40 



NATURE 



[May 8, 1890 



areas, and that the increase was chiefly in flat fish, though also 

 in round fish. At the same time, there was an increase in the 

 take of all classes of fish in the free waters outside, but in 

 general the increase in this case was in round fish, rather than 

 in flat fish. So far, then, the experiment promised to show an 

 immediate and most beneficial result. In 1888, however, the 

 take of fish was very much diminished. The average num- 

 ber of fish of all kinds captured in the Firth of Forth 

 per "shot" amounted to 211. In 1887 the corresponding 

 average was 351, and in 1886, 251. There was also a consider- 

 able reduction in the average take in offshore waters, but the 

 reduction was less than that in the closed area. Moreover, the 

 proportional decrease of flat fish was greater than that of round 

 fish in the closed waters, and this was more marked in the off- 

 shore waters. In St. Andrew's Bay there was, similarly, a 

 great diminution of all kinds of fish, especially of flat fish ; but 

 outside, in the free sea, there was an increase in the flat fish and 

 a great decrease of round fish. These negative and partly con- 

 tradictory results were, without doubt, due to the exceptionally 

 stormy weather in 1888. It shows, however, the great difficulty 

 and complication attending fishery investigations. Nothing 

 could seem to be more obvious than that, if trawling were pro- 

 hibited in a certain area, less fish would be caught, and that 

 their numbers would increase. The first results of the trawling 

 experiments go to show that this is by no means necessarily the 

 case, but that there are causes more powerful than beam-trawling 

 which affect the numbers of fish in any season. 



There are also statistics showing the relative amounts of fish 

 caught by line in restricted and unrestricted areas — that is to say, 

 areas where beam-trawling is prohibited and where it is per- 

 mitted. The^e statistics show an increase in the weight of fish 

 caught by line has taken place in 1888, ifi both areas, but that 

 it is proportionally larger in the unrestricted than in the re- 

 stricted areas. The increase is not due to a larger number 

 of boats and men engaged in fishing, for these have actually 

 decreased. The statistics of line-fishing are certainly curiously 

 contradictory to tho^e of beam-trawling, for whereas, in 1888, 

 the latter mode of fishing showed a decrease of flat fish in 

 closed areas, the line-fishing showed an increase of flat fish. 



It is really impossible to draw any conclusions from statistics 

 extending over so few years. After ten years of work we shall 

 be in a better position to judge the result of the experiment of 

 c'osing certain inshore waters against trawlers. So far, it must 

 be confessed that no case whatever has been made out against 

 them, and the line fishermen seem to be quite as efficient in 

 depopulating a district. From the way in which the summaries 

 of the statistics are written, the Fishery Board may be suspected 

 of an unconscious leaning towards the interests of the line- 

 fishermen. 



No fewer than 129 pages are devoted to the statistical tables 

 referred to. 



A very interesting Report is given in Section B (biological in- 

 vestigations) by Prof. Ewart on the spawning of British marine 

 food-fishes. Space forbids a detailed criticism of this Report, 

 but it is definite and satisfactory, and shows that, contrary to 

 the common belief, the majority of British food-fishes do not 

 come inshore to spawn, but at the spawning season they congre- 

 gate in shoals in deeper waters. 'I'his Report is followed by a 

 paper on the food of fishes, by Mr. Ramsay Smith. The greater 

 part of the observations and records necessary for this work 

 were carried out by Mr. Thomas Scott, who is a veritable giant 

 in practical work at sea. The paper on the pelagic fauna of the 

 Bay of St. Andrew's, by Prof Mcintosh, may be considered as 

 complementary to Mr. Ramsay Smith's paper, since the pelagic 

 organisms are considered from the point of view of food for 

 adult and larval fish. Prof. Mcintosh's paper, giving a record 

 of all the pelagic organisms observed throughout the year, is a 

 thorough and important contribution to our knowledge of the 

 subject, and has a high practical value, especially that part of it 

 relating to fish ova and larvae. At the same time, it may be 

 questioned whether the subject of fish food is not dragged in a 

 little too much. Is it perfectly ingenuous to give a series of 

 beautifully-coloured drawings of the metamorphoses of Actino- 

 trocha, and to label them " Pelagic fish food" ? 



The descriptions of, and suggestions abouf, the mussel and 

 clam beds are of obvious practical interest, and Dr. Edington's 

 paper on the Saprolegnia of the salmon disease gives projiise of 

 a wide extension of our knowledge of a difficult subject. 



