Bro 
a 
proportion of each of the most important species to the whole yield of each separate 
water. 
{| 
| Cod Coalfish |Haddock Ling | Tusk | Hake 
| | 
| ey VE | % | % %o | %o 
Parents Seat es DOA) Ne zer a ER 
Norway N. of Stat......... 81.1 6.0 2.9 ull DO | 
Tcelan TEE ee a: 59.6 3.9 20.8 2.4 0.1 
ERE VEY ROXEIS} seul AN ee: 47.7 3.0 29.9 2.2 0.7 Bee 
INOTÉNASCAR EN Bra. 18.8 1.3 45.1 2.5 0.3 0.5 
N.W. of Great Britain ..... 19:7 9.5 23.6 9.7 0.7 2.6 
S.W. - — Es 4.4 0.6 5.4 3.1 Be 31.7 
BEN OÙ IST. à os oomoaoue ne Je 0.8 0.7 AN 65.2 
Portugal and Morocco ...... | SAN 2 41 0.5 Hee 41.0 
All waters... | 441 | 33 25.0 2.9 1.0 22 
According to this table, there is no region in which the cod plays so great a part 
as in the Norwegian coastal water. This single species here amounts to over 80 % of 
all bottom fish taken. In Iceland and Faeroe waters also, the cod is an extremely important 
item; in the North Sea, the percentage fails below 20 %, while west of Great Britain 
it decreases rapidly to ml. South-west of Great Britain lies the southern limit of distri- 
bution of the cod. Considerable similarity in this latter respect is exhibited by the coal- 
fish, ling and tusk, which, like the cod itself, are pre-eminently Norwegian Sea fish. 
The haddock is of most importance in the North Sea, where it furnishes something 
approaching half of the total yield in bottom fish; it is found, however, in great quanti- 
ties farther north, especially in the Barents Sea. The fact that it is not caught in quan- 
tities in Norwegian waters is due, as I have endeavoured to show in the work above 
mentioned, partly to the nature of the bottom, and partly to trade considerations. 
The hake is a more southerly form, being met with first in the North Sea, and oc- 
curring in greatest numbers in the warmer water of the Atlantic coast of Europe. 
This peculiar distribution of the different species would seem to coincide with a 
certain constant difference in the temperature of the water; in evidence of this may be 
adduced the fact that the fish on the eastern and western sides of the Atlantic live under 
corresponding conditions in this respect. From the chart, Fig. 1, it will be seen, that 
the line of 10°C. at 100 metres depth may be drawn on the eastern side off the south- 
west coast of Ireland, whereas on the American side it goes much farther south. The 
area of most frequent occurrence of the cod falls between the 6° and 8° isotherms, the 
prevailing temperature off the coasts of southern Iceland, at the Faroes, on the New- 
foundland Banks, and off the coasts of the northern states of America. 
The American statistics give the following catches of cod, haddock, and coalfish, 
in 1906 (in cwts.): 
Cod Haddock Coalfish 
Northern States........ 40.000 21.000 7.900 
Central A Tee 1.400 200 50 
Southern re 0 0 0 
