Rāwhiti's Rana Rewha at Omākiwi Cove with caulerpa washed up on the beach. Photo / Susan Botting
Rāwhiti's Rana Rewha at Omākiwi Cove with caulerpa washed up on the beach. Photo / Susan Botting
Seven North Island councils are calling on the Government to throw more money and support at one of the world’s worst invasive marine seaweed pests recently discovered in the Bay of Islands.
Councils from Northland to Whangārei, Auckland, Bay of Plenty, Tauranga, Hamilton and Waikato are seeking more money and support from the Government, to fight what Northland Regional Council deputy chairman Jack Craw called the “foot and mouth” of invasive marine seaweeds.
The seven councils form New Zealand’s heavyweight Upper North Island Strategic Alliance (UNISA), their combined area producing more than half of the country’s GDP. It has taken the unusual step of sending a strongly-worded letter to Minister for Biosecurity Damien O’Connor, Northland-based Minister of Conservation Willow-Jean Prime and Acting Minister Oceans and Fisheries David Parker, calling for better resourcing in what they say is a marine pest unconcerned with regional boundaries.
More than 70 per cent of New Zealand’s marine vessels are found along the alliance’s coastlines.
“On behalf of... UNISA I am writing to express our utmost concern regarding the recent detection of the invasive seaweed caulerpa in the Bay of Islands,” Bay of Plenty Regional Council chair Doug Leeder said in a letter from the councils to the Government this week.
“This is not just an issue for Northland beaches and recreational fishing, it’s a New Zealand Inc issue,” Leeder said.
“[Exotic] caulerpa species pose a significant threat to our precious marine environments and standing back and allowing further spread is untenable to our communities.”
Northland Regional Council (NRC) biosecurity working party chair Geoff Crawford said at least $100 million was needed in the first instance towards sorting out the new Bay of Islands discovery.
Mainland caulerpa was first discovered by mana whenua in Omākiwi Cove on May 3 in a mainland New Zealand first.
The Ministry for Primary Industries (MPI) and local mana whenua are days away from the start of banning anchoring and kaimoana gathering around Omākiwi, where 16 hectares of the weed have been confirmed in the last week.
Caulerpa at Omākiwi Cove. Photo / Susan Botting
“We understand that caulerpa appears to be well established at Omākiwi Cove and poses a significant risk as a source for further spread throughout the upper North Island and the rest of New Zealand,” Leeder said.
“We wish to acknowledge the recent change in attitude from Biosecurity New Zealand in taking a more proactive stance towards exploring options for managing caulerpa, and strongly encourage you and your Government to ensure they are adequately resourced to effectively contain this challenging pest,” Leeder said to each of the ministers.
“This new detection represents a significant range expansion from the previous known sites of Aotea (Great Barrier Island) and Ahuahu (Great Mercury Island).”
Leeder said more surveillance was needed to see if caulerpa had spread along the mainland coast.
“The incursion of this type of organism poses potential risks to biodiversity in the marine environment.”
Leeder said the alliance’s seven councils did not have the funding to “get this thing under control”.
The Government’s Ministry for Primary Industries is running the caulerpa response nationally through its Biosecurity New Zealand arm.
“The upper North Island regional and unitary councils are willing to ‘lean in’ to support management attempts but we can’t do this alone, especially given regions have no authority to manage inter-regional movements,” Leeder said.
He said other areas in New Zealand could take the lead from the caulerpa efforts in Northland, Great Barrier and Great Mercury Islands.
“As sea temperatures rise, like they have done in the last couple of years, there’s more likelihood of this incursion spreading south.”
Crawford said eradication remained the NRC’s main focus when it came to the pest in the Bay of Islands.
The invasive superspreader seaweed was found in almost 20 per cent of the locations urgently checked by NRC and Niwa divers in the week leading up to a landmark May 31 Bay of Islands caulerpa hui at Te Rawhiti Marae.
Crawford said it was frustrating MPI had not had a proactive plan in place in advance of caulerpa being found to have spread beyond its Great Barrier Island stronghold to the Bay of Islands.
It was now more than a month since it had been discovered in the Bay of Islands and the Government ban on anchoring in Omākiwi was not yet in place.
