Fantastic insights into the development of one of (or possibly "THE") first Catch & Release River Fly Fisheries in Japan. Heroic efforts by local activist Shouichi Saitou

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THE ITOSHIRO RIVER
A case study
from Japan
Photo:JohnPearson
LESSONS FRO M FURTHE R AF IE LD
SALMO TRUTTA SALMO TRUTTAwww.wildtrout.org www.wildtrout.org
SAITO SHOICHI (TRANSLATION BY MIWA SATOSHI)
AN INTRODUCTION
J
apan is an island nation whose
collective land-mass is elongated in an
approximately north to south orientation.
Located just at the centre of the country,
is the Itoshiro River. The river is one of
several large tributaries in the upper reaches
of the Kuzuryu River which flows into the
Sea of Japan. The Itoshiro River originates
in the southern skirts of the Hakusan
range. Although most of the Kuzuryu River
watershed is in Fukui prefecture, the first
20km of the Itoshiro River flows through
Gifu prefecture. There lies a village called
Itoshiro, where 270 people live. Although
small, the village has a long history. The
fishing for this stretch of the river is managed
by the Itoshiro Fishery Co-operative.
RIVER ADMINISTRATIONS
IN JAPAN
The fishing in most of the rivers in Japan
is administered by fishery co-operatives,
bodies established by local fishermen
under a law called the Fisheries Act. A
fishery co-operative manages the fishery of
a certain range of water bodies following
the guidance of the prefectural government
with the approval of the prefectural
governor. Originally, fishery co-operatives
consisted of commercial fishermen.
However, as with most other freshwater
fishery co-operatives in Japan, there are
now actually no commercial fishermen in
the Itoshiro co-operative. Although fishery
co-operatives are obliged to enhance the
populations of designated fish species
and to maintain the environment of the
fishery in return for the fishing rights for
the particular water (including the right to
sell fishing licenses to recreational anglers),
both the enhancement of fishery resources
and environmental protection have not
been effectively conducted in most places.
This is because, usually, no catch limit is
set for either commercial or recreational
fishermen in rivers. Consequently, fish
populations and ecosystems are easily
devastated by inevitable overfishing,
regardless of how many hatchery fish are
released by the co-operatives. We have
to conclude that the present miserable
condition of inland fisheries has been caused
by the management strategy which relies
exclusively on the stocking of hatchery fish.
CATCH-AND-RELEASE
Fifteen years ago, some anglers stood up
against such management policy. They
proposed the creation of a fishery where
the practice of catching and releasing fish
(C&R) is obligatory, so that the ecosystem
with a self-sustaining trout population
would be resurrected. They thought it would
improve both the quality of the fishery and
the river environment. The Itoshiro Fishery
Co-operative accepted the plan and created
a fishery zone governed by catch-and-release
regulations in a tributary creek called
Tougegawa (toh-geh-gah-wa). As well as
the requirement to return fish to the river,
the regulations also include artificial lures
or flies only, barbless hook only, and single
hook only.
The creek was selected because it has
many places that would potentially serve
as spawning grounds for fish. The effect
of the regulations immediately appeared
in the spawning season of that year, as the
number of redds markedly increased in
the creek. Ever since (for more than 10
years), the population density of the trout
in the creek has always been the highest in
the area managed by the Itoshiro Fishery
Co-operative, despite the fact that the
creek has never received any stocking of
hatchery fish after the new regulation was
implemented. This success has proved that
a self-sustaining, healthy trout population
can recover if fish survive during the fishing
season. It also silenced people who first
opposed the no-kill regulation 15 years ago,
saying that the released trout would die
once they were hooked. The success has also
changed co-operative members’ attitudes
toward stream management, leading to the
creation of spawning grounds for trout,
and later, to the construction of a spawning
channel for fish.
For most people in Japan, the purpose
of angling is to eat fish, and hence the idea
of a strict catch-and-release policy has not
been understood widely. “If you don’t eat
the fish you catch, why would you fish in the
first place?” is the general response of people
who first hear about catch-and-release
fishing. In addition, the Fisheries Act is the
only law which governs both marine and
freshwater fisheries, and trout fishing has
also been managed according to this law.