The Report concludes with a careful record of physical obser- 

 vations made in the North Sea. The value of the physical 



work of the Board would be much enhanced if arrangements 

 could be made for taking daily observations at definite stations 

 around the Scotch coast. Such observing stations have been 

 established by the United States Fish Commission and by the 

 German Commission for the Scientific Investigation of German 

 Seas, and have been fruitful of results. 



The Fishery Board, it may be noticed, is only engaged in one 

 experiment — that of closing certain areas against beam -trawling. 

 The remainder of the work is in the preliminary stage of in- 

 quiry. In the earlier stages of fishery investigation, a large 

 amount of biological and physical inquiry into the natural con- 

 ditions of the sea is absolutely necessary, as a guide for future 

 experiments upon marine organisms. To those who do not 

 consider the matter attentively, these investigations may seem 

 useless and superfluous, but they are not. It nmst be observed, 

 however, that these inquiries are not an end in themselves, as 

 in philosophical biology, but must be undertaken solely with the 

 view of applying the experience gained to future attempts to 

 solve the fishery problem. For example, an inquiry into the 

 food of the different species of fishes of a district need only be 

 made once ; it is sufficient for practical purposes to know what 

 they do generally eat, without inquiring what they may eat in 

 exceptional circumstances. An inquiry into the relations of 

 pelagic organisms is most useful as a guide to the life-conditions 

 and food of fish larva and certain adult fish, but a great deal of 

 strictly scientific work on this subject is useless ; the morphology 

 and phylogeny of each pelagic organism has not the slightest 

 bearing on fishery questions. 



The statement of the fishery question is perfectly simple. 

 Given a continuous decrease in a number of valuable fish, due 

 to over-fishing, how may the diminution be checked, and a con- 

 tinuous future supply be insured ? The answer to the question 

 is very difficult. Life in the sea is beyond control, and, to a 

 large extent, beyond observation, for the trawl and dredge give 

 a very insufScient idea of the conditions of marine life. There 

 is not so close an analogy between agriculture and fisheries, as 

 is sometimes implied in language. The sea cannot be parcelled 

 out into inclosures ; it cannot be cultivated with different kinds 

 of crops at will ; its fishes cannot be kept in confinement and 

 protected from their enemies and the weather, nor can they be 

 fed at regular periods as live stock are. It is misleading to talk 

 of "reaping a harvest that is never sown," when the power of 

 sowing and caring for the crop is out of reach. The ultimate 

 aim of all scientific investigations in fishery matters must be to 

 find out what circumstances are in human power to control, and 

 to show how that control may best be exercised. 



The first and obvious subjects for control are the fishermen 

 themselves. If they are the cause of the depopulation of the 

 seas, such a check may be put upon their proceedings as to 

 obviate the evil. This may be done in one of two ways : by 

 prohibiting fishing altogether in certain specified areas, as has 

 been partially done by the Scotch Fishery Board, so as to afford 

 centres from which fish may spread into the surrounding seas, or 

 by the establishment of close seasons for different species of fish. 

 Both methods are attended with great difficulties, which have 

 been discussed over and over again. They may be summed up 

 as hardship to the fishermen, and the impossibility of prevent- 

 ing the destruction of one species of fish whilst another is being 

 fished for. To establish a close season which would prevent any 

 breeaing-fish being caught, would be to prohibit all fishing for 

 three parts of the year. Secondly, the ova of breeding-fish may 

 be artificially fertilized, the fry hatched out and turned out in 

 great numbers to re<-tock the waters that have been depopulated. 

 This method is said to have been attended with success, and 

 demands a further trial ; but it must not be supposed that this 

 process in any way resembles the rearing of domestic animals on 

 land, or even the culture of fresh-water fish. The fry, once 

 turned out, are lost sight of, are exposed to the attacks of 

 numerous enemies, and are beyond all further human care. 

 Thirdly, fish might be protected by the wholesale destruction of 

 their natural enemies other than man, just as game is protected 

 by the destruction of stoats, carrion-crows, and other vermin. 

 No doubt a general massacre of cormorants, gannets, and dog- 

 fish would make a great difference to the annual destruction of 

 fish on our coasts, but in the case of the birds, such a course would 

 meet with great opposition ; and in the case of dog-fishes, 

 extermination, or even an appreciable reduction in number, 

 would be nearly impossible. Lastly, attempts may be made at 

 culture sensti stricto. Young fish may be caught by the ordinary 

 methods, and kept in suitably constructed fattening-ponds until 



