250
and water temperature between the surface and
bottom layers are great due to less mixed freshwater in the surface layer and intruded seawater
in the bottom layer. The vertical movements are
suspected to indicate foraging activity because
bursts occurred during the vertical movements.
These surveys on habitat use by Japanese sea
bass in Tokyo Bay revealed that these fi sh use rivers, river mouths, and ports, in addition to fi shing
grounds. Resource management for this species
has focused only on commercial fi shing zones,
which overlooks many other important habitats
for the conservation of this and similar species.
For a more effective resource management of this
species, barriers to cooperation among different
jurisdictions and administrations surrounding the
habitats of Japanese sea bass must be overcome.
In particular, the jurisdictions and administrations in coastal waters are complex due to many
different activities, including fi sheries, aquaculture, ports, waterways, infl uent rivers, and water
quality. Each of these components has different
management groups and objectives. Therefore, to
realize effective management of the habitats of
some fi sh, objective data are needed on habitat
use by the fi sh to accommodate the diverse uses
of coastal waters. Managers widely recognize
that biodiversity is one of the most important elements for sustainable development, but they do
not have the objective data needed to determine
appropriate habitat protection. These observations that Japanese sea bass use rivers, ports, and
the sea may provide a motive to examine
cooperative management among managers of
different habitats. For example, these fi sh frequently encounter leisure anglers in river
mouths, but no regulations currently exist on
fi shing in these areas.
Fishermen and local governments play the primary role in the management of fi sh in the sea.
Nevertheless, no management has been instituted
for this species in rivers, although sport fi shers
generally respect catch-and-release rules. The
Kameyama Dam is located in the upper reaches
of the Obitsu River (Fig. 1 ) and has become a
popular fi shing spot for black bass ( Micropterus
salmoides ), an invading species. Black bass were
intentionally introduced by anglers and have
caused damage of indigenous river ecosystems in
Japan (Senou 2005 ). The Japanese Ministry of
Environment prohibited the import, transport,
and keeping of the species by the Invasive Alien
Species Act in 2005 (Ministry of the Environment
of Japan 2005 ) because the black bass is a carnivore that feeds on small fi sh and alters indigenous
ecosystems (e.g., Brown et al. 2009 ) through
top–down control like Nile perch (e.g., Barel
et al. 1985 ). This fi shing spot is located in the
reservoir separated from the river by Kameyama
Dam. However, the black bass may move from
the reservoir to the lower Obitsu River when the
dam is drained. If they move into the lower reach
of the river, the black bass could compete with
the Japanese sea bass for small baitfi sh. Therefore,
we recommend that Chiba Prefecture institute
strict supervision of or abolish fi shing of black
bass in this area to protect indigenous resources.
To do this, organizing a discussion among stakeholders in the river catchment (e.g., dam and river
managers, citizens, and anglers) is necessary to
discuss to persuade anglers to abandon game
fi shing of black bass.
Ethics Statement
This study was carried out with permission from
the Ethics Committee of the University of Tokyo,
Japan (Permit No. A11-6, A12-9).
Acknowledgments We express our thanks to Mr. T. Mori
and Mr. N. Miyata for their help with the fi eldwork
and Dr. H.-J. Ceccaldi, Dr. Y. Henocque, Dr. Y. Koike,
Dr. G. Stora, Dr. M. H. Tusseau-Vuillemin for editing our
manuscript. This study was supported by the Ocean Policy
Research Foundation, Sanyo Techno Marine Corporation,
and the Program of Bio- logging Science of the University
of Tokyo (UTBLS).
References
Alabsi NM, Tanoue H, Komatsu T, Charef A, Mitani I, Kato
M, Horii T, Aoki I, Miyazaki N (2011) Measurement of
the swimming behavior of a deep- water fi sh, the splendid alfonsino ( Beryx splendens ), in captivity using
micro data loggers. J Fish Aquat Sci 6:309–321
Barel CDN, Dorit R, Greenwood PH, Fryer G, Hughes N,
Jackson PBN, Kawanabe H, Lowe-McConnell RH,
Nagoshi M, Ribbink AJ, Trewavas E, Witte F, Yamaoka
K (1985) Destruction of fi sheries in Africa’s lakes.
