PROJECTS /
Detecting Caulerpa
Project Summary
Caulerpa poses a catastrophic threat to marine ecosystems
Early detection is vital in the fight against this invasive weed
Developing underwater surveillance tools for local communities
Photo Credit / NIWA
A CATASTROPHIC THREAT
A crisis is looming with the presence of exotic caulerpa, an invasive seaweed posing a catastrophic threat to the marine environment, coastal ecosystems and way of life for local communities in northern Aotearoa.
Described as the world’s worst marine pest, exotic caulerpa spreads quickly, forming thick, suffocating mats which smother other species and is incredibly difficult to eradicate. It destroys biodiversity and has the potential to radically change the ecology of our coastal habitats down to 40m+!
As we’ve seen internationally, early detection is vital in the fight against this invasive weed. Left unchecked, it can have catastrophic ecological, economic, social and cultural impacts. In the Mediterranean, it’s estimated up to 50% of fish biomass was lost which would be devastating for seabirds, fish species and the recovery of scallops and crays if it was not controlled in New Zealand.
A Race Against Time
The clock is ticking with caulerpa rapidly spreading in New Zealand waters, with significant infestations now present off Rāwhiti in the Bay of Islands, Aotea Great Barrier Island, Waiheke Island, and elsewhere in the Hauraki Gulf. Tracking its growth and understanding exactly where it is and to what extent is proving difficult for scientists and communities. Underwater geolocation is complex and getting divers out to survey the seafloor requires a lot of time and resources, making it a slow and costly process.
THE IMPACT
BY NUMBERS
An est. 50% of fish biomass has been lost in the Mediterranean due to caulerpa
Caulerpa can radically change marine ecology down to depths of 40m+
ROVs can survey an underwater area 3x faster than a SCUBA survey
INNOVATIVE DETECTION
Peter Miles, a trustee at the Mussel Reef Restoration Trust / Revive Our Gulf project and an engineering technologist is on a mission to help remove this barrier and speed up detection across Aotearoa by developing a low-cost Remotely Operated Vehicle (ROV) tool which can be adopted by iwi and local communities for detecting both caulerpa and other invasive species.
This pilot project is already looking to be a game changer as ROV surveys are both 3x faster and cost a third of SCUBA dive surveys. Seafloor imaging technology is widely available already, but it’s expensive, making it inaccessible for many community groups. The aim of this project was to create a low-cost, high-quality option, hosted on an easy-to-use platform, and having achieved this the focus has now turned to operationalising it.
Going forward, there’s also the potential to automate the ROVs to scan an area and adopt AI technology to identify caulerpa, further reducing costs and increasing detection and monitoring capability.
The information from this project (including the hardware and software used) will be open source making it widely accessible and as low-cost as possible.
“Finding and treating caulerpa will be a large version of Whack-a-Mole. You’ve got to be out there and surveying to see it. All the sightings (bar one) so far have come from locals being out there, so getting them the tools they need will be key.”
Peter Miles
REVIVE OUR GULF
OUR IMPACT
While caulerpa is a monumental issue requiring a national response, Live Ocean saw the opportunity to contribute to the solution by partnering with the Mussel Reef Restoration trust and other funders to support Peter Miles’ work.
“Everything is harder in the ocean – you’ve got weather, the need for boats, difficulties with underwater geo-location and the need for specialist divers. Detection is a critical tool in the caulerpa response, and this innovative work aims to significantly scale up the speed of surveillance and reduce the cost using ROVs and machine learning.” says Sally Paterson, Chief Executive – Live Ocean Foundation
HOW YOU CAN HELP
Exotic caulerpa can get snagged on anchors, chains and dive and fishing gear and be accidentally moved to new locations. There are simple actions you can take to help stop the spread:
- When out at sea – before leaving a location, check your vessel’s anchor and anchor chain, and any equipment you’ve used in the water for any tangled seaweed. If you have an automatic retrieval system, still look out for any attached pieces of seaweed.
- If you find any type of seaweed – remove it, bag or contain it securely so it can’t get back into the water, and take it ashore for disposal in a rubbish bin.
Peter Miles
Trustee, Revive Our Gulf
Peter has a background in engineering, marketing, and business development. As a jack-of-all trades entrepreneur he has founded and exited a couple of businesses (ControlVision – Robotics & Machine Vision; Bookabach – Holiday Rentals). He loves boating, sailing, fishing and snorkeling the Hauraki Gulf.
Since 2019, Peter has been lending his talents and problem-solving abilities to mussel reef restoration efforts in the Hauraki Gulf; creating the enabling environment for collaboration and bringing together teams to crack a winning restoration formula to enable the deployment of restoration activities at scale.
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