THE BEHAVIOUR AND PHYSIOLOGY OF HERRING AND OTHER CLUPEIDS 351
The lamp would appear to the fish as a point source, stimulating only
one eye at a time. This would give the effect of unilateral blinding,
causing the fish to swim in a deviating path to the light. While this
might occur in clear water and might be the explanation for those fish
seen swimming in a disorienhted and disturbed manner near lights
(e.g. Ryzhenko, 1901), it does not so eatlily explain the orientated
swimming in the vicinity of lamps reported by some authors, nor
attraction in very turbid water. It seems not unlikely that different
explanations may apply to different species.
4. Lightfihen'es
Scharfe (1963) has given a comprehensive review of the use of
lights by fishermen. Dragesund (1958) gave some details of this in the
Norwegian fishery for Atlanto-Scandian herring, while Radovich and
Gibbs (1954) described the blanket net used in Japanese fisheries for
sardines. The use of lights has been developed most by Russian
fishermen (Borisov, 1956) and by the Japanese. The most recent
development is the use of light to attract clupeida initially into a region
where they become influenced by an electric current. This leads them
to the inlet of a pump, from whence they are pumped on deck. This was
described by Smith (1955) on an experimental basis for young Clupeu
p a k i i , and engraulids in Puget Sound. This method of fishing is now
in extensive use, for instance in the Caspian, as a means of catching
Clupeonella (e.g. Nikonorov, 1968). A theoretical discussion of the
various factors involved in determining the optimum conditions for
establishing a light fishery is given by Hels and Lwvastu (1962).
V. Reaction to nets and other ob8tack.a
A review of the reaction of fish, in many inatancea clupeidn, to
nets was given by Mohr (1960), who discussed the I.U?IIWR involvcd and
the importance of ecological and physiological factors and of learrning
in captive fish.
1. Reaction to stationary nets
Experiments at sea all point to the importance of sight in avoiding
such nets. Tokarew and Aslanova, quoted by Mohr (1960), reported
the desirability of nets being as invisible as possible in the North Sea
herring and in the Black Sea sardine fishorios. Aslanova gave reaction
distances to nets of 4 m to a few cm, depending on turbidity and light
intensity. v. Brandt (1954) showed the better catching power of Perlon
nets in the Baltic herring fishery. Andreev (1066) discussed also the
advantage of having nets of low visibility.
The lamp would appear to the fish as a point source, stimulating only
one eye at a time. This would give the effect of unilateral blinding,
causing the fish to swim in a deviating path to the light. While this
might occur in clear water and might be the explanation for those fish
seen swimming in a disorienhted and disturbed manner near lights
(e.g. Ryzhenko, 1901), it does not so eatlily explain the orientated
swimming in the vicinity of lamps reported by some authors, nor
attraction in very turbid water. It seems not unlikely that different
explanations may apply to different species.
4. Lightfihen'es
Scharfe (1963) has given a comprehensive review of the use of
lights by fishermen. Dragesund (1958) gave some details of this in the
Norwegian fishery for Atlanto-Scandian herring, while Radovich and
Gibbs (1954) described the blanket net used in Japanese fisheries for
sardines. The use of lights has been developed most by Russian
fishermen (Borisov, 1956) and by the Japanese. The most recent
development is the use of light to attract clupeida initially into a region
where they become influenced by an electric current. This leads them
to the inlet of a pump, from whence they are pumped on deck. This was
described by Smith (1955) on an experimental basis for young Clupeu
p a k i i , and engraulids in Puget Sound. This method of fishing is now
in extensive use, for instance in the Caspian, as a means of catching
Clupeonella (e.g. Nikonorov, 1968). A theoretical discussion of the
various factors involved in determining the optimum conditions for
establishing a light fishery is given by Hels and Lwvastu (1962).
V. Reaction to nets and other ob8tack.a
A review of the reaction of fish, in many inatancea clupeidn, to
nets was given by Mohr (1960), who discussed the I.U?IIWR involvcd and
the importance of ecological and physiological factors and of learrning
in captive fish.
1. Reaction to stationary nets
Experiments at sea all point to the importance of sight in avoiding
such nets. Tokarew and Aslanova, quoted by Mohr (1960), reported
the desirability of nets being as invisible as possible in the North Sea
herring and in the Black Sea sardine fishorios. Aslanova gave reaction
distances to nets of 4 m to a few cm, depending on turbidity and light
intensity. v. Brandt (1954) showed the better catching power of Perlon
nets in the Baltic herring fishery. Andreev (1066) discussed also the
advantage of having nets of low visibility.