168 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



It will be seen that the figures given above indicate for 

 the Mersey grounds similar changes to those which have 

 taken place further north. The conclusions for the two 

 areas mutually confirm each other. Whatever part of the 

 year be considered, the same marked increase of soles and 

 decrease of plaice and dabs, and the same ambiguity of 

 results with regard to whiting and shrimps is to be 

 noticed. It would appear that we are really justified in 

 concluding that there has been a marked increase in the 

 number of young soles, and an equally marked decrease 

 in the number of young plaice and dabs present on the 

 Lancashire nursery grounds. 



It is possible to regard the numbers of young fishes on 

 these nurseries as dependent on the numbers of the same 

 adult fishes on the off-shore grounds. That is, the more 

 soles (say) present on the off-shore grounds and spawning 

 there, the more young fishes will be found in the shallow 

 water grounds, also, other things being equal, the number 

 of adult soles on the off-shore grounds within the next 

 two years may depend on the number of young hsh on the 

 nurseries. This is because the eggs and larva 1 , resulting 

 from spawning fish outside, drift in towards these shallow 

 waters, and the young fishes settle there for a time. Then 

 as they grow they move outwards to replenish the off- 

 shore grounds. Perhaps it might be possible, if we 

 thoroughly understood the whole matter, and possessed 

 sufficient trawling observations, to forecast the approx- 

 imate abundance of fish on the off-shore grounds one or 

 two years ahead, from our knowledge of the abundance of 

 young fish on the nurseries. At any rate, such consider- 

 ations illustrate the importance of a thorough knowledge 

 of these in-shore water fisheries and their changes. 



