— 11 _ APPENDIX E: HEINCKE 



with bag of very small meshes, for the capture of the youngest bottom-stages of the food- 

 fishes. We call this apparatus the new Heligoland young- fish trawl. It is a trawl 

 of 20 m. in length, 5 m. in the wings in front, 3 m. in the bag and 12 m. in the true 

 middle part of the net. The ground-rope and head-rope measure each 14 to 15 m. in 

 length. The two wings, which each join on to '/a of the front part of the middle portion 

 of the net, are constructed in the same round shape as the middle portion. The ground 

 rope is a so-called leaded rope, i. e. a hemp rope with lead weights round it. The width 

 of the meshes of the net, decreases from ca. 4 cm. in front to V2 cm. behind, by 9 stages; 

 the mesh in the bag, which is 3 m. long, is also V2 cm., and is reduced on tarring the 

 net to 4 mm. The bag is closed by a rope. 



The same two otter-boards are used in this trawl, as serve for the upper boards of 

 the 3-otter-boards net. The chief differences between this and the ordinary otter-trawl 

 are, that the upper and lower parts of the net are exactly alike; it differs from Petersen's 

 trawl by its smaller length and the quite different structure of the wings. Its great 

 capacity for taking the bottom-fishes seems to be due to this special construction, as well 

 as the leaded ground-rope and the small size of mesh in the bag. It bites deep into the 

 ground right from the wings; the edges of these are arched inwards like the middle 

 portion of the net; lastly, the small mesh does not permit even the smallest of the bottom 

 fishes to escape. 



We fish with this Heligoland young-fish trawl at all depths and even on tolerably 

 rough ground, usually however but a short time, about 15 to 30 minutes and with the 

 low speed of 1 nautical mile per hour. With longer fishing, the net fishes so well and is 

 often so full, that it is difficult to get it in and it may be torn, though on the whole, it 

 has the advantage of great resisting power. 



This net undoubtedly catches the youngest stages of all our food-fishes; we 

 can well believe this at least, for the plaice, dab, long-rough dab, whiting [G. merkmç/us), 

 cod, haddock, Gadus Esmarki and others. We have not rarely obtained several hundreds 

 of the commoner species from the most different depths down to 140 m., thousands indeed 

 in a single short haul of 20 to 30 minutes; in addition also, numerous individuals in 

 older stages and even quite large specimens, 50 cm. and more. The catches of the various 

 invertebrates of all classes were, in many cases, enormously large. As a specially striking 

 proof of the great fishing capacity of this net, it may be mentioned that we have taken 

 the interesting small gobioid, Crystallogobius Nilssoni, which has hitherto been considered 

 a rare fish, in thousands of specimens. 



A second net we employ for the capture of ground-dwelling young fish with good 

 results, is the so-called shrimp-net or trawl, which the fishermen of our shallow seas 

 ("Wattenmeer") use for catching Crangon vulgaris — but with the difference, that we 

 fix the net to otter-boards instead of a beam, and make the bag of the same thick material 

 as for the Heligoland trawl. 



The shrimp trawl differs from the Heligoland trawl by its smaller size (10 m. in length, 

 of which 3 m. go to the bag; 6 m. in breadth, in front) and by the complete absence of 

 wings. It fishes just as sharply and is usable in the same depths as the other — but it 

 catches much less. 



^ 4. The fishing for the larger bottom fish. 



For this purpose, we ordinarily use on our research-steamer the large otter-trawl with 



2* 



