Ongoing Exotic Caulerpa blog ;

Updated 16 December 2024

• MPI have placed a Controlled Area Notice at Waiheke in an area from Thompsons Point into Onetangi Bay. View mapped information on the Community Viewer here and Waiheke specific information for visitors here.

• MPI have not been able to confirm the recent sighting in a new area is exotic Caulerpa - the reason is that the underwater video is are not clear enough, perhaps due to the light and water clarity on the day. The consideration is now to return to this spot for a 2nd inspection with either with a diver and camera or the ROV

• 6.12.24 - MPI provides news on recent diver surveys by NIWA which have observed changes in some of the areas previously surveyed at Waiheke. The MPI description is ‘dieback’ which might mean the the leaves are looking unwell but the plant is still alive. More research is needed here and in other regions.

• 27.11.24 - A report to MPI has been made for verifying a small but suspicious sighting at a new location

• 27 dives were completed yesterday 27 November with the underwater ROV operated by Logan Marine in an area from Owhanake to Hakaimango Point on the Northern Coast - a mix of shallow and deeper transects - outcome is pending. WMP is planning a further 5 days of these surveys and is currently finalising funding to enable this mahi to proceed

• Ngāti Pāoa have updated that NIWA have been doing some dives in the Onetangi area to observe what some are calling ‘die-back’ which has also been seen at some loctions at Aotea Great Barrier.

• 21 November 2024 - Two recent community sightings have been assessed by MPI and deemed as negative.

• 26 October 2024 - after a few days of strong Northerly winds and swell a project team member has found what we suspect to be, Exotic Caulerpa on the beach at Onetangi , amongst other seaweed washed ashore by nature. There are no boats anchored in the bay, nobody diving or fishing all which would be unsafe in these weather conditions.

• 23 October 2024 - Biosecuity NZ are hosting a Community hui at Onetangi Hall to discuss the option of placing a Controlled Area Notice in the Onetangi area. Timing is 5:30 until 7pm.

• 19 October 2024 - Our Regen Divers are in the water today doing an open water aspect of their training. This means more eyes in the moana as we remain vigilant for signs of the bad stuff.

• 17 October 2024 - Pou Rāhui iwi are working in partnership with Regional and District Councils to prepare a business case to investigate how we best deal with the threat of Caulerpa. A community hui was held in Pt Chevalier to draw on local knowledge and experience and provide the local community with an opportunity to provide input into the business case.

• 11 October 2024 - A sucessful afternoon with WMP contracting 30 survey transects in the Oneroa and Owhanake areas. No confirmed new sightings of EC were observed in the area’s checked. There were a few videos from the ROV marked for review and sightings of healthy Fan Worm in a number of areas.

• On 4th October WMP and contractors Logan Marine attempted an underwater video survey day using the ROV (Remote Operated Vehicle). This was only two days after a Northerly weather event and whilst the swell had eased the undersurface energy was evident and showing signs of the rainfall run-off. Unfortunately after five dives the visibility was found to be too poor for meaningful data to be captured. One video run was marked as requiring further review which was within the known incursion area. We await the wind direction to return to the South West before attempting an another survey day - not before 11th October 2024

• MPI/Biosecurity NZ announce a funding application process for $6.3M through the GETS system closing 15th October 2024

• A new Community Viewer Map has been released by MPI/Auckland Council showing surveillance progress by a range of groups and agencies.

• The EC National Advisory Group, appointed by Biosecurity NZ has its 3rd hui on 6th Sept 2024

• 26 August 2024 - WMP updates the Frequently Asked Questions resourses - read here

• The Hauraki Gulf Forum will meet on 26th August 2024 - Exotic caulerpa features in several ares of the Agenda - Biosecurity NZ/MPI will provide updates & a letter from Ngāti Pāoa Iwi Trust’s to the Minister of Bisecurity (with a proposal for building a case for an Iwi-led response) will be tabled.

• 7 August 2024 - Biosecurity Minister Andrew Hoggard has announced a further $10 million dollar funding injection to finance the ongoing development and testing of techniques to remove exotic caulerpa. How this applies to the Waiheke situation is not yet understood.

