182 SEA FISHERIES 



water ? And all those species which rush to the coast, 

 into our estuaries, creeks, and bays, wherever the water is 

 shallow : herring, sardines, cod, mackerel, rays, gur- 

 nards, and tunny ? And the soles and all the flat-fish 

 which come to spawn along the coast ? And their fry, 

 born of pelagic eggs, and swept hither and thither by the 

 currents : these also, despite the currents, find their way 

 back to the coast. The very young plaice of the Danish 

 coast make an irruption into the brackish basins of Lum- 

 fjord. The fry of bar, gobies, grey mullet, false smelt, 

 eels, gilt-heads, conger, and turbot, and lately even the fry 

 of the sardine, leave the open sea for the lagoons of 

 brackish water along the coast of the Mediterranean, 

 the Adriatic, and the Atlantic. Is not this fact the very 

 principle and basis of the dams, valli, fishponds and fish- 

 marshes of Comacchio, Arcachon, and Sables-d'Olonne ? 

 Does not fresh water attract fry as powerfully as do cur- 

 rent ? All migrations of edible fish tend towards the shore, 

 the confines of land and sea. And as a regular and constant 

 migration is the primordial condition of industrial fishery, 

 it is upon the confines of land and sea, upon the con- 

 tinental plateau, that our fishing-grounds are concentrated. 



Such a coincidence gives us food for reflection. What 

 is the meaning of this localisation of our fishing-grounds 

 upon the confines of land and sea, that is, of two different 

 elements ? 



If we pass these fishing-grounds in review, 1 we find 

 that each constitutes a fairly heterogeneous environment, 

 but the principal characteristics are found in all. The 

 Atlanto-Saharan banks receive warm water, tepid water, 

 and cold water. The banks of Newfoundland are an estuary 

 formation still in process of deposition. They are swept 

 by the warm waters of the Gulf Stream and the cold waters 

 1 See Chapters II. and III. for details. 



