106 TEANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



Nature of the Fishing Grounds — their Regulation. 



Most of the region investigated lies inside the three-miles' 

 limit, and trawling by steam vessels is everywhere prohibited 

 within this zone. In addition, trawling by any kind of vessel 

 is prohibited in Luce Bay by the Fishery Board for Scotland. 

 Trawling by motor-propelled vessels is permitted, by licence 

 issued by the Lancashire and Western Sea-Fisheries Joint 

 Committee, in Carnarvon and Cardigan Bays. There are 

 regulations with respect to the size of trawl-mesh, which is now 

 measured all round the mesh in the Lancashire and Western 

 District and in the Cumberland District. Trawling by steam 

 vessels is prohibited in the three-miles' zone round the Isle of 

 Man. Vessels fishing for shrimps employ a trawl-mesh of 

 2 inches, and they are not supposed to retain any fish if these 

 are less than 8 inches in total length. The mesh of stake-nets 

 is also regulated, and is 7 inches measured round the four sides. 

 There are no restrictions on the times of the year when trawling 

 that is otherwise legal may be practised, and there are no 

 restrictions on the sizes of fish of any species that may be landed 

 and offered for sale. 



Most of the whole region in question is what is called a 

 " nursery ground." This is particularly the case in the Solway 

 Firth, in the estuary of the Duddon, in Morecambe Bay, and in 

 the estuaries of the Bibble, Mersey, and Dee. Here there are 

 enormous tracts of sand-banks, which are laid bare at each 

 ebb-tide, and there are innumerable shallow channels through 

 these banks. The water is rather cold in the winter on these 

 shallow estuaries and rather warm in the summer — that is, 

 the extremes of temperature are greater in the bays and 

 estuaries than they are in the sea, just offshore. Sometimes 

 there is considerable ice formation in Morecambe Bay. The 

 higher temperature in the spring, summer, and autumn, and 

 the lowering of the specific gravity of the water by that coming 

 from the land are very favourable conditions. Water draining 



