Because of the attention at present focused on the artificial rearing of plaice and other flat fish, there has been a revival of interest in the shallow sandy areas where the first bottom stages of these fish live. An additional interest in such areas derives from the growing threat of marine pollution. A need is being increasingly felt for more basic data on the structure of animal communities in unpolluted coastal waters, and on the range of natural variation within these communities so that base lines can be set, against which changes due to pollution may be assessed. With all these interests in mind, a detailed study is at present under way from the Marine Laboratory, Aberdeen, of the fauna of Scottish coastal waters. This paper, dealing with some of the preliminary results, describes the range of macrobenthic biomass of intertidal sand communities, and discusses the variations.

Although a good deal of attention has been paid to the type of sediments found in the south-western English Channel as a whole (see, for example, Allen, 1899; Stride, 1959, 1963; Flemming & Stride, 1967) very little work has been done on the local distribution of sediments in the immediate coastal area. The only data on the sediments in St Austell and Mevagissey Bays appear to have been given by Holme (1961), but even he provides details for only three stations. Some information on sediments in these bays in less recent times can be obtained from early Admiralty surveys, although the accuracy of some of the very old data may be questioned.

This investigation of the bottom fauna of St Austell and Mevagissey Bays was prompted by the feeling among local fishermen that the increasing amount of china-clay waste being deposited in the bays was adversely affecting the local fishery. Physical pollution on a large scale can harm a fishery in a number of ways. The smothering of shellfish grounds is often to be expected, and where the pollutant contains a high proportion of very fine particles there is the danger that unstable clay banks will build up and constitute a purely mechanical hazard to trawling and potting. In this paper, however, we are concerned only with the effects of clay-waste pollution upon the bottom fauna, since it had been suggested that clay deposition might be impairing St Austell and Mevagissey Bays as feeding grounds for demersal fish.

Previous work on the biological effects of china-clay waste includes that of Miss N. Sproston (1945, unpublished), who examined the effects of suspended clay upon some species of pelagic fish. This worker was unable to demonstrate any recognizable effect of mica particles (present in clay waste) upon the gill tissues of fish taken from polluted water at Pentewan. However, Herbert et al. (1961) recorded cases of gill damage in Salmo trutta from china-clay-polluted reaches of the River Fal. These workers also showed that ‘the bottom fauna in the control streams was on average 3.3 times greater than in the polluted part of the Fal and 19 times greater than in the polluted part of the Par’.

Three species of grey mullet have been recognized in the English fauna, namely, Thick-lipped, Thin-lipped, and Golden. There have been several revisions of the Mugilidae, and the names preferred here are: Thick-lipped grey mullet, Crenimugil labrosus (Risso); Thin-lipped grey mullet, Liza ramada (Risso); Golden grey mullet, Liza aurata (Risso).

Despite the widespread occurrence of Eurydice pulchra Leach on sand beaches along the Atlantic coasts of Europe and around Britain (Jones & Naylor, 1967), there has been no detailed work on growth and reproduction in this species until a recent account by Salvat (1966), who carried out investigations on breeding populations of this species and the closely allied E. affinis at Arcachon, south-west France. Apart from this there are some brief generalized observations on the reproductive cycle of E. pulchra in ecological studies upon the fauna of sandy beaches (Watkin, 1941, 1942; Scott, 1960; Lagardère, 1966), and some reference to reproduction in other species of the genus is given by Fage (1933), Bacesco (1948), and Soika (1955). In view of some contrasting accounts given by previous authors and the lack of detailed observations on British material, present investigations were carried out into the reproduction and life cycle of E. pulchra and E. affinis in South Wales. Estimates of the reproductive potential of each species are made and discussed in relation to actual population densities recorded on the beaches.

