The effects of nutrient enrichment of natural water bodies range from small increases in plant biomass and production, to gross deterioration of water quality. The input of nutrients (e.g. nitrogen and phosphorus) to the sea off NW Europe (especially the North Sea) has increased dramatically over the last three or four decades (Folkard & Jones, 1974; Bennekom et al., 1975; Postma, 1978; Cadee, 1986a) but there is uncertainty about the effects on the ecosystem. One possible effect might be to induce changes in the phytoplankton community. Such an effect has been reported for the North Sea, where increases in flagellate algae have been observed (Gieskes & Kraay, 1977; Postma, 1985; Cadee, 1986b; Batje & Michaelis, 1986). Phaeocystis is one such alga, and its purported involvement in the formation of large quantities of foam, observed on European beaches (Batje & Michaelis, 1986; Weisse et al, 1986), together with evidence that the alga is a source of atmospheric sulphur compounds (Barnard et al, 1984) (with implications for atmospheric acidity), has attracted particular attention and concern

Using a 24-year time series of monthly samples, the factors correlated with long-term variation in the abundance and growth of sole, Solea solea, in Bridgwater Bay in the Bristol Channel, England are identified. This bay offers shallow estuarine habitat used by sole as a nursery area. Sole first enter the bay in July when 2–3 months old and after a residence of 4–5 months, the majority migrate offshore at the beginning of winter to return the following April. By three years of age most have left the bay never to return although occasional large fish up to 480 mm in length are caught. Sole were found to be highly seasonal in their growth and only increased in length during the months of May to August inclusive. In recent years, there has been an approximately exponential increase in sole abundance that is highly positively correlated with seawater temperature during the early part of the season. The average length of fish in September, at the end of their first growing season, showed significant between year variation, ranging from 65·3 mm in 1989 to 79·8 mm in 2003. This variation was positively correlated with the North Atlantic Oscillation (NAO) winter index for the winter prior to their birth. Between year recruitment variation is correlated with both water temperature and the rate of growth. High temperatures allow faster development and a positive NAO index increases productivity and offers more food. Both of these positive influences act to reduce mortality resulting in stronger year-classes. No relationships between sole and other fish and macro-crustaceans living in the nursery were identified.

Baited traps deployed at 7800 m in the Atacama Trench off northern Chile, captured over 400 specimens of Eurythenes gryllus. This is the greatest depth of occurrence reported for the species. Of the 398 specimens available for study, all but three were female, giving a sex ratio very different from any reported previously. Female specimens measured 29–76 mm in length, and all were immature. Length/frequency distributions based on total length, peraeonite 1 length, and coxa 4 oostegite length were unimodal. Relationships between total length, and peraeonite 1 length, oostegite length, and wet weight were established. Oostegite development appeared to be precocious compared with published data. Subtle differences in peraeon, urosome, gnathopods, coxa 4, peraeopod 7, and epimeron 3 morphology, and the growth of oostegites separate Atacama Trench specimens from previously described material. The morphology exhibited by these specimens lies outside the known variability of E. gryllus, and suggests that this pan-oceanic entity may be undergoing incipient speciation.

Evidence for the presence of silica in the costae of Stephanoeca diplocostata Ellis has been provided by a combination of light and electron microscopy. The solubility of costae in hydrofluoric acid has been demonstrated. The presence of silicon in the costae has been strongly confirmed by means of the X-ray analytical electron microscope (EMMA) but tests for a crystalline substructure by means of electron diffraction were negative; it is concluded that silicon is present in a crystallographically amorphous form. Preliminary observations on other biological aspects of the organism include the presence of a sac-like membrane between the lorica and protoplast, the presence of immature costal strips within the cytoplasm and the nature of ingested food. The phyletic position of the group is briefly discussed with special reference to mitochondrial substructure.

A nocturnal larval hatching rhythm is described for the lobster Homarus gammarus. In natural illumination cycles, hatching takes place shortly after darkness with the hatching process lasting for about 1 min or less. One female lobster can release batches of larvae each successive night for periods of from 2 to 6 weeks, depending on size and water temperature during the period of hatching. The hatching rhythm persists, though slightly out of phase, when lobsters that have been releasing larvae for some time are kept in constant darkness, but in constant illumination hatching may be delayed for 2 or 3 days and when it does occur it is erratic and non-rhythmic. Larvae that do hatch in constant illumination appear to do so without parental assistance. Onset of darkness synchronizes the rhythm but an endogenous component is involved in controlling it.

