Six hundred and seventy nine specimens of Platichthys flesus (L.) were caught in summer (July–September) 1998 and 1999 from three regions of the Polish zone of the Baltic Sea: the Gulf of Gdańsk, the Pomeranian Bay and the open sea off Łeba. The biometric measurements (length, weight, age) and sex of the specimens were recorded. The specimens were examined for occurrence of parasites. The intensity, relative density and prevalence of infection were calculated.

This paper presents information on the stomach contents of four northern bottlenose whales Hyperoodon ampullatus (Odontoceti: Ziphiidae) from the north-east Atlantic, an area for which there are few recent data on the feeding ecology of this species. Two of these whales were relatively recent strandings, a female stranded in August 1993 at Hargen (the Netherlands) and a male stranded in February 1997 on the island of Tåsinge (Denmark). Stomach content samples were also examined from a juvenile male stranded in November 1885 at Dunbar (Scotland) and a female stranded in August 1956 on the island of Texel (the Netherlands).  Food remains from the four samples consisted almost entirely of cephalopod beaks. Some fish remains were also found in the stomach of the Hargen and Tåsinge whales, and the latter also had crustacean remains in the stomach. The cephalopod prey consisted mainly of oceanic cephalopods: Gonatus sp. (probably G. fabricii, Cephalopoda: Teuthoidea), Taoniuspavo and Histioteuthis sp. for the Dunbar whale; Gonatus and Teuthowenia megalops for the Texel whale; Gonatus for the Hargen whale and Gonatus, T. megalops and Taonius pavo for the Tåsinge whale. Other prey species found in the Tåsinge specimen included the squid Histioteuthis reversa, H. arcturi, and the octopods Vampiroteuthis infernalis and Vitreledonella richardi. Based on the size of the lower beaks, the squid eaten included juvenile and mature individuals of the most important species (Gonatus and Teuthowenia megalops). The fish remains consisted of vertebrae of Gadidae and fish eye lenses (Hargen whale) and two Trisopterus otoliths (Tåsinge whale).  The results from this study are in agreement with those of previous authors in that cephalopods in general, and G. fabricii in particular, are the main prey of the northern bottlenose whale and other toothed whales in northern latitudes.

Fecundity and size at maturity of the European lobster Homarus gammarus (Crustacea: Decapoda) was estimated in four coastal regions of Ireland. Egg size increased with carapace length (CL) (egg size=0·9939×ln (CL)−3·0809). The size–fecundity relationship for all coasts combined was (fecundity=0·0044×CL3·1554).  Physiological maturity was assessed using ovary colour, ovary factor, ova size, abdomen width/CL ratio, cement gland activity and moult status as criteria. Size at 50% maturity varied from 92·5 to 96  mm depending on region. The size–maturity relationship for all coasts combined was (Maturity= 1/(1+exp(14·595−0·15598×CL))). Over 60% of lobsters in the commercial landings were under the size at 50% maturity.  Relative reproductive potential (RRP) of different size-classes was calculated from the size–fecundity and size–maturity models and the numbers by length in the landings. The modal RRP size-class was 98–100 mm. The commercial landings were dominated by the 86–92  mm size-classes.

A new species of Cerapopsis (Cerapopsis takamado) is described from the Atlantic coast of Morocco. The genus Cerapopsis, synonymized with Photis Kröyer for nearly a quarter of a century is re-established and now known to contain two species.

Dinophysis sacculus (Dinophyceae) is a potential producer of diarrhoeic shellfish poisoning (DSP). Population dynamics of this dinoflagellate was followed in the Varano lagoon, south-east Italy, with the objective of determining the seasonal abundance of D. sacculus and the relationship to environmental factors. The seasonal occurrence of this dinoflagellate showed a rather wide temporal distribution and increases in cell numbers were observed in late June and November. Dinophysis numbers seasonal changes appeared to be dependent on chemico–physical factors and dissolved nutrients. Three morphologically distinct forms of D. sacculus were found during the sampling period (March 1997–February 1998) related to the life history of the species and not to environmental conditions. In this mussel fishery, D. sacculus presence and proliferation were not associated with biotoxicity.

Diets of the four main flatfish species, Arnoglossus laterna,Bothus podas (Bothidae), Buglossidium luteum and Solea solea (Soleidae), inhabiting shallow sandy bottoms near the Gulf of Fos (north-west Mediterranean) were analysed to elucidate food partitioning between their juveniles (1+ group) in nursery areas. The two Soleidae were principally active during the night, and the two Bothidae during the day. The four species all mainly fed on the three most abundant categories of prey in the area (polychaetes, molluscs and crustaceans) but showed different food preferences. Arnoglossus laterna and B. luteum mainly preyed on crustaceans and molluscs (gastropods and bivalves) whereas Bothus podas and S. solea preyed principally on polychaetes and bivalve molluscs. Food niche width was clearly higher in A. laterna and Buglossidiumluteum (13·3 and 14·2 respectively) than in Bothus podas and S. solea (3·2 and 3·6 respectively). Overall food niche overlaps (T) obtained for each pair of fish ranged from 0·33 to 0·58. Overlap was higher between species of the same family but did not reach a significant level. Food niche overlap differed according to the period of the day but did not show any important seasonal variation. Differences in feeding rhythms, food preferences and body sizes, reduced the direct food competition between the juveniles of the four flatfish species, allowing their coexistence within the same nursery zone, despite close periods of settlement.

