100 > THE COALFISH OE SAITHE 



The Main Coalfish Grounds were, according to English 

 statistics : 



But it is onl}^ to the northward and westward of Scotland 

 that it forms a really important part of the catch. Very few 

 coalfish are caught at less than 30 fathoms, and most of them 

 came from 40 to 100 fathoms. Numbers are caught on the 

 Porcupine Bank, West of Ireland. 



Life-History 



The life-history of the coalfish is given by Hjort.^ It spawns 

 from January to May, for choice, at depths from 50 to 100 

 fathoms, and generally at 80 fathoms, on the slopes of the coastal 

 banks, just as does the hake. But whereas hake spawn almost 

 entirely in the Atlantic, the spawning grounds of the coalfish 

 have been located in the Atlantic, in the North Sea, and in the 

 Norwegian Sea. The North Sea spawning grounds are confined 

 to the northern extremity of the banks north-west of Shetland, 

 and the deeper portion and extreme edge of the Eomsdal Bank 

 — the grounds known to Norse fishermen as Tampen. Here 

 many hundreds of hauls with tow-nets have found the surface 

 covered with thousands of eggs in the early part of the year. 

 Hjort notes that the eggs float only in water of 35 per mille 

 salinity, i. e. very salt indeed. There is usually ^ little water 

 as salt as this, except in the central portion of the North Sea 

 north of the Tees-Skawlino in February, and off the Shetland 

 Banks. 



Very soon after spawning has taken place, both the large 

 coalfish and their eggs^ completely disappear from the spawning 

 grounds. The period of incubation is said by the Americans 

 to be nine days at 43° F., and six days at 49° F., which is about 

 a week shorter than the hatching period of cod. The fry 

 similarly float at the surface for a much shorter period than 

 cod — who may be drifting for as much as three months. 



1 Some Results of the Internationa Ocean Besearches, Scot. Ocean Lab., 

 Rutland Street, Edinburgh. Depths of Ocean, Chap. X. 



2 But in 1904 apparently the abnormal influx of Atlantic water made the 

 North Sea unusually salt, 



=' The eggs are -044 inch in diameter, i. e. about 795,000 to the quart. 



