A Kaipara District Council spokesperson previously said it did not have the authority to close the boat ramp and could face a legal challenge if it did so.
Kai Iwi Lakes’ Lake Taharoa is considered Northland’s main gold clam entry risk due to the large number of visitors from outside the region.
Thousands of people are expected to descend on the lakes for the summer holidays.
If the clam is introduced at the lakes, there are fears the pest could then spread around the region.
Craw, who is a national biosecurity specialist and NRC’s biosecurity and biodiversity working party chair, said he was surprised with KDC’s decision not to close the boat ramp given the high risk since the Taranaki find.
Craw’s call comes along with that of Kaipara leader Ric Parore (Te Kuihi), who wants the Lake Taharoa boat ramp closed before Christmas.
New Plymouth’s Lake Rotomanu was closed to motorised boats on November 12 after freshwater gold clams were discovered by a young person during a kids’ fishing competition. Draining the lake is being considered.
Craw said the Lake Taharoa boat ramp closure would only be temporary until the best local way of dealing with the clam reliably could be found.
“It’s only one summer,” he said.
Northland Regional Council deputy chair Jack Craw. Photo / Susan Botting
Craw said motorised boats posed the biggest spread risk because the pest, which was invisible to the naked eye when very young, could linger in motors which still had water in them.
The arrival of boats from outside the region to Kai Iwi Lakes over summer coincides with the clam’s breeding season in Waikato.
Kaipara District Council did not specifically respond to Craw’s new calls this week. Instead, referring to its previous response that said a legal opinion indicated that doing so could make it liable for a judicial review challenge.
“KDC sought legal advice that advised KDC does not have the authority to close the boat ramp under section 53 (1) of the Reserves Act, any such decision could be legally challenged through judicial review,” KDC manager community services Glynis McCarthy said at that time.
McCarthy said there was strong community interest in retaining access to Lake Taharoa for recreational boating.
“Previous proposals to restrict motorised vessels have generated notable community opposition.
“Any decision by council involving restricted access – particularly without (the legal backing of) a (Ministry for Primary Industries) Controlled Area Notice (CAN) in place – may results in public backlash or complaints regarding fairness, access rights or perceived overreach,” McCarthy said.
In June, KDC voted against the recommendation of its own Lake Taharoa governance committee which wanted to close the boat ramp due to the clam risk.
Recommendations around the boat ramp’s use are made through the committee but the full council votes on those recommendations.
He was aware KDC had not had a chance for its Taharoa governance committee to meet in the new council term, given the delays in the council being sworn in due to recount challenges.
Craw said NRC had on Monday written to Biosecurity New Zealand again asking for it to put a Controlled Area Notice (CAN) around the use of Lake Taharoa in place.
The regional council is also monitoring six other popular Northland recreation lakes for gold clams, all in the Far North – Lake Manuwai near Kerikeri, Rotopōtaka Lake (Coca Cola Lake) at Karikari Peninsula, Lake Ngatu near Waipapakauri, Lake Wahakari near Te Kao, Lake Waipareira near Waiharara and Lake Ngakeketo near Cape Rēinga.
Craw said freshwater gold clams were a major threat for Northland farmers as the clams can block intakes and water pumps.
NRC wants a new motorised boat management system for the lakes, similar to one used in Lake Ōkataina, Bay of Plenty.
NRC also wants a monitored automated gate across the Lake Taharoa boat ramp, which it will pay $40,000 towards and is seeking KDC support for monitoring and gate maintenance.
Visitors with motorised boats would get a QR code confirming biosecurity check participation. This would then be used to grant boat access.
NRC biosecurity manager incursions and response Nicky Fitzgibbon said this would strengthen compliance outside current manned biosecurity checkpoint hours at the lake.
These on-site Lake Taharoa biosecurity checks are run with NRC, Te Roroa, Te Kuihi, KDC and the Department of Conservation.
Fitzgibbon said those at NRC’s gold clam working party meeting in Dargaville on Thursday were supportive of the concept.
She said NRC wanted to balance immediate risk reduction over the summer with a long-term approach, which had included lake access being restricted to Northland-only vessels and a permanent boat wash station.
■ LDR is local body journalism co-funded by RNZ and NZ On Air.