Northern Divers NZ

Northern Divers NZ Commercial Diving, Engineering Services, Marine Services, Boating

Proud of our Team! Bring the sheild home boys! Up the Mighty Northland Taniwha!
20/08/2026

Proud of our Team! Bring the sheild home boys! Up the Mighty Northland Taniwha!

Throw Back - This photo was taken 11 years ago on a DSV in the Persian Gulf. Im not sure what I was tasked with doing bu...
17/08/2026

Throw Back - This photo was taken 11 years ago on a DSV in the Persian Gulf. Im not sure what I was tasked with doing but the All Blacks were dominating in the world cup at the time. I was one of a handful of kiwis on the job working in the oil fields up there.

As exciting as that life was, I am so happy to be back home trying to contribute in a positive way in our water ways around Taitokerau.

28/07/2026

Over the past six months Northern Divers NZ Ltd (NDNZ) has been under contract to the Conquer Caulerpa Charitable Trust (funded by Foundation North and MPI) to survey, treat and extract exotic caulerpa throughout the Bay of Islands.

We found:
Caulerpa had spread from the original Omakiwi site as far as Tapeka Point and Roberton Island;
Large infestations around Opito Bay (close to Paroa Bay);
A meadow forming at Otaio Bay (Urupukapuka Island)

The NDNZ team:
used our purpose built extraction system to remove caulerpa from Hauai Bay, Onepoto, Motukiekie Island, Paroa Bay, Otaio Bay, Long Beach, Waitata Bay and Tapeka Point
decimated the meadow at Otaio Bay
removed up to two tonnes of caulerpa per day
carried out transects across just over 300km
stopped caulerpa meadows from forming in the Bay of Islands

Key Observations:
Catchment areas appear to be eastward facing rocky outcrops.
High density and high coverage areas are found in calm sheltered sites.
The plant can grow and spread relatively uninterrupted and attaches to solid material only (rock, shell and other debris) not sand.
All infestations located on the sand had attachment beneath the sand onto hard material.
Movement - Not die back. In Otaio Bay we observed that caulerpa is moving, not dying - detaching and moving around with water movement and reattaching at its new destination.
The large amounts of detached plants appear to act as protection for the reestablishing new plants, creating a nest that shelters re-emerging plants.
When the water temperature drops below 18 degrees the dense plants begin to release from the reef and can be removed extremely easily. There is little resistance, therefore the best time for removal.

Specified sites at Paroa and Motukiekie where caulerpa was extracted in January 2026, using our purpose built extraction system, have been revisited multiple times with no sign of regrowth.

Northern Divers NZ Ltd have developed a diver operated extraction tool system for the removal of exotic Caulerpa and oth...
25/07/2026

Northern Divers NZ Ltd have developed a diver operated extraction tool system for the removal of exotic
Caulerpa and other invasive species, following surveillance dives in the Bay of Islands in 2025. Our dive
team made multiple infestation discoveries across the Bay of Islands. The infestations were small and
sparse, which we felt were not suitable for the treatment methods presented at the time.
The concept of the tool is based on a device used to clean fish tanks. Where the tool would be able to
separate heavy and light material – up taking of the light material (Caulerpa) and leaving behind the heavy
sand and gravel.
We focused a lot of our energy on the containment and dewatering section of the system. We really
wanted this part of the system to be ‘bullet proof’- no leaks, ample discharge and total containment. Which
we have achieved.
Most of the components are custom made, which makes the tool simple yet specialized. We have been
able to power the system with a compact and powerful water pump that helps us to achieve the desired
suction, and we are able to operate the tool at any depth with no change in its performance.
This method of removal is a targeted approach that does not have a negative effect on surrounding marine
life and taonga species. We can remove Caulerpa from any substrate, fully contain it and discharge the
filtered and unwanted water back into the ocean.
The extraction system has been designed to be compact enough that it can be fitted and operated from
most small vessels by a relatively small team, making it a viable and cost-effective method for treatment.

(late post) Helping our mates out at Johnson Bros, while they fine tuned their awesome machine in the Bay of Islands. So...
25/07/2026

(late post) Helping our mates out at Johnson Bros, while they fine tuned their awesome machine in the Bay of Islands. So good to see Northlanders out there creating and innovating. Nice job boys.

Northern Divers score Gold AGAIN!It’s good recognition of the systems we have in place and the effort our team puts into...
14/03/2026

Northern Divers score Gold AGAIN!

It’s good recognition of the systems we have in place and the effort our team puts into working safely on every job. Thanks to the crew for maintaining high standards out in the field.
We appreciate the continued support from our clients and partners.

Our team out in Taitokerau carrying out investigation works. It was a pleasure sharing our mahi out in the field with ou...
14/03/2026

Our team out in Taitokerau carrying out investigation works. It was a pleasure sharing our mahi out in the field with our Patuharakeke whanau as well.

Some of our team went out to hariru our whanau from Patuharakeke out at Marsden Cove. Learning about the awesome mahi th...
16/02/2026

Some of our team went out to hariru our whanau from Patuharakeke out at Marsden Cove. Learning about the awesome mahi they are doing on the moana and whenua. We really enjoyed discovering our family connection and sharing our whakaaro around kaitiakitanga.

We also had the privilege of learning about this tohora (whale) named Ben and put her back together again. What powerful experience.

Thank you for having us, We are looking forward to collaborating in the near future.

Kia Ora!

Address

Whangarei

Telephone

+642102600611

Website

Alerts

Be the first to know and let us send you an email when Northern Divers NZ posts news and promotions. Your email address will not be used for any other purpose, and you can unsubscribe at any time.

Shortcuts

Share

Category