Structure and climate of the east North Atlantic are appraised within a framework of in situ measurement and altimeter remote sensing from 0°–60°N. Long zonal expendable bathythermograph/conductivity–temperature–depth probe sections show repeating internal structure in the North Atlantic Ocean. Drogued buoys and subsurface floats give westward speeds for eddies and wavelike structure. Records from longterm current meter deployments give the periodicity of the repeating structure. Eddy and wave characteristics of period, size or wavelength, westward propagation speed, and mean currents are derived at 20°N, 26°N, 32·5°N, 36°N and 48°N from in situ measurements in the Atlantic Ocean. It is shown that ocean wave and eddy-like features measured in situ correlate with altimeter structure. Interior ocean wave crests or cold dome-like temperature structures are cyclonic and have negative surface altimeter anomalies; mesoscale internal wave troughs or warm structures are anticyclonic and have positive surface height anomalies. Along the Eastern Boundary, flows and temperature climate are examined in terms of sla and North Atlantic Oscillation (NAO) Index. Longterm changes in ocean climate and circulation are derived from sla data. It is shown that longterm changes from 1992 to 2002 in the North Atlantic Current and the Subtropical Gyre transport determined from sla data correlate with winter NAO Index such that maximum flow conditions occurred in 1995 and 2000. Minimum circulation conditions occurred between 1996–1998. Years of extreme negative winter NAO Index result in enhanced poleward flow along the Eastern Boundary and anomalous winter warming along the West European Continental Slope as was measured in 1990, 1996, 1998 and 2001.

The analysis of remotely sensed altimeter data and in situ measurements shows that ERS 2 radar can monitor the ocean permanent thermocline from space. The remotely sensed sea level anomaly data account for ∼2/3 of the temperature variance or vertical displacement of isotherms at a depth of ∼550 m in the Subtropical North Atlantic Ocean near 32·5°N. This depth corresponds closely to the region of maximum temperature gradient in the permanent thermocline where near semi-annual internal vertical displacements reach 200 to 300 m. The gradient of the altimeter sea level anomaly data correlates well with measured ocean currents to a depth of 750 m. It is shown that observations from space can account for ∼3/4 of the variance of ocean currents measured in situ in the permanent thermocline over a 2-y period. The magnification of the permanent thermocline displacement with respect to the displacement of the sea surface was determined as −×650 and gives a measure of the ratio of barotropic to baroclinic decay scale of geostrophic current with depth. The overall results are used to interpret an eight year altimeter data time series in the Subtropical North Atlantic at 32·5°N which shows a dominant wave or eddy period near 200 days, rather than semi-annual and increases in energy propagating westward in 1995 (west of 25°W). The effects of rapid North Atlantic Oscillation climate change on ocean circulation are discussed. The altimeter data for the Atlantic were Fourier analysed. It is shown how the annual and semi-annual components relate to the seasonal maximum cholorophyll-a SeaWiFS signal in tropical and equatorial regions due to the lifting of the thermocline caused by seasonally varying ocean currents forced by wind stress.

In the years 1996 and 1997, the pattern of deposition of beached coral heads and pieces onto the shore of Telecom Bay within the Cape d'Aguilar Marine Reserve, Hong Kong suggested that typhoons were a significant natural perturbation. In August 1997, 808 pieces weighing 60,930 g were washed up following passage of Typhoon Victor. 1997 was also Hong Kong's wettest year on record and a survey of the living corals in the reserve in 1998 showed changes in a number of ecological parameters of species richness, composition and diversity but, most noticeably, that the formerly dominant Goniastrea aspera had been superseded by Platygyra sinensis. In 1998 and 1999, this was reflected in the changed proportions of these two beached corals. Dramatically lowered salinities in the bay during July and August 1997 may have effected this change in relative dominance. Following Typhoon Dan in October 1998, 342 pieces of corals weighing 75,600 g were collected. The 1996 and 1997 pattern seemed to be repeating itself. 1999 was a bad year for severe tropical storms and typhoons in Hong Kong, seven being reported upon. Yet, after each one only 12,490 g (Typhoon Leo), 3390 g (Typhoon Maggie), 3550 g (Severe Tropical Storm: no-name), 55 g (Typhoon Sam), 4500 g (Typhoon York and Typhoon Cam) and 3160 g (Typhoon Dan) were washed up. That is, the seven tropical depressions deposited about 27,640 g coral, approximately the same amount as only Typhoon Sally in 1996 (25,000 g) and Tropical Storm Penny and Typhoon Babs in 1998 (24,574 g) and less than half that of Typhoon Victor in 1997 (60,000 g). In July 1996, Cape d'Aguilar was declared a marine reserve, fishing banned in its 18 hectares of sea and ghost nets removed. The fishing ban seems to be halting the dislodgement of corals and they are thus not now being beached by typhoons.

