bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hydrographic Observations in the Eastern Irish Sea With Particular Reference to the Distribution of Nutrient Salts
Authors: Jones P. G. W. , Folkard A. R. 
Published: May 2009

INTRODUCTIONStudies on the physical hydrography of the Irish Sea, based mainly on temperature and salinity observations, have been made by Bowden (1955) and Lee (1960). The current systems in various parts of the Irish Sea have been investigated by Bowden & Sharaf El Din (1966), Harvey (1968), Ramster & Hill (1969) and Hill & Ramster (1971). Various smaller-scale physical observations made by other workers have been listed by the above authors.There are not as many references in the literature to the distribution of nutrient salts in the Irish Sea. Jones & Haq (1963) measured phosphate in Liverpool Bay as part of an investigation into the distribution of the alga Phaeocystis. Slinn & Offlow (1968) have made regular routine measurements of phosphate, nitrate and silicate over a number of years off Port Erin, Isle of Man. Ewins & Spencer (1967) measured phosphate, organic phosphorus, nitrate and silicate in the Menai Straits, and Liss (1969) surveyed the distribution of silicate in the western Irish Sea.During recent years the Fisheries Laboratory at Lowestoft has investigated the distribution and ecology of plankton and larval plaice in the Irish Sea, and a supporting programme of both physical and chemical hydrographic observations has been made in the area. Ramster & Hill (1969) and Hill & Ramster (1971) have summarized the results of the Lowestoft current measurements. The present paper describes an investigation into the distribution of temperature, salinity, phosphate, nitrate and silicate. The occurrence of Phaeocystis is also reported as an extension of the earlier work by Jones & Haq (1963).
The Relation between Dinoflagellates and the Bioluminescence of Sea Water
Authors: Tett P. B. 
Published: May 2009

INTRODUCTIONDinoflagellates have often been held responsible for a large part of the phosphorescence of the surface waters of the sea. In temperate waters, dinoflagellates are seldom the most abundant constituents of the phytoplankton, and until recently little experimental evidence has been available to support this assertion. Until recently there have been few careful attempts to determine which particular species of dinoflagellates are luminescent, or to relate total luminescence to numbers of dinoflagellates present.
The Plague of Octopus on the South Coast, and its effect on the Crab and Lobster Fisheries.
Authors: Garstang Walter 
Published: May 2009

Until the spring of 1899 the true or common octopus (Octopus vulgaris, L.) had been comparatively rare in the neighbourhood of Plymouth during the past ten or twelve years—i.e. since the opening of the Plymouth Laboratory in 1888. Specimens could only be obtained for the aquarium at long intervals, in spite of the tempting inducements offered to fishermen. As much as ten shillings has more than once been given to fishermen for a specimen of this voracious mollusk. On the other hand, the smaller and less powerful octopod known as Eledone cirrosa was almost always obtainable, and the octopus tank in the aquarium was rarely devoid of several specimens.In the early part of last year (1899) the situation began to change, and we were for the first time able to keep the tank supplied with a number of true octopus, since which date there has been no difficulty in procuring an unlimited number of specimens, either from the professional fishermen or in the ordinary course of our own fishing operations.We noticed this increase in the abundance of octopus before there was any means of judging whether it was a purely local phenomenon, or was observable over a wider area. The first specimens were brought to us in January, and from May onwards they were obtained in increasing abundance. Early in the same year, however (though I have no exact record of the date), a visitor from the Channel Islands informed me that the increase of octopus in those islands was so great as to have already caused much damage to the shell fisheries there, since the octopus entered the pots of the fishermen, and destroyed the crabs and lobsters which had been caught.
Nitrate in the Sea.
Authors: Harvey H. W. 
Published: May 2009

1. A method of estimating nitrates in sea-water is described.2. A considerable concentration of nitrates occurs in the depths of the ocean and a very low concentration (0 to 10 parts per 1000 million of nitrate-nitrogen) in the surface layers of those areas where there is no upwelling of water from below.3. The nitrates in the water of the English Channel, twenty-two miles south-west of Plymouth, are almost entirely utilised by phytoplankton in the summer, and commence to be reformed from ammonium salts at a greater rate than they are utilised by the end of the summer.
Seasonal Changes in the Silica Content of Natural Waters in Relation to the Phytoplankton.
Authors: Atkins W. R. G. 
Published: May 2009