The overriding metabolic advantages of aerobic as compared with anaerobic respiration have resulted in its use by the majority of multicellular organisms. However, in some habitats oxygen is limiting to such an extent that anaerobic respiration becomes a necessity for survival. It has frequently been demonstrated that the extent of anaerobiosis depends, obviously, on the degree of oxygenation of the environment (see reviews by von Brand, 1944, 1945; Beadle, 1961). Hence, not only are there entirely anaerobic organisms but many other organisms exist which, in times of anoxic stress, are able to undergo a partial, or facultative, anaerobiosis. Lindeman (1942) discovered that, at low temperature, aquatic chironomid larvae could survive the entire winter anaerobically in the anoxic hypolimnion of freshwater lakes. Similarly, but to a lesser extent, pond-living crayfish of the genus Cambarus are more resistant to low oxygen concentration than stream-living individuals (Park, 1945). Walshe (1948) has also been able to establish a similar relationship in a group of stream and ditch dwelling chironomid larvae.

The area of Christchurch and Poole Bays has been cut by the sea in the period since the breaching of the Chalk ridge between the Isles of Wight and Purbeck late in the Flandrian transgression. Erosion of the soft Tertiary rocks must have been fast and is still active. In the Barton area the cliffs have been receding at about 1 m/year since 1895 (May, unpublished). There the cliffs are composed of badly cemented sands and sandy clays, capped with plateau gravels about 3 m thick, and erosion of them has released large quantities of sand and gravel, sufficient to maintain features such as Hurst Spit. This Spit approaches within 1.3 km of the Isle of Wight, but is separated from it by the tidal channel of the West Solent, in this area up to 60 m deep. In these narrows the south west flowing ebb current reaches 2.25 m/sec, whereas the flood current only reaches 2 m/sec.

While preparing a report on Echinodermata from the Stilly Isles, based on collections made by the University of London Sub-Aqua Club but including also earlier records by various authors (F. W. E. Rowe, J. nat. Hist., in the Press), it became apparent that the species generally known as Cucumaria saxicola Brady & Robertson and C. normani Pace, from Mortensen's classic handbook (1927), have not been satisfactorily reassigned generically since the break-up of Cucumaria sensu extenso and need new generic names in conformity with current views on generic distinctions in the Dendrochirotida.

Mortensen (1927), in his survey of the Echinoderms of the British Isles, includes seven species in the genus Cucumaria: C. frondosa (Gunnerus); C. elongata Düben & Koren; C. hyndmanni Thompson; C. saxicola Brady & Robertson; C. normani Pace;C. lactea (Forbes) and C. planci (Brandt), this last species being wrongly credited to von Marenzeller.

C. frondosa is a plump to barrel-shaped animal with ten large, bushy tentacles, podia, at least in the older specimens, not restricted to the ambulacral areas, a calcareous ring with no posterior bifurcations on the radial plates or any fusion of the ventralmost radial and adjacent interradial plates and spicules of the body wall comprising thin, multilocular, smooth or slightly thorny plates, these being more or less restricted to the posterior region and to the podia in older animals. It has been designated type-species of the genus by Panning (1949), thus delimiting Cucumaria sensu stricto. The other species included by Mortensen cannot be treated as being congeneric with frondosa by virtue of their elongate body, ten relatively small tentacles of which the ventralmost two are smaller than the remaining eight, podia restricted to the ambulacral areas, calcareous ring showing a tendency, in some forms, to develop posterior bifurcations on the radial plates and fusion of the ventral-most radial and adjacent interradial plates and the differing form and combinations of spicules of the body wall.

In recent years the general adoption of high-speed plankton samplers has given new impetus to studies of the distribution and survival rate of larval and post-larval fishes; instruments ranging in size from the small Hardy Indicator type to enlarged versions of the Gulf III have been widely employed (e.g. Glover, 1953, 1961; Gehringer, 1952, 1962; Ahlstrom, Isaacs, Thrailkill & Kidd, 1958; Bary, de Stefano, Forsyth & van den Kerkhof, 1958; Bridger, 1958; Hempel, 1959, 1964; Miller, 1961; Kinzer, 1962, 1966; Clarke, 1964; Beverton & Tungate, 1967). At Plymouth a version of the Gulf III proved exceptionally useful for rapid surveys of the distribution of macroplankton indicator species in the Western English Channel and approaches in 1958–60 (Southward, 1962).

