Trawling on the Solway. 195 



fish and the fisherman? The answer is one which gives us a 

 glimpse of the wonderful interdependence of living things and 

 their dependence upon natural phenomena. The naturalist is 

 frequently confronted with this linking together of all living 

 things, till he may well ask whether there is such a state as 

 independence anywhere in the universe. 



It will not be necessary here to follow link by link the chain 

 of facts which connect the prevalence of fish of certain kinds in 

 the Solway with the gigantic forces .which keep in motion the 

 whole of the sea bottom, but we will outline the prominent points 

 which are obvious to the observer without any very intricate 

 research. 



The presence of an abundance of fish depends absolutely 

 upon the presence of an abundance of food, and this food in its 

 turn depends upon other foods, and so on right down to the lower 

 forms of life whicji connect the vegetable and animal kingdoms. 

 All these creatures depend upon a suitable environment, and this 

 is provided in the Solway by the action of the tides. One might 

 almost call the loose, shifting sand a live bottom and the sodden, 

 mud-charged sand a dead bottom. In the former many kinds of 

 marine life take refuge, notably shrimps and cockles, and in the 

 latter comparatively few useful creatures live. The shrimps and 

 cockles, which form such important items in the diet of the flat 

 fish, live largely in the sand, but draw their food from the water, 

 consequently the loose, clean sand suits them better than the sand 

 which is never stirred by the tide, and which becomes sour and 

 sodden and mixed with mud. Sometimes a large area of sea 

 bottom, owing to a .sudden change in the currents, remains undis- 

 turbed for vears. Such an area becomes absolutely unproductive, 

 and the creatures which existed there before the change took 

 place are either smothered or driven away. I have seen 

 thousands of cockles killed bv a sudden deposit of fine mud on the 

 top of the sand. This simply means that they cannot breathe, 

 and consequently they die unless a strong tide or a gale of wind 

 quickly causes the bottom to be cleansed. The shrimps are quite 

 as dependent on a loose, clean bottom, for thev lie buried for long 

 periods, especially in the spring time, when they arrive from 

 deeper water, tempted by warmer weather, only to be overtaken 

 by a return of the cold, and possibly snow water from the hills. 

 Their refuge is at hand, and thev disappear deep into the sand till 



