Gyrodinium aureclum formed an extensive red tide off the south and south-west coasts of Ireland in 1978. Here are presented observations, made off Kinsale, about the biology of the bloom and the nutrient water chemistry associated with the bloom. Comparisons are made with other Gyrodinium red tides which have been recorded in the literature.

There is a long history of research on the ormer, Haliotis tuberculata L., in the Channel Islands. Stephenson (1924) was concerned with the reason for the diminution in the number of ormers off the shores of Guernsey and undertook a three months' investigation during the summer of 1923 and published brief notes on his results for further investigation. Tanner (1926) also made some brief notes on various aspects of the biology and ecology of the ormer which he said were based on 30 years' observation. In two reports (1929, 1937), Crofts dealt with aspects of bionomics, anatomy and early development of ormers with brief accounts of reproduction. Brehaut (1957) reported tagging experiments on the movement and growth of ormers and Forster (1967I gave more detailed information on these aspects, having earlier (1962) published a study on the quantitative measurement of the ormer population.

It has previously been shown in Cerastoderma edule that during periods of active growth the increments between successive growth bands each correspond to a period of tidal immersion. They can therefore be used to record instantaneous growth rates. For shells which, like Cerastoderma, conform to the Bertalanffy equation, such increments can be used independently of age and size to measure the Bertalanffy constant over brief intervals.

According to its mouthparts Calanoides carinatus is a herbivorous filter-feeder (Mensah, 1974a; Schnack, 1978) that is often associated with phytoplankton blooms. The species has been reported from the three oceans and the Mediterranean (Vervoort, 1946). Interest in this copepod is increasing due to its apparent importance as a dominant link between phytoplankton and fish in upwelling areas. Its presence in surface waters is regarded as an indication for upwelled water (Bainbridge, 1972; Binet, 1973). Population dynamics and life-cycle have been studied best on the West African shelf (Mensah, 1974b; Binet & Suisse St Claire, 1975; Petit & Courties, 1976; Binet, 1977). Courties (1978) has recently given a comprehensive review of the literature on C. carinatus. In the above-mentioned studies, generation time usually is estimated by measuring successive peaks of larval stages and adults as well as using sex ratio and length distribution. In spite of its importance, C. carinatus has not yet been successfully reared in the labora-tory. Tomasini & Petit (1977) determined experimentally the developmental time of eggs and some copepodite stages, but could not obtain all stages. Schnack (1978) studied the feeding behaviour in feeding and assimilation experiments using various species of algae on board ship.

Results from the Continuous Plankton Recorder (CPR) Survey have been used to extend the observation by Boalch & Harbour (1977 a) of the occurrence in January 1977 of a diatom Coscinodiscus nobilis (Grunow), new to British waters. Samples have been taken by the CPR to the west of the British Isles since 1948 and along the English Channel since 1957. C. nobilis was not identified until the spring of 1977, thus confirming the observations by Boalch & Harbour. It reappeared in 1978 when it was found further north in the Irish Sea.

The intertidal bivalve, Cerastoderma edule, when grown under constant conditions of temperature, salinity, water flow, light and food supply lays down faint internal shell bands at approximately semi-diurnal intervals, though with wide variations in periodicity from individual to individual. Animals grown continuously immersed under natural light/ dark cycles on a raft or below the tide marks produce similar bands. These bands are very faint compared with those in the shells of animals grown intertidally or under simulated semi-diurnal tidal conditions of emersion and immersion. The bands of intertidal animals also differ in their almost exact coincidence with the number of emersions. Cockles subjected to a diurnal cycle of immersion lay down strong bands coinciding approximately with the number of daily emersions, together with irregular faint bands. Thus the total number of bands exceeds the number of emersions.

There are many Haliotis species which are widely distributed along the rocky coasts of temperate and tropical zones, most of them inhabiting the shallow sublittoral areas. Many of them form an important part of the fisheries industry in such countries as Japan, U.S.A., South Africa and Australia. In Guernsey, the Channel Islands, the ormer Haliotis tuberculata L. has been gathered as a local delicacy at low tide of good spring tides - locally known ‘ormering’.

Extensive tagging experiments have been undertaken at various places in the world for other species of haliotids, dealing with their growth and movement (Cox, 1962; Newman, 1966; Poore, 1972; Shepherd, 1973). For H. tuberculata, two tagging experiments, in which the growth and movement of sublittoral ormer populations were dealt with in detail, have been reported (Brehaut, 1958; Forster, 1967).

