Description:

A kina culling tool designed for ecological restoration and ergonomic precision.

This project responds to a critical issue in New Zealand’s marine ecosystems. Kina (sea urchins) are an invasive species that decimate kelp forests when left unchecked, leading to widespread reef degradation. Current restoration efforts rely heavily on manual kina culling - labour-intensive work carried out by divers using rudimentary tools like metal pipes. Through collaboration with a marine biologist who regularly leads culling dives, we identified two major problems: 1) existing tools cause severe wrist strain during long, repetitive use; and 2) crushed kina often leave no visible trace, making it difficult for divers to track progress across large reef areas. The opportunity lay in rethinking the tool itself - to improve diver wellbeing, increase efficiency, and contribute meaningfully to ecosystem regeneration.

Our strategy was to design a field-ready kina culling tool rooted in real environmental and ergonomic needs. Reefguard reimagines the culling device not just as a bludgeon, but as a modular, adaptable system co-developed with its users. The concept focused on reducing injury, improving underwater communication, and enabling long-term sustainability through low-cost construction and reparability. By grounding every decision in diver feedback and testing, Reefguard balances technical function with ecological responsibility.

Reefguard is composed of a lightweight but durable modular shaft, made from standardised pipe to allow for local sourcing, easy repair, and user-led modification. Telescoping perforated sections allow the user to adjust length depending on reach or diving environment. Threaded ends accept interchangeable heads - accommodating various kina sizes and dive conditions. A custom-engineered head geometry improves kina split efficiency and leaves a visible trace on the reef, helping divers mark cleared zones. The integrated wrist stabiliser keeps the wrist in a neutral position, distributing load evenly through the arm and reducing the risk of repetitive strain injuries. The form and function were refined through repeated testing, with durability, ergonomics, and modularity guiding every iteration.

Reefguard is elevated by its direct alignment to real-world, on-the-ground environmental work. It isn’t a speculative product - it is already in use. Its success lies in its simplicity: no electronics, no rare materials, no waste. Just clear, adaptable design thinking. The tool is made from readily available parts, meaning it can be repaired, modified, or rebuilt by divers in remote regions. This reduces costs, extends product life, and avoids the waste typical of more complex gear. By embedding sustainability into every choice - from ergonomic protection to modular construction - Reefguard supports both human and ecological health. It empowers divers not just to do their job, but to do it better, longer, and safer.