Nature 315:19–20
H. Tanoue et al.
and water temperature between the surface and
bottom layers are great due to less mixed freshwater in the surface layer and intruded seawater
in the bottom layer. The vertical movements are
suspected to indicate foraging activity because
bursts occurred during the vertical movements.
These surveys on habitat use by Japanese sea
bass in Tokyo Bay revealed that these fi sh use rivers, river mouths, and ports, in addition to fi shing
grounds. Resource management for this species
has focused only on commercial fi shing zones,
which overlooks many other important habitats
for the conservation of this and similar species.
For a more effective resource management of this
species, barriers to cooperation among different
jurisdictions and administrations surrounding the
habitats of Japanese sea bass must be overcome.
In particular, the jurisdictions and administrations in coastal waters are complex due to many
different activities, including fi sheries, aquaculture, ports, waterways, infl uent rivers, and water
quality. Each of these components has different
management groups and objectives. Therefore, to
realize effective management of the habitats of
some fi sh, objective data are needed on habitat
use by the fi sh to accommodate the diverse uses
of coastal waters. Managers widely recognize
that biodiversity is one of the most important elements for sustainable development, but they do
not have the objective data needed to determine
appropriate habitat protection. These observations that Japanese sea bass use rivers, ports, and
the sea may provide a motive to examine
cooperative management among managers of
different habitats. For example, these fi sh frequently encounter leisure anglers in river
mouths, but no regulations currently exist on
fi shing in these areas.
Fishermen and local governments play the primary role in the management of fi sh in the sea.
Nevertheless, no management has been instituted
for this species in rivers, although sport fi shers
generally respect catch-and-release rules. The
Kameyama Dam is located in the upper reaches
of the Obitsu River (Fig. 1 ) and has become a
popular fi shing spot for black bass ( Micropterus
salmoides ), an invading species. Black bass were
intentionally introduced by anglers and have
caused damage of indigenous river ecosystems in
Japan (Senou 2005 ). The Japanese Ministry of
Environment prohibited the import, transport,
and keeping of the species by the Invasive Alien
Species Act in 2005 (Ministry of the Environment
of Japan 2005 ) because the black bass is a carnivore that feeds on small fi sh and alters indigenous
ecosystems (e.g., Brown et al. 2009 ) through
top–down control like Nile perch (e.g., Barel
et al. 1985 ). This fi shing spot is located in the
reservoir separated from the river by Kameyama
Dam. However, the black bass may move from
the reservoir to the lower Obitsu River when the
dam is drained. If they move into the lower reach
of the river, the black bass could compete with
the Japanese sea bass for small baitfi sh. Therefore,
we recommend that Chiba Prefecture institute
strict supervision of or abolish fi shing of black
bass in this area to protect indigenous resources.
To do this, organizing a discussion among stakeholders in the river catchment (e.g., dam and river
managers, citizens, and anglers) is necessary to
discuss to persuade anglers to abandon game
fi shing of black bass.
Ethics Statement
This study was carried out with permission from
the Ethics Committee of the University of Tokyo,
Japan (Permit No. A11-6, A12-9).
Acknowledgments We express our thanks to Mr. T. Mori
and Mr. N. Miyata for their help with the fi eldwork
and Dr. H.-J. Ceccaldi, Dr. Y. Henocque, Dr. Y. Koike,
Dr. G. Stora, Dr. M. H. Tusseau-Vuillemin for editing our
manuscript. This study was supported by the Ocean Policy
Research Foundation, Sanyo Techno Marine Corporation,
and the Program of Bio- logging Science of the University
of Tokyo (UTBLS).
References
Alabsi NM, Tanoue H, Komatsu T, Charef A, Mitani I, Kato
M, Horii T, Aoki I, Miyazaki N (2011) Measurement of
the swimming behavior of a deep- water fi sh, the splendid alfonsino ( Beryx splendens ), in captivity using
micro data loggers. J Fish Aquat Sci 6:309–321
Barel CDN, Dorit R, Greenwood PH, Fryer G, Hughes N,
Jackson PBN, Kawanabe H, Lowe-McConnell RH,
Nagoshi M, Ribbink AJ, Trewavas E, Witte F, Yamaoka
K (1985) Destruction of fi sheries in Africa’s lakes.
Nature 315:19–20
H. Tanoue et al.