November ii, 1503J 



iVA TURE 



55 



of the Moray Firth. Minimum captures on the inner areas 

 or outer " deeps " are not necessarily connected with 

 " migrations." The remarlcable oscillations described as 

 occurring in the small plaice of the eastern area of the 

 North Sea, viz. that they pass outward and again " work 

 their way backward " inshore, would have been less 

 phenomenal and would not have required the aid of 

 " hibernation " if researches on the same size on the 

 western shores (British) had been systematically carried 

 out, along with an inquiry into the early post-pelagic and 

 subsequent stages below the sizes selected. Migrations, 

 indeed, loom largely in the international work, even to the 

 supposition that the cat-fish (.\narrhichas) is as regularly 

 migratory in the spring as the halce is in autumn. More- 

 over, large plaice were common in the Moray Firth before 

 its closure, and are still there, the smaller finding ample 

 scope in the shallows and the larger sufficient depth within 

 the area. In regard to seasonal changes in the stock of 

 plaice, it has long been known that captures in mild 

 weather are greater, and that a cold, frosty morning 

 diminishes them, but it does not follow that such captures 

 give trustworthy information as to " maximum and mini- 

 mum densities." ^The changes on the various " banks " 

 naturally follow tne spreading of the younger plaice sea- 

 wards, but " hibernation " of small plaice and immigra- 

 tion of large, mature fishes rest largely on conjecture, as 

 does also the notion, marking notwithstanding, that large 

 numbers of mature fishes " migrate from the north for 

 spawning purposes." The supposed scarcity of large plaice 

 in the deeper water in winter may be due to other causes 

 than migration, though congregation for spawning pur- 

 poses is reasonable. Mr. HefTord's paper on the propor- 

 tionate distribution of the sexes of plaice in the North 

 Sea does credit to his ability, but his conclusions would 

 need the support of longer experience, especially as a large 

 inner area, viz. from Montrose to Kinnaird Head, has been 

 omitted. The notion that the proportion of sexes of plaice 

 may yet indicate the intensity of trawling in a given region 

 i.s scarcely warranted. 



Vol. X. consists of a bulky report dealing with the 

 whole period (1902-7). It reiterates the problems to be 

 solved and the methods followed by the administrative 

 committee, with a summary of the results, besides a series 

 of special reports by seven responsible authors. Some of 

 these reports have previously been published, and have 

 received attention elsewhere, so that they need not be 

 alluded to. In the summary of the results the adminis- 

 trative body deals first with tlie depths and hydrography 

 of the oceanic regions investigated. Then the spawning 

 conditions and spawning places of the gadoids (seventeen 

 in number) are considered, and it is to be noted that the 

 investigation of both is now held to be complete, a view 

 some may doubt, considering the scattered cruises of the 

 steamers, and when on the next page it is stated that the 

 spawning places cannot always be given with absolute 

 certainty. The summary is full of interest, but in the 

 case of several species the limitations given by the com- 

 mittee need re-investigation, and, for instance, no differ- 

 entiation of the areas of the British coast has been 

 attempted as regards the cod. The third head treats of 

 the "natural conditions in the spawning regions," and 

 an effort is made to connect temperature and salinity with 

 the spawning process. The gadoids, however, are not the 

 only fishes in these waters, and there is perhaps little more 

 in the matter than that an Arctic, a temperate, and a 

 tropical fish finds — each in its own waters — the most suit- 

 able spawning conditions. Besides, the refinements of 

 temperatures and salinities, however interesting scientific- 

 ally, count for little in the main question put before the 

 investigators by the British Government. It was well 

 known that wherever the conditions of life were suitable, 

 there the pelagic larvte and young fishes were found with 

 great regularity, irrespective of currents, temperatures, and 

 salinities. No current is known which will take the larval 

 cod with unfailing regularity in one direction and the 

 haddock in another, which will keep the larval dabs and 

 top-knots often in deeper water whilst the plaice is with 

 unfailing accuracy sent to the margin of the beach. No 

 currents, temperatures, or salinities will explain why in 

 1008 the herring fishing was very successful in the 

 northern Scotch area and less successful in the southern, 

 NO. 2089, VOL. 82] 



and why in 1909 exactly the reverse was the case. In this 

 connection, Schmidt also gives no reason why the ova and 

 fry of Gadiis hiscus are not carried far from their spawn- 

 ing place. What can those famiUar with the subject make 

 of the following : — " .According to the spawning time, first 

 the cod eggs, then the haddock eggs, and lastly the whiting 

 eggs are involved in the movement of the currents"? 

