40 PELAGIC FAUNA. 



Another net has been extremely successful at St Andrews 

 in examining the pelagic fauna near the bottom, viz., one 

 constructed after the manner of a small trawl. The trawl- 

 heads are of very light iron, the beam a slender bar of elm, 

 8 feet 6 inches long, and the net (18 feet long) is in the form of a 

 trawl-net, but composed of cheese-cloth, with a terminal region 

 3 feet in length of fine cotton cloth. The mouth of the net 

 is elevated about 9 inches from the ground by being drawn 

 " taut " between the trawl-heads, and has an oblique aperture 

 of 3 feet from beam to foot-rope. This is a fatal net for 

 larval fishes and the multitudes of invertebrates at various 

 stages that haunt the bottom-water in early spring, and should 

 be used only for a short time. 



The mathematical apportionment of the animals composing 

 the pelagic fauna therefore fall.s short of the German method 

 (Prof Hensen's), but for all practical purposes connected with 

 the fisheries the plan here adopted is fairly satisfactory. It 

 gives at a glance the vast resources to be found in the sea fur 

 the nourishment of the food-fishes — resources ranging over the 

 vegetable as well as the animal kingdom, the latter compre- 

 hending representatives of every class from the fishes downward. 

 Moreover, an intimate acquaintance with this pelagic fauna 

 alone, and leaving out of view for the moment all reference to 

 the multitudes of animals in sand and mud, under stones and 

 elsewhere, and which are all beyond interference by man, 

 demonstrates the unsatisfactory position of those who labour, 

 either through misapprehension or simply ad captanduvi — 

 to prove that a beam-trawl deprives the food-fishes of nourish- 

 ment by rendering the sea-bottom barren (sic)— just as a 

 roving enemy might starve the flocks of a population by 

 burning the grass. 



The importance of the pelagic fauna in supplying nourish- 

 ment for fishes cannot be over estimated, for while the adults 

 of many food-fishes might obtain support from the bottom- 

 fauna alone, it is certain their post-larval and young stages 

 could not. Further, the remarkable adaptation whereby the 

 most minute post-larval forms, such as the very young cod, find 

 in the pelagic organisms every want supplied is a striking 



