MANAGEMENT OF FISHERY RESOURCES
25
which would improve the fisheries of the area as a whole. Thus the
damage done by herring trawlers in reducing the haddock catches is
less than the extra value of herring taken by the trawlers; therefore
restriction of herring trawling to protect the haddock fishery would
not be justified when considering the North Sea as a whole. This
example also illustrates an important practical difficulty in complex
fisheries. I n a simple fishery the restrictions and benefits of regulation
can be equitably shared-if the effort should be reduced by 20%, then
each group of fishermen can reduce their effort by SOY0, and their share
of the catch will be unaltered. I n the North Sea, the losses are being
sustained by the haddock fishermen (mainly Scotsmen) and the herring
trawlers (from other countries) are unrestricted ; if the biological
conclusions had been different, and herring trawling should be restricted
in order to increase the total North Sea catch, then the losses would all
have been to the herring fishermen, and the gains to the haddock
fishermen. These considerations do not, of course, make the need for
proper management any less, but do increase the need for the proper
quantitative understanding of quite complex biological situations, and
for the balancing of the interests of each group of fishermen. They show
that while the ultimate objective of fishery management in a region
might well be to ensure the greatest total net yield from all the stocks
taken together, this objective must be modified to ensure that the
restrictions and gains are equitably shared. It may, however, still be
attained if there is some system whereby those with the biggest gains
pay compensation in some form to those with small gains, or losses.
111. METHODS OF REGULATION
A. Types of regulation
Any regulation can affect the stocks of fish and future catches only
in one or both of two ways : by changing either the total fishing effort
(i.e. the fishing mortality, the proportion of the stock caught each
year), or the sizes of fish caught. However, a variety of different
methods of regulation can be used to achieve one or other of these
results ; they include : (a) limitation on the sizes of fish that can be
landed ; (b) closed areas ; (c) closed seasons ; (d) limitation on the type
of gear ; (e) limitation on total catch ; and (f) limitation on total effort.
The effectiveness of these methods must be judged against the
objectives of management, which will generally be to achieve the
greatest surplus of total value of catch over the total cost of catching it.
Thus, regulations to change the sizes of fish caught should not increase
the cost of fishing ; regulations aimed at reducing the fishing mortality
by some restriction on the amount of fishing, which are intended to
25
which would improve the fisheries of the area as a whole. Thus the
damage done by herring trawlers in reducing the haddock catches is
less than the extra value of herring taken by the trawlers; therefore
restriction of herring trawling to protect the haddock fishery would
not be justified when considering the North Sea as a whole. This
example also illustrates an important practical difficulty in complex
fisheries. I n a simple fishery the restrictions and benefits of regulation
can be equitably shared-if the effort should be reduced by 20%, then
each group of fishermen can reduce their effort by SOY0, and their share
of the catch will be unaltered. I n the North Sea, the losses are being
sustained by the haddock fishermen (mainly Scotsmen) and the herring
trawlers (from other countries) are unrestricted ; if the biological
conclusions had been different, and herring trawling should be restricted
in order to increase the total North Sea catch, then the losses would all
have been to the herring fishermen, and the gains to the haddock
fishermen. These considerations do not, of course, make the need for
proper management any less, but do increase the need for the proper
quantitative understanding of quite complex biological situations, and
for the balancing of the interests of each group of fishermen. They show
that while the ultimate objective of fishery management in a region
might well be to ensure the greatest total net yield from all the stocks
taken together, this objective must be modified to ensure that the
restrictions and gains are equitably shared. It may, however, still be
attained if there is some system whereby those with the biggest gains
pay compensation in some form to those with small gains, or losses.
111. METHODS OF REGULATION
A. Types of regulation
Any regulation can affect the stocks of fish and future catches only
in one or both of two ways : by changing either the total fishing effort
(i.e. the fishing mortality, the proportion of the stock caught each
year), or the sizes of fish caught. However, a variety of different
methods of regulation can be used to achieve one or other of these
results ; they include : (a) limitation on the sizes of fish that can be
landed ; (b) closed areas ; (c) closed seasons ; (d) limitation on the type
of gear ; (e) limitation on total catch ; and (f) limitation on total effort.
The effectiveness of these methods must be judged against the
objectives of management, which will generally be to achieve the
greatest surplus of total value of catch over the total cost of catching it.
Thus, regulations to change the sizes of fish caught should not increase
the cost of fishing ; regulations aimed at reducing the fishing mortality
by some restriction on the amount of fishing, which are intended to