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these data are published to give us an idea of the average relation 

 between landed fish and fish thrown overboardo Russell (1932), 

 referring to Borley in an English report of 1927, shows figures on 

 the amount of fish thrown overboard from English trawlers© They are 

 4 percent of the total catch of cod, 17 percent of the haddock and 

 4 percent of plaice, by weight* Russell (1932) shows that during 

 the period 1926-30 the first-class English steam trawlers discarded 

 10 percent of the haddock and 4 percent of the plaice catches overboard© 

 Converted to niimbers these weight figures will be respectively 14 

 percent and 17 percent. Russell thinks that the 4 percent for plaice 

 is too lowo It may be assumed that with the increase of the Over= 

 fishing, the percentage increased since 1930o For the last decade 

 we believe that we may assume an average of 6 percento 



Bowman (1932) made an exact study on the amount of haddock thrown 

 overboard during the period 1924-29 in a very intensively=fished part 

 of the North Sea. This area is bounded by latitude 50° N and 57-l/2° N 

 and longitude 1° W and 2° w (900 square sea miles). Much young haddock 

 is present in this area. 51 percent of the total catches in numbers 

 or 35 percent in weight was thrown overboard in this area. 



De Veen (1938) observed the landings of trash in Holland during 

 the period July 1937-June 1938. He found that during this period 

 the "betters", luggers, and small draggers caught about twice as much 

 trash as marketable fish. For the steam trawlers the relation between 

 marketable and trash fish was about 1 s 1. The good market for trash 

 and the decline of the marketable part of the fish stock, stimulated 

 the fishing for trash by the small ships during the past 5 to 10 years 

 before World War II. The high trash landings of these ships during 

 the period 1937-38 may, therefore, not be viewed as representative 

 for the period 1919-30. It appears more correct to asstme that, on 

 the average, 50 percent of the total catches of the Dutch fishing fleet 

 on the plaice grounds consisted of trash. This is the figure establish- 

 ed for steam trawlers by de Veem, Tesch (1925) reports that plaice- 

 trash formed 35 percent of the total weight of trash. We may assume 

 that about 85^ of the catch of marketable fish consisted of plaice. 

 A simple sum shows that about 30 percent of the total catch was plaice 

 trash. The Dutch ships destroyed far more small plaice than the 

 English vessels, since the Dutch fished almost exclusively on grounds 

 where young plaice are abundant. The Germans probably caught somewhat 

 smaller amounts of trash as they used fairly large-meshed nets. ThereforOj 

 we assume that the plaice catches of the Dutch, Belgian and German Vessels 

 consisted on the average of 25 percent plaice-trash. It appears to us 

 that this figure is more likely to be too low than too high. 



The Danish destroyed very few undersized plaice with their 

 "snurrevaad* (seine). We asstjme it to be 2 percent. 



During the period 1918-38, the Danish took 25 percent of the 

 plaice catches, the English 42 percent and the other countries 33 

 percent. 



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