293
from local industrial sectors. This continued up
to the 1980s.
Fisheries of Okayama survived through these
changes, and the marine ecosystem continued to
provide limited spawning and nurturing ground
for more than 60 species that are targeted fi sh
stocks. During the same period, the number of
fi shers engaged with low-impact aquaculture for
oyster and seaweed has increased, but numbers of
trawling and netting have been decreased; the
number of fi shers has decreased into half during
the last two decades. To respond to both ecological degradation and decline of small-scale fi shing
industry, from the 1970s, the Okayama government, together with other prefecture governments
in the Seto Inland Sea region, has engaged with
the maintenance of the fi sh stock and recovery of
the coastal environment.
4
The Design of Marine
Ranching Projects
Marine ranching is a system to implement to
enhance the fi sh stock by creating ideal habitat
for fi sh artifi cially. There are several procedures
and also various environmental factors that we
need to take into account, particularly to recreate
healthy nutrient circulation and ecological continuity of marine ecosystem serving to accommodate the habitats, which fi sh require to mature
and live.
To implement marine ranching, we fi rst
assessed the state of marine ecosystem in terms
of its habitats and biodiversity, if the area is suitable for nurturing targeted species and identifi ed
the need for supplemental assistant to the marine
ecosystem, including deploying artifi cial reef in
order to orchestrate the total package of different
marine habitats for different stages of fi sh life
history. After this initial assessment, we studied
fi sh behaviors, including their mobility pattern
and swimming ability into the consideration as
we design the area of marine ranching. This is
necessary because for nurturing area for juveniles in particular, we need to design a contrived
spatial structure with mechanistic feeding system
within the current marine ecosystem by putting
the sea grass bed and cultivating small prawn and
crabs for their food.
The fi rst selected area for this project was in
the west part of Okayama, the sea area of 350 ha
between two small islands, Takashima and
Shiraishi-jima. Then, the second was in the east
part, called Hinase. For both areas, we selected
seven species including the Japanese red sea
bream, gilthead, rockfi sh, marbled rockfi sh, sea
bass, red-spotted grouper, and fat greenling. So
far, the fi rst ranching has doubled the catch
amount of targeted species and marked approximately 15 % increase of the general fi sh catch.
However, it has also created a confl ict between
commercial and recreational fi shers, who are
attracted by the ample fi sh stock.
It is important to note that the success of fi rst
ranching owes to local fi shing communities
whose member conducted the day-to-day maintenance of the artifi cial reef and feeding system and
took an initiative to designate volunteer non-take
zones. The member of the fi shing community in
the second area is now utilizing the marine spatial planning and integrated coastal management
to consider ecosystem-based measures such as
MPA in the area. In this community, there have
already been volunteer activities by fi shers to
reconstruct sea grass bed by replanting the seed
for the last 30 years (Fig . 1 ).
5
Conclusion: Satoumi
and Marine Ranching
The sustainability of Japanese coastal fi sheries
has been at stake for social and ecological pressures accumulated by various anthropogenic
activities, including fi sheries and coastal pollutions for several decades. Then, how can coastal
communities protect their environment while
maintaining economic activities that use marine
resources sustainably?
This question can be addressed by investigating either national or regional approaches in
marine policy that successfully promote the sustainable use of coastal ecosystem services. It can
also be answered through the analysis of local
coastal attempt, which we described in this paper.
Reviving the Seto Inland Sea, Japan: Applying the Principles of Satoumi for Marine Ranching Project…
from local industrial sectors. This continued up
to the 1980s.
Fisheries of Okayama survived through these
changes, and the marine ecosystem continued to
provide limited spawning and nurturing ground
for more than 60 species that are targeted fi sh
stocks. During the same period, the number of
fi shers engaged with low-impact aquaculture for
oyster and seaweed has increased, but numbers of
trawling and netting have been decreased; the
number of fi shers has decreased into half during
the last two decades. To respond to both ecological degradation and decline of small-scale fi shing
industry, from the 1970s, the Okayama government, together with other prefecture governments
in the Seto Inland Sea region, has engaged with
the maintenance of the fi sh stock and recovery of
the coastal environment.
4
The Design of Marine
Ranching Projects
Marine ranching is a system to implement to
enhance the fi sh stock by creating ideal habitat
for fi sh artifi cially. There are several procedures
and also various environmental factors that we
need to take into account, particularly to recreate
healthy nutrient circulation and ecological continuity of marine ecosystem serving to accommodate the habitats, which fi sh require to mature
and live.
To implement marine ranching, we fi rst
assessed the state of marine ecosystem in terms
of its habitats and biodiversity, if the area is suitable for nurturing targeted species and identifi ed
the need for supplemental assistant to the marine
ecosystem, including deploying artifi cial reef in
order to orchestrate the total package of different
marine habitats for different stages of fi sh life
history. After this initial assessment, we studied
fi sh behaviors, including their mobility pattern
and swimming ability into the consideration as
we design the area of marine ranching. This is
necessary because for nurturing area for juveniles in particular, we need to design a contrived
spatial structure with mechanistic feeding system
within the current marine ecosystem by putting
the sea grass bed and cultivating small prawn and
crabs for their food.
The fi rst selected area for this project was in
the west part of Okayama, the sea area of 350 ha
between two small islands, Takashima and
Shiraishi-jima. Then, the second was in the east
part, called Hinase. For both areas, we selected
seven species including the Japanese red sea
bream, gilthead, rockfi sh, marbled rockfi sh, sea
bass, red-spotted grouper, and fat greenling. So
far, the fi rst ranching has doubled the catch
amount of targeted species and marked approximately 15 % increase of the general fi sh catch.
However, it has also created a confl ict between
commercial and recreational fi shers, who are
attracted by the ample fi sh stock.
It is important to note that the success of fi rst
ranching owes to local fi shing communities
whose member conducted the day-to-day maintenance of the artifi cial reef and feeding system and
took an initiative to designate volunteer non-take
zones. The member of the fi shing community in
the second area is now utilizing the marine spatial planning and integrated coastal management
to consider ecosystem-based measures such as
MPA in the area. In this community, there have
already been volunteer activities by fi shers to
reconstruct sea grass bed by replanting the seed
for the last 30 years (Fig . 1 ).
5
Conclusion: Satoumi
and Marine Ranching
The sustainability of Japanese coastal fi sheries
has been at stake for social and ecological pressures accumulated by various anthropogenic
activities, including fi sheries and coastal pollutions for several decades. Then, how can coastal
communities protect their environment while
maintaining economic activities that use marine
resources sustainably?
This question can be addressed by investigating either national or regional approaches in
marine policy that successfully promote the sustainable use of coastal ecosystem services. It can
also be answered through the analysis of local
coastal attempt, which we described in this paper.
Reviving the Seto Inland Sea, Japan: Applying the Principles of Satoumi for Marine Ranching Project…