The short-term response of Mediterranean upper infralittoral macroalgal species to experimental human trampling was investigated. Disturbances of six different intensities were applied within the integral reserve of the Ustica Island marine protected area (Italy, Mediterranean Sea). The dominant macroalgal species Cystoseira brachicarpa v. balearica and Dictyota mediterranea were strongly affected by human trampling. Higher levels of disturbance significantly affected both algal percentage cover and canopy at an increasing rate. Three months after trampling, for both variables it was highlighted that the algal recovery from disturbance was incomplete, being significantly different among trampling intensities. The current study revealed that in the short-term it was not possible to identify critical levels of trampling that are sustainable for this shallow community.

This work is an interpretation of a chronological data set on abundances of estuarine soft substrate invertebrates using an ecological approach. The data were collected in the framework of the European programme COST 647 (Coopération Scientifique et Technique) on coastal benthic ecology which terminated in 1992. Species numbers and selected environmental factors were recorded at two stations in the Baie de Somme (France) from 1981 to 1992. Inter-annual and seasonal variations in benthos numbers were analysed using a plotting procedure based on a non-probabilistic approach, proposed by Andrews in 1972. Ecological groups of species were identified and succession in time described, coinciding with alterations in the landings of cockles Cerastoderma edule. The chronological data set was processed through the application of the cumulated function, giving directly intensity and duration of any changes in relation to the climate and water quality, especially potential eutrophication manifestations.

To assess the recovery of the lagoon in the Valle di Gorino, Italy, the macrobenthic assemblages were studied throughout a two year period, i.e. before and after the opening of a floodgate. Three stations were located along a gradient of confinement, and sampled for macrofauna, water and sedimentary parameters. Analyses were performed through univariate and multivariate techniques. The macrobenthic assemblages were characterized by a small total number of species, strong dominance in number by a few of these species, and low diversity, but changes in community structure and composition were clearly recognizable. Significant negative correlations were found between macroalgae and macrobenthic community attributes. The altered hydrological regime due to the opening of the floodgate disrupted macroalgal cycles and altered the related macrofaunal successional dynamics: species linked to the macroalgal degradation phase became dominant throughout the Valle. After the intervention, all areas exhibited similar species composition and abundances, and appeared to be in a permanently disturbed condition. A rescaling of environmental conditions repositioned species roles in the community: those species which were typical of a certain phase of the former successional progression, were successively dominating the whole lagoon, irrespective of time and the estuarine gradient. After the intervention, the spatial and temporal distribution of macrobenthic taxa was under the control of factors linked to organic enrichment of the sediments.

The meiofauna of the St Lawrence estuary was investigated in the intertidal zone of the Parc du Bic (Quebec, Canada). Five nematode assemblages were distinguished by a cluster analysis: A1 and A2 (upper-tide level); A3 (mid-tide level); A4 and A5 (low-tide level). Discriminant function analysis showed that exposure time during low tide was the most important environmental factor in determining differences between assemblages. Chlorophyll-a, phaeopigments, sediment water content, and per cent of silt followed in the same order. Nematode densities (400–1500 ind 10 cm−2) were found to be lower than those generally reported for other estuarine intertidal zones of the eastern Atlantic coast. Mean nematode biomass in the five assemblages ranged between 96±14 and 248±86 μg Corg 10 cm−2. Deposit feeders were generally the dominant nematode feeding group in terms of abundance and biomass. Correlation of epigrowth-feeders with chlorophyll-a and phaeopigments, respectively, suggested that in the upper-tide level, old or partially degraded phytodetritus contribute more to the diet of this nematode feeding group; and in the low-tide level epigrowth-feeders may rely more on ‘fresher’ phytodetritus.

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.

