Geoscience Reference
In-Depth Information
WCO amendment hearing this status had been
reviewed and the population was recognized
as a separate undescribed species,
Galaxias
aff.
gollumoides
'Nevis' or Smeagol galaxias (Allibone
et al
., 2010).
As the WCO hearing progressed it became clear
that Smeagol galaxias was a very important feature
of the river and the proposal to construct dams
was seen as a major risk with 11.5% of the known
sub-populations likely to be flooded by reservoirs.
Worse still, the reservoirs could be colonized by a
migratory galaxiid, the k oaro (
Galaxias brevipinnis
),
a piscivorous predator with an ability to climb damp
surfaces in its movement upstream. Protection of
the remaining Smeagol sub-populations with fish
barriers was not seen as sufficiently reliable for a
species so rare (Allibone, 2009).
An assemblage of rare and threatened plants
occurs on the valley floor alongside the river in
a part of the valley modified both by historic
gold mining and grazing. While the connection
between these plant species and the river posed
a difficulty in protecting it by a WCO, they were
identified as an outstanding feature of the Nevis
valley and one that would be at risk from hydro
development as their habitats would potentially be
flooded (Ministry for the Environment, 2010b).
The Nevis also provides habitat for a range
of native water birds including banded dotterel
(
Charadrius bicinctus
), black shag (
Phalacrocorax
carbo
), and paradise shelduck (
Tadorna variegata
)
but this aspect of the native fauna was not
considered a significant feature in the WCO
hearings. Of more significant interest was the
Nevis skink (
Oligosoma toka
sp. nov.) which, like
Smeagol galaxias, is only known from within the
Nevis valley but may have a wider distribution.
It has only recently been described as a separate
species (Chapple
et al
., 2011) and is at present its
official threat classification is considered to be 'Data
Deficient'.
a bustling community with several hotels and a
school. Mining continued in the valley into the
20th century but then petered out. What remains is
a succession of interconnected historic sites, mined
areas, dredge ponds, water races, stock yards,
buildings - some in ruins and others occupied -
all now softened over time but still visible and
very accessible. The NZ Historic Places Trust gave
evidence that it was a historic area of national
importance but again the connection to the river
loomed as a legal issue.
WCO hearing outcome
The Tribunal released its decision in August 2010
and concluded that Smeagol galaxias is a new
outstanding characteristic of the river. They also
concluded that both historic values and rare
plants on the Nevis valley floor are outstanding
features but not sufficiently connected to the river
to be covered by the WCO (Ministry for the
Environment, 2010b). In the Tribunal's estimation
the additional trout fishery characteristics - trophy
trout and backcountry character - did not cross the
'outstanding' threshold and they considered that
landscape and kayaking evidence simply confirmed
values already recognized. On the strength of
Smeagol galaxias the Special Tribunal determined
that dams and diversions should be absolutely
prohibited on the Nevis River but an appeal to the
Environment Court was lodged against the decision
by Pioneer Generation Limited and hearings have
yet to commence.
Conclusions
Until the 1990s, rivers in New Zealand were
subject to major modification from flood control
and drainage activities, point-source pollution was
a common problem, and water allocation for
out-of-stream uses was not well managed. The
incremental loss of river resources saw pressure
to introduce a mechanism to protect nationally
outstanding waters through WCOs. Twenty years
Historic values
The Nevis is a remote and isolated valley but in New
Zealand's gold rush of the 1860s onwards it became
