In many instances the results of an investigation have both a general and a particular value. For instance, at Plymouth Mr. F. S. Russell is making a study of the vertical distribution in the sea of the larger plankton organisms (young fishes, crustacea, etc.) and of the change in such distribution during day and night. In its general aspect the study is of interest to biologists, but it happens also to bear directly on our knowledge of the herring fisheries. Vertical distribution apparently varies with the particular species: the species upon which the herring feeds are now pretty accurately known: the depth at which those species are likely to be found during the day and night will therefore affect the depth at which feeding shoals of herrings will be found by the drifter fleets. Thus in his study of the plankton in the Shields fishing area made in July, 1922, Mr. Savage, of the staff of the Ministry of Agriculture and Fisheries, not only found that the small catches taken by drifters were accompanied by scarcity of food plankton, but also suggested that, owing to the short summer nights, the plankton did not rise upward at night to the surface, and that therefore such herrings as were present probably did not rise high enough in the water to be captured in the drift nets. The meetings of workers in marine science organised by the Challenger Society three times a year provide the occasion for full discussion between the staffs of Departments and Independent Stations of matters of common interest and the inter-relation of the researches on which they are severally engaged. Station of the Marine Biological Association, Plymouth. The An extension of the building, which has provided very much better facilities both for the biological and physiological sides of the work, has been completed and taken into use number of outside workers has increased steadily year by year, and during the busy periods practically all the available accommodation, including the rooms in the new building, was occupied. The work of the staff has made good progress. On the fishery side special attention is still being given to the study of the herring, which is the basis of the most important winter fishery in this district. An extensive series of samples has now been taken during three consecutive seasons, and all the fishes have been measured, the vertebrae counted and samples of their scales preserved for study, so that the age of the fish and its rate of growth can be ascertained. Definite year classes are found in the commercial landings, and these can be traced from year to year. The counting of the vertebrae has shown Savage, R.E. "The Plankton of a Herring Ground", Ministry of Agriculture and Fisheries, Fishery Investigations, Series 11, vol. IX., No. 1, 1926. that there is a marked tendency for the average number of vertebrae to be low in samples taken at the eastern end of the English Channel (off Brighton) and to be high in samples from the mouth of the Channel and off the " Smalls." At the same time, relatively high values as well as relatively low ones have been obtained in individual samples from almost all the areas investigated, so that there seems to be a possibility, by the use of this method, of getting information about the origin of the shoals. Investigations of the oyster-beds of the Fal Estuary and of the Thames Estuary at West Mersea have yielded interesting comparative results. Special attention has been given to an exact determination of the spawning periods in each area, and of the relation of these to temperature, tides and other physical conditions. Rate of growth and conditions of growth have also been studied, as well as the sex changes from female to male and back again to female which the oyster has been shown to undergo. The organs of feeding and of digestion of the oyster and allied shell-fish have been the subject of a special research from both the anatomical and the physiological points of view. The food consists in most cases of finely divided particles, chiefly of a vegetable nature, and the peculiar structure and physiological action shown by the alimentary canal are special adaptations to deal with such food. Plankton investigations have again received much attention, the work on the vertical distribution of macroplankton, including the pelagic stages of young fish, being of much interest and value. The larval stages of the different species of crabs, which occur in the Plymouth neighbourhood, have been specially studied, and this study has made good an important gap in our knowledge of plankton organisms. Systematic observations of the temperature, salinity and currents of the waters of the English Channel have been continued, as well as determinations of phosphate and nitrate content at different seasons. Amongst other minor constituents of the water to which attention has been given are silicates and arsenates. Experiments on the inheritance of eye-colour in Gammarus chevreuxi are giving results of exceptional interest and it is thought of great physiological importance. The full value of this work will only be obtained after considerable further research. The same is true of the fundamental investigations which are being carried out in the physiological department on amoeboid movement, on the vibrations of cilia and on muscular contraction. Marine animals appear to be specially suitable for studies of this character. Station of the Scottish Marine Biological Association, Millport. Superintendent: Mr. R. Elmhirst, F.L.S. During the year Mr. Orr and Miss Marshall have continued their joint investigation of the inter-relations between plankton and physico-chemical factors in the sea, a full report on which has now been published. Their work on Loch Strivan, begun in January, 1926, was concluded, the loch being visited weekly until the beginning of December. Some conclusions can be drawn from the results of this and previous years' work on the relations between the plankton and the chemical and physical factors investigated. A close relation can be made out between the density of the diatom population and the chemical reaction, dissolved oxygen content and phosphate content of the sea water. An increase in the number of diatoms is followed by a rise in the first two and a fall in the last. The actual number of diatoms, however, does not always correspond closely to the