7 
TRAWLING EXPERIMENTS. 
It was only possible to conduct trawling experiments in the 
Committee’s district on four occasions, and at the last experiment 
the trawl was caught by an anchor, thus rendering the results 
incomplete. The conditions and the detailed statement of the fish 
caught at each haul are given in tables I and II, and the results 
are summarised in terms of catch per one hour’s trawling in 
table III. 
The experiments of 1909, although few in number, are 
interesting, however, because they link the important facts given in 
the last report with reference to the experiments made in the winter 
of 1908-9 with the experiments of the following summer. It was 
found that there was the greatest possible contrast in the bays 
where the experiments are made between the summer and the 
winter. In the summer relatively large numbers of plaice and dabs 
with other species occupy the sandy grounds of the bays and in the 
winter very few plaice and practically no dabs and other species 
liable to be caught by the trawl net are to be met with. 
The plaice gradually increase in numbers during the early 
months of the year, reaching a maximum from about June to 
October, and they rapidly decrease in numbers again in November 
and December. There is thus, as I put it, an annual flow and ebb 
of the plaice population. During the outward and inward 
migration median plaice are caught within the district by the 
inshore fishermen and just beyond the district by trawlers. It is 
about March that the median plaice are replaced outside the district 
by large plaice arriving from deeper water. 
It is gradually becoming clear therefore that during the year 
there is a wholesale migration with reference to depth affecting all 
sizes of plaice. The small plaice, so to speak, move into the region 
previously occupied by the median, the latter into the region where 
the large plaice were congregated and the large spread into the 
deeper and wider areas beyond. The migration experiments tend 
to show that the large and median plaice about to become mature 
do not always come back again. Their place is taken by others to 
some extent at least derived from areas further south. But the 
immature plaice do not leave the immediate region of the coast. 
They move inshore in the spring and summer following the 
small plaice. Even the large mature plaice, as I have previously 