1. The method of Dienert and Wandenbulcke permits of the estimation of silicate in solution down to the limit of 0-04 mg. of silica per litre, which cannot be distinguished from zero. The phosphate normally present does not interfere with the reaction.2. All fresh waters examined were found to contain more silicate than does the water of the English Channel.3. The water of Plymouth Sound is richer in silicate than that of the sea.4. At Station El in the English Channel silicate decreases during spring, from a winter maximum of 200-240 mg. per cubic metre, so that from April to June, 1925, the amount left, recorded as 40 mg. per cubic metre, was indistinguishable from zero. At this time the water was stripped of phosphate also. Silicate increased again till early July, decreased in August and again in November ; the times of decrease are suggested as being those of diatom increase.5. In deep Atlantic water silicate is much more abundant than in the English Channel; values from 360 mg. per cubic metre at 1000 metres to 1200 mg. at 3000 metres were obtained. In winter at any rate the surface value in the Atlantic is similar to that off Plymouth, about 110 mg.per m3 in 1925.
Modification by Habitat in the Portuguese Oyster Ostrea (Gryphcea) angulata.
Authors: Orton J. H. , Awati P. R. 
Published: May 2009

While working on the beds in the River Blackwater, Essex, a collection of Portuguese oysters, which had been dredged along with native oysters (O.edulis) from the river and creeks, was seen at a glance to show a distinct average difference in shape from the usual type of Portuguese oyster. The ordinary Portuguese oyster as seen exposed for sale is usually im-ported when quite small, or occasionally well-grown, and relaid on English beds at or above low-water mark to grow and fatten. Orton* has shown by definite experiments on the same beds that the Portuguese oyster spawns and spats in English waters in favourable (hot) weather. There can be no doubt, therefore, that the Portuguese oysters dredged had grown in situ from larvae which had developed in the waters of the river and creeks. In Portugal and France the Portuguese oyster is stated to occur at and just below low water springs (see Bashford Dean, Bull. U.S.F.C. XI, 1891 (1893), p. 368), and is apparently hand collected at the present day for export purposes.A difference in shape in native oysters is very common, but Bell and others have so far found it a very difficult matter to correlate any particular shape with a particular environment. Indeed, Bell stated, in a letter, that each locality seems to have its own type of shell-growth in the native oyster. Such a difference as that noted above in the Portuguese oyster was therefore deemed worthy of some attempt at expression.
Stages in the Life History of Calanus finmarchicus (Gunnerus), Experimentally Reared by Mr. L. R. Crawshay in the Plymouth Laboratory
Authors: Lebour Marie V. 
Published: May 2009

[The stages in the development of Calanus finmarchicus described and figured by Miss Lebour in the present paper were taken from culture jars given into my charge by Mr. L. R. Crawshay, when he left the Laboratory to undertake military duties in connection with the war. In one jar at that time the first copepodid stage, from eggs laid in the jar, had just been reached, and the technical details for the successful rearing of the animals had been mastered. The experiments had been conducted with great care, and all possible precautions had been taken to prevent contamination. Subsequently the experiments were repeated up to a certain point by myself and some additional stages obtained to complete the series.The cultures were made in 2-litre glass beakers, containing “outside” sea-water filtered through a Berkefeld filter. In order to secure an even temperature the beakers stood in the circulating water of the Laboratory tanks, and a pure culture of the diatom Nitzschia closterium was used as food.—E. J. Allen.]
Notes on the Œcology of Cirratulus (Audouinia) tentaculatus (Montagu)
Authors: Flattely F. W. 
Published: May 2009

