_
_
EFFECT OF TBAWLING ON INVERTEBRATES.’
absence of proof), swarms of” the young would settle” on the
sites thus bereft of their predecessors.
This interchange
'
.
between the surrounding water and the bottom was pointed
out in the Trawling Report, thus :—‘ The sedentary fauna of
any such ground ’—referring to shing—banks—‘ brought up in
the trawl, does not, however, give the whole explanation,
it
—
—
has to be remembered that almost throughout the entire year
a
constant succession of eggs or young forms is given off
_
__
the inhabitants’ (on the bottom), ‘while there is another and *
less minute increment derived from the older forms which are
forsaking pelagic life to settle on the
It is the vast
…:
.
abundan'ce of the pelagic fauna (which often has no connection
‘
-
with the particular ground examined), f0r instance, that is so f '
important in regard to the food of the herring.
_Again, the forms immersed in the sand are, for the most,
__
part, free from serious injury, This was pointed out, speaking -
‘
of Certain annelids, in the Trawling Report, as follows :—‘ The .
trawl has little or no effect on such as the foregoing, for their - ' _
tubes in general are buried in the sand, their lives being passed“,
in boring through it—for food and for shelter. So difcult is “j
_
it to interfere with annelids sunk in the sand that one may
“
sweep over a sandy surface, in which rare forms lurk, again
"
and again, without discovering their presence.
Even' if a
_.
dredge is dipped, perhaps, only a head with its tentacl‘es
reward the
Yet the sand ma'y teem with them
from 5._ «fathoms shorewards, and every spadeful—at extreme
_
'
°;10wWater—may produce several. A single storm would appear -
_
“. to inict greater destruction on these than it is possible to
-
do by
,
‘
…A careful summary of the effects of the trawl on the sea— '
”bottom and its fauna was giVen at the end of ‘! the chapter on 1
the "‘
of the Trawling-Grounds in relation to
J
,Eishesî" and, with all the experience since gained,
if any change can
be 'made.
The
only fact of moment to be stated is that ill
several yeæs
—
‘
Roÿdl,’Gommis&imi on
‘
&? @@, 18853 ip. 368;
:»
:
_
EFFECT OF TBAWLING ON INVERTEBRATES.’
absence of proof), swarms of” the young would settle” on the
sites thus bereft of their predecessors.
This interchange
'
.
between the surrounding water and the bottom was pointed
out in the Trawling Report, thus :—‘ The sedentary fauna of
any such ground ’—referring to shing—banks—‘ brought up in
the trawl, does not, however, give the whole explanation,
it
—
—
has to be remembered that almost throughout the entire year
a
constant succession of eggs or young forms is given off
_
__
the inhabitants’ (on the bottom), ‘while there is another and *
less minute increment derived from the older forms which are
forsaking pelagic life to settle on the
It is the vast
…:
.
abundan'ce of the pelagic fauna (which often has no connection
‘
-
with the particular ground examined), f0r instance, that is so f '
important in regard to the food of the herring.
_Again, the forms immersed in the sand are, for the most,
__
part, free from serious injury, This was pointed out, speaking -
‘
of Certain annelids, in the Trawling Report, as follows :—‘ The .
trawl has little or no effect on such as the foregoing, for their - ' _
tubes in general are buried in the sand, their lives being passed“,
in boring through it—for food and for shelter. So difcult is “j
_
it to interfere with annelids sunk in the sand that one may
“
sweep over a sandy surface, in which rare forms lurk, again
"
and again, without discovering their presence.
Even' if a
_.
dredge is dipped, perhaps, only a head with its tentacl‘es
reward the
Yet the sand ma'y teem with them
from 5._ «fathoms shorewards, and every spadeful—at extreme
_
'
°;10wWater—may produce several. A single storm would appear -
_
“. to inict greater destruction on these than it is possible to
-
do by
,
‘
…A careful summary of the effects of the trawl on the sea— '
”bottom and its fauna was giVen at the end of ‘! the chapter on 1
the "‘
of the Trawling-Grounds in relation to
J
,Eishesî" and, with all the experience since gained,
if any change can
be 'made.
The
only fact of moment to be stated is that ill
several yeæs
—
‘
Roÿdl,’Gommis&imi on
‘
&? @@, 18853 ip. 368;
:»
: