SOME ECONOMIC ASPECTS OF SHORE LIFE 283 



such periods as the rising and faUing tides enable these 

 animals to visit and utilise the region. 



Shore Fishes. — The use of shrimp, seine and other nets 

 is supplemented in some districts by the use of permanent 

 weirs, baulks, and stake nets. The coast of N. Wales from 

 the Menai Straits to Cohvyn Bay affords several examples 

 of these permanent fish weirs, which entrap a variety of 

 species, at times including large numbers of mackerel. 

 In one tide 7000 mackerel were taken in a baulk at Birkdale 

 (Rept.of Superintendent of Lanes, and Western Sea Fisheries, 

 for Quarter ending 30th September, 191 5). 



Any one visiting the enormous tidal areas of Morecambe 

 Bay can hardly fail to be impressed by the variety and extent 

 of stake nets, stream nets, baulks, etc., some fixed, others 

 temporary, which occur mile after mile. Most of these 

 are designed to capture fish which do not belong permanently 

 to the actual tidal zone but visit it for feeding purposes, and 

 hence must exercise a very marked influence upon its per- 

 manent fauna. The flat-fish : Plaice, Flounder, and Dab, etc., 

 are undoubtedly those of chief commercial importance : 

 their larval stages are partly inshore, and even when older 

 they continue to be largely inshore feeders, especially during 

 the summer months. The commercial round-fish can be 

 regarded as chiefly summer visitors, when they are taken 

 by net or line in large numbers (Mackerel, Mullet, Gar, 

 etc.). Particularly are many fish attracted by the larvae 

 and young forms of the shell-fish beds of the inshore waters 

 and tidal zone. Nevertheless, these commercial fish are not 

 shore dwellers in the strict sense, as are the various Wrasses, 

 and the numerous species of Blennies, Gobies, and Rock- 

 lings, that breed within the tidal zone. We may summarise 

 the relation of coastal fishes to the tidal zone somewhat as 

 follows : — 



I. Species that pass through tidal waters during migration : 



{a) To spawn in the sea — Eels. 



The larvae ascend, and thus these fish normally traverse 

 the tidal zone twice during their life-history. Sticklebacks 

 may migrate to shallow coastal waters to breed. 



