Key Takeaways
- A decommissioned 60‑year‑old fishing trawler, the Twofold Bay, was deliberately sunk off Hawke’s Bay to become an artificial reef and dive site.
- The project, led by the not‑for‑profit LegaSea, required three years of planning, extensive environmental stripping, and adherence to international guidelines such as the London Protocol.
- Approximately 800 + volunteer man‑hours were spent removing engines, oils, and other hazardous materials to make the vessel safe for marine life and divers.
- The wreck now rests at about 17 metres depth near Napier, on the edge of Pania Reef, and is expected to develop into a thriving habitat for sponges, mussels, barnacles, anemones, sea squirts, and fish species such as blue cod, snapper, and kingfish.
- Local iwi (Mana Ahuriri Trust), recreational fishers, commercial seafood representatives, and scientists all support the initiative, noting its potential to boost biodiversity, provide educational diving opportunities, and foster community stewardship of the marine environment.
- Monitoring will continue to assess ecological connectivity with the adjacent Pania Reef and to track the reef’s development over time.
Project Origins and Vision
The idea to sink the Twofold Bay emerged from LegaSea’s broader mission to restore New Zealand’s marine abundance, biodiversity, and ecosystem health. Recognising that many coastal areas, including Hawke’s Bay, are relatively exposed and lack complex underwater structures, LegaSea sought to create a purpose‑built artificial reef that could serve both ecological and recreational functions. By repurposing an old fishing trawler, the project symbolically transforms a former agent of habitat disturbance into a platform for regeneration.
Planning, Permissions, and Protocol Compliance
Bringing the vision to life demanded three years of meticulous preparation. LegaSea consulted widely with stakeholders, secured the necessary resource consents, and aligned the operation with the London Protocol—the internationally recognised framework for preventing marine pollution from dumping. This protocol mandated a two‑year consultation phase, ensuring that environmental impacts were assessed and mitigated before any physical work began.
Volunteer Effort and Environmental Stripping
A core component of the preparation was the removal of all potentially harmful substances from the vessel. Volunteers contributed over 800 man‑hours to strip the Twofold Bay of its engines, fuel systems, lubricants, batteries, and any other contaminants. According to Brett Rigby of LegaSea Hawke’s Bay, this painstaking decontamination was essential not only to meet regulatory standards but also to guarantee that the wreck would be “dive safe” and would not leach toxins into the surrounding water as it deteriorated.
The Scuttling Event
Once the vessel was cleared, the actual sinking was a controlled, low‑impact process. Crews opened strategically placed holes in the hull and added ballast concrete to allow gravity to guide the trawler to the seabed. The entire descent took roughly ten minutes, witnessed by a flotilla of about forty boats that cheered and sounded their horns as the Twofold Bay slipped beneath the waves. The deliberate, gradual approach avoided explosive fragmentation, preserving the ship’s integrity for divers and marine colonisers alike.
Location and Depth
The wreck now rests in approximately 17 metres of water, positioned near Napier on the outer edge of Pania Reef. This depth was chosen to balance accessibility for recreational divers with sufficient water column to support a diverse assemblage of marine life. Proximity to the existing Pania Reef also offers the potential for ecological connectivity, allowing larvae and mobile species to move between the natural and artificial habitats.
Anticipated Ecological Development
Over time, the submerged trawler will undergo colonisation by a succession of organisms. Early settlers are expected to include biofilms, sponges, green‑lipped mussels, barnacles, anemones, and sea squirts. These foundation species will create structural complexity and provide food and shelter, attracting higher trophic levels such as blue cod, snapper, and kingfish. As the steel corrodes and the hull breaks down, additional niches will form, further enhancing biodiversity and contributing to the overall health of Hawke’s Bay’s marine ecosystem.
Cultural and Community Perspectives
Local Māori representatives, particularly Shade Smith of Ngāti Kahungunu, highlighted the poetic irony of converting a former bottom‑trawling vessel into a reef‑builder. Smith noted that the project exemplifies a shift away from destructive fishing practices toward active restoration, and he emphasized the importance of monitoring the reef’s development to understand its integration with the nearby Pania Reef. Meanwhile, Joe Reti of the Mana Ahuriri Trust expressed enthusiasm for the upcoming lifting of an 18‑month rahui (temporary closure), which will allow iwi members to reintroduce rangatahi (youth) to the site for diving and cultural reconnection.
Stakeholder Support and Shared Benefits
The scuttling drew praise from a broad coalition of interests. Lisa Futschek, Chief Executive of Seafood New Zealand, lauded the collaboration between commercial and recreational fishers, describing the initiative as a “shared user of the moana” that delivers multiple benefits—ecological, educational, and economic. Scott Macindoe, president of the New Zealand Sport Fishing Council, echoed this sentiment, stressing that restoring marine abundance is a long‑term endeavour that thrives on community belief, cooperation, and imaginative stewardship.
Monitoring and Future Outlook
Ongoing observation will be critical to gauging the success of the artificial reef. Scientists plan to track species colonisation, growth rates, and any changes in water quality or sediment dynamics around the wreck. Data collected will inform future reef‑creation projects both within New Zealand and internationally, offering a practical model for converting decommissioned vessels into valuable marine assets while adhering to strict environmental safeguards.
Conclusion
The intentional sinking of the Twofold Bay represents a convergent effort among environmental NGOs, iwi, fishing communities, and government bodies to repurpose a redundant fishing trawler into a thriving artificial reef. By removing hazardous materials, following international protocols, and engaging volunteers, LegaSea has laid the groundwork for a habitat that promises to enhance biodiversity, provide safe diving opportunities, and reinforce cultural connections to the sea. As the wreck settles and life begins to flourish on its steel skeleton, the project stands as a testament to what can be achieved when diverse stakeholders unite around a common goal of marine restoration.