430 



NATURE 



[August 28, 1890 



whiting, ling, and other fishes is a steady one, and though many 

 are replaced in the sea by the fishermen it is doubtful if they 

 will survive. The smaller of the first three, indeed, are generally 

 dead when brought on board. The use of the hook, on the other 

 hand, for the capture of flat fishes — more particularly plaice in 

 sandy bays — contrasts favourably with the work of sailing trawlers 

 on the same ground, since a larger size of fish on the whole is 

 secured ; though scarcely a single fish thus obtained is mature. 

 It is probable that the smaller mouth of the pleuronectids pre- 

 vents the younger forms from so readily taking the hook, the 

 size of which, moreover, would appear to be related to that of 

 the young fishes captured. The liners themselves as a rule apply 

 the remedy, since they leave the ground frequented by small 

 fishes, e.g. haddocks, and seek more mature forms. They 

 appear to be aware that these young fishes haunt the same 

 area a considerable time. This practice cannot be too much 

 commended. 



Beam-trawling and otter-trawling, again, are credited with 

 the capture of many young (immature) fishes. In the case of 

 the beam-trawl, now so extensively used, if the meshes of the 

 net be small and work carried on inshore, or where multitudes 

 of young fishes are, large numbers especially of flat fishes are 

 taken. In ordinary steam-trawling for profit, as observed off 

 the east coast in 1884, however, the actual captures of small 

 {immature) fishes were not as a rule serious. For the most part 

 they consisted of common and long rough dabs, neither of which 

 when adult is a large fish, though both, besides other uses, form 

 an important item in the diet of the more valuable fishes. Off 

 Girdleness (Aberdeenshire), however, a considerable number of 

 young cod were captured in autumn, yet every one of these was 

 used as food and was saleable. In the open offshore water 

 very few young plaice are procured, almost all being of 

 considerable size ; but in inshore water, e.g. in such bays as 

 St. Andrews, vast numbers of small plaice may be captured 

 with a naturalist's trawl {i.e. one with a small mesh), and 

 considerable numbers with the ordinary trawl of either sailing or 

 steam trawler, one of the latter in 1884 having about sixty boxes 

 as its catch. Though the very young plaice are abundant at the 

 tidal margin, yet no graduated lines, indicating an increase in 

 size as we proceed outwards, seem to occur, very small forms 

 being found in the outer lines of St. Andrews Bay as well as 

 those approaching low-water mark.^ 



In steam-trawling for profit, the condition of the captured 

 young fishes depends on the length of time the trawl has been 

 ^own, the state of the sea, and the condition of the bottom. 

 Thus, if the trawl has been at work for five hours the younger 

 fishes are often dead, and, if not, would probably die if replaced 

 in the water, whereas when the trawl of a sailing boat has been 

 down only an hour the majority would probably live if returned 

 to the sea. If the sea be rough, the pitching of the vessel in 

 hauling causes the bag of the net and its load of fishes to strike 

 the side of the ship, and thus the snouts of the fishes are broken 

 and many killed. In the same way soft muddy ground is fatal 

 to the fishes in the trawl, just as in a less degree, the soft sand of 

 the beach proves destructive to trout swept down by a spate. 



Shrimp-trawling is another method of fishing proportionally 

 more destructive to young fishes than perhaps any other. As 

 carried on, for instance, in the estuary of the Thames by sailing 

 boats near Canvey Island and towards Tilbury Fort, multitudes 

 of small soles, dabs, plaice, bib, whiting, and other forms, e.g. 

 unctuous suckers and Cotti, are retained by the small-meshed net, 

 and before the sifting of the shrimps is concluded the majority 

 have succumbed. Nor are hand-nets and the larger ones drawn 

 by horses less destructive. All cause a frequent and great drain 

 on the young fishes, especially in some places on such valuable 

 forms as soles, turbot, and brill, while the food procured for the 

 public is small in comparison with the loss of fish-food. There 

 should be no insuperable obstacle to the immediate substitution 

 of these methods by others less wasteful to fish-life. The 

 French shrimp-trap, for instance, as recommended by Prof. 

 'Giard and M. Roussin, is a step in the right direction. 

 88; The use of the "sweep-net" on sandy shores for procuring 

 •sand-eels is followed by the capture of numerous young cod, 

 green cod, gurnards, whiting, trout, turbot, brill, dabs, plaice, 

 flounders, and other forms. The net has wings of 4-inch mesh, 

 and a centre of strong netted curtain-gauze, so that small fishes 

 are secured in hundreds. The net is worked by two men, one 

 in a boat, the other on shore, and is especially destructive in 



■> This appears to differ from the results of the Garland's recent work. 

 iNO. 1087, VOL. 42] 



estuaries. The little fishes thus captured escape the trawls of 

 both sailing and steam-vessels. 



