Taiga Bean Goose at Sarobetsu, Japan 53
©Wildfowl & Wetlands Trust
Wildfowl
(2013) 63: 40–55
interchangeable; one zone cannot be
replaced by another, as each one has its own
characteristics that attract geese. For
example geese never used Lake Panke
during the 10-year study period, despite its
close proximity to Lake Penke. Lake Panke
seems to have no attraction for geese,
although some swans use it. The habitat in
each of zones A, C and E , including Furaoi
Oxbow Lake (the core spring staging site
within Sarobetsu), should be surveyed and
assessed to help develop appropriate
conservation measures for the area. The tiny
lake of
c
. 0.15 km
2
and the surrounding
farmland in zone D are used throughout the
season, and has supported 16% of the Taiga
Bean Geese wintering in Japan each spring,
at the peak of the migratory period.
The Sarobetsu Plain was designated as a
National Park (Rishiri-Rebun-Sarobetsu
National Park) in 1974 (Ministry of the
Environment of Japan 2012). Part of zone
B is situated within the Special Protection
Zone (a zone of special importance within a
Special Area) designated within the National
Park, with Lake Penke and part of zone C
occurring within the Special Area (
i.e
. the
area where the environment should be
conserved within a National Park).
Protection under National Park legislation
does not extend to the zones A, D or E.
Lake Penke, Lake Panke and its surrounding
wetland (2.56 km
2
) were additionally
designated as a National Special Wildlife
Protection Area in 1992 (Konno 1998) and
as a Ramsar site in 2005. Wildlife therefore
is protected there. Sediment accumulation is
contributing to the silting up of Lake Penke,
however, with the lake shrinking from 1.9
km
2
in 1957 to 1.5 km
2
in 1976, 1.4 km
2
in
1995, and 1.3 km
2
in 2005, and predicted to
be just a stream by 2100 (Maruyama 2007).
The Hokkaido Prefectural Government
designated Lake Kabuto as a Wildlife
Protection Area in 2005 until 2017
(Hokkaido Prefectural Government 2012).
Lake Kabuto (like Lake Penke) is decreasing
in size; its present area is about half of that
recorded in 1947, mainly due to drainage of
the surrounding farmland (Saito
et al
. 2008).
The Furaoi and Teshio Oxbow Lakes have
no protection measures and a recent
government-funded development project
installed a sluice between the Teshio River
and Furaoi Oxbow Lake to reproduce a
brackish environment in the lake. Tons of
sand were poured into the lake over an area
of 0.096 km
2
(more than half of the water
surface), including the emergent plant
habitat, in February and March 2010 with a
view to covering the muddy bottom and to
altering the water quality to a sufficient
degree to support production of Corbicula
Clams
Corbicula japonica
(Hokkaido Regional
Development Bureau, unpubl. data). Rumoi
Development
and
Construction
Department of Hokkaido Regional
Development Bureau removed sand from
the emergent plant habitats to deeper parts
of the lake in June 2010 after protests by the
Japanese Association for Wild Geese
Protection. It is too early at present to
estimate the impact of the work done so far.
Nevertheless, research for
Corbicula
reintroduction is still ongoing.
Corbicula
only
occurs in brackish environments which are
unfavourable for Water Chestnuts and
Water Oat, both of which are important
natural food sources for Taiga Bean Geese
(Miyabayashi
et al.
1994).
