PG
J. A. GULLAND AND J. E. CARROZ
result in the long run in about the same, or possibly even greater,
catches with less fishing, should ensure that the cost of fishing can be
reduced roughly in proportion to the reduction in fishing mortality.
The need for enforcement must also be considered and a good regulation
should be both easy and inexpensive to enforce. An important step
towards proper fulfilment of a regulation i s the belief by the fishermen
that the regulation is necessary to produce better catches in the future,
and that foreign fishermen are also obeying the regulation (to many
fishermen, a foreigner is anyone outside his immediate circle). To
reduce this suspicion of “ foreigners ” it is important that enforcement
is not only effective but also seen to be effective. Lately several
international commissions have taken steps towards joint enforcement
by inspectors of different nationalities on each other’s vessels.
(a) Size limits are effective methods of controlling the size of fish
removed from the stock for those fisheries where undersized fish which
are caught accidentally can be returned to the water alive, or where the
fisherman can judge the size of fish before capture. Thus size limits are
widely used in lobster (Homarus spp.) and rocklobster (Panulirus, Jasus,
etc.) fisheries, where the animals are caught in traps, and in whaling,
where the gunner can judge the size of the whale quite closely before
deciding to fire the harpoon.
I n most fisheries the chances of undersized fish surviving after being
returned to the water are small. Even if the fish are alive when brought
on deck, the fisherman’s first interest is in looking after the fish he is
going to market (e.g. gutting them and putting them on ice), and
preparing the gear to catch more fish, and only afterwards may he
return the undersized fish to the sea, by which time they will be dead.
Even for lobsters a significant proportion of the undersized animals may
die, either from the direct effort of capture and removal from the sea or
from increased exposure to predators (Bowen and Chittleborough,
1966). Where few undersized animals survive, size limits by themselves
will only reduce the present landings without helping to improve future
catches or landings. However, size limits can be of indirect value by
discouraging the fishermen from fishing in areas or with gears that
would catch quantities of undersized and hence commercially valueless
fish. They can help the enforcement of other regulatory methods, such
as mesh regulation or closure of nursery areas, by reducing the
economic attractions of infringement.
(b) Closed areas and (c) closed seasons can be considered together as
they can often be combined, i.e. closure of a certain area for a limited
period, have similar effects and, in fact, for some migratory fish may be
virtually equivalent. As limitations on the amount of fishing they are
J. A. GULLAND AND J. E. CARROZ
result in the long run in about the same, or possibly even greater,
catches with less fishing, should ensure that the cost of fishing can be
reduced roughly in proportion to the reduction in fishing mortality.
The need for enforcement must also be considered and a good regulation
should be both easy and inexpensive to enforce. An important step
towards proper fulfilment of a regulation i s the belief by the fishermen
that the regulation is necessary to produce better catches in the future,
and that foreign fishermen are also obeying the regulation (to many
fishermen, a foreigner is anyone outside his immediate circle). To
reduce this suspicion of “ foreigners ” it is important that enforcement
is not only effective but also seen to be effective. Lately several
international commissions have taken steps towards joint enforcement
by inspectors of different nationalities on each other’s vessels.
(a) Size limits are effective methods of controlling the size of fish
removed from the stock for those fisheries where undersized fish which
are caught accidentally can be returned to the water alive, or where the
fisherman can judge the size of fish before capture. Thus size limits are
widely used in lobster (Homarus spp.) and rocklobster (Panulirus, Jasus,
etc.) fisheries, where the animals are caught in traps, and in whaling,
where the gunner can judge the size of the whale quite closely before
deciding to fire the harpoon.
I n most fisheries the chances of undersized fish surviving after being
returned to the water are small. Even if the fish are alive when brought
on deck, the fisherman’s first interest is in looking after the fish he is
going to market (e.g. gutting them and putting them on ice), and
preparing the gear to catch more fish, and only afterwards may he
return the undersized fish to the sea, by which time they will be dead.
Even for lobsters a significant proportion of the undersized animals may
die, either from the direct effort of capture and removal from the sea or
from increased exposure to predators (Bowen and Chittleborough,
1966). Where few undersized animals survive, size limits by themselves
will only reduce the present landings without helping to improve future
catches or landings. However, size limits can be of indirect value by
discouraging the fishermen from fishing in areas or with gears that
would catch quantities of undersized and hence commercially valueless
fish. They can help the enforcement of other regulatory methods, such
as mesh regulation or closure of nursery areas, by reducing the
economic attractions of infringement.
(b) Closed areas and (c) closed seasons can be considered together as
they can often be combined, i.e. closure of a certain area for a limited
period, have similar effects and, in fact, for some migratory fish may be
virtually equivalent. As limitations on the amount of fishing they are