 It has not been shown that the currents which distribute 

 the eggs of the pollack and the poor cod in the .Atlantic 

 in spring have their equivalents in the summer when the 

 same fishes spawn in the North Sea, though there is little 

 fear as to the safety and distribution of the eggs of these 

 and all other marine fishes. The guarded remarks of the 

 committee are therefore warranted, viz. " the investiga- 

 tions we are discussing here are far from being able to 

 solve so great a problem." Especially does this apply 

 to the notion that all the young green cod which swarm 

 on the Scottish coasts have been spawned on the North 

 Sea bank, and that the cod makes long migrations for the 

 purpose of spawning. 



On the important problem of sea-fish hatching the com- 

 mittee make very cautious remarks, basing their views 

 mainly on Knut Dahl's paper. In this it is shown that 

 in small Norwegian fjords where cod spawn the captures 

 by tow-nets were not influenced to any extent by the 

 addition of thirty millions, and that the captures varied 

 much in different years. No difference also was noticed 

 in the quantitative occurrence of young littoral fishes each 

 year. They found no proof of an increase of local stock 

 by artificial hatching, but they do not discourage further 

 experiments. The foregoing is in marked contrast with 

 the results of Fulton in the upper waters of Loch Fyne, 

 where shore-fishing with a pusli-net found an increase of 

 young plaice during the six j'ears in which 141 miUions of 

 young plaice were added, as compared with the following 

 six, in which none were added. Yet in glancing at his 

 figures it would appear that in four of the years in which 

 none were added the average captures per hour compare 

 favourably with those in which millions were put in, and, 

 further, that a fifth year is second highest on the list 

 even of the favoured years. The chances of error in work 

 carried out in the circumstances, and the great variation 

 from eight to 112 per hour when no addition was made, 

 combine with other points to render this experiment in 

 need of confirmation. 



Seventy pages are devoted by the administrative body 

 to the distribution, growth, and migrations of the older 

 stages of the important food-fishes, and to some practical 

 fisheries questions in the light of the resuUs obtained. 

 Under the former head the cod, haddock, and whiting 

 alone are dealt with, the ages being determined by 

 measurements by Helland Hansen, who finds little varia- 

 tion in the numbers of large and extra large haddocks 

 during the years of investigation, and by the rings on the 

 scales by Damas, whose prolix paper might well have 

 been abbreviated. The reliance on the catches, for 

 instance, of the haddock, in the deeper water of the 

 North Sea as proving migration is open to question, and 

 the remark by the administrative body that the reporters 

 are not warranted in explaining the " marked " seasonal 

 migrations, some of which are connected with the occur- 

 rence of shoals of herring, is safe. 



One of the most interesting and important contributions 

 is that of Jobs. Schmidt, on the distribution of the pelagic 

 fry of the gadoids and the spawning regions of the gadoids 

 In the North .'\tlantic from Iceland to Spain. He lays, 

 however, too much stress on his experiences of Icelandic 

 currents in treating the conditions in the North Sea, and 

 shows too evident a tendency to make out a case for the 

 hydrographer. 



Of the Scottish Board's report, it need only be said that 

 it proves the prosperous condition of the Scottish fisheries, 

 for though the total does not reach that of the previous 

 year (1907), yet the deficit is due solely to herrings, the 

 " catch " of other fishes being greater in 1908 than in 

 1907. It is a decade since the ruin of the lemon-dab 

 (" lemon sole " of the Board) was in sight, yet the 

 " catch " of this fish exceeded by almost 1200 cwt. that of 

 1907, when the record did not vary much from the pre- 

 ceding years. It is sometimes forgotten that the amount 

 of flat fishes rises or falls according to the amount of 



