The reproduction of the plaice has been studied in the North Sea (Wimpenny, 1949; Barr, 1963), in the eastern and western English Channel (Houghton & Harding, 1976) as well as in the bay of Douarnenez (Deniel, 1981). In 1972, Lahaye described the sexual cycle of the plaice caught in the Portsall area.

After the wreck of the ‘Amoco Cadiz’ off Brittany in March 1978, more diversified studies of this species were made to assess the effects of the oil spill on the plaice stocks in the contaminated area. In Lannion and Morlaix Bays, these fishes exhibited a clear decrease of growth, fin necrosis and an absence of recruitment in the population in 1978 (Desaunay, 1981; Maurin, 1984). In the Abers Wrac'h and Benoit, estuaries of the north-west coast of Brittany (Fig. 1) which were gravely affected by the oil spill, Haensly & Neff (1979) and Miossec (1981, 1984) noted a big change in reproduction. Conan & Friha (1981) observed abnormally low growth for plaice in Aber Benoit.

Dogfish eggs would appear to be eminently suitable for physiological study because of their large size, easy availability (egg laying seems to be continuous throughout the year except for a break during the autumn (Craik, 1978)); their long lasting development (between 240 and 300 days from laying to hatching (Foulley & Mellinger, 1980a)); the clear separation between yolk-sac and embryo, and the fact that eggs are normally laid in pairs (opening up the possibility of keeping one of them as control whilst experimenting upon the other).

As well as being a popular sport fish, the bass (Dicentrarchus labrax L. 1758) is a valuable commercial species in England and Wales. In 1984 bass landings in England and Wales were estimated to have a first sale value of between £5–6 million (G. D. Pickett, personal communication). Concern has been expressed about the vulnerability of the stock to overfishing and to variability in recruitment, and there have been a number of studies of bass biology, distribution of the eggs and larvae, and of possible migratory movements of the fish during the adult phase, (Kennedy & Fitzmaurice, 1968, 1972; Kelley, 1979; Holden & Williams, 1974; Dando & Demir, 1985). This paper reviews the published data on eggs and larvae and presents new data on their distribution and abundance in the English Channel and southern North Sea between 1981 and 1984.

Published information on the diet of bass in U.K. waters is limited. The very young fish, mainly 0- and 1-groups, have been investigated in the Fleet (Dorset) by Bass et al. (1983), in the Severn Estuary by Aprahamian & Barr (1985), and at the Kingsnorth power-station outfall in Kent by Langford (in preparation). Limited data for older fish have been given by Sant (1978) for the central Welsh coast and by Hester (1980) for the Cornish coast. An early report by the present author reviewed the feeding habits of 250 bass aged 3–16 years caught in 1946–52 in Devon and Cornwall (Kelley, 1953). Data for southern Irish waters have been given by Kennedy & Fitzmaurice (1972), and for west Brittany waters by Boulineau-Coatanea (1969). Other reports from mainland Europe are concerned chiefly with young bass reared in the etangs of the south and west coasts of France and in similar habitats on the coasts of Spain and Italy. There are similar reports from Tunis and Israel. These more specialised studies are listed by Barnabe (1980).

Previous records of Blackfordia virginica, from river estuaries and marineconnected lagoonal systems, show the species to be euryhaline and eurythermal. The collection of the medusa in the estuary of the River Mira provides not only a second record for the eastern North Atlantic but also further evidence of the medusa's requirement for such conditions. It is known to tolerate salinities of 3–35‰ (distribution). Measurements of salinity in the Mira Estuary in April and November 1984, when the medusae were collected, were 15 and 32.5‰ respectively (J. Paula, personal communication).

Blooms of the dinoflagellate, Gyrodinium aureolum have been recorded on the coasts of Europe and are fully reviewed by Tangen (1977) and Boalch (1979). The significance of these blooms is considerable, and with the increase in the eutrophication of inshore waters they are now an important factor influencing the ecology of coastal waters (Boalch, 1984). Their numbers increase to concentrations in excess of five million cells per litre during warm, stable conditions resulting in the waters becoming a greenish-brown colour, ‘slimy’ and with a characteristic smell (Boalch, 1979; Jenkinson, 1986). At these concentrations there are reports that local fauna may be adversely affected and certain species will die.

Television cameras and video equipment are well established as tools in many areas of marine research and have been reviewed by Barnes (1963), Myrberg (1973), Harris (1980), and Holme (1984, 1985). The TV camera is usually mounted on a remote sledge (Machan & Fedra, 1975; Holme & Barrett, 1977) or submersible, often with arrays of lights, and lacks the manoeuvrability that is necessary for many types of detailed survey and behavioural recording. Commercial and industrial uses also demand high-resolution equipment that is often contained in bulky underwater cases capable of operating at great depths and well below that possible by the conventional SCUBA diver. It is not unusual for the equipment to be used in conjunction with external lighting units where natural light levels are too low for the use of ambient light, and is dependent on an external power supply normally situated in the surface support vessel or within a submersible (Sisman, 1982).

Three genera of Acanthonotozomatidae have been recorded from the British Isles, Iphimedia, Panoploea and Odius. The latter genus is distinctive, but the former two differ from one another only in the relative development of the palp of maxilla 1, which is variable throughout the group. It is shorter than the outer plate in P. minuta and P. eblanae, a little shorter than the outer plate in I. vicina, equal in length to the outer plate in I. quasimodius and longer than the outer plate in I. obesa and I. serratipes. There appears, therefore, to be no good phylogenetic justification for separating the two genera, and following Ruffo & Schiecke (1979, 1982) the genus Panoploea is relegated to the synonymy of Iphimedia.

