The
Whangateau Harbour is recognized as the most unspoiled mainland estuary
in the Auckland Region, with abundant shellfish and a wealth of healthy
intertidal habitats and estuarine plants. Thanks partly to
its
small catchment area, and the fact that subdivisions to date have been
on flat sandy areas rather than hill slopes with clay soils, impacts
from silt and fertilizer runoff have been less than in other estuaries.
With
the right weather conditions the water in the harbour is a pure, clear
snorkeller’s paradise. Water clarity is aided by the
filtering
action of large numbers of cockles. The Whangateau Harbour is
similar to what other estuaries in the Auckland Region must have been
like in historical times.
The Whangateau HarbourCare Group is
committed to keeping this very special harbour in the best condition
possible for the well-being of wildlife and marine life and for the
enjoyment of present and future generations. This is entirely
consistent with Vision Rodney which seeks to avoid degradation of the
natural environment.
The following key points sum up many of the
concerns of the Whangateau HarbourCare Group for the welfare of the
Whangateau Harbour. We believe that if these points were
actioned, the future high quality of the Whangateau environment would
be given its best chance.
1.
The whole catchment of Whangateau should be in the Rodney
District Council proposed Green Buffer Zone, not part of the Mixed
Rural Activity belt.
Reasons: Whangateau is
clearly the
only mainland estuary in the Auckland Region which still possesses a
high degree of environmental integrity. The waters are often
remarkably clear, there are large beds of shellfish, very healthy
saltmarsh and seagrass habitats and firm sandflats. In
combination these are indicators of high environmental values missing
from most other mainland estuaries in the Auckland Region.
Only
the proposed Green Buffer status would potentially ensure maintenance
of the current high environmental values of the estuary. The
potential for additional subdivision, even into lifestyle blocks,
allowed for in the Mixed Rural Activity Belt, would be deleterious to
the future quality of the harbour waters and its marine life.
Measures to minimize sediment and nutrient runoff into streams and the
estuary should be diligently encouraged (eg. riparian planting.
2.
No further subdivision should
be allowed on
the slopes of the Whangateau catchment, including the proposed Omaha
Park development.
Reasons:
Any subdivision or
urbanization of this higher ground would inevitably increase sediment
and stormwater runoff into the Whangateau and degrade this present very
high quality estuarine environment.
3.
Extreme
care must be taken during
imminent and future pine harvesting in the north and northwest
catchment of the Whangateau, and to encourage future reversion to
native vegetation.
Reasons:
Historically the
northern and
northwestern part of the harbour is the only area which has suffered
from considerable sediment input. Following original felling
of
native forest largely for spars and boat building, and subsequent
farming, quarrying and landfill operations, quantities of sediment
entered the harbour from the Omaha River, Birdsall Creek and Ashton
Creek, as well as into Tramcar Bay. Two to three metres of
silt
have choked the harbour in this area and the harbour is just beginning
to stabilise after that input. Further sedimentation is
likely
from pine harvesting operations and without extreme care the clear
water and high quality of the harbour environment will be lost.
4.
Protection
of estuarine
vegetation, particularly salt marsh, should be encouraged (or enforced)
along the Whangateau Harbour side of Point Wells, both north and south
of the Omaha Causeway.
Reasons:
Estuarine vegetation,
especially saltmarsh, coupled with retention of the natural shoreline
contour, is very important for prevention of coastal erosion.
Rodney District Council has a policy of protection of estuarine
vegetation, perhaps partly for this reason. Saltmarsh is also
an
important habitat for some rare native birds. This stretch of
saltmarsh is currently being severely attacked by local residents , who
have been bulldozing and burning saltmarsh, poisoning and chainsawing
mangroves, and installing concrete and other rubble in attempts to
control the resulting shoreline erosion, on what is technically public
land on the esplanade reserve. There is relatively little of
the
natural shoreline left around the harbour, and this zone is where it is
most actively being destroyed at present.
5.
Mataitai
status or Community Fisheries Plan in the Whangateau Harbour.
