118 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



Luce Bay (in October, November, and December), the 

 Cumberland coastal grounds, the " Nelson Buoy " grounds, 

 the "Mersey Estuary," the "Bed Wharf-Beaumaris Bay" 

 region, Carnarvon and Cardigan Bays. 



(b) Trawling experiments were made continuously from 

 1890 to 1920 by the sailing vessels employed on police work 

 in the Mersey Estuarine area. All these experimental hauls 

 were made by the same officer, Capt. George Eccles, a highly- 

 experienced fisherman. Two series were made, one with the 

 ordinary small trawl-net of 6-inch mesh, and the other with 

 the ordinary shrimp-trawl net of 2-inch mesh. Some other 

 similar series of hauls were also made in other parts of the 

 District. 



(c) Comparative hauls with trawl-nets of 4-inch, 6-inch, 

 and 7-inch meshes were made. 



(d) Samples of the plaice caught on the various grounds 

 were regularly sent to the Liverpool laboratory. These were 

 examined in detail : 



They were measured as above and sorted into groups of 

 n to n-\-l cms. 



The whole lob of fish in each group was weighed to the 

 nearest gram and the total weight was divided by the 

 number of fish. Average weights were so recorded. 



The length- weight coefficient " k " was then calculated 

 (see Ann. Rept. Lancashire Sea-fish. Laby. for 1911, p. 17). 



Each fish was dissected ; the sex was determined, as 

 well as the stage of maturity ; the age was determined by 

 inspection of the rings on the earstones and the food contents 

 of the stomach and intestine were often identified. 



(e) Observations were made by the " Fish-Measurers," 

 W. C. Smith, A. E. Buxton, and Gr. Sleggs, on board steam 

 trawlers, smacks, and half-decked trawlers. This work 

 began in 1920. It was mostly restricted to the offshore 

 grounds and to the shallow water area of the Solway Firth. 