The geographic distributions of most surface-dwelling species of planktonic Foraminifera are now well-known (Bé, 1959, 1960, 1977; Bé & Hamlin, 1967; Bé, Vilks & Lott, 1971; Bé & Tolderlund, 1971; Tolderlund & Bé, 1971; Bé & Hutson, 1977). These distributions, established from species abundance in plankton net collections, have been used to correlate abundance with physical and chemical variables (primarily temperature and salinity) in an effort to establish the factors which control the geographic range of these shelled protists. Significant correlations have been derived from these comparisons and the temperature and salinity ‘limits’ and ‘optima’ of a number of species have been reported (e.g. Bé & Tolderlund, 1971).

Orbulina universa d'Orbigny is a spinose planktonic foraminifer which occurs throughout surface waters of the tropical, subtropical and transition zones of the world ocean (Bé & Tolderlund, 1971). This species is unique among planktonic Foraminifera in that its life cycle is composed of two growth stages. The juvenile stage is a trochospiral form which is enclosed within a terminal spherical chamber in the adult stage. O. universa is relatively omnivorous, and consumes a variety of prey that range in size and quality from phytoplankton to copepods (Bé et al. 1977; Anderson et al. 1979; Spindler et al. 1984). In addition, each individual harbors several thousand zooxanthellae which presumably are an additional source of nutrition for the foraminifer (Be et al. 1977; Hemleben & Spindler, 1983; Spero & Parker, 1985).

Killary Harbour is a fjord or sea loch on the west coast of Ireland. With the growth of aquaculture the harbour has become the site of both raft mussel cultivation and more recently, salmon farming. The successful management of these resources requires a detailed knowledge of the harbour's hydrography and ecology. In 1980/1 an extensive survey of the harbour was made. Papers dealing with primary productivity (McMahon & Patching, 1984) zooplankton (Ryan et al. 1986) and the biology of mussels (Rodhouse et al. 1984 a, b, 1985) have already been published. In this paper, we describe the phytoplankton of the harbour and factors which influence distribution and growth.

In the most recent monograph of the marine planarians Wilhelmi (1909) described only one new species, viz. Procerodes dohrni, which nevertheless was strikingly similar to P. lobata (Schmidt, 1861). More recently Den Hartog (1968) has described inadequately a rather similar species, P. ireneae, and the taxonomic status of these three species is now somewhat confused, making proper identification difficult. For the present paper the available material of these species has been re-examined with the view of elucidating their taxonomic status.

The Molpadiida is an order of sea cucumbers identified by their stout body, the posterior region narrowing to simulate a tail and the absence of tubefeet. Typically they inhabit muddy environments from shallow water to abyssal depths. In the past the great variability in the taxonomic characters of this order has led to the formation of many genera and species (Heding, 1931, 1935), but more recently it has become apparent that many diagnostic characters change markedly during the life history of these holothurians and as a result fewer species are now recognised (Deichmann, 1940; Pawson, 1977). In a revision of the Atlantic molpadiids Deichmann (1940) recorded just three species from the north-east Atlantic (Molpadia blakei, M. musculus and Hedingia albicans) with a further three species from the Arctic Ocean and Norwegian Sea (M. arctica, M. borealis and Eupyrgus scaber). To these Sibuet (1974) added the new genus and species Cherbonniera utriculus found in the Bay of Biscay.

A species of Eulalia, keying out as E. pusilla Örsted, 1843 in Fauvel (1923) and Hartmann-Schröder (1971), was collected at Plymouth in 1986. This species does not however agree with the original description, nor does it occur in the Danish waters from where E. pusilla was first described. The confusion apparently stems from Quatrefages (1865) and Saint-Joseph (1888) who both incorrectly applied Örsted's name to this more southerly species, the latter author providing the first accurate description.

The analysis of the complex trophic relations characteristic of plankton communities is much simpler in an isolated body of water than in the open sea. In fact, in the open sea physical processes make many biological phenomena difficult to recognize, and advection and turbulence generally make it impossible to sample repetitively the same population of organisms for long periods of time.

There are 290 described species in the tube-dwelling family Sabellidae (Fauchald, 1977), but our knowledge of their reproductive biology is limited, in whole or in part, to no more than 30 species (McEuen, Wu & Chia, 1983; Knight-Jones & Bowden, 1984). In the monogeneric subfamily Myxicolinae, the diminutive Myxicola aesthetica (=dinardensis) (Claparède) is known to undergo scissiparity (Caullery & Mesnil, 1920; Okada, 1934; Knight-Jones & Bowden, 1984). For the larger species, M. infundibulum (Reinier), the only information on reproduction is: an illustration of the sperm (Claparede, 1870), the conclusion that it spawns during the autumn in the Bay of Fundy and adjacent waters (MacKay, 1977 a, b), and that autotomy has not been observed and regeneration is limited to the branchial plume (Wells, 1952).

Detailed studies of post-larval shell, hinge and/or internal morphogenesis, from metamorphosis to the completion of development, are available for a very small number of infaunal bivalves (for review of studies see Webb (1984). This paper continues the description, using scanning electron microscopy (SEM), of the post-larval ontogeny of some common infaunal bivalves from north-west European communities and presents the development of Nucula turgida, Venus striatula, Spisula subtruncata and S. elliptica. The association between larval shell morphology and certain features of development in some protobranch bivalves is examined.