneously with egg development. During the end of the reproductive season (September–October), synchrony was retarded as recovery of the ovary was slower than egg development. The pattern of functioning of the female gonad should allow production of several broods during the season.

Combining the use of scanning electron microscopy and microcinematography with functional and behavioural observations has clarified many aspects underlying the feeding processes of the small planktonic sergestid shrimp Acetes sibogae australis. In captivity Acetes sibogae australis is an opportunistic feeder that uses four principal feeding modes to capture a wide size range of prey: Artemia nauplii (<0.33 mm), copepods (<1mm) and moribund Acetes (up to 25 mm). Prey capture is effected by combined actions of the first three pairs of pereiopods and the third maxillipeds before transfer to the more dorsal second maxillipeds. The second maxillipeds are the principal appendages used in securing, manipulating, sorting and rejecting prey before insertion into the vicinity of the inner mouthparts.

Food resource partitioning and trends in feeding strategies were examined in 3882 individual decapod crustaceans collected from 1989 to 1990, using bottom trawls at depths between 380 and 2261 m in the Catalan Sea (western Mediterranean). The vertical distribution of available food resources near the bottom was the most important factor responsible for food resource partitioning among bathyal decapod crustaceans by depth stratum and season. Decapods were assigned to five different trophic groups according to the food resource exploited and feeding strategy employed (macroplankton feeders, macroplankton-epibenthic feeders, epibenthic feeders, epibenthic-endobenthic feeders, and deposit feeders). There was little dietary overlap, indicating that species did partition the available resources. Overall, dietary overlap values among species increased with depth. Although a trend to increase H’ values for diets with depth was observed, this was not significant (P < 0.10), whereas differences in the percentage of empty stomachs and the frequency of foraminiferans and pteropods in the foreguts increased significantly (P < 0.05) with depth. This last result is indicative of a progressive increase in the importance of deposit feeding in decapod crustaceans as depth increases.

The reproductive biology of the gregarious Mediterranean vermetid gastropod Dendropoma petraeum (Mollusca: Gastropoda) has been studied in the south-eastern coast of Spain. It apparently is a gonochorisric species with the sex ratio biased toward females (71%). A broad peak of more intense reproductive activity occurs in spring months and an inactive reproductive period during winter. The gonad of the males develops about two months before those of females, and storage of sperm by females has been observed. Internal fertilization takes place after the capture of pelagic spermatophores.

The egg capsules lie free within the female mantle cavity, and females brood up to 86 capsules simultaneously (the highest number reported for any vermetid gastropod). The size of the capsules is somewhat variable and increases slightly from those containing first stages of development (mean = 678×579 μm) to those containing late stages (mean = 996×693 μm). Each egg capsule usually contains a single large egg or embryo, but sometimes two (8.2% of the capsules) or rarely three (0.24%). Production of egg capsules by females seems to be continuous throughout the reproductive period (from March to October).

The unsegmented eggs measure from 440 to 507 μm in diameter (mean = 482) and are the largest reported for any vermetid gastropod. Nurse eggs are not present, and therefore most of the intracapsular nutrition comes from the internal yolk of the embryo.

Development is lecithotrophic without a pelagic larval phase. The late intracapsular veliger stage metamorphoses within the capsule and hatching occurs at a crawling juvenile stage.

In order to establish the suitability of oyster bags as a method for Manila clam culture, Ruditapes philippinarum (Mollusca: Bivalvia), five batches of clams (mean live weight 0·55 g) were placed on the ground in the intertidal zone of Eo Estuary in March 1993. Four batches were sown in bags at different densities (100, 250, 500 and 1000 clams per bag) and one sown at 160 clams per m2 in sand–gravel bed covered with plastic netting.

In August 1993 and April 1994 all batches were picked up and survival, live weight, length, height and thickness recorded. Survival of clams at the highest density was significantly lower than survival at lower densities in August 1993 (60·5%) and April 1994 (26·7%), but no differences were found among the other treatments. In addition, we found differences in growth between sets in both dates, with the best growth in the lower densities and reduced, density-dependent growth in the bags. Biometric relationships were also affected by density at the end of the experiment. High density had a greater influence on reducing shell height than on length or thickness.

It was concluded that traditional ground culture in Europe is, from both the biological and the economical viewpoints, more efficient than oyster bag culture. However, oyster bags may be useful for temporary storage or as nursery system for clams.