Since recreational fishing is not considered
in the Fisheries Act, catch-and-release would
be an improbable scenario to the original
policy-makers. Therefore, the only guidance
issued by local governments (which
supervise fishery co-operatives) has been the
suggestion to release hatchery fish into any
empty rivers that have been overfished by
recreational fishermen. In such a situation,
the introduction of a “no kill” policy into
fishing is still difficult; it is not easy to
establish catch-and-release zones as even a
small percentage of the total area managed
by a fishery co-operative.
CRE ATI NG S PAW NI NG
G ROUNDS
Japanese rivers are usually steep and
headwaters are often fragmented by small
dams to control soil erosion. These dams
pose serious problems to fish habitat. In
particular, they are impassable obstacles for
spawning trout migrating upstream, and
every autumn, pools under these dams are
“The creek was
selected because it
has many places that
would potentially
serve as spawning
grounds for fish.”
The village of Itoshiro
One of many small dams in the
headwaters of the Itoshiro river
ワイルド・トラウト・トラスト寄稿資料
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2. 28 29
LESSONS FRO M FURTHE R AF IE LD
SALMO TRUTTA SALMO TRUTTAwww.wildtrout.org www.wildtrout.org
often crowded with fish which have nowhere
to go. To help these fish, a small spawning
channel was developed on the right bank
of the Itoshiro main river, just under the
first dam. The creek is 1 – 1.5 metres across
and 200 metres long. In autumn, many
fish exploit this man-made creek. From
October to November, the creek is filled with
numerous iwana, which particularly prefer
small streams for spawning.
Although the construction of such a
waterway requires a substantial amount of
work, once it is created it can be kept for
years with only annual maintenance before
each spawning season. Furthermore, we
hope that the natural reproduction in this
creek will enhance a wild trout population
that is better-adapted to the environment of
the Itoshiro River than hatchery fish. Unlike
simply stocking the river with hatchery fish,
the management of fisheries such as this
one contributes to the local community by
recovering and maintaining a sustainable
ecosystem. This raises the motivation of
people who are involved in this activity. The
creek did not yield a great result in the first
year; we had to find our way at first. Year by
year, however, we learned
things such as which current
velocities iwana prefer for
spawning, or what the best
stream environment is for
newly hatched larvae or fry.
The spawning channel has
been refined accordingly
and the stream condition has
improved steadily. Now in
its fourth year, the waterway
looks completely like a
natural tributary creek. An unexpected
virtue of the creek is that it has become the
place where people can readily observe the
spawning behaviour of fish and learn how
animals sustain their lives.
There are two indigenous salmonids in
the Itoshiro River: amago and iwana. These
two species differ substantially in their
preference for spawning grounds. Iwana
like slower water and smaller streams,
whereas amago do not necessarily need
small streams to spawn – though they have
rather strong preferences about the size of
gravel and water velocity. Therefore, the
small man-made creek has been utilised
well by iwana but to a lesser extent by
amago. Nevertheless, the number of amago
that spawn in the creek may increase
in the near future, considering their
tendency to come back to their original
birthplace. Incidentally, amago actively
exploit spawning grounds made by simply
spreading gravel over the river bottom where
the water velocity is appropriate. Where
the water flow is faster than a certain level,
there is no deposition of silt or sand, so that
the spawned eggs can penetrate deep into
the gravel, which is probably important for
amago. In fact, if you dig up the redds after
spawning, you will find the eggs of amago
buried surprisingly deep within the gravel,
whereas the eggs of iwana are found in much
shallower layers. This spawning behaviour
of amago might have developed to protect
eggs from being dug up by iwana, which
spawn about a month later. Thus, when
constructing a spawning channel, we believe
it is important to make a layer of large gravel
that cannot be moved by fish. We have made
a deep layer of gravel larger than 10cm
under the smaller gravel on the bottom of
our creek, so that eggs fall down into spaces
among the large gravel and are protected
from other fish that come to spawn later.
In addition, the condition of the creek
needs to be maintained after hatching,
because hatched fish remain in the creek for
up to a year. Therefore, a certain amount of
water flow must be maintained throughout
the year. To construct the creek, we selected
a spot where plenty of spring water is
available, and hence there is always a certain
amount of water flowing in the creek even
when the supply from the main river ceases.