The present study has laid emphasis on the structure and growth of a shore population which has been the most important object of ormering to date.

Hermit crabs, Pagurus bernhardus L., are common inhabitants of the littoral zone where they may be found in pools and puddles on the lower and middle portions of rocky shores. Only small specimens are normally found between the tidemarks but large crabs are found sublittorally as deep as 450 m. Unlike many of the animals found at a similar level on the shore, such as mussels, barnacles and winkles, Pagurus does not penetrate estuaries to any great extent. However, the smaller animals found in the littoral zone are likely to encounter reduced salinity levels caused by rainfall and terrestrial runoff.

The chlorophycean alga, Brachiomonas submarina var. pulsifera Droop, was grown in two bacteria-free chemostats, differing only in the amount of light each received. Investigations were made into the changes in biochemical composition and calorific value of the cells when they were grown at different growth rates. This information was used to help to explain changes in the growth efficiency of the rotifer Brachionus plicatilis Miiller, grown in a bacteria-free chemostat which was linked to one of the algal chemostats, the algae being supplied as the source of food.

Siboglinum ekmani can accumulate labelled alanine, glycine, phenylalanine, glutamic acid, galactose, glucose, mannose, acetic acid, palmitic acid, lactic acid and glycollic acid from sea water at concentrations between 1 and 100 μM/1. Uptake of fructose and mannitol was not detected. The neutral amino acids were absorbed against a concentration gradient, probably by a carrier-mediated transport mechanism, and similar mechanisms may exist for acidic amino acids and glucose. Most of the compounds entered into the metabolism, but 90% of the glycine accumulated was retained as free amino acid. The presence of glucose appeared to depress uptake of alanine, but uptake of glucose was stimulated by alanine.

The functions and structure of the pericardial glands (Keber's organ) of bivalves were reviewed by White (1942). The cells of this gland have been considered to have an excretory role and Grobben (1887) suggested that the cells of the pericardial gland could be compared with the chloragogen cells of annelids.

Intertidal organisms are particularly prone to the effects of both crude oil and to the chemicals commonly used to disperse the oil, following an oil spill at sea (Smith, 1968). A large body of literature now exists on the lethal effects of crude oil and dispersants but little progress has been made towards elucidating the toxic mode of action of these chemicals, nor to understanding what effects they exert when present in sub-lethal concentrations. Since the gills of aquatic animals are generally the most delicate of the epithelia exposed to the environment, it is likely that they will be most prone to damage by pollutants. Whilst previous workers using light microscopy (e.g. Clark, Finley & Gibson, 1974; Blanton & Robinson, 1973) have reported gross damage to the gills of mussels and fish following exposure to crude oil, there was no information available on the nature of the cellular damage at the ultrastructural level. In this study, we describe the nature of the lesions produced in the gills of the common intertidal limpet Patella vulgata following exposure to the water soluble fraction of North Sea crude oil and to the dispersants BP 1100 X and BP 1100 WD. A description of the ultrastructure of normal gill plates of Patella has been published previously (Nuwayhid, Davies & Elder, 1978).

An intensive study of the benthos at six deep-water stations in the Gulf of Gascogne was undertaken by the Centre Océanologique de Bretagne, Brest (during 1972–4) (Laubier & Sibuet, 1977, fig. 1). These stations were repeatedly sampled with a variety of gear during seven different ‘Biogas’ cruises, and over 1900 sipunculans belonging to 16 species including one new to science were collected. Table 1 lists these species and their abundance at the six stations. Specific station data on the samples can be obtained from the authors.

The ubiquitous nature of sipunculans is well documented by this work. Of the 72 dredge hawls made, 86% contained sipunculans, while 80% of the 54 trawl collections yielded sipunculans. Sample CP 01 with 165 sipunculans belonging to five species was the richest collection. The efficiency of the collecting gear and richness of the fauna is indicated by the fact that 24% of the individual collections yielded four or five species while 12% yielded 6–9 species, compared with the usual 1–3 species often collected. At Sample DS 62 a single haul yielded nine out of the 12 species at Station 1.

The following section contains brief comments on the species and their distribution. Full descriptions of these species and additional references can be found in Stephen & Edmonds (1972) and Cutler (1973). The subgenera of Golfingta follow Cutler & Murina (1977) and Cutler (1979).