Cirratulus tentaculatus is found inhabiting the wet, sandy, somewhat foul mud of the Aberystwyth shore, chiefly in the Laminarian zone, although it also occurs in rock pools higher up the shore in which there is sufficient depth of sand containing the necessary organic matter. The presence of the worm in its natural habitat is indicated by a group of delicate, elongate, rosy or yellow coloured filaments of tentacular appearance which protrude from the sand into the pools left by the receding tide. These filaments nearly always display a certain amount of movement, either waving gently from side to side or curling slightly from the tips. The amount of motion and also the colour of the filaments will depend on the degree of freshness of the water in the pool, and this, of course, will, in its turn, be related to the state of the tide.Specimens are not easy to collect owing to the marked propensity the animal exhibits for lying with its body beneath stones or pieces of rock embedded in the mud. In rock pools or crevices where there is but little depth of sand and the animal lies with its body more or less parallel to the surface collection is almost impossible. This response to stimuli of contact and pressure, or, as M. Georges Bohn has it, this “thygmotactism,” is very marked, and, in the aquarium, when specimens are placed in a vessel containing sand and a few stones, the animals will roam about till some portion, at any rate, of their bodies is undergoing pressure from those stones.
The Food of Young Herring
Authors: Lebour Marie V. 
Published: May 2009

The Herring season of 1923–24 was a peculiarly good one, the fishery continuing from the end of October into the beginning of February.Newly hatched Herring were first observed on December 17th, 1923, and post-larvæ were abundant up to March, 1924, in the neighbourhood of Plymouth.Investigations were made into the food of these young Herring, and the probable depth at which they were feeding. Hauls with Young Fish Trawl were made near the surface, midwater, and near the bottom, and tow-nettings were also taken. It has, however, now been found by Mr. Russell that the samples assumed to be near the bottom were possibly in reality some distance above it.
Temperature and the Viscosity of Protoplasm
Authors: Pantin C. F. A. 
Published: May 2009

(1) The effect of temperature on the viscosity of the protoplasm has been determined in the unripe eggs ofNereis diversicolorby the centrifuge method.The viscosity rises as the temperature falls, the rise becoming rapid near 0°C.(2) These changes of viscosity with temperature are similar to those described by Weber (21) in the protoplasm of certain plant cells.(3) Attention is drawn to the fact that the temperature coefficients of biological processes should be corrected for the viscosity of the protoplasm in which they occur.(4) It is shown that the relative changes of protoplasmic viscosity with temperature are probably of the order required to make the temperature coefficients of biological processes constant when corrected for the viscosity factor.(5) The magnitude of the temperature coefficients of biological processes when corrected for viscosity changes is probably of the same order as that of the temperature coefficients of a chemical process when corrected for changes in the viscosity of its medium.
A New Type of Luminescence in Fishes. II.
Authors: Hickling C. F. 
Published: May 2009

Texperiments are described which indicate that there is a physiological problem quite apartfrom the chemical problem of luminescence in the secretion of Malacocephalus Icevis(Lowe). The luminiferous substances are present in granules, which behave as though each were bounded bya membrane whose permeabilities resemble those of a typical cell, but differ from a cell in that they have little or no power of recovery from adverse conditions.For optimal luminescence they require (i) a medium of a certain osmotic pressure,(ii) a certain range of alkalinity, (iii) a certain range of temperature, and (iv)abundant oxygen. Sea-water is not necessary for luminescence.If they are exposed to extremes of acidity or alkalinity, or of hypotonic or hypertonic solutions, irreversible changes rapidly set in in the membrane of the granule, whereby the power of luminescence is lost.In artificial conditions the rapid fading of the light from the initial brilliance is probably due to an increasing acidity caused by the accumulation of the products of oxidation.
The Food of the Bottom Fauna of the Plymouth Fishing Grounds
Authors: Hunt O. D. 
Published: May 2009