• A proposal for the next phase of surveillance is being prepared

• The WMP Marine Monitoring panel continues to meet every 3 weeks to keep the communication channels open on the local situation

• 3 July - The recently formed Aotea Caulerpa Response Team (ACRT) held a community hui at Claris attended by WMP

• Matariki arrived and Ngāti Pāoa Iwi Trust held an update on their activity at Piritahi Marae on the long weekend, Sunday 30th June. The Governments Accelerated programme supported NIWA to further develop new technologies such as AI algorithms to identify exotic Caulerpa from the images captured by ROV’s and towed cameras. During this work a small incursion was found at Nani Island on Waiheke’s Northern Coast. This is slightly to the West of the Thompsons Point incursion and indicates a drift Westward of the problem. WMP has requested that NPIT treat this area as soon as possible perhaps with their woolen benthic mats which are currently being tested nearby.

• 25 June - Marine Monitoring Panel meet for their regular 3 week catch-up - ongoing ROV surveys are considered important to continue so that it is known which harbours & bays remain safe for activity

• 27 June - Hauraki Gulf Caulerpa Community information hui attended by WMP

• On 2nd June 2024 Ngāti Pāoa Iwi Trust advised they are working closely with the Ministry of Primary Industries and NIWA on testing new technologies and new techniques for the identification of exotic Caulerpa around Waiheke. It is understood that this is part of the Governments Accelerated Programme.

• A Community Workshop was held by Waiheke Marine Project on Waiheke on 15th May, with MPI support to help identify a range of marine pests and share information on what to do if they are seen. An update on the exotic Caulerpa situation was provided by MPI. Ngāti Pāoa Iwi Trust displayed photo & video information on their Treatment trial from earlier this year.

• 25 ROV transects were completed by WMP/Logan Marine on 9th May with a crisp Southerly making its presence felt. No new incursions were detected. The area of operations was between Owhiti Bay and Onetangi which extends from the area surveyed in April. The aim was to tighten the grid covered in earlier mahi.

• Next Survey day using the underwater ROV is planned for 9th May 2024

• 30 underwater surveillance transects were completed on 4th April 2024. Funded with thanks by Auckland Council this was day 4 or 5 planned runs. No new Caulerpa sightings in the area focused on which was East of Owhiti Bay towards Horuhoru, Gannet Rock. The contractors were Logan Marine with a crew from NPKW & the community.

• TV One Sunday Programme airs on 10th March - ‘DEAD IN THE WATER’ view it here

• Divers commissioned by Ngāti Paoa Iwi Trust are checking the textile coverings during the week ending 1st March

• Minister Hoggard made an announcement regarding Government funding today, 23rd Feb 2024 - view the news release here

• Underwater ROV surveying took place on 20th Feb 2024 between Oneroa Bay and Nani Island (East of Palm Beach). A mixture of new and previous locations were explored - good news - no new detections.

• WMP is planning the 3rd of 5 more funded Underwater ROV surveys to occur in mid-February - thanks Auckland Council for helping with these

• After a period of very settled weather, the Removal and Textile covering trial coordinated by Ngāti Paoa Iwi Trust was able to continue until 13th February 2024

• Opopoto bay was the focus for the Suction removal trial

• Thompsons Point was the focus area for placing 11 x Textile Covers. These are expected to biodegrade leaving their steel weights for later recovery

• Ngāti Paoa Iwi Trust ran a treatment facility at the Old Blackpool School site on Waiheke. Seaweed & substrate are treated with freshwater, vinegar or detergent before bagging, drying, storage and eventual transport to Waiheke Transfer Station

• Observers have heard reports of apparent activity in the area which is restricted by a rāhui

• On 31 January, the Removal Trial contractor was able to start on site in the Onetangi Bay area.

• On 20th January NPIT postponed the Removal/Treatment trial due to unfavourable weather forecasts over the planned week.

• On 18th January, two project divers checked the Woodlands Bay area viewing the known incursions. Images have been shared with NIWA for analysis. Evidence of less than healthy plants was sighted in this area.

• Ngāti Paoa Iwi Trust have shared that the Suction dredge removal and Biodegradable benthic mat laying trial is scheduled to begin on 22 January 2024 (weather & pending contractual matters willing).

• Composting trials are underway by a project team member at a site in Tryphena which are proving to be very positive.

• The first of five planned new ROV surveys took place on 10th January 2024 exploring the Owhanake bay area. Fortunately no Exotic Caulerpa was detected and the next day will focus on the coast further east, towards Oneroa bay.

