372 KECEKT KEPORTS Of FISHERY AUTHORITIES. 



All urea like the Firth of Forth is therefore, to a very large extent, 

 iudepeudeiit of the outer seas so far as concerns its supply of dabs, it 

 being in large measure self-productive. 



" The differences above described between the plaice and lemon soles 

 and the dabs seem to furnish a reasonable explanation of their decrease 

 and iucrease respectively. When beam-trawlers were prohibited from 

 working in the Firth of Forth and St. Andrews Bay, they naturally 

 concentrated their efforts in the free waters outside, and trawling 

 operations there have very greatly increased since the Bye-laws were 

 passed. The immediate consequence of the cessation of trawling in the 

 Firth of Forth and St. Andrews Bay appears to have been an increase 

 in the abundance of flat-fishes within the closed areas, as shown by the 

 very high averages in the year 1887. The fact that this increase was 

 not only not maintained, but that a progressive decrease in plaice and 

 lemon soles occurred subsequently, indicates another influence, namely, 

 excessive trawling on the offshore grounds where these fishes spawn. 

 This would affect the abundance of the important flat-fishes, such as 

 plaice and lemon soles, in two ways. By general overfishing, the 

 numbers are decreased on the fishing-ground, as indicated by the 

 averages for the open area ; and in the second place, by the removal of 

 too great a proportion of the mature spawning fishes, the supply of 

 floating eggs and larvpe to the inshore closed areas, and upon which 

 they are dependent, is diminished below the normal, with the result that 

 the supply of adults is also subsequently diminished. This appears to 

 me to be the only feasible explanation of the facts stated, and it would 

 indicate protection of the spawning areas as the proper course to be 

 pursued. The protection of the immature fishes, which has been so 

 strongly advocated by many authorities, will not, it can be safely said, 

 be sufficient in the areas under consideration. This is clearly proved 

 by the fact that the fish which, above all others, has the nurseries of its 

 young located in the inshore waters is the plaice. The distribution of 

 immature plaice is special in this respect, by far the largest number 

 being got near the shore, and fewer and fewer the further from the 

 shore.* In the Firth of Forth and St. Andrews Bay immature plaice 

 have therefore been particularly well protected since 1886, and yet this 

 is the species whose diminution is most marked. 



"The results of the trawling experiments hitherto conducted in 

 the Firth of Forth and St. Andrews Bay point to two main conclusions 

 of great importance for fishery regulations. One, which may be 

 regarded as demonstrated, is that the mere closure of even large areas 

 in tlie territorial waters, such as the Firth of Forth and St. Andrews 



• "Fide 'The Distribution of Immature Sea Fish and their Cajjture by various Modes 

 of Fishing,' Part III., Eujhth Anniuil Report, p. 166." 



