{ 49 ) COMM. B — DEC. 1903 — APPEND. B 
The results obtained by the “Poseidon” were not constant, but on the 
whole her catching power, as regards Pleuronectidae, was distinctly less than that 
of the “Huxley” (viz., 0,6 for P. platessa; 0,8 for P. limanda). The “Wodan” 
showed constantly a greater efficiency than the “Huxley” as regards Plewronectidae, 
and this relative efficiency increased throughout the course of the experiments on 
the different grounds visited, namely, from 2,1 to about 4,2 for P. platessa, and 
from 1,9 to about 14,5 for P. limanda. It is noticeable that the relative efficiency 
of the “Huxley”, as compared with the “Wodan”, declined pari passu with a 
decrease in the size of the P. platessa and an increase in the size of the P. amanda 
on the grounds successively examined; and it is remarkable that the decline was 
much greater for P. limanda than for P. platessa. On returning to Lowestoft 
after the experiments, the Captain of the “Huxley” found a hole in the cod-end 
of the net; but it seems improbable that this discovery provides a sufficient 
explanation of the difference in efficiency, except possibly as regards the last haul 
on the Texel Ground. 
General Conclusions 
The differences in efficiency shown by these experiments (with the exception 
of the “Thor”) appear to have been chiefly due to differences in the weight and 
nature of the ground-rope. Further experiments are, therefore, desirable, in which 
special attention may be paid to this point. The weight of the ground rope 
should be determined in each case, both before and after use; and each vessel 
should make experiments, independently as well as comparatively, on the effects 
of definite changes in the weight of the rope, e. g., by the addition of varying 
lengths of iron chain. 
The nets of the “Poseidon”, “Wodan” and “Huxley” are so nearly alike in 
size that it is worthy of consideration whether these vessels could not with 
advantage employ a trawl of identical pattern. It would then be possible to 
summarise the trawling results of these three vessels in the reports of the Inter- 
national Council without discrimination. 
The trawl used by the “Thor” is so different from that used by the other 
vessels, both as regards the selective action of the net and the total catching power, 
that exact comparability between the records is precluded. 4 
The evidence as to the “Goldseeker’s” net and catching power is insufficient 
for conclusions; but it appears equally desirable that the “Goldseeker” should 
employ the same form of trawl as the “Poseidon”, “Wodan” and “Huxley”. 
15th December 1903 
WALTER GARSTANG 
Convener 