1. The food of the bottom fauna of the Plymouth fishing-grounds, at an average depth of 27 fathoms, lias been investigated. This has been done by the examination of the stomach contents of animals, both fresh and preserved, and supplemented by observation of living animals in aquaria.2. The sources of food have been discussed. Attention is drawn to the importance in these regions, not so much of organic detritus, which is considered by Petersen and Blegvad to be the only important ultimate supply in Danish waters, but of the contributions from the plankton itself and from the considerable microflora and microfauna inhabiting the bottom deposits.3. Petersen and Boysen Jensen have stated that the detritus present in Danish waters can be traced almost entirely to the annual decay of the Zostera beds. The area occupied by Zostera in Plymouth waters is very smalLin.comparison with that in the Danish fjords and the detritus found here, though considerable in quantity, and in appearance much as described by Petersen, must originate largely from other sources. The possible1 sources of origin apart from land-sources are the coastal Algse and the plankton. A consideration of the annual production of each of these' suggests that the plankton is the more important factor.4. Blegvad has classified marine animals according to their food into Herbivores, Carnivores, and Detritus-eaters, but this classification does not fit the conditions in the area here studied and is not therefore of general application. Herbivores are absent from these grounds, and few of the animals could be described strictly as detritus-eaters. The animals fall into the following natural groups, according to their food and the mode and location of their feeding:—A.Carnivores—Animals which feed mainly upon other animals, either living or as carrion.B.Suspension-feeders—Animals which feed by selecting from the surrounding water the suspended micro-organisms and detritus.C.Deposit-feeders—Animals which feed upon the detritus deposited on the bottom, together with its associated micro-organisms.5. Following the preceding classification the food of the common animals of the Plymouth fishing-grounds has been described briefly.
Water Movement and Sea Temperature in the English Channel
Authors: Harvey H. W. 
Published: May 2009

During the last three years further evidence has been obtained that water of relatively high salinity, from the Atlantic to the south-west of the entrance, enters the English Channel past Ushant (1).It is of interest to summarize this evidence in view of the suggestion (2) that the English Channel is cut off from the Atlantic for considerable periods.The surface samples of very high-salinity water, collected in the Channel by the Ministry of Agriculture and Fisheries, suggest the possibility of masses of oceanic water moving into the Channel past Ushant from time to time; and they further suggest that this oceanic water divides in the western end of the Channel, one part moving direct into the North Sea, through Dover Straits, and the other part turning and passing out northward between Land's End and the Scillies. This is discussed by Mr. J. R. Lumby (see p. 670 of the present number of this Journal).
Note on the Plymouth ‘Nitzschia’ Culture
Authors: Hendey N. Ingram 
Published: May 2009

For nearly fifty years a small marine organism has been cultured at the Marine Biological Association's Laboratory at Plymouth, mainly to be used as a food supply in rearing marine larval forms.The cultures were originated by the late Dr E. J. Allen in 1907. The first record of these cultures and the methods used to maintain them were published by Allen & Nelson (1910) in a paper describing methods for obtaining persistent cultures of eighteen species of plankton diatoms. One of these cultures flourished so successfully that subcultures have been distributed to many laboratories and institutions both in Europe and America. This organism was named Nitzschia closterium W. Sm. forma minutissima. The authors, however, did not describe the organism or produce an illustration, so the combination can be considered only as a nomen nudum.
The development of the ascidian Pyura microcosmus (Savigny)
Authors: Millar R. H. 
Published: May 2009

Several recent papers have dealt with the development of members of the ascidian family Pyuridae (Hirai, 1941; Berrill, 1948; Millar, 1951; Sebastian, 1953), but the total number of species with known larvae is still only five, in spite of the large size of the family.The present paper deals with the embryonic development, the larva, and the post-larval development of Pyura microcosmus (Savigny).
The abundance ofOctopusin the English Channel
Authors: Rees W. J. , Lumby J. R. 
Published: May 2009

During 1950, the Common Octopus (Octopus vulgarisLamarck) was to be found along the south coast of England in greater numbers than at any time since Garstang (1900) reported on the ‘plague’ on the coasts of Devon and Cornwall in 1899–1900.In earlier papers (Rees, 1950, 1952) the distribution of the octopus in our northern waters was reviewed, and it was demonstrated that this species is an immigrant which breeds on our south coast only rarely. It reaches these coasts by being brought there as a planktonic larva by the water circulation in the English Channel and by migrations of the adult. The most important factor in controlling the movements of the adult, however, might be expected to be the water temperature in the English Channel—where the species is at the northern limit of its breeding range and might therefore be extremely sensitive to slight changes in temperature.
An improved ‘vacuum’ grab for sampling the sea-floor
Authors: Holme N. A. 
Published: May 2009