• Samples have been removed from Thompsons Point area and are being analysed in a lab at Auckland University. The tests include observing the effects of ultra-violet light on the weed

• Ngāti Paoa Iwi Trust are finalising plans for Marker Buoys, a Suction dredge and benthic mat laying - a 10 day trial supported by MPI is proposed for mid-January 2024

• A sample tested has been confirmed to be Caulerpa Parvifolia

• A Waiheke focused communications programme has been proposed by WMP to Auckland Councils Biosecurity team

• A WMP team member is observing a composting trial at Aotea-Great Barrier as an environmentally friendly disposal solution

• Further ROV surveys are proposed to continue monitoring the three known incursion sites

• WMP & NPIT are speaking with the Eastern-end Residents Group on 5th November

• WMP and Logan Marine have conducted two ROV survey days (1st and 9th September) for the Department of Conservation (DOC) in the Te Matuku Marine Reserve area on Waiheke’s Southern coast. No Exotic Caulerpa was detected in the 44 transects completed - the results are being analysed now, to produce a full report.

• Waiheke Boating Club members received information at their AGM held on 10th September 2023

• Other potentially at-risk areas will share their survey results to the WMP tracking map eg. The Noises Islands.

• MPI’s NIWA divers in late August detected sparse Exotic Caulerpa in new zones in the shallower areas of Onetangi bay - refer tracking map

• WMP attended a hui organised by NPIT on Waiheke with MPI/Biosecurity and DOC - 5th September 23

• Indicator buoys for several primary treatment zones are being considered

• A range of treatment methods to suit the range of site conditions are being researched

• MPI have contracted NIWA to continue their delimiting dives from 28th August 2023 - 4 diving days are scheduled in this phase - their situation report is expected any day.

• 6 WMP divers conducted 2 dives each on 26th August 2023 increasing the understanding of the sites in the Thompsons Point/Opopoto bay areas

• Ngāti Paoa Iwi Trust laid a rāhui on Friday 25th August 2023

• ROV survey were conducted East of Onetangi on 25th August 2023

• Ngāti Paoa divers were active from 21 August 2023 in the ongoing survey

• ROV underwater surveys continued on 18th August 2023

• SCCAT (California) visit Waiheke to view the discovery and provide advice to the coordination group on 12th August 2023

• 29th July 2023 - Exotic Caulerpa is discovered in Waiheke waters by Waiheke Marine Projects underwater ROV programme
  
  

Guided by the common ground commitments formed during the Future Search of 2020, vigilance and a deeper understanding towards marine biosecurity in our region is interlinked with the project goals. Utilizing three forms of knowledge and the project's Ngāti Paoa ki Waiheke’s lead,  in-water Pipi ~ sub projects we are in a strong position to assist with surveillance, education, monitoring and removal (if necessary) of invasive marine pests. 

The Regenerative Diving programme, annual Kōura dive surveys, Kelp Gardeners and community Beach Cleans are examples of providing community participation and opportunities for building a greater defense network.

Exotic Caulerpa - the story so far - early 2023

Whilst there has been no sign of it on Waiheke’s coast so far, the discovery of the Exotic Caulerpa seaweed species in four locations around Aotearoa/New Zealand is very concerning. If it were to arrive here it would seriously hamper the mahi of the project, suck away scarce resources and have a long tail of detrimental outcomes for our people and livelihoods.

The spread of exotic caulerpa, an invasive seaweed, is of great threat to Tīkapa Moana and its communities. Known to be present at Aotea Great Barrier and Ahuahu Great Mercury Islands since 2021 and most recently found in the Bay of Islands, and now Kawau Island - the next most likely place for its spread being the nearby coastlines and populated islands favoured for shelter and anchorage like those surrounding Waiheke Island.

Read a summary of the exotic caulerpa threat presented by WMP in April 2023

MPI (The Ministry of Primary Industries - Manatū Ahu Matua) began their response in July 2021 and placed a CAN (Controlled Area Notice) at Aotea Great Barrier and Ahuahu Great Mercury Islands - more recently a CAN has been placed in the Bay of Islands. These include zones marked with buoys to prevent gathering of fish and kaimoana as well as the anchoring of all craft designed to reduce the risk of this exotic weed being transferred to other areas on equipment. 

Waiheke Marine Projects Steering Group discussed the potential implications of an incursion at Waiheke and conducted discussions with Biosecurity NZ and Waiheke’s Local Board throughout 2022.

Whilst working to further understand the threat, in November WMP formed a local panel and requested Biosecurity NZ prepare a contingency plan (with WMP participation) to be ready for a rapid local removal and eradication response whilst beginning a surveillance programme.

The beginning of surveillance on Waiheke Island

Early in the Aotea Great Barrier discovery time, MPI using NIWA divers conducted checks in selected sites around Waiheke and nearby islands without discovering exotic caulerpa.