The salmon-stake nets, on sandy beaches, secure many small 

 turbot and brill from 5^ inches upwards. 



The stow or bag-net for sprats, as used by yawls in estuaries 

 of rivers, is a small-meshed net of great length, fixed to the side 

 of the vessel by the upper beam, and into which immense 

 numbers of young herrings and sprats, and sometimes many 

 sparlings, are swept by the current, besides various round food- 

 fishes, flat fishes, and unsaleable forms, such as Cotti, Montagu's 

 suckers, and pipe-fishes, not to allude to an occasional salmon. 

 The captured fishes are now and then used for manure, and much 

 valuable food is thus lost to the community. 



The small-meshed sprat-nets (pole- nets) of the Forth are also 

 responsible for great captures of small herrings and sprats for 

 manure, as well as for the destruction of young round fishes, 

 such as cod and whiting. The capture of whitebait in the 

 Thames is another instance of the wholesale destruction of very 

 young fishes. 



From the foregoing brief sketch it will be apparent that no 

 special kind of fishing is responsible for the capture of small 

 (immature) fishes, and that legislative measures, to be effectual, 

 must, more or less, cover all. The question, therefore, is beset 

 with difficulties. The prohibition of the landing and sale of 

 such fishes would, of course,, shut them out of the market, but it 

 would not prevent their being captured ; and while they might 

 be returned to the water as soon as practicable, the mortality, 

 as already indicated, would be considerable. It is difficult to 

 see how, by any modification of apparatus, these small fishes 

 would be enabled to escape capture by liners, trawlers, shrimpers, 

 seine, and other net-fishermen. As recommended to the Trawl- 

 ing Commission of 1884, the mesh of the trawl-net might be 

 enlarged. Thus, for 9 feet at the cod-end, it might have a 

 2-inch mesh ; then, for 12 feet, 2^-inch mesh ; next, 3 and 3J- 

 inch mesh ; and, finally, a 5-inch mesh towards the beam. The 

 enlargement of the mesh will not altogether prevent the loss of 

 young fishes, but it will diminish it. Moreover, a limit to the 

 time the trawl is down might be considered. The pressure of the 

 larger on the smaller fishes when the bag of the net is hoisted 

 by the derrick, and the swinging of the heavily-laden bag on the 

 side of the ship in rough weather, however, are elements of 

 disaster apparently beyond control at present. If the bag of 

 the net with its fishes could be lifted horizontally into a raft or 

 other apparatus level with the water, much injury to the con- 

 tents, both young and adult, would be avoided ; but the practical 

 difficulties are great. In the other modes of fishing in which 

 young fishes are captured in great numbers, and where restrictive 

 measures are inapplicable, the obstacles would seem to be best 

 met by the modification of apparatus and by the trained 

 intelligence of the master-fisherman. 



The question as to what constitutes an immature fish has not 

 hitherto, perhaps, received that strict attention which it merits. 

 In the trawling investigations of 1884 the term "immature" 

 was not used in the strictly scientific sense — that is, in connection 

 with the reproductive organs, though these were examined in 

 all the species. The term, indeed, was purposely employed as 

 nearly synonymous with unsaleable. Recently, Dr. Fulton, the 

 energetic Scientific Secretary to the Fishery Board for Scotland, 

 has had a large number of fishes examined — chiefly by Mr. T. 

 Scott, on board the Garland— \}ci€yi: sizes and the condition of 

 the reproductive organs carefully noted, and the results, as 

 elaborated by him, are given in a paper about to be issued by 

 the Fishery Board in their Blue-book for 1890.^ The paper is 

 one of very great interest, and there can be little doubt that the 

 term "immature" ought to be restricted to fishes that have 

 never spawned ; and it may thus happen that such may be 

 saleable, e.g. in the case of the plaice, brill, turbot, cod, and 

 others. On the other hand, mature food-fishes may be unsale- 

 able from their small size, as in the case of the flounder, 

 dab, and long rough dab, though, as already mentioned, 

 these are important as the food of some of our most valuable 

 fishes. As given by Dr. Fulton the smallest ripe food-fishes 

 procured in the Garland's trawl were as follows : — Plaice I2 

 inches, lemon-dab 8 inches, dab 6 inches, long rough dab 6 

 inches, flounder 7 inches, craig-fluke (witch) 14 inches, turbot 

 18 inches, brill 16 inches, sail- fluke 9 inches, haddock 10 inches, 

 whiting 8 inches, cod 20 inches, gurnard 8 inches, and catfish 



' I have to thank Dr. Fulton for an early proof, issued, by the sanction of 

 ihe Secretary for Scotland and the Fishery Board, in connection with the 

 I nternational Conference. 