Reasons:
The cockle beds in the Whangateau are the best remaining in the
Auckland Region. As many beds near Auckland have become
depleted,
or have been closed in an attempt to allow recovery, more pressure is
applied to the Whangateau beds by people traveling here from greater
Auckland. Current fisheries controls will be insufficient to
prevent overfishing of the Whangateau shellfish beds. A
Mataitai
would allow more targeted controls to prevent future depletion of
cockles in Whangateau. It is important that numbers remain
very
high in the harbour as this is a major reason for the clarity of the
water. The cockles are so abundant that they filter out
plankton
and detritus, so that often the water leaving the harbour on a falling
tide is clearer than that coming in from the open sea. A
Mataitai
or Community Fisheries Plan could also deal with the use of set nets in
the harbour, which are indiscriminate bulk fishing methods
inappropriate in this area.
6.
Marine Reserve or Scientific Reserve
status for the
southern arm of Whangateau, south
of the Omaha Causeway (Waikokopu Creek).
Reasons:
This
area is unique in the Auckland Region. It has firm sandflats
and
a rich mosaic of salt marsh, seagrass, mangrove and other habitats of
high ecological value, and is bordered to the east by the Omaha Taniko
Wetlands Scientific Reserve and an area of covenanted coastal
forest. Its preservation in its natural state is a high
regional
priority.
7.
A no-fishing zone
(marine reserve?)
should be established around Horseshoe Island and the channel and
sandstone reefs towards Point Wells.
Reasons:
This area
is becoming a very popular snorkeling zone with high educational
value. Such areas are rare in Auckland estuaries.
Flounder
used to be present in huge numbers here (Ina Shaw, personal
communication) in the 1940’s and 1950’s. Allowing flounder
and
other fish numbers to build up here would enhance this area
dramatically and provide a unique opportunity in the Auckland Region
for snorkellers to enjoy and learn important ecological lessons about
estuaries, mangroves, and their values to marine life. This
area,
and another similar reef in the southern arm of the harbour, are the
main nursery area for parore inhabiting the coast from Pakiri to Takatu
(Mark Morrison, NIWA).
8.
Sewage
input to the Jones Road
treatment station should be limited to that from the Whangateau
Catchment only.
Reasons:
The Whangateau Harbour
environment is of uniquely high quality in the Auckland
Region. Although the Jones Road treatment station operates to a very
high
standard, it is inevitable that nutrient loadings into the upper
harbour will increase over the long term as a direct result of release,
albeit indirect, of treated effluent into the water table, on to the
golf course, and hence into the harbour, with long term enrichment
results on the harbour. Once the legitimate sources of sewage
for the plant are all connected (existing Omaha, plus Point Wells, and
possibly Whangateau) that is sufficient in the long term for the
Whangateau to cope with. There is little environmental
justification to import sewage from another catchment (eg. Matakana)
just because in the short term it may seem convenient to do so.
9.
Vehicles and
tractors should be kept off
the sand flats, because they damage shellfish beds.
Reasons:
Boats are frequently launched
or retrieved in the low tide channels,
using tractors traveling more or less randomly across the sand flats
and shellfish beds. It is also becoming increasingly common
for cockle gatherers to drive to the cockle beds instead of
walking. This not only damages the shellfish beds but encourages
over-harvesting
if the shellfish don’t have to be carried far. Consideration
should be given to upgrading the harbour classification to Coastal
Protection Zone 1, or at least to apply the same rules re vehicles that
apply in C.P.1.
10.
Mangrove
control should be limited
to annual removal of seedlings from new areas and adjacent to beaches
and utility areas. Existing areas of established mangroves
should be retained in their present state.
Reasons:Mangroves,
particularly large mature mangroves, serve important ecological
functions as a nursery and feeding area for fish, primary producer of
organic matter in the harbour food chain, and as substrate and shelter
for a wide variety of marine life (high biodiversity value).
They
also provide erosion protection to shorelines, and act as a sediment
trap for some of the silt runoff from poorly managed land
catchment. It is recognized that in some areas their spread
is
becoming a nuisance and that in some areas control may be
justified. The best way to do this is to routinely remove
seedlings so that the mangroves do not spread further.
Chainsawing and poisoning 35-year-old mangroves as has been occurring
is not appropriate.