Dissolved amino acids, in both the free state and combined as polypeptides, play an important part in the marine biochemistry of nitrogen. These compounds are excreted by phytoplankton (Fogg, 1962, 1966; Stewart, 1963; Hellebust, 1965) and zooplankton (Johannes & Webb, 1965; Webb & Johannes, 1965) and are utilized by algae (Syrett, 1962), bacteria (Proom & Woiwood, 1949) and marine invertebrates (Stephens & Schinske, 1961). Experiments with cultures have shown, indeed, that some species of phyto-plankton will not grow, or grow only with difficulty, if certain amino acids are absent (Harvey, 1938; Provasoli & Gold, 1957; Droop, 1957, 1959, 1962). In addition to their direct biochemical role, amino acids may also serve to complex trace metals, such as copper and iron, and keep them readily available for assimilation by marine organisms (Harvey, 1938; Fogg, 1959; Provasoli, 1963; Kent & Hooper, 1965; Saunders, 1957).

Many metallic elements are concentrated by marine animals to levels far in excess of their concentrations in sea water itself. This concentration extends not only to those elements which are known to have biochemical functions, but also to others which have no established biological role (e.g. cadmium and lead). Little is known about the mechanisms by which trace elements are concentrated, or about the manner in which they are held in the tissues. As a preliminary to the investigation of concentration mechanisms, reliable data are required concerning the distribution of the elements in a variety of marine animals.

Recently Lochhead (1968) has described the feeding and swimming behaviour of Conchoecia based on observations of C. spinirostris Claus and a species that was probably C. curta Lubbock. During the last four biological cruises by R.R.S. ‘Discovery’ observations have been made on living specimens of C. spinirostris which supplement Lochhead's observations.

The stomach is the principal region of extracellular digestion in the alimentary tract of Ciona intestinalis (L.) (Yonge, 1925; Morton, 1960). The region is oval and has a lining epithelium thrown into 30 or 40 longitudinal ridges. Previous authors have described the following cell types in this gastric epithelium: a mucous cell (Roule, 1884; van Weel, 1940); an un-differentiated cell (Yonge, 1925; Millar, 1953; Fouque, 1954); an absorptive cell (Yonge, 1925; Berrill, 1929; van Weel, 1940; Morton, 1960); a storage cell (Yonge, 1925; van Weel, 1940) and several different secretory cells (Roule, 1884; Yonge, 1925; Berrill, 1929; van Weel, 1940; Millar, 1953; Fouque, 1954; Morton, 1960). The present paper reports a re-investigation of the gastric epithelium by histochemical methods and by electron microscopy, and a comparison of the observations with those of previous authors. The fine structure of the gastric cells is compared with that of cell types in the ‘liver’ of Pyuridae (Degail & Lévi, 1964) and in the alimentary tract of other animals.

It has been suggested (McLusky, 1968 a) that migrations of Corophium volutator (Pallas) may occur in response to salinity. This suggestion was based on distributional evidence from the estuary of the River Ythan, Aberdeenshire, and assumed that the animals are able to detect salinity and exhibit a behavioural response to it. The presence and nature of such a response has been investigated by means of choice experiments. Burrowing, swimming and feeding behaviour of C. volutator have been studied by Meadows & Reid (1966) and Morgan (1965).

Eurydice pulchra Leach is a common intertidal isopod of sandy beaches. Its occurrence around the British Isles has been described by Jones & Naylor (1967), and Salvat (1966) has described the life cycle and intertidal distribution of the species on the west coast of France. There are several records of its intertidal distribution in Britain (Elmhirst, 1931; Pirrie, Bruce & Moore, 1932; Rees, 1939; Watkin, 1942; Brady, 1942; Holme, 1949; Southward, 1953; Colman & Segrove, 1955; Perkins, 1956; M. Ladle, unpublished) and these suggest that its distribution is variable. Watkin (1942) found that the population structure of E. pulchra in late March and early April was comprised of ‘two distinct groups’ and similar findings were made in July by Scott (1960). The present study was made on a large intertidal population in the sands of the Dovey Estuary, Cardinganshire.