Spontaneous rhythmic activity in the lugworm Arenicola marina (L.) is believed to be under control of a pacemaker located in the ventral nerve cord and oesophageal plexus (Wells, 1937). Since the rhythmic component which often dominates the spontaneous behaviour of polychaete worms consists of movements resulting in irrigation of the tube or burrow, and thus ventilation of respiratory surfaces, pacemaker control of the rhythm differs strikingly from reflex control of ventilation in other animals.

The discovery of the association between the sponge Desmapsamma anchorata (Demospongiae: Poecilosclerida: Desmacididae) and the octocoral Carijoa riisei (Cnidaria: Alcyonacea: Clavularidae) on an Indonesian reef enlarges the widespread dispersion of these Atlantic species in the Indo-Pacific area. The species involved and their morphological adaptations resulting from the association are described. When covered by the sponge, C. riisei develops an irregular branching pattern and a dense nematocyst layer where the ectoderm comes in contact with the sponge tissue. The finding of fertile colonies suggests that the Indonesian population of C. riisei is self-sustaining.

The reproductive cycles of four limpet species, Patella depressa, Patella ulyssiponensis, Patella vulgata and Patella rustica are described for several locations in northern and central Portugal. Patella depressa and P. ulyssiponensis displayed almost continual gonad activity, with two main spawning periods, September–January and March–June, and minor spawning events dispersed throughout the year. Patella vulgata and P. rustica exhibited highly synchronized reproductive cycles, with well-defined breeding and resting periods. Gonad development in P. vulgata started in September and spawning took place from November–December to March. In P. rustica development started in June and spawning occurred from September–October to December–January. Compared to the 1980s these results suggest that breeding periods are becoming longer in southern species and shorter in northern species.

Repopulation by green sea urchins Strongylocentrotus droebachiensis of a steeply sloping rock bottom was monitored at a wave-exposed headland (Chebucto Head) following a disease outbreak that caused mass mortality in September 1999. Density and size of urchins were sampled in four depth strata: at 8–10 m in an urchin grazing aggregation (front) along the lower margin of a kelp bed, at 12 m and 16 m on a bedrock ramp, and at 24 m on a cobble and boulder field where urchins were unaffected by the disease. Shoreward migration of adults along the ramp from the surviving population at 24 m was the primary means of repopulation, which was augmented by recruitment via planktonic larvae. At 16 m, urchin density stabilized (at ∼50 urchins m−2) within six months of the die-off while repopulation at 12 m took more than eight months. A grazing front of large urchins (40–60 mm, test diameter) had formed along the lower edge of a kelp bed by January 2002, which reached densities of up to 284 urchins m−2. Video surveys at Chebucto Head and two adjacent locations of similar bathymetry revealed an extensive urchin population between 25 and 55 m depth, with a mean density on rocky substrata of 73 urchins m−2.

The Adriatic Sea, being a semi-closed and shallow basin, is more sensitive to anthropogenic impact than other areas of the Mediterranean Sea. Given the crucial role of meiofauna in the marine ecosystems, temporal series of data on this benthic assemblage are fundamental to give new insights into the health status of this basin. A data set (decade 2002–2012) on the meiofauna of two river mouths (Foglia and Metauro) close to a Natural Park (Monte San Bartolo, Central Adriatic Sea) has been analysed and related to several environmental parameters. In particular, changes in the meiofaunal structure, abundance and diversity have been investigated in order to evaluate possible variations of ecological quality status (EQS), in accordance with the Water Framework Directive. The structure of the meiofaunal assemblage appeared significantly different in the period studied, with a higher abundance of annelids in 2002 and an increase of nematodes in the following sampling campaigns. Among the faunal parameters, the Shannon and Pielou indices suggested a decline of the EQS over time, likely mainly due to the negative effect of chlorophyll-a peaks, which may highlight the influence of eutrophication phenomena and an enhancement of the organic matter supply. The lowering of the EQS of the study area suggests the need to intensify management and conservation efforts in the coastal systems, and supports the use of the meiofaunal assemblage as a useful bioindicator.

