MANAGEMENT O F FISHERY RESOVRCES
9
built up by regulation is the Pacific halibut. This large, long-lived and
ecouomically valuable fish is particularly vulnerable to overfishing and
by the 1920s the stocks had been severely depleted. As a result of
conventions between the two countries concerned (U.S.A. and Canada)
the amount of fishing in 1960 was about half w h a t it was in 1930; the
stock has been increascd one- to threefold, and the catches have
increased from a minimum of 43 million lb in 1931 to more than 65
million lb in 1960 (Chapman P t al., 1962). The management of this stock
has thus been highly successful in maintaining the stock and the catch,
but the full benefits of management have not been achieved. Although
the amount of fishing, in terms of the impact on the stock, has been
halved, the costs have been nowhere near halved, since the number of
ships operating has increased while the length of season has been very
severely reduced. Both the catching and marketing side of the industry
are therefore operating at a very low level of efficiency (Crutchfield and
Zellner, 1963).
I n the absence of regulation and management of the over-exploited
stocks, the response of the industries concerned has been to turn to
other, more distant or less immediately attractive stocks. After the
North Sea had shown itself to be capable of producing only limited
quantities of the preferred species-cod,
plaice, etc.-the
fishing
industries of the industrial nations, such as England and Germany,
turned to the " distant water " grounds, especially Iceland and the
Barents Sea.
I n the North Sea, fishing was continued with the existing vessels
which were not suitable for fishing the more distant grounds, and as
these vessels were lost or scrapped without being replaced the level of
exploitation in the North Sea by countries with interests on distant
water fishing fell. Thus, even in 1050, virtually all the English North
Sea trawlers then operating were built before 1925." As a result the level
of fishing on the North Sea plaice stocks has recently been lower than
a t any time (other than during the war periods) for the past eighty
years ; this, combined with favourable natural conditions has provided
record catches in 1964 (incidentally confirming the predictions, by
Russell (1942), Bevcrton and Holt (1957) and others, based on the
analysis of the heavily fished stocks of the 1930s, that a moderate
decrease in the amount of fishing would give an increase in total catch)
(Gulland, 1967, 1968a). The catches of other iiiiportant demersal species
(cod and haddock) have also been very high in recent years. These fish
are caught by rather different groups of vessels from plaice, haddock
* VcsscIs of other countries, especially Uenmark, rrmained fishing in the North Sea
but changed in part t o other stocks, such as hcrring or sand-eels.
9
built up by regulation is the Pacific halibut. This large, long-lived and
ecouomically valuable fish is particularly vulnerable to overfishing and
by the 1920s the stocks had been severely depleted. As a result of
conventions between the two countries concerned (U.S.A. and Canada)
the amount of fishing in 1960 was about half w h a t it was in 1930; the
stock has been increascd one- to threefold, and the catches have
increased from a minimum of 43 million lb in 1931 to more than 65
million lb in 1960 (Chapman P t al., 1962). The management of this stock
has thus been highly successful in maintaining the stock and the catch,
but the full benefits of management have not been achieved. Although
the amount of fishing, in terms of the impact on the stock, has been
halved, the costs have been nowhere near halved, since the number of
ships operating has increased while the length of season has been very
severely reduced. Both the catching and marketing side of the industry
are therefore operating at a very low level of efficiency (Crutchfield and
Zellner, 1963).
I n the absence of regulation and management of the over-exploited
stocks, the response of the industries concerned has been to turn to
other, more distant or less immediately attractive stocks. After the
North Sea had shown itself to be capable of producing only limited
quantities of the preferred species-cod,
plaice, etc.-the
fishing
industries of the industrial nations, such as England and Germany,
turned to the " distant water " grounds, especially Iceland and the
Barents Sea.
I n the North Sea, fishing was continued with the existing vessels
which were not suitable for fishing the more distant grounds, and as
these vessels were lost or scrapped without being replaced the level of
exploitation in the North Sea by countries with interests on distant
water fishing fell. Thus, even in 1050, virtually all the English North
Sea trawlers then operating were built before 1925." As a result the level
of fishing on the North Sea plaice stocks has recently been lower than
a t any time (other than during the war periods) for the past eighty
years ; this, combined with favourable natural conditions has provided
record catches in 1964 (incidentally confirming the predictions, by
Russell (1942), Bevcrton and Holt (1957) and others, based on the
analysis of the heavily fished stocks of the 1930s, that a moderate
decrease in the amount of fishing would give an increase in total catch)
(Gulland, 1967, 1968a). The catches of other iiiiportant demersal species
(cod and haddock) have also been very high in recent years. These fish
are caught by rather different groups of vessels from plaice, haddock
* VcsscIs of other countries, especially Uenmark, rrmained fishing in the North Sea
but changed in part t o other stocks, such as hcrring or sand-eels.