September 2, 1920] 



NATURE 



31 



and their possible influence on the winter herring 

 fisheries, is a subject worthy of further investigation. 

 Enough is known as to the' influence of variations in 

 the great oceanic currents upon ilie movements and 

 abundancx; of migratory tislies to indicate the need 

 for further and more complete investigation of the 

 subject. 



Prof. Herdman pointed out that, though we may 

 suspect that the periodic changes in the physico- 

 chemical characters of the sea may be correlated with 

 the distribution at diWerenl seasons of tlie microscopic 

 organisms that are an imf)ortant source of food to 

 larger animals, the matter has still to be proved and 

 worked out in detail. The plankton curve has to be 

 traced and the succession of organisms explained in 

 terms of environmental conditions, including the ion- 

 concentrations in the water and the amount and 

 quality of solar radiation, and that not only in tem- 

 perate seas, but also in the tropics and in all the 

 oceans, and at various depths. H is known that 

 many marine animals are profoundly affected in their 

 distribution by the hydrographic conditions. For 

 example, it has been shown that the herring of our 

 summer fisheries is influenced in its movements by 

 the temperature of the water, the catches being 

 heavier in seasons when the water is colder, so long 

 as it is not below 545° F., when the shoals break up 

 and disperse. 



Bionomics is the basis from which all oceanographic 

 work on the biological side started, and there is still 

 much to be done in tracing and explaining the life- 

 histories and distribution and relations of marine plants 

 and animals. In this connection. Prof. Herdman 

 referred to the recent investigations of Dr. Joh. 

 Schmidt, who has devoted the present summer to an 

 oceanopraphic expedition in the Atlantic, the work of 

 which included a search for the spawning eel. 



The whole of the large question of the evaluation 

 (if the- sea — a natural extension of the old-fashioned 

 faunistic work — is a great field for research lying 

 before the oceanographer of the future. Dr. Peler.s<'n 

 in Denmark has done notable work in the Kattegat 

 and the Limfjord, but it is probable that the "animal 

 communities" which he has dcfmetl differ in other 

 seas, and will have to be worked out independently 

 in each marine area. Prof. Herdman cited the 

 excellent marine surveys made by Sumner at Wood's 

 Hole and by the Royal Irish Academy at Clare Island 

 as work on the right lines as a preparation for the 

 'v.iluation of large areas. 



similarly, sysK'matic plankton work, studied inten- 



\'ly and treated statistically, and cori-elated with 

 the food of migratory fishes an<l of the post-larval 

 and other young stages of all food fishe?, is a 

 promising subject requiring much further investiga- 

 tion. Dr. Iljort's suggestion that the future ycar- 



i .ses of commercial fishes may dejiend not onlv 

 ■n favourable spawning seasons, but also upon an 

 ict coincidence between the appearance of thfl 



\to-plankton in sufficient quantitv in spring and 



■ time of hatching of the larval fishes, provides a 

 'iject of careful and difficult investigation and of 



' ir-rearhing practical importance. A cognate 



-iibject bearing upon the same practical results — vi/. 



lure commercial fisheries — is Dr. Johnstone's 



nonstration of a natural periodicifv in the abund- 



■ e of (-ertain fish. The extent and causes of this 

 I iodiritv clearly call for further investigation ; and 



inv discussion of. say, pre-war and post-war fisherv 



I'istics, the possibility of this nerimlirilv affecting 



• question must \v kept in mind. 



Prof, flerdman emphasised the point that it is 



Itnpossihle fo keep purely scientific research and in- 



vestigations with a practical end in view completely 



N" '''>? X. Vf)F . 106] 



separate. They are inter-related, and the one may 

 become the othier at any point. It was in the purely 

 scientific investigation of the bionomics of the 

 "warm" and "cold" areas of the Faroe Channel, 

 in the Triton in 1882, tliat Tizard and Murray in- 

 cidentally discovered the famous Dubh-.\rtach fishing- 

 grounds which have been so extensively exploited 

 since by British trawlers. It was a French man of 

 science, Prof. Coste, who made the investigations and 

 recommendations that started the flourishing oyster 

 industries at Arcachon and in Brittany. It was his 

 purely scientific studies of the deep-sea deposits that 

 enabled Sir John Murray to discover the valuable 

 phosphatic deposits of Christmas Island. 



Metabolism, the cycle of changes taking place in 

 the sea, the income and expenditure and the resulting 

 balance available, is perhaps the department of 

 oceanography which deals with the most fundamental 

 problems and is most in need of immediate investiga- 

 tion. 



The question of the abundance of tropical plankton 

 as compared with that of temperate and polar seas, 

 the distribution and action of denitrifying bacteria, 

 the variations of the plankton in relation to environ- 

 mental conditions, the determination of what con- 

 stitutes uniformity of conditions over a large sea- 

 area from the point of view of plankton distribution, 

 the questions of the ultimate food of the ocean, the 

 supply of the necessary minimal substances such as 

 nitrogen, silica, and phosphorus to the living 

 organisms, and the determination of the rate of pro- 

 duction and rate of destruction of all organic sub- 

 stances in the sea — these are some of the fundamental 

 problems of the metabolism of the ocean, and all of 

 them require investigation. Most of these, moreover, 

 are cases where the biologist or the oceanographer 

 requires to appeal for assistance to the bio-cnemist. 

 In fact, in many oceanographic investigations team- 

 work, in which the specialists of two or more sciences 

 unite in tackling the problem, leads to the best results. 



To the question, then : Is there need for further 

 investigation of the ocean ? Prof. Herdman answered 

 emphatically in the affirmative, and referred, in con- 

 clusion, to the two suggestions made in his presi- 

 dential address : (i) that there should be establishedat 

 Cardiff a department of oceanographic and fislieries 

 research, and (2) that there should lie a great national 

 oceanographical expedition — that is, another Chal- 

 lenger expedition, fitted out by the British .\dmiraltv, 

 and embracing all departments of the science of the 

 sea investigated by modern methods under the best 

 expert advice and control. Such an expedition would 

 require long and careful preparation, so even though 

 the present time may seem to some inopportune to 

 press such an undertaking, if this suggestion is re- 

 ceived with favour by oceanographers, it might be wise 

 to form a preliminary committee to collect information 

 and prepare a scheme. 



Prof. J. Stanley Gardiner urged that to obtain 

 results in economic work on fisheries there must be 

 advance in wider scientific research. He endorsed the 

 suggestion of the president for the establishment of 

 oceanographical investigation in Cardiff, and s.iid that, 

 in his opinion, if this country is to keep in the fore- 

 front of oceanographical research, a new Challenger 

 expedition has become necessary. 



Dr. K. J. Allen supported the proposals for a new 

 deep-sea expedition, and illustrated the need for 

 further researches on marine organisms by reference 

 to his recent ex|)erimenfs at Plymouth on the culture 

 of plankton diatoms in artificial sea-water. He found 

 that in solutions of pure chemicals, having ns nearly 

 as possible the composition of sen-water, to which 

 nutrknt salts such as nitrates and phosphates were 