In the sprat the utricular receptors are closely associated with the bullae, structures which convert pressures into liquid displacements, and with other structures concerned with detecting vibrating sources. This paper considers morphological features which relate to questions of mechanical coupling between utriculus and bulla, and of the number and orientation of the receptors.

A seasonal cycle in byssal attachment strength of Mytilus edulis is described in a population of mussels on the South Wales coast. Attachment strength reaches a maximum in September with a minimum in May.

INTRODUCTION

Many seasonal cycles of a physiological nature have been described in the common mussel Mytilus edulis L. (reviewed by Gabbott, 1976; also Pieters et al. 1978; Zurburg et al. 1978), some of which, for example the annual accumulation and subsequent utilization of energy substrates, appear to be linked to gametogenesis. Following spawning in the spring the gonads of Mytilus enter a resting phase; metabolic demands are low. Glycogen and protein are accumulated in the tissues at this time as phytoplankton is abundant. Gonadal development commences in autumn when phytoplankton density has declined and energy is supplied by the utilization of stored reserves. Pieters et al. (1978) have suggested that the resulting decline in reserves is accentuated by the need for greater byssus production at this time to secure the mussels against the rigours of autumn and winter storms. No accounts exist of field studies which might support this hypothesis.

This is the first detailed analysis of cephalopod beaks from the stomach of a northern bottlenosed whale, Hyperoodon ampullatus (Forster, 1770). The digestive action of many predators barely affects the chitinous beaks of cephalopods and some cetaceans accumulate the beaks in considerable numbers in their stomachs. The present beaks are clean and unbroken.

Identification of cephalopod beaks from stomachs of predators such as sperm whales (see Clarke, 1977), seals (Clarke & Trillmich, 1980) and albatrosses (Clarke, Croxall & Prince, 1980) throws considerable light on the biology and relative ecological importance of the species of cephalopods concerned as well as providing useful information on the diet of the predators.

The inter-organ nutrient transport in echinoderms has presented an interesting but as yet unresolved problem for more than eighty years. During that time two systems have been proposed as candidates for the transporting medium or transport route, namely the coelomic fluid and the haemal system.

Evidence is given which suggests that harbour seals use some form of echolocation. When visual cues are reduced, these seals make click vocalizations similar to those of animals which are known to echolocate. They are able to find live fish in total darkness, producing clicks while doing so.

Electrical responses were obtained from the utriculus of the sprat (Sprattus sprattus L). during stimulation by bursts of oscillatory pressures ranging in frequency from 2·5 to 880 Hz and in amplitude from 0·12 to 220 N m−2 (28–93 dB above threshold). These responses had double the frequency of the stimulus and we argue that they were given by two major groups of utricular receptors, one group (decompression or d-receptors) responding to movements of the utricular floor away from the fenestra of the auditory bulla, the other group (compression or c-receptors) responding to movements of the utricular floor towards the fenestra. These groups were identified with oppositely oriented groups of utricular hair cells coupled mechanically by the rigid base on which they lie. Responses grew with increasing stimulus strength over a range of over 100 dB, the slope of the log-log relation decreasing with the larger stimuli. Above 40 Hz the delays between responses and mechanical displacements were very small and the amplitude of response depended only on the amplitude of displacement and not on frequency. Below 40 Hz the sensitivity declined more steeply with reduction of frequency than would be expected from the mechanical responses of the utricular floor. When stimulating frequencies were mixed the responses were not those expected on the hypothesis that different groups of receptors were excited by the different frequencies but those expected if all displacements of the utriculus towards or away from the fenestra from a rest position gave responses in either one or other of two major groups of receptors. The response to mixed frequency pressure waves was such that high peaks were exaggerated and information about polarity preserved. The response of the utriculus to the first cycle of a burst of sinusoidal pressure stimuli was usually larger than that to subsequent cycles.

The faunas of volcanic islands must necessarily be introduced, and more recent introductions can be recognized by the patterns of their distributions. This is obvious in the Canary Islands, where we have spent 30 days studying distributions of Spirorbidae. We now regard these as a distinct family following Pillai (1970). We sampled all the major islands, by shore collecting and diving to about 10 m, and on almost all we found nine Mediterranean species, namely Protolaeospira striata (Quiévreux, 1963) and the eight opercular incubators (species of Pileolaria and Janua) that have been recorded from both Marseilles (Zibrowius, 1968) and Chios (Bailey, 1969).