The sampler to be described takes a small unstratified sample of the sea-bed, the sample being subject to a minimum of loss while being brought up. Such samples are of use in survey work, or for studies on grade size, mineralogical composition, chemical properties, or microfauna and flora of the deposits.Although core-samples, in which the original stratification is retained, can be taken in soft muddy sediments without difficulty, it is not at all easy to take cores of sand or gravel. On such deposits an unstratified sample may be the best that can be obtained. Coarse sediments may be sampled by a dredge fitted with canvas bag, but when a small sample is required quickly, a light instrument which can be lowered vertically from the ship on a rope or hydro-graphic wire is needed. ‘Snapper’ samplers do not always take a satisfactory sample as the jaws may be prevented from closing by a pebble or shell wedged between them, much of the sample being lost while hauling up (cf. Stetson, 1938, p. 7). Stetson describes an instrument which takes a small semicircular core of sediment, the sample being sealed in the coring tube while being brought up, so preventing any loss of material. While no doubt taking good samples, the instrument is rather heavy (57 kg) and complicated in construction.
Twin Gastrulæ and Bipinnariæ of Luidia sarsi, Düben, and Koren
Authors: Gemmill James F. 
Published: May 2009

Early in June of this year (1914) I received from the Plymouth Marine Laboratory through the kindness of Dr. E. J. Allen, F.r.s., several Thermos flasks containing quantities of a culture of Luidia in the early blastula stage. This culture was made for me by Mr. James Gray, King's College, Cambridge, to whom, and to Dr. Allen, I desire herewith to express my indebtedness. The larvæ were little the worse of the journey to Glasgow, but it seemed to me that they showed even greater irregularities of form than might have been expected from Mortensen's (13) description of blastula formation in our species. However, in the end, abundance of perfectly typical young bipinnariæ were secured from the contents of the various flasks. The abnormal larvæ became gradually fewer through death, and those which survived could be isolated without much trouble, since they exhibited less capacity for keeping near the surface of the water than their healthier brethren. A great many of the early malformations were of the nature of double or twin formation, and it soon became evident that the teratological type in question, namely, double monstrosity, was about to receive a more varied expression, and to attain a more advanced stage in development, than it had ever before been my good fortune to find in any starfish culture.In the accompanying illustrations two series of abnormal larvæ are figured, one at the gastrula stage (Figs. 1–11), and the other at that of the early bipinnaria (13–21). As a description is appended to each figure, only questions of general interest need be dealt with here.
The Vertical Distribution of Marine Macroplankton. An Observation on Diurnal Changes
Authors: Russell F. S. 
Published: May 2009

INTRODUCTION.1. A series of hauls with the ring-trawl were made at five depths in water 50 metres deep, so that samples were obtained approximately in daylight, at dusk, at midnight, at dawn, and again in daylight.A depth-recorder was used with the net giving a graphic record of its path through the water.2. Examination of the catches demonstrated the diurnal changes in vertical distribution of the species caught by the ring-trawl.3. Four types of behaviour were shown:—(a) A definite migration to the surface in the dark hours of certain forms living in the deeper layers in the daytime.(b) An expanding of the distribution of other organisms, that in the daytime had a zone of maximum abundance in the deeper layers, so that they were evenly scattered from the surface downwards.(c) Certain animals showed no or very little change in their vertical distribution during the dark hours.(d) A movement up to the midwater region by those forms that during the daytime adopt either a truly benthic existence or are congregated in the water layers immediately adjacent to the sea floor.(Lists of species grouped under their respective types of behaviour are to be found on page 780.)4. Many such observations are required before conclusions can be drawn as to the normal diurnal behaviour of plankton animals: this is a definite record of what occurred in this locality in mid-July at a period of full moon in fair weather.