amount of change produced. A diatom increase begins in the surface layer and spreads gradually into deeper water. Diatom increases during the summer are more frequent in this area than in the open sea and are preceded by a reintroduction of nutritive salts into the upper layers due to the vertical mixing caused by wind. The amount of sunshine in the early part of the year does not exert any apparent influence on the date of the spring diatom increase in the Clyde sea area. The occurrence of dinoflagellates is apparently related to high temperature and low salinity. The spring diatom maximum came earlier in 1927, and work is in progress on photosynthesis at different levels in the sea. It has been found that during the increase little photosynthesis goes on below the surface layers, for the diatoms are so numerous that they shut off a great deal of the light. After they have decreased in numbers the level at which photosynthesis can go on sinks deeper. The maximum amount is found sometimes at the surface and sometimes deeper according to light conditions. It is proposed to continue this work on photosynthesis in the sea and in cultures of diatoms on shore. Mr. R. Macdonald. Carnegie Research Fellow, has published two papers containing the results of his investigations into the biology of Euphausids as outlined in previous reports. Further, he has described a new type of Nauplius of Meganyctiphanes norvegica and drawn attention to irregularities in the development by which certain later stages are sometimes omitted. From this he has suggested that in the larval history of M. norvegica, in common with that of certain other Euphausids, there is an indication of evolutionary progress in the order Euphausiacea. Thanks to the courtesy of the English Ministry he has had an opportunity to extend his work on to the Atlantic Shelf. He hopes to visit northern waters with the concurrence of the Fishery Board for Scotland. Meantime he is completing his investigation on the life history of Thysanoessa. It is most satisfactory to report the installation of electric light and power at this Station, also that the old library has been equipped as a research room. During the During the year facilities were provided for twenty-one workers, ten of whom rank as research workers. Dove Marine Laboratory, Cullercoats: Armstrong College, Newcastle-upon-Tyne. Director: Professor A. Meek, D.Sc., F.Z.S. Herring investigations have been made in conjunction with the Ministry of Agriculture and Fisheries and in continuation of the work done in previous years. The work done for the Ministry has had reference to the shoals found in Northumberland waters and the bait herrings landed at Shields in the early part of the season. From April to September some seventeen samples comprising 3,400 fish were examined for length, sex, development and age; records of the scales were made also to allow of growth calculation. In the beginning of the season our waters were frequented by shoals of recovering spents: afterwards summer shoals of developing fish predominated. This change was accompanied by a change in age composition. To the beginning of June the samples contained about 40 per cent. of four winter-ringed fish, the 1922 year-class, but thereafter, and even in August, when catches of over 100 crans were landed, four winter-ringed fish were scarcer and the predominating year-group was that with three winter rings. From the small quantities of spawning fish landed, and the development of many of the later samples, there would appear to be a migration from our grounds to others for the purpose of spawning. Arrangements have been come to with the Ministry for an extension of the grounds sampled, and, by including the Scarborough shoals, it may be possible to get some evidence of this migration. The extended investigations which have been pursued since 1919 have been continued as opportunity permitted. Twenty-two samples, comprising some 4,000 fish, have been examined and have come from Shetland waters, North of Scotland. East Anglian Fishery, Firth of Forth, Firth of Clyde, and North-West and South of Ireland. The data are being examined, and it is hoped to bring together the results of the whole of these extended investigations and give an account of the changes which have occurred in the fisheries. 62001 The E following is given as an example of change. Fish with four winter rings from the North of Scotland spring spawners are considered in each year when present in sufficient numbers. Year. 1920. 1921. 1922. 1923. 1924. 1926. 1927. Size at 3rd year ... 26.2 25.9 25.5 21.7 24.1 22.5 23.6 cm. There is further evidence from shoals of spring spawners of migrations to more rapid growth areas, and the following will show the nature of the data : AVERAGE SIZE AT FORMATION OF WINTER RINGS (CM.) Plankton.-A programme of work has been agreed on after consultation with the Ministry. Monthly cruises from April to August inclusive are being made off the Northumberland coast at a series of stations approximately 5 and 10 miles from the shore. The work was commenced at the earliest opportunity allowed by the changes necessary for nets and gear, and the examination of the catches is well in hand and will be completed shortly. Experimental fishings were made with the old and new nets to give data for purposes of comparison with our previous work. The results of the use of the same type of net, fishing simultaneously, indicate that there is much disparity in the distribution of planktonic forms. Hydrography. The scheme of research includes detailed and periodical examination of the waters of the Northumberland coast. Quarterly cruises are made and data with regard to temperature, salinity, and soluble phosphate content have been obtained. The maximum salinity was found in September. In January the mean salinity was less, and in April lower still. The lowest salinity was obtained in the north, in the neighbourhood of the Farne Islands; and the effect of land drainage was seen in the increase in surface salinity with distance from shore. As regards the phosphate concentration, the inshore surface waters gave a higher phosphate content than the offshore surface waters, indicating again, it is suggested, the influence of land drainage. No very great seasonal variations were experienced, though in September the surface values were certainly lower |