A total of 57 comparative hauls using a rectangular midwater trawl with a fishing mouth area of 50 m2 (RMT 50) were carried out along the sides of an imaginary triangle south of Madeira in 1986. A total of 1258 cephalopods were caught, giving a mean of 22 per haul with a range from 0 to 67. The nets were used with a diver's light on the top bar which was either switched off or was operated with a 20, 70 or 150 W bulb, powered by a car battery. A significantly greater number of individuals per haul was caught with lights on than without lights, increasing from a mean of 13·5–25·1, a factor of 1·8. Similarly, the number of species caught was increased from a mean of 7 to 10·4, a factor of 1·5 and the volume of cephalopods was increased from a mean of 41·1–162·3ml, a factor of 3·9. Similar comparisons made for catches during day or night separately and on the three courses separately also showed marked increases with the lights. Samples show that increase in power of the lights increased the total number of cephalopod individuals caught. In the 12 species with more than ten individuals, in 33 of the 36 comparisons (of number of individuals, species and volumes) there is an increase with the light. The most influenced species was Taonius pavo which increased in numbers by a mean factor of 3·9 times with 20W, 4·0 times with 70W and 6·1 times with 150W when compared with the numbers caught with no light.

Growth in Loliolus noctiluca (Myopsida: Loliginidae) in Western Port, Victoria, Australia was studied from statolith growth increments. Tetracycline staining experiments verified previous work on tropical forms of this species that showed growth increments to be deposited daily. A logistic growth function described the relationship between length and increment number. There appear to be major differences in the form of growth, longevity and life history pattern between tropical and temperate forms of this species. These are probably attributable to differences in environmental conditions.

The scorpaenid Maxillicosta scabriceps (Teleostei) and the platycephalid Platycephalus longispinis (Teleostei) were trawled seasonally for a year from shallow (5–15 m) and deeper (20–35 m) waters in four distantly-located regions of the inner continental shelf of south-western Australia. The former species was more abundant in southern regions, which is consistent with its temperate distribution, while the latter species was more abundant in deep than shallow waters. Unlike M. scabriceps, P. longispinis with total lengths < 110 mm were rarely caught, indicating that this latter species only moves on to the sandy substrate of the inner shelf when it reaches a certain size. As M. scabriceps increased in size, the contributions of mysids, amphipods and oxyrhyncan crabs to the diet declined, while those of carid decapods and brachyrhyncan crabs increased. The invertebrate fauna ingested by the smallest length-class of P. longispinis, 110–139 mm, was similar to that of the same and largest length-class of M. scabriceps. However, unlike M. scabriceps, this length-class of P. longispinis consumed teleosts, despite having a relatively smaller mouth. The contribution of teleosts subsequently increased as P. longispinis increased in size, a feature reflected by the relatively low dietary breadth of large fish. The marked shift in the types of prey ingested by P. longispinis as it increased in size accounted for the fact that, in contrast to M. scabriceps, there was limited dietary overlap between the larger and smaller members of this platycephalid. The ability of P. longispinis to ingest other fish is presumably related to the fact that platycephalids lie just under the substrate surface and are thus concealed from their potential prey, and that they are able to emerge rapidly and pursue their prey.

The demography of a lagoonal population of Lipophrys pavo over a four year period is described. This population exhibited high variability in recruitment and mortality and as a result, in age structure and density. During the study the average size at a given age decreased. This decrease was not linked to growth variation. Changes in demography and length structure are interrelated and could be linked to stressful environmental conditions and to reproductive patterns of this species.

Lipophrys pavo (Risso, 1810) is a common species in shallow waters of the rocky littoral of the Mediterranean sea (Zander, 1972; Patzner, 1984). This species differs from other Blenniidae by its ability to colonize biotopes where hard substrates are scarce (Moosleimer, 1980; Almada et al., 1994; Ruchon, 1995), and by its great euryhaline and eurythermal tolerance limits (Marion, 1890; Paris & Quignard, 1971; Zander, 1972; Müller et al., 1973; Moosleitner, 1988; Patzner & Seiwald, 1988). This euryvalence has allowed L. pavo to colonize brackish and soft-bottom lagoons of the Gulf of Lion where it is the single Blenniidae present (personal observation). Lipophrys pavo is a gonochoric species exhibiting strong sexual dimorphism (Zander, 1975; Papaconstantinou, 1979). Males are territorial nest breeders during the spawning season (Patzner et al., 1986), and females are batch spawners (Fishelson, 1963a; Patzner, 1985a).

