SCIENTIFIC WOBK IN THE SEA-FISHERIES. 217 



they soon gravitate to the bottom as the eye joins its neighbour 

 of the opposite side, meanwhile approaching the margin of the 

 tide, where they may be found in numbers amidst the muddy 

 sand of the beaches, and where they are comparatively safe. 

 During growth they are constantly shifting from the shallower to 

 the deeper water, where the adults are found. Thus, while the 

 adults may suffer from trawl or hook, their places are filled by 

 an ever-constant stream of young — in the case of Plaice — in such 

 numbers that hitherto their extermination has defied man's most 

 elaborate ingenuity and far-reaching cupidity. 



Bear in mind how often the approaching extinction of this 

 and that fish has been predicted — how the fishery for Soles, for 

 instance, has had its days numbered about a quarter of a century 

 ago, even by scientific men, it may be, out of touch with the sea. 

 Yet what does Nature teach us in the estuary of the Thames ? 

 For five or six hundred years at least the limited area of this 

 estuary has been persistently and almost daily fished for Shrimps 

 by man, and his nets have simultaneously captured and killed, 

 amongst other fishes, numerous young Soles (and I have to 

 thank Dr. Murie for his genial aid in the expedition to secure 

 them) — tiny wafers which are blown on the gunwale of the boats, 

 to which they adhere, in sifting ; whilst the larger examples, at 

 various stages, are picked out with the debris, and, as a rule, also 

 killed. Since the area referred to has been calculated to send 

 daily to London at least two thousand gallons of Shrimps,* the 

 drain on these young fishes is enormous ; yet, it may be asked, 

 has it affected in any marked manner the prevalence of the adult 

 Soles throughout these centuries, and, moreover, has the sea 

 been impoverished in regard to Shrimps? Mr. Shaw Lefevre 

 (now Lord Eversley) has recorded a case where, in Morecambe 

 Bay, a far greater destruction of young flat-fishes was caused by 

 the drying up of the shallow pools between tide-marks by the 

 sun than by all the local shrimpers, of which the flounder- 

 fishermen complained. The fishermen, however, had a ready 

 rejoinder when this was pointed out by the Commissioners, viz. 

 that the natural loss was allowed for by Providence, but not that 

 caused by shrimping. It must not, however, be supposed that 

 this wholesale destruction of young fishes is treated with in- 



* Mr. Spencer Walpole, Fish. Exhib. Lit. vol. i. p. 47, 1884. 

 Zool. Mh ser. vol. XI., June, 1907. s 