The distribution of Pectenogammarus planicrurus Reid around the British coast appears to be restricted to a few scattered areas. As far as is known it has only been recorded in three localities.

The first of those is the ‘type locality’, described by Reid (1940), at Saltdean, Sussex. Here the upper region of the shore consists mainly of flint pebbles, the middle shore mainly of sand with patches of flint and chalk pebbles and the lower shore of boulders of chalk on a solid chalk base. Reid found it plentiful under stones near high water mark.

In a brief survey of the south coast beaches, from Brighton, Sussex, to Deal, Kent, in the summer of 1965, P. planicrurus was found in large numbers on the chalk and flint beaches associated with the coastal outcropping of the chalks of the North and South Downs. By far the largest populations were found at Seaford, Sussex, where, unlike Saltdean, the pebbles and gravel extend down to low water and P. planicrurus was not restricted to the upper part of the beach as it was at Saltdean. It appears that the ‘type locality’ described by Reid (1940) does not give a true picture of the vertical range of distribution of the species.

The second locality is at Port Erin, Isle of Man, where Jones (1948) observed P. planicrurus ‘under stones’ between H.W.N. and L.W.N. at Spaldrick on the north side of Port Erin Bay. Jones did not find this species in sufficient numbers to formulate a general idea of its habitat.

Fish are perhaps one of the most highly parasitized of animal groups, and the unnatural crowding which occurs in hatcheries and aquaria favours the greatly increased possibility of heavy infestation by some parasites. Such hazards have been recognised in freshwater fishes for some time (see, for example, Dogiel, Petrushevski & Polyanski, 1961), and diseases of marine fishes are now beginning to receive increasing attention (Sindermann, 1966).

Two distinct forms of the megrim, Lepidorhombus whiff-iagonis (Walbaum), exist, a southern form which ranges from the Mediterranean to the British Isles and a northern form which ranges northwards from the north of Ireland and the North Sea (Richardson, 1860; Kyle, 1913; Furnstein, 1935; Dwivedi, 1964). Kyle and Richardson considered these forms to be separate species. The southern form of megrim extends into the English Channel with Start Point, 3° 40' W, the approximate eastern limit of its distribution (Cligny, 1905). However, this fish is common only at the western entrance of the Channel since it is abundant only in depths below loom (Dwivedi, 1964). Little is known of the separate megrim populations in the geographical range of the southern form. Studies of meristic characters indicate the existence of at least three populations, one in the Mediterranean and along the coast of Portugal, another in the Bay of Biscay and the third south of Ireland and in the entrance to the English Channel (Cligny, 1905; Dwivedi, 1964).

Until recently there has been very little information on the quantities of phytoplankton nutrients in the Irish Sea. Slinn (1958–1966) has reported the weekly variations in the nutrient concentrations at a station off Port Erin, Isle of Man, and studies on the nutrient conditions in the Menai Straits have been carried out by Jones (unpublished) and Ewins & Spencer (1967). Liss (1969) has reported on the results of winter surveys of reactive silicate near the Irish coast, and from three stations near the Welsh coast (Anglesey, the Lleyn Peninsula and Fishguard). The present paper describes studies carried out in the inshore waters near Aberystwyth in Cardigan Bay during 1967 and 1968. This investigation formed part of a study of the seasonal occurrence of the phytoplankton and the growth conditions in this shallow, inshore region.

In 1883 Romanes first demonstrated the capacity of starfish to detect the presence of food. He claimed to be able to lead them in any direction by holding a piece of crab an inch or two from the end of one of the arms. He concluded that if the food was not more than a few inches away the starfish could smell it and move towards it. Milligan (1915 a-c) observed that Asterias rubens moved towards a dead pipefish from distances of 1½ in to 2 ft., and emphasized that the determined movement left no doubt that the starfish could smell the fish. Regnart (1928) found that A. rubens could locate food hidden in a bait chamber, moving away from the aerator in the centre of the tank.