A comparison of photographs taken on the eastern shore of Salcombe harbour before and after the disappearance of much of the Zostera marina L. shows that where previously there existed extensive sand banks, stabilized by the growth of this plant, there has been a lowering of ground level of 2 ft. or more, due to the washing away of the sand where the Zostera has died. Much of the ground is more stony than before and has become largely covered with seaweed attached to the stones. The buried fauna is not as rich as it was and some species previously common are rare or have disappeared altogether. A few small patches of Zostera still survive, but the plants are shorter with narrower leaves than before.

The waters of La Réunion, a French island located in the south-western Indian Ocean, have never been investigated for cetacean diversity. Dedicated daily surveys were conducted in 2004–2007 to assess cetacean diversity off the western and southern coasts of the island. A total of ten species was observed during the survey period, including two baleen whales and eight odontocetes. Four additional species that had not been observed at sea were reported stranded. The most frequent delphinid species were the Indo-Pacific bottlenose, the spinner and the common bottlenose dolphins, which were observed year-round. Photo-identification data showed a high recapture rate of Tursiops aduncus, strongly suggesting a resident population. The humpback whale uses the coastal waters of La Réunion seasonally, during winter. The high proportion of mother–calf pairs indicated that La Réunion might represent a breeding area for this species. Pantropical spotted dolphin, melon-headed whale and Fraser's dolphin were sighted at a medium frequency, in offshore waters, and tended to favour the southern part of the island. Three coastal species were frequently using the newly created Marine Protected Area (MPA), supporting the view that cetacean conservation issues have to be included in the MPA management plan currently in progress.

The uptake of 134Cs by 36 species of marine and freshwater fish and shellfish has been measured, and for selected species has been shown to depend on a power of the weight. For plaice, lobster, and eel, over thousand-fold ranges of weight, the uptake varies according to ω0.78. The times taken to reach half-equilibrium concentrations vary according to a value between ω0.25 and ω0.29, e.g. for a 100-fold increase in weight there is a 3.5-fold increase in half-value time.

The American whelk tingle, Urosalpinx cinerea (Say), a gastropod enemy of oysters, has been introduced to Britain with American oysters and is now established in the rivers Blackwater, Colne, Crouch and Roach in Essex and on the Kentish Flats off Whitstable. Evidence available concerning the migratory powers of Urosalpinx is conflicting, but it is probable that migration is of local significance only in the spread of this pest. To infest new areas tingles or their spawn must be transported by human or other agency, for Urosalpinx has no free-swimming larval stage, the eggs being deposited in capsules from which fully formed young tingles emerge.

Females of Urosalpinx grow more quickly than males and reach a larger size. In males the annual increase in shell height never exceeds 0·2 cm. after the first 3 years, and is generally rather less. In females an annual increment of 0·2 cm., or slightly more, is general up to the age of about 7 years, after which it gradually falls. Males and females of the same age differ in height by about 0·25 cm. Growth marks are frequently to be seen on the shell and are of value in assessing growth rates. In both sexes a maximum age of 13–14 years may be reached. Urosalpinx reaches a much greater average size in Britain than in its natural habitat on the Atlantic coast of the U.S.A.

Females may deposit some spawn during the first 2 years of life, but the amount is insignificant in relation to the production of older tingles. Spawning begins when the water temperature in its seasonal rise reaches 12° C. Adult females may deposit an average of 25 egg capsules at a single laying, but it is possible that further capsules are deposited later in the season. The bulk of the spawn is deposited in May and June on British beds, but a few freshly laid capsules may sometimes be found in August and September. The average period of incubation is about eight weeks. Young tingles usually begin to emerge early in July. The average number of young emerging from each capsule is 11–74. Urosalpinx appears to be more prolific on British oyster beds than in America.

The genus Bathyporeia has featured in many reports on the ecology of sandy beaches, yet little is known of the annual reproductive cycles of the species in British waters. Watkin (1938,1939a, b, 1941, 1942) has studied the taxonomy and aspects of the ecology of the genus, and more recently Salvat (1967) has described the annual reproductive cycle of B. pilosa Lindstrom, B. pelagica (Bate), B. sarsi Watkin and B. guilliamsonia (Bate) on the west coast of France. The present report is the result of an investigation into the vertical distribution and annual reproductive patterns of B. pilosa and B. pelagica on a sandy beach at Ynyslas, Cardiganshire. Whilst enabling comparisons to be made with Salvat's data, this study also forms the basis for an investigation into the ecophysiological complex of B. pilosa and B. pelagica.