In December 2022, Hauraki Gulf Forum contributed a grant to Hauraki Gulf Conservation Trust for WMP to begin marine monitoring and surveillance to detect exotic caulerpa. Two Remote Operated Vehicle (ROV) surveys were undertaken by Logan Marine Projects, one in January and one in March 2023. The area’s were on the Northern coast and selected for their higher frequency anchoring potential. Tangata whenua were crewing the survey vessel on both survey days enabling capability development in marine monitoring techniques and consequent inspiration to bring mātauranga Māori to marine monitoring moving forward.

The underwater ROV is capable of high-quality video recording of the sea floor and runs a 50m transect, each transect with a GPS coordinate. Over 5,000m2 of seafloor has been surveyed to date. Results from the two ROV events produced high quality video imagery that will allow WMP to make the coverage data accessible on a digital map.

Thankfully no exotic caulerpa was observed however the very limited area covered was far from being sufficient to be considered a comprehensive survey.

All the same, both Biosecurity NZ and Auckland Council advised they were impressed with the imagery collected and have requested the data be shared with their agency databases.

If you discover a suspected Exotic Caulerpa example, please

• Take a photo

• Record the location, date & time - GPS position if possible

• Phone 0800 80 99 66 (MPI hotline)

• If you can, place everything in a sealed bag

• Don’t return it to the sea

• Check your anchor, chain, windlass and anchor-well

• Check your fishing gear - hooks, reels, and rods

• Check your Dive gear, belts, tanks, wetsuits, fins and spear-guns

• Wash everything on land using a friendly detergent

MPI have produced a video to help identify this seaweed - view it here

Proposal to remove - 2022

Waiheke Marine Project has been encouraging the formation of a contingency plan which could be executed as soon as the smallest sign of Exotic Caulerpa appears. At the core of this suggestion is a request to remove any biomass in a speedy and safe way before it becomes logistically and financially tougher to address and before it can impact a marine environment that is currently in focus for increased protection and restoration - In the prior year and for the eventual recovery of kōura tipa, kutai & pāua a Rāhui was placed by Ngāti Pāoa (January 2021)

Following a removal process at applicable scale, ongoing monitoring and spot removal will be key and this is something that WMP with its ‘people in the water’ activity can contribute volunteers toward whilst helping to target eventual eradication.

Exotic Caulerpa overseas

International experience and action research with the caulerpa genus has shown that early detection is critical to frontend effective removal and eradication. Thus, the Waiheke Marine Project and Ngāti Paoa ki Waiheke (NPKW, the mana whenua rōpu guiding the WMP) decided to proactively learn and prepare for early detection.

Southern California Caulerpa Action Team (SCCAT)

The invasive marine alga Caulerpa taxifolia was discovered June 12, 2000, in California at Agua Hedionda Lagoon

Field containment and treatments began 17 days after the discovery due to:

• timely identification and notification of the infestation;

• the proactive staff of the San Diego Regional Water Quality Control Board who deemed this invasion tantamount to an ‘oil spill’, thus freeing up emergency funding;

• the mobilization of diver crews already working at the site.

  Read more in the presentation here

Caulerpa info from other regions and agencies;

Note: this is not a complete list and will be added to as knowledge of efforts to combat Exotic Caulerpa grows

• Aotea Great Barrier Island - Motairehe Marae

• Aotea Great Barrier Island - Aotea Great Barrier Envionmental Trust

• Kawau Island - Ngāti Manuhiri

• Ahuahu Great Mercury Island - Ngāti Hei

• Te Rāwhiti Inlet, Bay of Islands - Northland Regional Council

• NIWA - involved in the Biosecurity response

• Marine Pests website

Other threats

Exotic Caulerpa is unfortunately not the only threat we face in Tīkapa Moana/Te Moananui-a-Toi. Since 2005, Biosecurity NZ reports having  detected more than 360 introduced species in Aotearoa/New Zealand of which about half have been able to establish themselves. They have required substantial responses and impacted the environment, marine and aquaculture industry, recreational and customary users. 

Examples of current species causing concern are;

• Diseases of Fish, Crustaceans and Shellfish

• Aquarium Caulerpa

• Wakame/Undaria 

• Mediterranean Fan worm

• Asian Clam

• Asian Paddle Crab

• Chinese Mitten Crab

• European Shore Crab

• Northern Pacific Seastar

• Australian Droplet Tunicate

• Speckled and light-bulb ascidians 

• Clubbed Tunicate/Leathery sea squirt

• Pyura sea squirt

Whilst Waiheke Marine Project does not have the resources to address all of these threats it does aim to collaborate with Auckland Council, MPI & Biosecurity, other agencies and nearby communities to avoid their effects in whatever way it can.