NORTH SEA INVESTIGATIONS. 103 
proportion in that condition increased rapidly, whilst there was a 
considerable decrease in the total number as compared with that 
obtainable on the same grounds earlier in the season. Our operations 
were not carried on late enough to show the final disappearance of 
the species, but I am given to understand that none, or hardly any, 
are to be found in the Humber in December. I am told, on authority 
which I have found reliable in other matters, that the prawns, on 
leaving the Humber, pass to the deeper grounds along the Yorkshire 
coast, and I know that the species is to be found there in the winter. 
It has a very wide vertical range, extending well beyond the 100- 
fathom line on our western coasts. 
Recent literature—The very interesting report of Professor 
Herdman “ On the Lancashire Sea Fisheries Laboratory ” (Liverpool, 
1893) deals with shrimp-trawling in some detail. From certain 
statistics collected by Mr. Dawson it is evident that the number of 
small fish captured in that district by shrimp-trawlers is infinitely 
greater than anything we have to deal with here. Both shrimps and 
“shanks” (the local name for our prawn, Pandalus annulicornis) 
appear to be taken by trawlers, but it is not remarked whether there 
is any difference, as here, in the amount of fish taken in company 
with these two crustaceans. Mention is made of a prawn-net, pre- 
sumably a trawl, devised by Mr. Dawson, in which a horizontal bar, 
3 inches above the ground, is substituted for the ordinary ground- 
rope. This is an adaptation, probably an unconscious one, of a 
principle which has been employed for some years in the bottom 
tow-nets used at the St. Andrews Marine Laboratory.* The object 
is to catch prawns and pass over small flat-fish, and, according to 
Mr. Dawson, this object is achieved. It is also claimed that such a 
net picks up less débris than one of the ordinary pattern, and there- 
fore fishes better on dirty ground. This is of some importance, as, 
although a very thick ground-rope is used by Humber fishermen to 
avoid the capture of “ ross,” they often catch a good deal, especially 
early in the season, before the winter’s accumulations of the Sabel- 
laria have been to some extent trawled flat. Still it is open to 
doubt whether a rigid bar would not be an additional difficulty in 
case of contact with a clay bank, and it would perhaps be better to 
replace this by a taut rope. In any case I do not see how such a 
contrivance would lessen the capture of young cod and whiting, 
which are the only important fish caught in any numbers on our 
prawn grounds, 
* T understand that a similar contrivance has long been used for fishing rough grounds 
at Yarmouth. 