Minke whale (Balaenoptera acutorostrata) surfacing intervals were recorded over a period of three years in the coastal waters of Mull, Coll and the Small Isles, in the north-west of Scotland. Significant differences in surfacing intervals were noted both throughout the day and throughout the year. Surfacing intervals were shortest at noon and in the months of June and July. Surfacing intervals were longest both mid-morning and mid-afternoon and during May and August. Differences in surfacing intervals were interpreted to be the result of ecological changes such as different foraging strategies. Consequently, the results of this study have an impact on the methodologies and designs of minke whale sightings surveys.

This paper reports on the distribution of epifaunal hydroids associated with deep-sea corals collected from the boreal north-west Atlantic. Thirteen hydroid species were collected from only four coral specimens, suggesting that northern corals support highly diverse epifaunal communities.

A new species of the cold-temperate austral amphipod genus Carangolia (Gammaridea: Urothoidae) is described from bathyal depths of the Bay of Biscay (north-east Atlantic). It was occasionally sampled in the south-eastern part of the Bay with sledges towed over muddy bottoms between 522 and 924 m water depth. This depth range falls mainly below the mud-line where the proportion of organic carbon increases in response to the deposition of silts and/or clay sediment. Most specimens were sampled by the lower net of the sledges, indicating a close association with the bottom. Abundance was relatively low, ranging between 0·18 and 4·90 ind 100 m−2, latter recorded below 700 m depth. The unusual massive appearance of Carangolia mandibles and its preference for bathyal foraminiferal oozes suggest that it is a specialized foraminifer consumer. The antitropical distribution pattern currently displayed by the genus could be an artefact due to equatorial submergence.

This study deals with the associated fauna of Sabellaria alveolata (Annelida: Polychaeta) colonies on the central coast of Portugal. Samples were collected on two shores, Magoito and Avencas and a total of 137 taxa were found on both shores. In qualitative terms, χ2-test shows significant differences between shores. In Magoito crustaceans are the most abundant associated fauna while in Avencas polychaetes are the most abundant. Relative biomass and abundance per kg of sediment is much higher in eroded colonies than in developed ones and diversity seems to increase with reduced wave action.

The effect of aerial drying of biofilmed surfaces to simulate a tidal emersion upon the settlement preferences of spirorbid and bryozoan larvae was investigated using choice experiments with still water conditions carried out in the laboratory. Aerial drying of biofilmed slates and pieces of Fucus serratus for 1 h at 20°C negated their usual settlement-inducing properties to larvae of Spirorbis spirorbis, S. tridentatus and Flustrellidra hispida. Such larval settlement preference may contribute to observed variations in the natural distribution of these species in the intertidal.

Stable carbon isotope measurements (δ13C) were used to assess the sources of carbon assimilated by the fan mussel Pinna nobilis, in sea grass Posidonia oceanica meadows, and an associated shrimp Pontonia pinnophylax which occurs within this bivalve's mantle cavity. The primary carbon sources available to both animals displayed a wide range of δ13C values, from −12·3 to −22·3‰. The δ13C and δ15N of Pinna nobilis and Pontonia pinnophylax suggest that they assimilate carbon from similar sources, occupy comparable trophic levels and that their association is commensal.

The distribution and spatio–temporal variation of Helicolenus dactylopterus (Pisces: Scorpaenidae) population was studied from 816 bottom trawls developed along the Iberian coast. Multifactor analysis of variance was used to test the differences in abundance and biomass and cluster analysis was applied to detect differences in population structure. The results showed a bathymetric and latitudinal gradient in abundance and population structure along three geographic sectors in the surveyed area. In the southern area, the species was more frequent and showed a wider bathymetric distribution range than northwards. The depth range with the maximum frequency of occurrence was also wider in the southern area than northwards. Similar trends were observed in terms of abundance and biomass, with the highest and lowest indices in the southern and northern areas, respectively. The age composition of the catches showed that the population consisted mainly of young-of-the-year and juvenile fish. This fraction of the population is well represented, at a mesoscale, along the whole surveyed area, but adults are well represented only at a local scale, at the deepest strata surveyed in the southern area. In this case, recruits of age 0 and juveniles up to 4-y old were restricted to depths shallower than 500 m, while adult fish older than 6 y of age appeared below this depth. In the southern area, seasonal changes in the population structure were also observed, with modes of small fish (3–6 cm) from March to June, as a consequence of the species recruitment to the bottom. Some direct and indirect factors of biogeographic, environmental and anthropogenic origin affecting the observed gradient are discussed.