Thus, juvenile trout are safe and happy
even during a dry summer season. Such
ideal locations are not readily available, but
multiple water sources should be secured to
construct a spawning channel.
Nature tells us many things. We have
committed ourselves to the conservation of
our natural environment while learning a lot
of things from nature, and we will continue
to do so.
PASSING ON A LEGACY
There are a total of 10 pupils in the Itoshiro
primary school (ages 7 – 12) at present. We
have been teaching fly fishing to the third to
sixth graders once a week for four years. As
the school is located in the close proximity
of the no-kill area, the children walk to the
stream. Because this is a fly fishing class,
we teach them how to fish, but what we
actually want to impart is that the natural
environment of their home is irreplaceable
and that all living organisms here are
important companions to the people in
this village. We hope that these children,
when they grow up, will successfully
inherit the Itoshiro village together with
its surrounding natural environment and
that they will pass these priceless legacies to
future generations.
HOW TO PRESERVE THE
INDIGENOUS IWANA
Although only one species is recognised
taxonomically for the indigenous iwana,
it is known that there is a unique genetic
population in each watershed and that
the external appearances of the fish
substantially differ from river to river.
However, such local populations have been
lost in many places by hybridization with
hatchery fish, which have been released into
rivers for years. Fortunately, the Itoshiro
River has some tributary creeks that have
never been stocked. The indigenous iwana
found in such streams have a distinct
appearance from those found in other
places. In fact, a genetic analysis revealed
that the fish belong to a certain genotype
that is unique to the Itoshiro River.
Such a native population can easily be
compromised by the release of iwana with
different genetic constitution.
Trout anglers sometimes release fish
caught in lower reaches into upper streams.
If this is done in a stream where native
iwana dwell, the pure genetic strain of the
indigenous fish could easily be destroyed.
We believe it is also important to protect
these native populations.
TRA DI TI ONA L TE NKA RA
In Itoshiro, a traditional way of fly fishing
called ‘tenkara’ has been handed down from
the past. The tackle is very simple. The rod
(about 3 metres long) is made of a single
wild bamboo tree. The line is made by
twisting the hair of horse tail; the number
of hairs twisted is decreased toward the tip
to create a tapered line, the length of which
is about the same as the rod. A tippet of
about 90cm connects the line to a single
fly. In the past, when people in mountain
villages like Itoshiro led subsistance lives,
men in the village probably caught fish
using the tenkara method. This must have
been an ideal way of catching just enough
fish after at the end of the day for a family’s
supper. However, there are only three
traditional tenkara practitioners remaining
in Itoshiro now. Afraid that
this traditional style of fishing
would disappear in the near
future, we have started an
activity to teach tenkara to
younger people. We reproduce
the old fishing tackle and
introduce children to tenkara
as a traditional culture in our
fly fishing class.
OUR G OA L
The common ‘theme’ or
idea through all of our
activities in Itoshiro is
‘sustaining life’. We believe
it is most important to pass
on an understanding and
appreciation of the natural environment to
future generations.
People tend to help propagate and
conserve only animals or plants that are
directly useful to them. Such a biased
way of management is not in keeping
with the ethos of true conservation of
the natural environment. The ideal way
of environmental preservation might be
to leave the environment or ecosystem
untouched, as it is, without any human
interference. However, it would be
impossible to execute such a way of
management in the immediate future.
What we do think we can do now, as
individuals, is deal with nature in such a
way that minimizes the effect we exert on
the environment. We will try to disseminate
the idea of ‘the management of a river
that sustains life’ from Itoshiro as much as
possible, and, in the future, we hope that all
rivers in this country will be administered
according to this ideal.
“From October
to November, the
creek is filled with
numerous iwana,
which particularly
prefer small streams
for spawning. ”
y
v
s
s
n
T
b
a
im
it
lo
Creating spawning
habitat out of
stones and logs
The author giving a fly tying demo to
children at the Itoshiro Primary School The native iwana, on fly
Native Itoshiro iwana
The amago, a species that has been
introduced to the Itoshiro River
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