An occurrence of ‘milky water’ which covered a wide area of the North Sea in June 1975 is described. The water contained 20 mg/1 of an oil which was shown by capillary GC-MS to consist mainly (> 80%) of two wax esters 34:1 and 36:1. Analysis of the acids and alcohols released by hydrolysis, and interpretation of the wax ester mass spectra, indicated that the 34:1 ester was almost entirely composed of the alcohol-acid combination 20:1–14:0 and the 36:1 ester was composed of 22:1–14:0 (75%) and 20:1–16:0 (19%). Wax esters of virtually the same composition predominate in the lipids of the copepod Calanus finmarchicus which has the implication that the ‘milky water’ was caused by ageing of the oil released following a mass mortality of copepods. The lack of polyunsaturated wax esters and of astaxanthin is ascribed to oxidative degradation of these labile lipids following release into the sea. A copepod origin for the milky water is further supported by its containing small amounts of cholesterol and pristane, both of which are common to Calanus species.

We collected data on the distribution of fin whales (Balaenoptera physalus) and minke whales (Balaenoptera acutorostrata) in the Bay of Fundy, Canada from a whale-watching vessel during commercial tours between July and September 2002. A single observer recorded the positions, species, numbers and surface activity of whales encountered during boat tours. We controlled for biased search effort by calculating sightings rates for both species in cells measuring 2′ latitude by 2′ longitude throughout the study area. Sightings rates were calculated by dividing the number of sightings of fin and minke whales in each cell by the number of visits by the tour boat to that cell. We used generalized additive models and generalized linear models to examine the influence of benthic topography on whale distribution patterns. Models showed a non-linear relationship for minke whale sighting rates with increasing benthic slopes and a linear relationship for minke and fin whale sightings rates with increasing water depth. Sightings of minkes were concentrated in areas subject to tidal wakes near the northern tips of Grand Manan and Campobello Island. Fin whales were also found off the northern tip of Grand Manan but sighting rates for this species were highest in areas with less benthic sloping topography adjacent to the relatively deep Owen Basin. Foraging was recorded during 87% of all whale encounters and our results indicate that whale distribution in this area is likely to be influenced by depth, bottom topography and fine scale oceanographic features that facilitate foraging.

Scanning electron and optical microscopic examination of the hinge apparatus and primary ligament pit of two Recent mytilids (Mytilus edulis and Modiolus modiolus) revealed a similar sequence of ontogenetic changes in both species from the prodissoconch I stage through metamorphosis. Hinge-line dentition was absent at the prodissoconch I stage. Provinculum length and complexity increased throughout larval development with progressive lateral thickening characteristic of the family Mytilidae.

Data are given on the abundance of post-larval stages of teleostean fish in half-hour oblique hauls with the 2-metre stramin ring-trawl taken at weekly intervals at a position two miles east of the Eddystone lighthouse during the years 1930 to 1934 inclusive.

The seasonal composition of the catches is considered and it is shown that there is a gradual change over from the young of northern species of fish to those of more southern species as the summer advances. The relation between the spawning times of closely related species appears usually to be a function of their geographic distribution.

The period of maximum abundance of post-larvæ of spring-spawning fish occurs at different times in different years and this difference may be as much as a month. An apparent correlation between the times of abundance of young whiting and the previous temperature of the water has been shown.

The larval shell of molluscs contains a preserved record of the organism's growth and developmental history. Many investigators have utilized the information recorded in the larval shell morphology to infer mode of development.

Marine prosobranch gastropods were collected from intertidal sites from Maine to Florida and were cultured in the laboratory. Scanning electron microscopy was used to document the relationship of larval shell morphology to development. Four species with planktotrophic larvae, Crepidula fornicata, Crepidula plana, Cerithium atratum and Ilyanassa obsoleta, and four species with non-planktotrophic development, Crepidula convexa, Littorina obtusata, Busycon canaliculatum and Urosalpinx cinerea, were successfully reared through metamorphosis.