Geostatistical analysis was used to investigate the effect of drift kelp on the spatial distribution of the sea urchin Tetrapygus niger. The positions of all sea urchins were mapped in four experimental plots in the rocky intertidal zone of the central Chilean coast. When drift macroalgae were added, the sea urchins left the substratum irregularities, increased in number inside the experimental plots, and tended to form a dense aggregation around the kelp. After the drift macroalgae was removed, the aggregations disappeared and the sea urchins returned to the depressions and/or interstices of the substratum. The results suggest that the influx of drift kelp is the triggering factor in the formation of dense aggregations of this species.

The anatomy of the hook apparatus that attaches egg strings to the fish parasites Haemobaphes cyclopterina, Lernaeocera branchialis, Lernaeocera lusci, Lernaeenicus sprattae, Sarcotretes scopeli and Pennella balaenoptera (Copepoda: Pennellida) is described and illustrated. The hook rises from a cupulate base, extending posteriorly and anteriorly in the body cavity. The suspension of the apparatus in the trunk of the different species differs, but the function is similar. The hook tip enters the genital antrum, nearly penetrates the proximal end of the egg string, and continues into a notch on the antrum wall. The apex of the egg string acquires a concave depression like the finger end of a glove. In this way the string is mechanically attached inside the female genital segment. The mobile ectoparasites Lepeophtheirus salmonis and Hatschekia hippoglossi have hooks which function similarly, but perforate the strings.

Enhydrosoma curvirostre is redescribed from archived and new material with particular attention to the structure of the mouthparts and other details of the fine structure not previously reported. It is shown that the species cannot be maintained in Enhydrosoma but is more closely related to Cletodes, the genus in which the original author placed it. However, it is shown that the species must be assigned to a new genus, Spinapecruris, as a result of possessing autapomorphies on the maxillule (only seven setae on the basis), thoracopods 2–4 (a large spine on the distal margin) and possibly the caudal ramus (proximal insertion of seta VII) and lacking apomorphies which may define Cletodes.

Microphytobenthos are significant primary producers in many coastal systems. It is therefore important to quantify their biomass and productivity. Chlorophyll-a is often used as an index for microphytobenthic biomass. However, complications arise as most studies of sediment properties have been on a millimetre scale, whilst chemical and biological gradients in the surface layers of sediment occur over a microscale. The development of a new technique, the Cryolander (Wiltshire et al., 1997; Wiltshire, 2000), now allows microscale analysis of the sediment surface. Areas of high and low diatom biomass were compared using two coring techniques of different vertical resolution; the Cryolander method, with a vertical resolution of 0·2 mm and plastic core tubes (coarse coring), with a vertical resolution of 5 mm. Results indicated that, except at extreme biomass levels, coarse coring does not detect statistically significant differences in chlorophyll-a between obviously diverse sample sites. This may lead to misinterpretation of seasonal and spatial data when coarse coring is used. Furthermore microscale sectioning allows distinctions to be made between chlorophyll-a measured in the photic zone (photosynthetically active biomass (PAB)) and chlorophyll-a measured below the photic zone (photosynthetically inactive biomass (PIB)), allowing accurate determination of biomass specific primary production.

This is the first report on the presence of basking sharks Cetorhinus maximus in Galician waters (north-west Iberian Peninsula) from sightings, strandings and incidental catches by fishing gear. Morphometric, biological, geographic and temporal data on 19 basking sharks recorded from 1988 to 1998 are presented. Average total length is 401·4 cm. Male:female ratio is 0·6. Seventy per cent of records are from incidental fishing catches in bottom gill nets. Approximately 74% of sharks were recorded during February, March and April, which may suggest that the species occurs seasonally in this area.

There is sometimes a significant bias in the sex ratio of fish caught by longline. Usually, more females than males are caught. The possible reasons for unequal sex ratios in longline catches are listed and discussed. One sex could be more common in the area where the fishery takes place because there really is an unequal sex ratio in the population or because the other sex preferentially occurs in different places. Alternatively, longline fishery might preferentially catch one of the sexes. This could be a result of size difference between the sexes and thus a different response to the given hook size or bait size. Finally, sexes could differ in their feeding behaviour. There is growing evidence that females—not only of fish—are ‘energy maximizers’: they find food faster and spend more time feeding than do males. Thus, fishing methods using bait are likely to catch a higher proportion of females than fishing methods that do not use bait.

The purpose of the present study was to assess the relationship between sediment composition and biological community structure in mixed sands and gravel deposits of the eastern English Channel. Although some species are clearly associated with particular sediment types, the results confirm the lack of correspondence between community composition of the benthos and particle size distribution in unconsolidated sand and gravel deposits. The results also suggest that sample-to-sample variability commonly recorded in the species composition of macrofauna may reflect significant under-sampling by conventional grab sampling techniques. The implications of this for environmental monitoring and impact studies is discussed.