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Kermadec Ridge
Map ID number:
1
Location: Northeastern New
Zealand
Approximate area: 661,885km 2
Description of area:
The Kermadec Islands are geographically
isolated from New Zealand and other subtropical
and tropical islands that may serve
as source areas for planktonic larvae. The
area is characterised by steep rocky islets
and seamounts. The Kermadec Ridge connects
the deeper waters of the New Zealand
mainland with tropical waters to the north.
The neighbouring Kermadec Trench is the
deepest region in New Zealand’s Exclusive
Economic Zone, and one of the deepest in
the world.
Biological attributes:
The Kermadec Ridge has a diverse fish fauna
that includes several endemic species. The
area is isolated from mainland New Zealand
waters by the Tropical Convergence
and there are biogeographic affinities with
Norfolk Island and the Lord Howe Rise,
with a large subtropical species component
not found elsewhere in New Zealand. The
Kermadec Islands are home to the world’s
largest population of spotted black grouper
(Epinephelus daemelii), which is a protected
species.
Criteria for inclusion:
Species richness; endemism; representation;
conservation status/threat classification
both nationally and globally; extremities of
range and adaptation to environment; special
phylogenetic grouping; habitat complexity/
diversity; meeting ground – overlap between
biological regions (at national and global
regions level); links to global patterns.
Status and management:
Spotted black grouper are vulnerable to
exploitation because of their longevity and
large size (up to 2 m), their sex-changing
population dynamics, their existence in
shallow water (to 50 m), and their territorial
behaviour. They are protected by the
Wildlife Act (1953). The waters around all
the Kermadec Islands are protected by a
marine reserve. The reserve extends out to
12 nautical miles and encompasses an area
of 7,450km 2 .
State of information:
The ?-mark on Area 1 (Kermadec Ridge)
indicates uncertainty in placement of this
boundary due to insufficient sampling to
determine how far along the ridge the distinctive
elements of the fauna extend. This
boundary fluctuates with the seasonal movement
of the convergence zone. Basic knowledge
exists of the fauna, but the ecology is
virtually unstudied.
References and further reading:
Cole (2001), Cole et al. (1992), Francis
(1993, 1996, 2001), Francis et al. (1987).
Three Kings Islands
Map ID number:
2
Location: Northern New
Zealand
Approximate area: 6,411km 2
Description of area:
Tidal mixing around the Three Kings Islands
causes uplift of cold subsurface water. Steep
rock faces, caves and archways are notable
habitats found around the islands.
Biological attributes:
The Three Kings Islands have a moderate
level of biological diversity. Blue-finned
butterfish (Odax cyanoallix) is endemic
to the islands except for a few stragglers
recorded near Cape Reinga and on the east
Northland coast. (This species has one of the
most restricted geographical distributions
of any fish species in the New Zealand
region.) The protected spotted black grouper
(Epinephelus daemelii) is more common
here than anywhere else in New Zealand
except the Kermadec Islands. The uplift of
nutrient-rich subsurface water supports a rich
community of plankton, pelagic fishes (e.g.
trevally Pseudocaranx dentex) and seabirds
(especially red-billed gulls).
Criteria for inclusion:
Species richness; endemism; trophic/functional
diversity; representation (i.e. across
physical types); extremities of range and
adaptation to environment; special conditions
School of trevally
and specialised organisms; aggregations;
special phylogenetic grouping; meeting
ground – overlap between biological regions
(at national and global regions level.
Status and management:
Populations of reef-associated fishes such
as hapuku (Polyprion oxygeneios), bass (P.
americanus), and king tarakihi (Nemadactylus
sp.) are impacted by commercial and
recreational fishing.
State of information:
Basic knowledge exists of the fauna, but the
ecology is virtually unstudied.
References and further reading:
Brook (2002), Francis (1996), Hardy et al.
(1987).
BIODIVERSITY – NEW ZEALAND’S MARINE ECOREGION ■ 35
©2004 DOC, Te Papa Atawhai