FRESH WATER - Taranaki Regional Council

Daryl Gibson and Maitahi wetland.
REGENERATION AND
NEW GENERATION
Regeneration is becoming a generation game at the Maitahi wetland
near _ Okato.
The wetland spans the dairy farms of Merv Hooker and Bernard
and Pauline Gibson who, over a number of years, have achieved a
transformation by fencing indigenous vegetation, establishing new
plantings and carrying out willow control.
And now the Gibson farm is passing on to the next generation – but
the environmental commitment endures.
“It’s been a good project to be involved in and our son, who’s taking
over the farm, is keen to carry it on,” said Pauline.
Merv Hooker agreed, saying it’s been gratifying to see the re-growth
of the plant life along with increasing numbers of birds.
The Taranaki wetlands included one surrounded by the Egmont National
Park (Potaema) and one surrounded by native vegetation (Lake Rotokare).
Neither of these sites showed much evidence of impacts from human
activities, introduced plants or animals and so consequently obtained
high overall scores. Two other sites, Barretts Lagoon and Umutekai
wetland are located in rural settings, and consequently show some
evidence of changes in hydrology through the invasion of some dry land
plants, and impacts of weeds. These results establish a baseline from
which future monitoring can be undertaken.
(C) STREAMS
The natural character of Taranaki ring plain streams and rivers as
they fl ow from the mountain to the sea is that they meander often in
deeply incised channels. This is a result of centuries of erosion, which
has resulted in a stable river channel. A meandering stream includes
a diverse range of habitat types – deep pools, shallow riffl e areas,
areas of faster running water. Different species of fi sh have different
preferences for these habitat types.
73 Unpublished data.
Rob Tucker
“This area on our farm was regarded as waste land, and to have
it fenced off to protect the plant and bird life has given myself and
others great pleasure,” he said.
Both properties are also protected with a Memorandum of
Encumbrance on their titles, to ensure the environmental
enhancement is protected long into the future.
Although comparatively small at just 7.5 ha and no more than 10 m
across at any one point, the Maitahi wetland is a regionally signifi cant
wetland.
It makes a dramatic appearance in countryside dominated by pasture
lands, and contains a large variety of wetland vegetation and habitat.
Plant varieties include m _ ahoe, cabbage trees, raupo, sedges and fl ax
and among the birdlife are the rarely seen Australasian bittern and the
spotless crake.
The vegetation acts as a natural riparian fi lter for the Maitahi Stream
at an important location close to the coast, where water quality is
generally lower than at higher altitudes.
The restoration project began in 2002 and has been assisted by a
Taranaki Regional Council grant of $24,400 to help meet the costs of
fencing and willow control.
In 2004, young people from the Conservation Corps carried out
fencing, planting and spraying work at the wetlands. “Our programme
relies on projects like this to teach young people work skills,” said
John Bowie of the New Plymouth YMCA, which co-ordinates the
Conservation Corps.
For the Gibsons and Hookers, that just adds to the positive nature of
the project.
Small streams can provide habitat for rare invertebrate and fi sh species,
and can also play an important ecological role, such as providing
spawning sites for lamprey, and refuge from large fl oods in the main
stem rivers. For example, a fi sh survey undertaken in an unnamed
tributary of the Waiwhakaiho River, immediately after a large fl ood,
found over 50 redfi n bullies taking refuge in a 70 m reach 73 . Also
recorded were three adult eels that sought shelter while migrating
downstream to spawn at sea. A later survey undertaken during normal
fl ows recorded a much lower fi sh abundance.
Increasing intensifi cation of land use on the Taranaki ring plain continues
to see pressures being placed on the natural character of small streams
and rivers. Landowners, particularly in South Taranaki, are increasingly
undertaking land development by realigning or straightening sections of
streams, or undertaking land reclamation through piping small streams.
Recontouring these areas into land for grazing increases effective
production hectares.
The amount of piping of small streams or stream modifi cation that
has been consented over the past fi ve years is set out in Table 4.31.
State of the Environment Report 2009
133