Using Natural Fibres and Indigenous Knowledge to Develop Alternatives to Plastic Ropes Used in Mussel Aquaculture

Abstract

Aquaculture relies extensively on plastic materials, creating a need for lower‐plastic alternatives that retain the functional properties required for production. This study combined mātauranga Māori and science to identify natural plant fibres suitable for manufacturing mussel ropes and to evaluate their ability to catch and retain Greenshell mussel ( Perna canaliculus ) spat. Fifteen plant species were screened, with harakeke ( Phormium tenax ), tī kōuka ( Cordyline australis ) and pampas ( Cortaderia selloana ) selected for spat‐catching trials. Spat catch on extracted fibres did not differ among natural and plastic fibres ( F (3,187) = 1.2, p = 0.3), although catches differed strongly among sites and sampling events. Harakeke and tī kōuka were subsequently manufactured into corded ropes. These natural‐fibre ropes caught fewer spat than the larger commercial plastic spat‐catching rope, but both fibre types provided suitable settlement substrate and retained material integrity during deployment, with tī kōuka showing the greatest durability. The results demonstrate that natural plant fibres identified through mātauranga Māori can provide functional alternatives to plastic in mussel spat collection. Further development should focus on mechanised fibre extraction and rope manufacture, optimisation of rope structure and testing durability over longer production periods.