3i6 



NATURE 



[May 4, i«ji i 



we found them harassod by raids of the neighbouring' 

 K.'ichins and torn by internecine war. Now they are 

 claniuurinj* for roiid's which will enable- them to brinj* 

 their pnxluce to the railway. It will be interesting 

 to watch how long this almost idyllic social state 

 remains unaffected by the pressure of commercialism, 

 Mrs. Milne's account of their home life and indus- 

 tries is clear and comprehensive; and the value of 

 her book is increased by an excellent collection of 

 photographs. It is certain to survive as the standard 

 account of a most interesting people recorded at a 

 time when thty wt*^ little aff.ctrd by rxternal 

 influences. 



liELGIUM:S CONTRIBUTION TO THE 

 PLAICE PROBLEM.' 



THE plaice problem still occupies a prominent 

 position in the foreground of the internation.nl 

 investigations. The reason is not that the plaice is 

 the sea-hsh which contributes most wealth to the 

 countries concurned. In respect of total value landed 

 the fish is surpassed in England by the haddock, the 

 herring, and the cod, while in Belgium the total 

 value of soles annually l.inded is more than twice 

 that of plaice, which stands fourth in the list, after 

 haddock and herring. 



The reasons why the plaice is of such importance 

 that it has been made the principal object of investi- 

 gation on the parts of England, Germany, Denmark, 

 Holland, and Belgium are as follows : — 



(i) This fish constitutes a proportionately large as 

 well as much appreciated element in the ordinary 

 dietary of the poorer classes in the five countries 

 named. 



(2) The livelihood of large numbers of fishermen in 

 these countries depend on their ability to maintain 

 an adequate supply of this fish in the markets. 



(3) It is especially in regard to the plaice that the 

 crv of " depletion " of the fishing grounds, and of the 

 undue destruction of undersized and immature fish, 

 has been, and is still being, raised. 



(4) The plaice lends itself perhaps more readily 

 than any other fish to protective legislation, on account 

 of its comparatively restricted range, its regular dis- 

 tribution from the coast seawards according to size, 

 and its slow rate of growth. 



In view then of the urgent need which was ex- 

 pressed in discussions on the plaice at Royal Com- 

 missions and fishery conferences of a satisfactory 

 knowledge of the natural history of the fish on one 

 hand, and for trustworthy statistics showing the 

 actual condition of the fisherj' in time and space on 

 the other, it is not surprising that the International 

 Council took the matter in hand at the outset of 

 its career and arranged for a thorough investigation 

 of the plaice fisheries both from the biological and 

 from the economic point of view, an investigation in 

 which each of the five countries most interested was 

 appointed a share. The result of the large amount 

 of research which has been expended on the plaice 

 during the past few years is that we now possess a 

 considerable amount of information respecting the 

 movements of the fish at all stages of its career, the 

 age of the fishes, and their growth-rate in different 

 parts of the sea, their age and size at maturity, and 

 so forth, while the sea fisherv statistics of the various 

 countries bordering on the North Sea have been so 

 comnl':^tely reorganised that thev now show us. for a 

 quinquennial period at least, something like the actual 



T>^ Contribution Jk I'Etude biologique et ^conomique de la Plie. 

 l^ar G. Gilson. D*l<gu6 de la Belgique au Conseil international pour 

 n/? '•°". .* '* '"""^- Travaux de la Station de Recherches relatives a la 

 reche mantitne. Ostende. Fascictile IV. (Bruxelles : Imprimerie 

 Polleunis et Ceuterick, igio.) 



NO. 2166, VOL. 86] 



yield of different fishing grounds from vear u> v. : 

 and from month to month. 



.Although we have no conttn< 

 exact statistics of the plaice fishery exlending itr 

 last century, there can be no reasonable doubt tb 

 the condition of the fisher)' and the composition 

 the pl.'iicf po])ulation on the fishing grounds are vi-i 

 different to-day from what they have bi-en in ti 

 memory of the older fishermen, xmd fr.'\gmentar>' st 

 tistics of the numb«*r of baskets formerly taken ai 

 t.ot altogether wanting to show this. If the destrn' 

 tion of an •' accumulated stock" of old fishes (svr: 

 as is to be found in the Barents Sea at lb' 

 present day, and not so many years ago at Ic 

 land) was inevitable, and quite rational and economi. 

 the same can scarcely be said if the supply of fish .1 

 the present day is being maintained at the sacrifit • 

 of an increasing proportion of >lh*^^ smaller and nun : 

 less valuable sizes. If this actudlly is the trend ■ 

 the fishery at the present day, then, apart from tli' 

 possibility of an ultimate shortage of supply whi< 1 

 is at any rate threatened, it is obvious that the fishti 

 is not being exploited in a rational way. As Pro! 

 Gilson. in his important memoir, says: — "On s;»it 

 qu'il faut considdrer la capture en grande masse d- 

 jeunes plies, inaptes h la reproduction pour la plupari 

 et capable de gaf^ner en une annic le double et vtenu- 

 le triple de letir valeur, comme une op<^ration anti- 

 (''conomique .appelant une reforme." 



It is j^reatly to the credit of Prof. Gustav Gilson, 

 of Louvain, the Belgian delegate to the International 

 Council, that he has been able to carry out a plan 

 of researches in accordance with the international 

 programme, in spite of the great disadvantages 

 attending the lack of a special research steamer able 

 to work on the fishing grounds at all seasons, and 

 of a co;ist;d laboratory where material could be 

 examined fresh and continuously. 



The institution in Belgium which has assumed the 

 task of participating in the international investig 1- 

 tions is the Royal Museum of Natural History, which 

 maintains a station for sea fishery research at Ostend. 

 Solely with the aid of the resources of this institution 

 and entirely outside the official machinen.-. Prof. 

 Gilson has reorganised the sea-fishery statistics at 

 Ostend. Previous to 1904 these gave only the total 

 quantities and value of fish landed at the port with- 

 out distinction of species, size, number of baskets or 

 fishes, place of capture, &-c. From 1904 onwards. 

 thanks to Prof, Gilson 's efforts, all these and other 

 essential particulars are given in the statistical re- 

 turns, so that now the Belgian statistics are equally 

 precise and detailed as those of other countries border- 

 ing the North Sea. 



In the memoir under review the data collected with 

 regard to the plaice landed at Ostend are analysed 

 and coordinated from two points of views : — (1) So as 

 to show the principal features in the evolution 

 of the Belgian plaice fishen.' during the quinquennial 

 period (1904-8), and (2) to furnish indications of the 

 influence which a raising of the minimal size legally 

 established (18 centimetres) would probably exercise 

 on one hand on the reserves of plaice in the sea. 

 and, on the other, on the product of the fi'=hin:.' in- 

 dustrv in weight and value. 



It is impossible to indicate all the featin 

 evolution of the Belgian plaice fishery' during the 

 period iqo.i to uk>8 which are revealed bv 

 Prof. Gilson 's analysis of the Ostend statistics. It 

 will suffice to point out the most important feature 

 from the point of view of the present discussion. 

 This is to be found in the progressive increase from 

 year to vear of the proportion of small fish in the 

 catches of the sailing trawlers, which boats are re- 



