Te Pītau Whakarei Karahipi Scholarship - Seagrass Restoration

About this research

Intern: Breanna Hindmarsh, Te Aitanga a Hauiti, Ngāti Ira, Ngāti Porou, Victoria University of Wellington

Supervisor/s: Cawthron Institute

The internship is provided as part of the prestigious NPM and Cawthron Institute Te Pītau Whakarei Karahipi Scholarship.

Summary

Seagrass meadows [Zostera muelleri are one of Aotearoa’s most important coastal ecosystems. They provide crucial habitat and mahinga kai areas for fish/taonga species and other animals. These plants also sequester carbon from the atmosphere and trap sediment to reduce erosion (among other important roles). Unfortunately, Aotearoa, like many places globally, has experienced extensive seagrass decline, due to physical disturbance, deteriorating water quality and disease. 

To give seagrasses a helping hand, many countries are attempting seagrass restoration, using transplants from wild donor sites or harvesting/planting of seagrass seeds. In Aotearoa, restoration efforts have been trialled using transplanting techniques with some success. However, removing plants from donor sites places pressure on remaining healthy seagrass beds. Restoration using seeds or vegetative fragments could allow for large scale efforts without damaging existing seagrass meadows and has been successful overseas. 

Seagrass restoration using seeds has not been trialled in Aotearoa because it was thought that flowering (required for seed production) in Z. muelleri was rare. However, previous scholarship students demonstrated that flowering is more common than previously thought and that seeds can be successfully germinated (Hindmarsh & Hooks 2022). 

This project built on those research findings.