Cephalopod prey of several cetacean species from Hawaiian waters were identified and quantified from the beaks in stomachs of stranded individuals. The different species of cetaceans all appear to target different species and sizes of cephalopods. Beaks from two sperm whales (Physeter catodon) included a total of 312 upper and 292 lower beaks (mandibles) of cephalopods. All of the cephalopods represented by lower beaks were oceanic squid belonging to 20 or more species in 14 families. The major constituents of the whale diet were Histioteuthis hoylei (45% by number and 10·9% by dry weight), Ommastrephes bartrami (7·6% by number, 30·6% by weight) and Architeuthis sp. (only 0·7% by number, but 26·5% by weight). In a Risso's dolphin (Grampus griseus) stomach, 1051 upper beaks and 1349 lower beaks were present. Eighteen or more genera of cephalopods in 15 families were present. The major constituents of the Grampus diet were Enoploteuthis spp. (36·1% by number and 30·1% by dry weight) and Abraliopsis spp. (23·6% by number, but only 4·9% by weight) and O. bartrami (1·3% and 32·1% respectively). The melon-headed whale (Peponocephala electra) eats fish as well as cephalopods which are represented by only six lower beaks belonging to five genera, Enoploteuthis, Teuthowenia, Abraliopsis, Abralia sp. and Bathyteuthis abyssicola. The beaked whale (unidentified) contained two lower beaks which were O. bartrami. Stenella attenuata also eats fish and the sample contained lower beaks, one of Enoploteuthis sp. and seven of an Abraliopsis sp.

The stomach of a female northern bottlenose whale, Hyperoodon ampullatus (Odontoceti: Ziphiidae) stranded at Hiddensee Island, western Baltic Sea, on 23 August 1993 contained 7465 cephalopod beaks (4934 upper and 2531 lower). The lower beaks were identified, their rostral lengths were measured and used to estimate size and mass of the cephalopods consumed by the whale. All lower beaks belonged to one species, the boreoatlantic gonate squid Gonatus fabricii (Cephalopoda: Teuthoidea) indicating a mean squid mantle length of 21·9 cm and a mean squid wet mass of 220·7 g. The total squid biomass in the whale's stomach represented by the lower beaks was 598·6 kg. Assuming that all upper beaks belong to G. fabricii, the squid biomass taken by the whale was estimated to be 1089 kg. Besides the beaks partly digested squid gladii, spermatophores and 15 specimens of the fish parasite Sphyrion lumpi (Crustacea: Copepoda) occurred in the stomach. No fish remains were found.

Throughout lactation, pups of pinnipeds regularly vocalize, including during interactions with their mother. In all studied species of otariids and in some phocids, these calls exhibit sufficient acoustic variation for individual recognition. As female grey seals Halichoerus grypus (Pinnipedia: Phocidae) often pup in dense colonies, and regularly leave their offspring alone to go to sea, the selective pressure for mutual vocal recognition between mothers and pups could be high. To investigate call variation in pups of this species, 170 calls of ten individual pups were analysed. Out of seven acoustic features studied, location of maximum signal strength, the number of harmonics and the frequency and strength of the fundamental show the highest individuality. However, the apparent infrequent use of pup calls during mother-pup reunions suggests that vocal signals may not play the major role in pup discrimination by female grey seals, as observed in other phocids which females do not vocalize to their pup.

Fucus vesiculosus was transplanted from one locality with an impoverished flora to another with a species-poor but different vegetation. Discs of Fucus thallus incubated in culture showed a significant increase in epiflora in the transplants. The possible applications to routine monitoring of polluted estuaries are discussed.

Harmful effects of pollution on the algal biodiversity of estuaries have been reported in numerous floristic studies (e.g. Edwards, 1972). The species-list approach suffers from a number of quite serious flaws: it is highly labour intensive; the absence of sampling rigour makes it difficult to interpret the results; and it is unsuitable as a basis for routine monitoring. In order to overcome these objections, it was decided to see if Fucus vesiculosus L. (Algae: Fucophyceae) a perennial macrophyte with high tolerance to pollution, can function as a trap for spores of smaller algae in the same locality and so express, in some way, the species richness of the surrounding vegetation. The method adopted to test this idea was simply to transfer Fucus from one locality with an impoverished flora to another with a species-poor but different vegetation, and then to quantify the effects of transference on the diversity of the epiflora.