Local Govt | National News Video | Parliament Headlines | Politics Headlines | Search


Invasive kelp in Rangaunu and Houhora Harbours

Invasive kelp in Rangaunu and Houhora Harbours

Boaties and cray fishers are being asked for their help to stop a highly invasive kelp – Undaria pinnatifida – spreading into other parts of Northland beyond the Rangaunu and Houhora Harbours, where it has unfortunately already made itself at home.

Don McKenzie, Biosecurity Manager for the Northland Regional Council, says Undaria (also known as Japanese or Asian kelp) was first detected in Rangaunu and Houhora Harbours about three years ago.

“It’s a serious biosecurity issue because it can be hard to distinguish from native kelps, is fast-growing (up to one centimetre per day) and in other parts of New Zealand has already impacted on the aquaculture industry, fouling mussel lines and other equipment.”

Mr McKenzie says the kelp’s rapid growth rate means that as a marine pest it’s every bit as bad – if not worse – than Mediterranean fanworm, another unwanted marine pest currently confined to Whangarei Harbour.

Undaria’s presence has prompted a renewed call by the regional council for boaties to keep their hulls clean and for cray fishers to check their pots and other equipment if they are in the Rangaunu or Houhora Harbours over summer.

He says both recreational and commercial vessels (including cray fishers, especially if they’re laying pots) are at risk of unknowingly picking up undaria on pots, ropes and other gear if they’re in either harbour over summer.

“Both harbours are home to the only known populations of this opportunistic kelp in Northland and the challenge now is to contain it and keep it out of other harbours in the region.”

Mr McKenzie says that’s no easy task as vessels based in the Bay of Islands often travel to and from the Houhora and Rangaunu Harbours, with many commercial fishing vessels also operating out of Houhora.

“Some of these vessels could well travel to the abundant waters around The Three Kings Islands (Manawatawhi), heightening the biosecurity risk to this high value marine ecosystem.”

Mr McKenzie says vessel owners have a vital role to play in stopping the spread of marine pests like Undaria and is urging them to clean their boat hulls before they leave infected harbours.

“Council – and the wider community it represents – is reliant on boaties to be vigilant and act responsibly to ensure our marine environment is protected from invasive pests. I can’t stress this enough; we really do need vessel owners to clean their hulls before they leave Rangaunu and Houhora Harbours.”

Mr McKenzie says a soft cloth clean would suffice for vessels with a slime layer only.

“Anything more than that – such as evidence of actual Undaria growth – should be reported to the regional council. We’ll work alongside vessel owners to deal with this problem on a case-by-case basis.”

The regional council, along with a number of other regional councils, has also introduced a multi-pronged ‘Clean below? Good to go’ summer awareness-raising campaign. Visit www.marinepests.nz for more information.

“The inspection of a planned 2000 boat hulls in Northland over summer has been underway since late last year and divers are due to begin vessel inspections in the Houhora Harbour within the next few days.” (subs: from about 20 Jan)

Mr McKenzie says council is also in the process of adopting a new Marine Pathway Plan that introduces new rules on hull-fouling to prevent the spread of marine pests.

The guidelines are:

• Notify the Northland Regional Council if you find Undaria or other marine pests on your hull. Don’t try to remove them yourself
• Clean your boat hull regularly; keep fouling growth to no more than a light slime layer that can be removed with a soft cloth
• Apply antifouling paint, ensuring all ‘niche’ areas such as the base of the keel and any hard to access places, are coated and kept in good condition.
• Make sure your hull is clean and free of fouling before you travel to a new region
• Clean and dry marine equipment such as ropes, lines or pots, before using them in a new location
• Inspect areas of your boat, such as live bait tanks that retain seawater, in case they’re harbouring marine life
• Check anchors, trailers and other equipment for tangled weeds.

Mr McKenzie says information on a variety of marine and land-based pests is available online via www.nrc.govt.nz/pestcontrolhub


© Scoop Media

Parliament Headlines | Politics Headlines | Regional Headlines

Gordon Campbell: On The PM’s Indonesian Guest, And West Papua

As David Lange once said, it is almost impossible to get New Zealand to think about Indonesia, the huge nation sitting right on our doorstep.

The visit to this country early next week by Indonesian president Joko Widodo won’t change that situation, even though Widido will be the first major foreign head of state to be hosted by the Ardern government. More>>


Out By 24,000: Treasury Child Poverty Estimate Wrong

The Treasury has revised the child-poverty projections it provided to the Government in December 2017. As outlined in the Treasury’s 17 January media release, the previous estimate was based on code that included a modelling error...More>>


Mentions Russia: NZ Joins Condemnation Of Nerve Agent Attack

Foreign Affairs Minister Winston Peters says the New Zealand Government has grave concerns over the use of a chemical nerve agent in the United Kingdom resulting in critically serious injuries to some of those exposed. More>>


IPCA (And Privacy Commission): Police's “Exit International” Checkpoint Was Illegal

The Independent Police Conduct Authority has found that Police were not justified in stopping vehicles at a vehicle checkpoint to identify individuals who had attended an “Exit International” meeting in Lower Hutt on 2 October 2016. More>>


NZDF Coverup: Defence Admits Raid Was In Area Described In Hit And Run

When the book Hit and Run was published in March last year, the Chief of Defence Force Tim Keating held a press conference claiming the SAS had been in a different place on that date... The Defence Force has finally admitted that the “three photographs in the book are of Tirgiran Village”. More>>


"It Could Work" - Team NZ: New America's Cup Base Option

Auckland Mayor Phil Goff has welcomed Emirates Team New Zealand’s acknowledgement that a new fourth base option is workable and would see Auckland host the America’s Cup in 2021. More>>





Featured InfoPages