SEA-FISHERIES LABORATORY. 177 



trawl do not necessarily die. It will be seen by reference 

 to the hauls quoted on pp. 42-3 that a few large fish are 

 generally taken. These are always alive when brought 

 up from a drag of moderate duration, and if immediately 

 thrown back into the sea will most probably survive. We 

 refer to plaice, soles and dabs over 8 inches in length. 

 Flat fish from 3 to 8 inches are not so hardy, but many of 

 these are alive when the " net is fished,' 1 and probably 

 recover when put back into the sea. The vitality experi- 

 ments made by Mr. Dawson* and others in our district 

 have shown that quite a large proportion of such fish 

 recover when taken from the contents of the net and 

 immediately put into a tub containing running sea water. 

 But the flat fish under 3 inches long are in a worse case, 

 and the greater number of these are probably really 

 destroyed. They are small, and in the process of " sorting 

 the catch," all the larger animals (large fish, crabs, star- 

 fish) are thrown overboard first, so that small flat fishes 

 have to lie on the deck for a longer period than the others. 

 Small round fish, whiting, haddock and cod of less than 

 5 inches long are almost always dead when the contents of 

 the net are emptied on the deck. The larger round fishes 

 may be alive, but they seem to be less hardy than the flat 

 fishes. 



Of course the mortality among the fishes caught in the 

 shrimp trawl must depend to a very great extent on the 

 care of the fishermen in sorting the catch, on the facility 

 with which the net can be hauled, on the duration of the 

 drag, and on the temperature ; in warm weather the water 

 adhering to the gills is more easily evaporated and 

 contains less dissolved air. It is to the interest of 

 the fishermen to sort the catch quickly, and get the 



-Lancashire Sea Fisheries Laboratory Eeports for 1893, (p. 23) and 

 1894, (p. 30). 



M 



