Restoring mussel reefs and ecosystems in the Marlborough Sounds and beyond

Trevyn co-led a research project on restoring mussel reefs in the Marlborough Sound with Emilee Benjamin. Their work has received support and recognition from the science community and engagement from the local community.

“I’m passionate about research and marine science, so pursuing a PhD was a natural fit.” He eagerly awaits the examiner reports for his thesis submitted in March. 

Can you tell us a bit about your research?

“I am interested in coastal restoration and creative ways to recover our incredible coastal ecosystems that have been devastated by humans. More specifically, my research focuses on restoring mussel reefs in the Marlborough Sounds.”

How does your research relate specifically to climate change?

“In the environmental sciences, especially restoration research, the subject of climate change is unavoidable. Climate change is the most pressing issue impacting coastal ecosystems worldwide. Increased water temperatures lead to mass die-offs of coral reefs, while heatwaves decimate intertidal shellfish reefs. Increased storm events can rip up seagrass and seaweed beds while rising water levels threaten to eliminate the intertidal areas many ecosystems rely on.”

“Mussel reefs in the Marlborough Sounds were historically very common in the intertidal area, but overharvesting has decimated these sites over the years. One of our goals is to restore mussel reefs into the intertidal, but the environment isn’t the same as it was in the 1960s and 1970s when they were first harvested. Notably, temperatures have continued to rise, and extreme heat events are more common. This heat has killed off some of our restored mussel reefs, even at the previously-populated tidal heights. Ultimately, this means that due to climate change, the areas mussels can now thrive in may be smaller in the intertidal zone than they were historically. When restoring ecosystems, we’re hoping they survive for decades. Climate change is an undeniable reality in the coming decades, so we must prepare for it now.”

What are the accomplishments or milestones you are most proud of?

“We have restored upwards of 60 tonnes of mussels across over a dozen sites and demonstrated that these reefs are increasing local fish populations and serving as biodiversity hotspots. We have also identified significant potential bottlenecks in the current ecosystem, which we can target in the future to re-initiate natural recovery. In the community, we have partnered closely with the local mussel farming industry and local farmers to co-lead restoration efforts. We also work closely with local residents, councils, iwi, and researchers across multiple institutions to collaborate on the restoration initiative.”

“In 2021, we were presented with the Cawthron Marlborough Environmental Award. I won the Three Minute Thesis Asia-Pacific championship last year and received multiple research poster awards from the University of Auckland. Emilee has also secured funding from The Ministry of Primary Industries to continue our work.”

Where do you hope this qualification will lead you?

“I have accepted a postdoctoral position at North Carolina State University, where I will be looking at the restoration of other coastal ecosystems, including seagrass beds, oyster reefs, and salt marshes. Emilee will continue our work as postdoctoral research with the University of Auckland. She will develop the project to include other areas at the top of the South Island.” 

Can you share something about your experience completing your PhD with a Joint Graduate School?

“I completed my PhD with the Joint Graduate School at NIWA, based in Nelson. This provided some unique opportunities and a chance to experience a different research environment. Nelson has a good community of joint graduate students, mainly through Cawthron, which helps maintain some of that university feel.”

Is there anything else that you’d like to mention about your time at the University of Auckland?

“Emilee and I have had the support of our incredible advisers, Professor Andrew Jeffs and Dr Jenny Hillman, which has really underpinned the success of our research and restoration efforts throughout the last four years.”

Finally, tell us something about yourself we can’t learn by Googling you!

“I’m colourblind, which often surprises people!”