Nogen iakttagelser over fiskeyngel i trålfangster i Barentshavet

It appears that the trawl catches contain large quantities of smallerfish of several species which are killed and thrown overboard.Especially in regard of cod and haddock the amount of small andnon-marketable fish in proportion to the total catch varies in the differentareas.The content of non-marketable cod and haddock in the trawlcatches:A. Bear Island Bank: December 12th, 1932. Depth 220 m. Non-marketablecod 98,4 %. Haddock 0 %. Total 98,4 %. Catch: 766 cod, 0 haddock.(In th fine meshed net in addition 191 cod, 5 haddock.) Onesingle haul.B. Central portion of the Barentz Sea (Skolpen Bank). Jan. 1st to7th, 1933. Depth 156-210 m . Non-marketable cod 53 %. Haddock91,1 %. Total 68,8 %. Catch: 3952 cod, 2821 haddock. Total 6773individuals. (In the fine meshed net in addition 339 cod, 372 haddock.)4 stations with a total of 6 hauls with catches of non-marketable codand haddock varying from 61 % to 87,5 %.C. Edge of the Bank off Finnmark (Tanasnaget). January 9th to11th, 1933. Depth 105-230 m. Non-marketable cod 43,3 %. Haddock53,6 %. Total 45,6 %. Catch: 2820 cod, 827 haddock. Total 3647individuals. (In the fine meshed net in addition 80 cod, 245 haddock.)1 station with 7 hauls: catches of non-marketable cod and haddockvarying from 23,9 % to 65,9 %.D. Shallow Bank off Cape Kanin. Jan. 3rd to 5th 1933. Depth63-65 m. No non-marketable cod and haddock. Catch: 686 cod, 1450haddock. Total 2136 individuals (In the fine meshed net in addition5 cod). 2 stations with a total of 8 hauls .The cod end of the trawl, which I have had the opportunity toexamine on board the "Borgenes", was tied with 16 knots pr. 24 incheswhen new and waterproofed. A somewhat older cod end in use had1 or 2 more knots pr. 24 inches, which proves some shrinking of thenet by usage. On board the boat I procured some pieces of net madeof new waterproofed twine and I found out that mesh of the size of14 knots pr. 24 inches would allow small haddock of about 30 cmto escape.My impression is that something would be gained by the introductionof a size of mesh in the cod end of 2-3 knots less pr. 24inches than the one now generally used by the British trawlers.That the limitation of the size of mesh is a step in the rightdirection appears correct, judging from the experiments performed byattaching a piece of fine meshed net to the bag of the trawl. Thishas not only been tried during the investigations of S/S "Borgenes"last winter, but in addition several times on the cruises of "MichaelSars" during previous years.This moderate form of regulating the trawling operations for theprotection of the fry, will be of benefit not only to the cod and haddockpopulation, but will also protect several other varieties of fish.This will to some extent appear from ihe appended table of catches.