CHAPTER XV 

 Fishery Research 



To a naturalist the engrossing work of unravelling the many 

 mysteries of life in the sea and the quest for information 

 to enable a clear picture to be gained of the life stories of 

 the animals is all sufficient. But in these days of applied 

 science the naturalist is also called upon to utilize his 

 knowledge to help the many industries which are dependent 

 on the products of the sea. By far the most important 

 of these products are those fish that are eaten by man — 

 under the term edible fish are generally included both the 

 true fish and the shellfish which consist of crabs, shrimps 

 and oysters, etc. 



There can be no hard and fast line between oceanography 

 and fishery research, because all of the widely ranging 

 problems attacked by the oceanographer will be found to 

 have some indirect bearing on the lives of the fishes living 

 in the sea. Fishery research is, rather, a branch of oceano- 

 graphy, and its main concern is an attack on the problems 

 directly connected with those fish which form the chief 

 supplies of food from the sea. 



The foundations for the application of science to the 

 fishing industry must lie in a complete and intimate 

 knowledge of the life-history and habits of each fish. It 

 will perhaps enable the reader best to grasp the methods 

 and aims of modem fishery research if we describe how our 

 present knowledge has been gained of two fish, such as 

 the herring and the plaice, which differ widely in their 

 habits. Both of these fish are of the greatest importance 



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