Published and unpublished records of epipelagic calycophoran siphonophores from around southern Africa were examined for zoogeographic structure. There is a close match between prevailing patterns of surface ocean circulation and zoogeography, which while similar to previous studies of intertidal taxa and euphausiids, is different from them in some key details. Separate subtropical provinces are associated with both the Angola and Agulhas Currents, and the latter system has a marked influence on the composition of (warm-temperate) assemblages along the south coast of South Africa. The nearshore waters in the Benguela upwelling ecosystem (cold temperate) are distinct, but the Lüderitz upwelling cell does not appear to act as an internal boundary within the Benguela ecosystem, as has been previously noted for benthic communities. Species richness is greater in oceanic than coastal waters, and peaks in subtropical waters. High diversity is also noted offshore in the area between Capes Agulhas and Columbine, where water of Indian, Southern and Atlantic Ocean interact. Indicator species for each major water mass were tentatively identified.

The recent establishment of the lessepsian species Leonnates persicus (Annelida: Polychaeta: Nereididae) in Izmir Bay (Aegean Sea) was investigated. A total of four specimens were collected at three stations in December 2001, with two specimens having eggs within their coelomic cavities and parapodia. A re-description of the species together with its ecological and distributional aspects are provided.

Infauna diversity is reported from the Sabellaria alveolata reefs in the bay of Mont Saint-Michel in France, known as the greatest European reef formation. Polychaetes dominate the fauna, but other species also play a role in terms of reef functioning. Species richness of the associated infauna is much higher than that of the surrounding sediments and is concentrated mainly on the reef surface. Species richness clearly varied according to the three stages of reef evolution: the ‘degraded’ reef stage is different from the ‘ball-shaped structure’ and ‘platform’ stages. Multivariate analyses indicate that three species communities can be distinguished, each corresponding to a different stage of reef development. The number of species is very high, but only a few species are restricted to a particular reef stage. Variations of surface topography and spatial heterogeneity can explain unusual associations of species that make infauna associated with S. alveolata reefs very unique.

Moreover, the high densities of S. alveolata (up to 60,000 ind m−2) raise questions regarding the role of the reefs in the ecosystem of the bay. Anthropogenic influences, notably mechanical disturbances due to fishing activity, show a steady increase and may have a serious impact on the assemblage diversity and the ecological stability of the reef, even though recolonization of S.alveolata is possible in degraded reef areas. An important question that must be addressed is whether human activities could influence the role of S. alveolata reefs in the bay of Mont Saint-Michel.

Sub-lethal exposure of the marine amphipod Gammarus locusta to a range of copper concentrations (Cu) in water and spiked sediments were performed, and the resulting bioaccumulation of Cu into intracellular granules investigated. The presence of Cu-granules was demonstrated histochemically by the rubeanic acid method. The granules were quantified by automated image analyses (expressed as volume fraction, VV). The metal composition of the granules was characterized by X-ray microprobe analysis. The results showed that granules, rich in copper and sulphur, were formed in response to Cu exposure in water and sediment. These granules appeared in the B-cells of the hepatopancreas. VV values increased over the dose-range of Cu compared with control in water (P<0·001) and sediment (P<0·01) exposures. The abundance of the granules also increased with increasing whole-body Cu content, suggesting that at least part of the increasing Cu level was incorporated into the granules, as a strategy for Cu detoxification along with normal storage of Cu during the moult cycle. The presence of sulphur within the granules is thought to represent an organic detoxification mechanism for Cu. The formation of Cu-granules as a cellular response is a useful biomarker of Cu-exposure in ecotoxicological studies with amphipods. The rubeanic acid method is a useful screening tool for this copper.

The spectral sensitivities of five species of decapod crustaceans have been determined by electroretinogram measurements. Their spectral sensitivities conform to the general picture for marine crustacea with high sensitivity to blue-green wavelengths and some showing sensitivity to violet/near ultraviolet. Two deep-water species (Paromola cuvieri and Chaceon (Geryon) affinis) have spectral sensitivity maxima below 500 nm, whereas the three coastal species examined (Crangonallmani, Pandalus montagui and Nephrops norvegicus) are maximally sensitive to light of longer wavelengths (510 to 525 nm).

