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to determine practically whether the young fish brought 

 up in the trawl-net are worth returning to the sea, and I 

 hope that similar "vitality investigations" will be carried 

 on on board the fishery steamer here. A large tub or wooden 

 tank should be fixed on deck through which by means 

 of the hose and a waste pipe a circulation of sea water 

 can be kept up. Then after each haul of the trawl-net a 

 few fish should be picked out and put in the tub, their 

 species, size, and condition (e.g., "lively," "exhausted," 

 etc.,) being noted on a form, along with a statement as to 

 the time trawl was down and kind of net used. The fish 

 should be allowed to remain a definite time, say 30 or 40 

 minutes, in the tub and then the result (e. g., "recovered," 

 " dead," &c.) would be added to the form. Such statistics 

 would give a definite idea of the proportion of fish caught 

 under certain conditions which might be reasonably ex- 

 pected to recover if returned promptly to the sea. 



In making any regulations in regard to immature fish 

 the aim should be to allow as many fish as possible to 

 spawn once at least before being caught. Hence it becomes 

 of importance to know for our district the size at which 

 the various species become sexually mature. During this 

 coming breeding season we shall record the size, and the 

 condition as regards maturity, of all fish examined, with 

 the view of arriving at the minimum measurement at 

 maturity, and also the maximum of immaturity so as to 

 fix upon a fair average size below which no fish should be 

 taken. We want also to know for our own district (some 

 of these things cannot be taken from elsewhere, such as 

 the east or south coasts) exactly when (at what age) each 

 species spawns, and what the rates of growth are,* and 

 the average sizes in successive years, exceedingly difficult 

 matters to determine, as artificially reared fish may be 

 *See also Cunningham, British Association Report for 1891, p. 685. 



