'
FISHERY RESEARCH
32 5
as the -rheshes of the nets usedwere rather large” and the
-
smaller specimens could slip through with ”ease. Thus
_
we see how the coastal waters of Holland can form a nursery
ground for a very great number of the stock of plaice in
_
the
North
Sea.
This
discovery is - of great economic
importance.
It is on the survival of these sh that the
future stock of large plaice depends.
Immense damage is,
however, done on these grounds by long-shore shermen
seeking other sh.
So important an aspect has this assumed
that it has been seriously urged that at the time the young
plaice are there the grounds should be completely closed to
trawling shing craft.
»
—
'
»
From a size of four or ve inches onwards “we are
dependent on the statistics of the landings of sh ,for
information as to their general distribution.
But while
'
these gures will give information as to their distribution
they tell us nothing of the movements of the sh or of
-
ï, -
their subsequent growth.
It is here that the system of
marking the plaice has proved -invaluable.
A small piece
of silver wire is pushed through the back of the sh and on.
either end of it are attached small ebonite discs bearing a
_
‘
number.— The sh thus marked are then measured; and
'
their length, together with date and place of capture, is
inserted in a book opposite the number corresponding
'
With that on their discs.
The.sh are then liberated. '
Fishermen are notied that for each marked sh returned
to headquarters they will receive the market price of the
sh and a shilling for the disc.
When a sh is recaptured
it is oncemoæ'meaSu-red and, on comparing its length and
date and place of recapture with the origialdetails _for
'
'
the sh be”aring that number,_' one can immediately tell
_
;
how much it has grown and how
far it has travelled since
the day it was marked (Plate 115).
.
In order to study the population of plaice in a large area
FISHERY RESEARCH
32 5
as the -rheshes of the nets usedwere rather large” and the
-
smaller specimens could slip through with ”ease. Thus
_
we see how the coastal waters of Holland can form a nursery
ground for a very great number of the stock of plaice in
_
the
North
Sea.
This
discovery is - of great economic
importance.
It is on the survival of these sh that the
future stock of large plaice depends.
Immense damage is,
however, done on these grounds by long-shore shermen
seeking other sh.
So important an aspect has this assumed
that it has been seriously urged that at the time the young
plaice are there the grounds should be completely closed to
trawling shing craft.
»
—
'
»
From a size of four or ve inches onwards “we are
dependent on the statistics of the landings of sh ,for
information as to their general distribution.
But while
'
these gures will give information as to their distribution
they tell us nothing of the movements of the sh or of
-
ï, -
their subsequent growth.
It is here that the system of
marking the plaice has proved -invaluable.
A small piece
of silver wire is pushed through the back of the sh and on.
either end of it are attached small ebonite discs bearing a
_
‘
number.— The sh thus marked are then measured; and
'
their length, together with date and place of capture, is
inserted in a book opposite the number corresponding
'
With that on their discs.
The.sh are then liberated. '
Fishermen are notied that for each marked sh returned
to headquarters they will receive the market price of the
sh and a shilling for the disc.
When a sh is recaptured
it is oncemoæ'meaSu-red and, on comparing its length and
date and place of recapture with the origialdetails _for
'
'
the sh be”aring that number,_' one can immediately tell
_
;
how much it has grown and how
far it has travelled since
the day it was marked (Plate 115).
.
In order to study the population of plaice in a large area