A new species of the genus Caprella (Crustacea: Amphipoda: Caprellidea) is described based on the specimens collected from the Strait of Gibraltar, southern Spain. The new species, Caprella caulerpensis, was found living in mud bottoms with the seaweed Caulerpa prolifera (Forskål) Lamouroux. Caprella caulerpensis can be distinguished from the most related species, Caprella rapax, mainly by the number of articles in the flagellum of antenna 1, the morphology of the dactylus of gnathopod 2 and the pereonites length.

The death assemblage of molluscs (gastropods and bivalves) from the sandy beach at Harlyn Bay, north Cornwall is shown to be fully representative of the biodiversity of the regional species pool from all habitat types. The biodiversity measures used are average taxonomic distinctness (Δ+, the average degree to which species in an assemblage are related to each other) and variation in taxonomic distinctness (Λ+, the evenness of the spread of taxa across the taxonomic spectrum). A late Pliocene fossil assemblage of molluscs from St Erth Pits, north Cornwall, UK, is also not significantly different in biodiversity, in these terms, from the present-day regional species pool. The climate in the late Pliocene was similar to the present-day Mediterranean, suggesting that predicted changes in climate, by the end of this century, will not affect molluscan biodiversity, although the species composition will undoubtedly change.

The first record of a bivalve-inhabiting hydrozoan Eugymnanthea inquilina was found in Thermaikos Gulf, north Aegean Sea, eastern Mediterranean Sea, associated with Mytilus galloprovincialis. Analyses of biometric data point the same biological differences between the Mediterranean and the Japanese Eugymnanthea, as reported by previous researchers.

The relationship between the increase of the sea surface temperature observed off the Galician coast and the appearance of a tropical poikilotherm species Argonauta argo in these coasts is discussed. This is the first record of Argonautaargo in the north-west Iberian Peninsula. A female of this species was captured alive near the surface at dusk on 22 December 2000 in the Ria de Aldán (42°15′N–08°48′W). The specimen, a mature female of 70 mm mantle length and 96 mm shell diameter, died 36 hours after introduction in the tank.

There are just a few records of giant squid of the species Architeuthis captured alive. Two living sub-adult females of Architeuthis of 180 and 135 cm mantle length with total weights of 148 and 81 kg respectively, were caught 34 miles offshore in northern Spanish Atlantic waters (43°52.54′N–05°18.4′W) in December 1999 and January 2001. From April 1999 to January 2000 in the same area, another giant squid of 102 kg as well as a single tentacle measuring 5 m, and another tentacle of 2 m long were caught. Another five living specimens were captured and 11 more animals were caught dead during the last 15 years in the same area.

Statoliths of the jumbo flying squid Dosidicus gigas (Cephalopoda: Ommastrephidae) in the eastern Pacific in 1995, 1996 (non-El Niño years) and 1997 (El Niño year) were analysed to observe whether unusual temperature increases due to El Niño was recorded in the concentration of trace elements. In addition to calcium (the major element), trace elements of manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), and strontium (Sr) were detected. Strontium concentration in the calcified tissue of some aquatic animals changes with environmental variables. However, yearly comparisons revealed that Sr concentration did not significantly differ between the El Niño year and non-El Niño years. Instead, the Sr concentration differed with squid habitats. Strontium concentration in statoliths of D. gigas from Peruvian waters (high salinity) was significantly higher than those from Costa Rican waters (low salinity) regardless of El Niño.

The distribution, abundance and feeding behaviour of sea urchins (Paracentrotus lividus, Psammechinus miliaris, Sphaerechinus granularis) and the macro-algal biomass were assessed in two maerl beds within a north-east Atlantic coastal ecosystem (Bay of Brest, Brittany, France). To study the possible control of herbivorous sea urchins on the macrophytic algae, one maerl bed under the influence of urban sewage (northern site) was compared to one less influenced by urban and industrial outlets (southern site). Macrophytic biomass in the northern site was estimated as 40-fold higher than in the southern site where sea urchins were, on average, 38-times more numerous. Preliminary results support the hypothesis that grazing of sea urchin, even in low densities, can be a factor regulating the macrophytic biomass on maerl beds except in too nutrient enriched environments. So in the northern basin of the Bay, data pointed out the role of anthropogenic impacts on macrophytic biomass increase which was concomitant with the progressive disappearance of sensitive herbivorous species like sea urchins, both processes result in change in the ecosystem.