FISHES FROM THE SEA-BOTTOM 



449 



and farther south, near the Canaries, off Agadir, they may 

 even amount to two-thirds of the total catch. Soles are also 

 numerous. South of the Canaries we saw during our cruise 

 (see Chapter HI.) a considerable handline fishery for acanthop- 

 terygian fish {Dentex, Diagranwia, etc.) carried out on hard 

 stony and gravelly bottom. The trawl cannot be worked there, 

 where the acanthopterygians were present in enormous shoals, 

 outnumbering all other species. We had there a fauna entirely 

 different from the boreal fauna, lacking all the northern forms. 



All the way from western Ireland to the coast banks of 

 Morocco, fishing is carried on down to deep water, at least to 

 300 fathoms (500 to 600 metres). West of Ireland the trawlers 

 in April capture two kinds of ling (Molva violva and M. eiongata), 

 hake and breams (Pagelhis), down to 300 fathoms, and west of 

 Morocco they get large hake down to 200 or 300 fathoms. Fish- 

 ing thus goes on as deep as the fauna of the coast banks extends. 



As we have seen already, the Macruridae peculiar to the 

 fauna of the slopes, commence at about 500 or 600 metres. 

 Will this fauna of the slopes, particularly the Macruridae, Mora, 

 etc., ever be the object of a fishing industry.^* This question 

 is important, and the possibility of such an industry cannot 

 a priori be denied. If we consider that the " Michael Sars " in 

 one haul, with a comparatively small trawl, at Station 4 took over 

 300 fishes, some of which, as for instance the Mora, seemed just as 

 fit for the market as the tusk, it does not seem improbable that 

 improved technical appliances may render fishing profitable 

 even down to 500 fathoms and more. 



It is very interesting to note, as shown in the following 

 table, that the temperature in 300 fathoms (the limit of the 

 coast fish) is 10° C. — a temperature which we have previously 

 referred to as marking the southern limit of the northern forms 

 to the west of Ireland, where the southern forms commenced to 

 increase in abundance : — 



Depth limit 

 of fishing on 

 Atlantic slope. 



2 G 



