17 — APPENDIX H: GARSTANCx 



D. Trawling experiments 



From the beginning of the international investigations considerable importance has been 

 attached to the necessity of a thorough scientific exploration of the fishing grounds in the North 

 Sea, in the course of wliich the various hauls of the trawl should be accurately analysed, the 

 fishes counted, measured and weighed, and the general conditions of the experiments accurately 

 noted. As mentioned in the Christiania programme the object of these experiments should be 

 to provide material by whicli accurate charts might be prepared showing tlie distribution 

 of the various species of fish in all stages of their growtli. Although this ideal cannot be 

 attained in a short space of time, I have made a preliminary attempt to generalise the results 

 of the trawling experiments hitherto carried out. in order to show on the one hand what 

 progress has been made towards the attainment of this object, and on the other liand to 

 show which parts of the international area require increased attention from the steamers em- 

 ployed. It should be understood at tlie outset, however, that although scientific experiments 

 are able to throw light upon many of the same problems as those witli which fishery statistics 

 properly speaking, have to do, these experiments in no way replace the desirability of instit- 

 uting a uniform organisation of fishery statistics, since a Ijnowledge of tlie total quantity of 

 fisli landed at the ports is of primary importance for a coi-rect understanding of the resources 

 of tlie sea. On the other hand tliere are certain equally important matters upon which the 

 most perfectly organised fishery statistics can never tlirow the same amount of light as properly 

 conducted scientific experiments. Since tlie efficient regulation of tlie fisheries requires a proper 

 understanding of the life histories of the fishes concerned, it is clearly of importance that 

 investigations should be carried out in regions wliere the fishermen rarely fish as well as in 

 regions which the fishermen most habitually frequent. Moreover, on the coastal fishing banks, 

 where the intensity of fishing, so far as the plaice is concerned, attains its maximum, it is 

 notorious that the fishermen do not invariably retain the whole of their catches, but frequently 

 throw overboard a large proportion of the small or unmarketable fish. Fishery statistics and 

 mai-ket measurements throw light on the quantities and sizes of the fishes landed, but scien- 

 tific experiments on the fishing grounds alone throw a clear light upon the actual proportions 

 of large and small fish in different parts of the area under consideration. 



The steamers employed in the international trawling experiments are not all of the same 



build, but with the exception of the "Thor", employed by the Danish Commission, all the boats 



carry an otter trawl of practically identical si.^e and form, as reported on a previous occasion'. 



The net in general use is a 90 foot otter trawl. The English steamer in addition carries a 



43 foot beam trawl and a similar net has been employed by the Belgian Commission. Although 



the catching power of an otter trawl of this size slightly exceeds that of the beam trawl in 



question, the differance, so far as plaice is concerned, is very small, so that the results of 



the various experiments are fairly comparable one with another, with the exception of the 



smaller 50 foot otter trawl normally used by the Danish boat, and occasionally by the German 



steamer "Poseidon". 



' Rapports et Procè.s- Verbaux ties Réiuiioiis. vol II. (Amätei'dam meeting. Appendix ü.) 

 Appendix H ^ 



