120
C. F. HICI
which come up on the rising tide, and pass over the low barrier wall
to continue their feeding, may be stranded behind it as the tide falls,
and can be easily picked up. The barrier is of loose structure, so that
the water can easily pass through it as the tide rises and falls.
Such fish-corrals have been described by Hornell (1950) and there
are even traces of them in Britain (Davis, 1923). Culture does not
occur in such cases, since the fish are retained behind the barrier for
the duration of the falling tide only, and are removed before the tide
rises again.
The barrachois of Mauritius are slightly more elaborate and
permanent versions of the fish-corral (Hornell, 1926). I n Mauritius,
there is only a small rise and fall of tide. A wall of coral rubble is put
across the mouth of a small bay or creek ; in this wall are one or more
gaps, closed by removable grilles. Through these, and the porous walls,
the water in the barrachois is renewed with each tide, but the fish are
barred from escaping. When these barrachois were in use, they were
stocked with fish seined from the neighbouring lagoon; there was no
selection of the fish nor were any measures taken to improve their rate
of growth. The predictable result was that the few fish ultimately
produced were the predators, chiefly Barracouta.
On a much larger scale are the tidal fishponds of Hawaii. These are
very large enclosures (up to 250 acres each*) bounded by walls of basalt
rock, and equipped with sluice gates (Cobb, 1901). When Cobb wrote
his account there were some 3 217 acres of these ponds still in active
use, chiefly on Oahu. The gates were opened at favourable times of the
season and tide to take in fish, especially young Chanos and mullet.
When enough fish had entered, the gates were closed to prevent their
escape, but the water could be freely renewed through the porous
basalt wall. If insufficient fish had been taken, the pond operator would
engage fishermen t o catch young Chanos and mullet to place (alive) in
the pond. The fish would grow for some months until they had reached
commercial size, feeding on the resources of the pond, so that, though
culture measures are almost non-existent, these enclosures come near
to the definition of fish farming.
Another line of evolution is the pond enclosed by non-porous walls
of earth. A simple case is the pupukan of Luzon, in the Philippines.
This is a small earth enclosure with an area of about 2 hectare, which
has a wooden or bamboo screen gate. A mixture of transient or migra* Weights and measures are given as quoted by the author. For convenience the
llb=0*45 kg; 1 kg=2.2 lb; 1 quintal (qt)=100 kg; 1 acre=0.405 ha; 1 ha=2.47
following conversions are supplied.
acres; 1 Ib/acre=1.12 kg/ha; 1 kg/ha=0.89 lb/acre.
C. F. HICI
which come up on the rising tide, and pass over the low barrier wall
to continue their feeding, may be stranded behind it as the tide falls,
and can be easily picked up. The barrier is of loose structure, so that
the water can easily pass through it as the tide rises and falls.
Such fish-corrals have been described by Hornell (1950) and there
are even traces of them in Britain (Davis, 1923). Culture does not
occur in such cases, since the fish are retained behind the barrier for
the duration of the falling tide only, and are removed before the tide
rises again.
The barrachois of Mauritius are slightly more elaborate and
permanent versions of the fish-corral (Hornell, 1926). I n Mauritius,
there is only a small rise and fall of tide. A wall of coral rubble is put
across the mouth of a small bay or creek ; in this wall are one or more
gaps, closed by removable grilles. Through these, and the porous walls,
the water in the barrachois is renewed with each tide, but the fish are
barred from escaping. When these barrachois were in use, they were
stocked with fish seined from the neighbouring lagoon; there was no
selection of the fish nor were any measures taken to improve their rate
of growth. The predictable result was that the few fish ultimately
produced were the predators, chiefly Barracouta.
On a much larger scale are the tidal fishponds of Hawaii. These are
very large enclosures (up to 250 acres each*) bounded by walls of basalt
rock, and equipped with sluice gates (Cobb, 1901). When Cobb wrote
his account there were some 3 217 acres of these ponds still in active
use, chiefly on Oahu. The gates were opened at favourable times of the
season and tide to take in fish, especially young Chanos and mullet.
When enough fish had entered, the gates were closed to prevent their
escape, but the water could be freely renewed through the porous
basalt wall. If insufficient fish had been taken, the pond operator would
engage fishermen t o catch young Chanos and mullet to place (alive) in
the pond. The fish would grow for some months until they had reached
commercial size, feeding on the resources of the pond, so that, though
culture measures are almost non-existent, these enclosures come near
to the definition of fish farming.
Another line of evolution is the pond enclosed by non-porous walls
of earth. A simple case is the pupukan of Luzon, in the Philippines.
This is a small earth enclosure with an area of about 2 hectare, which
has a wooden or bamboo screen gate. A mixture of transient or migra* Weights and measures are given as quoted by the author. For convenience the
llb=0*45 kg; 1 kg=2.2 lb; 1 quintal (qt)=100 kg; 1 acre=0.405 ha; 1 ha=2.47
following conversions are supplied.
acres; 1 Ib/acre=1.12 kg/ha; 1 kg/ha=0.89 lb/acre.