strong focus on island eradication projects in northern NZ this year is
an indication of the growing commitment by community groups, DoC, ARC,
and private landowners to creating sanctuaries that aim to sustain and
enhance NZ’s biodiversity. Already in the Hauraki Gulf many islands
including Hauturu (Little Barrier), Cuvier, the Mokohinaus, Tiritiri
Matangi, Motuihue, Rakino, and Motuora are pest free. These sanctuaries
provide a safe haven for native species and create the potential for
wildlife populations to move naturally and be translocated between the
islands of the Gulf. Commonly these projects are initiated with aerial
bait drops to remove rodents and ground based programmes to remove
species such as cats and rabbits.
to home, Glenfern Sanctuary in Port Fitzroy undertook two aerial rodent
bait drops as part of a larger eradication programme to remove rats,
mice, rabbits, and feral cats within the 230 hectare sanctuary this
winter. This sanctuary area is made up of private landowners and a DoC
scenic reserve. At the same time this was carried out three of Ngati
Rehua’s Broken Island chain had drops undertaken by the ARC. A team of
people is always required to carry out any hand-baiting around buildings
and places where it is unsuitable for a helicopter drop.
Together with Motu Kaikoura Island and the chain of 24 islands that make
up the Grey, Nelson and Motuhaku groups (where an eradication programme
was initiated in 2008), this brings a significant area of small islands
off the Great Barrier coast closer towards a pest free status. In the
proposed DoC Conservation Management Strategy Rakitu (Arid Island) is
also listed for future pest eradication. These island chains are very
significant to the restoration of our once abundant seabird colonies
which have been decimated by rats.
Earlier in the winter the 3,850 ha Motutapu and Rangitoto Islands were
helicopter baited by DoC for rats, mice, rabbits, cats, stoats, and
hedge-hogs. The ‘mop-up’ of remaining pests following the drops is
currently underway using a range of methods. A team of 58 people were
involved in this eradication. Some non target effects occur to species
like pukeko and ducks but their numbers quickly recover in the absence
of animal pests. On Tiritiri Matangi following the removal of rats a
500% increase in invertebrates was measured within the first few years.
There will always be some risk but with careful management the few
losses are hugely outweighed by the subsequent gain.
The Hauraki Gulf Biosecurity Plan is also nearing completion with a
focus of maintaining a high standard of Biosecurity throughout the Gulf
and keeping the many islands of the Gulf that are now pest free with
that status. Both DoC and ARC have initiated campaigns over the last few
summers to heighten public awareness to this issue through a range of
measures including advertisements in boating magazines, a DoC/ARC
programme entitled Our Treasure Islands, announcements on boating radio
stations, and new signage at main boating ramps throughout the region.
There has been a particular focus on the boating community to keep
vessels pest free when boating in the Gulf. All major transport
providers are currently involved with DoC and ARC to put Biosecurity
measures in place on vessels. There are over 100 pest free islands in NZ
and the risk of reinvasion is always present – it’s not a matter of if,
but when. Monitoring for reinvasion is an on-going process as is having
a thorough and effective response to a known or suspected re-invasion.
More often than not, this is a single animal and in over 86% of cases
has been eliminated fairly quickly.
A bit further afield during this winter the eastern Bay of Islands group
made up of Motuarohia (Roberton Island), Moturua, Motukiekie, Okahu,
Waewaetorea, Urupukapuka, Poroporo and all the associated islets and
rock stacks initiated an eradication. This is aimed at eradicating rats
and mice with a follow up to cull any remaining stoats. Known as Project
‘Island Song’ this community initiative involved the Guardians of the
Bay of Islands, iwi, and DoC.
It is estimated that there are currently around 4000 community groups
involved in conservation in NZ – these range from a simple project
involving replanting a stream edge to the fully fenced 22,000 hectare
sanctuary created at Cape Kidnappers on private land. Cape Kidnappers
Sanctuary area includes a well visited gannet colony, golf course and
luxury lodge. To date they have translocated nine locally extinct native
species into the sanctuary area, including kiwi.
In response to the increasing public involvement in threatened species
and sanctuary management, government funding was granted in 2005 to
Landcare Research for the purposes of looking at increasing the
effectiveness of flagship sanctuaries. The Sanctuaries of NZ forum was
formed from interested groups who share information, discuss and debate
practices, hear current research, and network ideas. Landcare Research
takes the opportunity with the groups to research social sustainability,
monitor draft success measures with-in sanctuaries, undertake research
that helps sanctuary management, maintain a sanctuariesnz.org website,
and runs an annual workshop.
Over 40 sanctuaries (see Map below) have participated to date from all
over the country. Many of these sanctuaries were sparked off following
the establishment of six DoC “Mainland Islands” between 1995-1997. They
were sited in ecologically significant areas with the primary focus of
learning how to carry out ecological restoration in a mainland setting.
A great deal has been learned, to the benefit of the sanctuaries that
followed, by the addressing of management questions through rigorous
trials and experiments, intensive monitoring and evaluation, and the
development of standardised systems and processes. New poisons and
equipment have been trialled, 50+ studies written up and published, and
reporting practices refined. Operation Ark sites to protect critically
threatened species and DoC kiwi zones have been established since.
Within the over 40 sanctuaries that have been established there are
three main types of management - 15% are predator-proof fenced (do
eradication and surveillance) such as at Glenfern , 8% have a fence
planned, and 77% are not fenced (do sustained control) such as at Windy
Hill. Most of the sanctuaries have been established with the goal of
sustaining and improving biodiversity.
The sanctuary sites are :
• Experimentally restoring New Zealand ecosystems to indigenous
dominance and full species complement
• ‘New’, inspiring and innovative initiatives that have galvanised
communities to local conservation.
• Projects that aim to:
– Control or eradicate a broad suite of pests
– Reintroduce missing species
– Manage a permanent and substantial risk of reinvasion by pests
– Involve local communities
The combined sanctuaries area totals 63,638 ha, made up of 56,270 ha
(88%) of Public land and 7368 ha (12%) of private (including Maori)
land. Added to this are the pest-free islands which total 36,482 ha.
These areas make up just .24% of the NZ land area. This tiny percentage
represents our best integrated efforts at holding on to the native
species that are iconic to our country.
The creation of such sanctuaries, on islands as well as in protected
areas on the mainland, are essential because elsewhere in NZ there is
nothing to stop the overall loss of biodiversity and more species to
extinction. Five years after the launch of the NZ Biodiversity Strategy
in 2000 a review indicated that it was proving difficult to slow loss of
habitat and protect species from predation. The target goals set in 2000
were not being reached and that the creation of sanctuaries on both
private and public land with good habitat and reduced or eliminated
pests were the key.
On Great Barrier we have a number of sanctuaries that have developed
over the last ten years – besides the well established Glenfern and
Windy Hill Rosalie Bay Sanctuaries there is the Mohunga Peninsula
Sanctuary, the Schooner Bay Weed project, the Awana Catchment Trust, the
Medlands Beachcare, and the new Katherine Bay Restoration Trust. These
projects are the working models of community based conservation and pave
the way for the possibility of Great Barrier Island becoming the biggest
pest-eradicated sanctuary of them all.