What effect did the Kaikoura Earthquake have on the pāua populations of the area?

Correction – 20 August 2021

Giulia Trauzzi’s PhD is not formally part of the Moana Project, but rather is funded by Seafood Innovations Limited. However, Giulia hopes to use the high-resolution model developed for Kaikoura by the Moana Project to study pāua larval movement in the area, illustrating how such models can be used in fisheries research and management.

When I first came to Wellington in 2011, little did I know I would 8 years later. I’ve spent most of my life in Poggio Mirteto, Italy where I completed a bachelor’s in Biological Sciences and a master’s in marine biology with a final project on ancient DNA of the Mediterranean trout. Now I’m in the first year of my PhD at Victoria University of Wellington, Te Herenga Waka, and i’m delighted to be contributing my findings to Nga Ripo o Te Moana, the Moana Project.

The headline of my PhD is Pāua SNP development for monitoring recovery of pāua populations affected by the Kaikoura earthquake. This project has taken me to Kaikoura, a town on the east coast of the South Island of New Zealand, a very well-known summer destination. In November 2016, the town was highly affected by an earthquake whose magnitude (Mw 7.8) was one of the largest recorded in New Zealand. The most striking effect was the deformation of the seabed along 110 km of coastline which varied from -2.5m to +6m exposing a couple of the most productive fisheries of blackfoot abalone (H. iris) of New Zealand, which have remained closed ever since.

No gathering of shellfish and seaweed sign by Ministry of Primary Industries in Cape Campbell.

One of the goals of my project is to evaluate the genetic effects of this event on the pāua populations in the region and to potentially detect a genetic pattern for this species in the area. Although it is a population genetics study conducted by scientists, it would be impossible to collect samples and/or interpret the results without the knowledge of the local people whose lives and income depend on this species.

My fieldwork consisted of collecting samples from 80 pāua from nine different sites along the Kaikoura coastline which were affected differently by the earthquake. We were able to cover three sites every couple of days, when the weather and sea conditions allowed it. The pāua collection was carried out by three divers at the same time and each of them aimed to collect different size individuals. The processing of samples collected for both the Pāua Industry Council survey and my molecular analysis was carried out in the afternoons. The length of every individual was assessed with a caliper.

The shucking of each sample allowed to assess gender and maturity status. This process also exposed the attachment muscle of the pāua (white muscle that keeps the shell attached to the body of the marine snail), with what I was able to subsample for my genetic analysis. Every subsample was stored in 100% alcohol filled – tube, being careful to minimise cross contamination!.

H. iris juveniles, photo by Tom McCowan

H. iris individuals, photo by Giulia Trauzzi

Sample processing for genetic analysis, photo by Tom McCowan

Although I did not dive myself, I still felt like I connected with the place and its beauty at a safe distance (avoiding any shark encounters) and it allowed me to look closely to the coastline and its curious inhabitants: small ones and not so small ones. I was fascinated by the many Hector’s dolphins (Cephalorhynchus hectori) swimming around the boat and by the ever so cute “kekeno” or New Zealand fur seals (Arctocephalus forsteri) hilariously rolling around the rocky shores while sunbathing.

Chiton

NZ fur seals

H. australis or yellow foot pāua

Kelps

The coastline is paradise for a marine biologist! Among all sites, Ward North (+1.77 m) was the place where I felt the drastic effects of the earthquake the most. Unlike the other sites I visited during my trips, the earthquake had brought up structures (i.e. rocks), whose shapes, although beautiful, did not belong in the sunlight.

Giulia & round rocks in Ward North

Cape Campbell

Another thing that has stuck in my mind is the sound of the air and water coming out of the pores in the uplifted rocks in Cape Campbell. Like a million tiny bubbles popping at once. Although I didn’t have any memories of what these sites looked like before the earthquake, I could see that things were not supposed look like they did now. The proximity of the imposing mountains along the Kaikoura coastline to the sea, usually allows only the presence of a narrow strip of land. In the areas where the uplift was more significant, it is not like that anymore. I could walk for meters on the uplifted rocks before reaching the sea.

Cape Campbell

My fieldwork experience was positive, and it was an exciting adventure, but it was also a wake-up call on the impact of the earthquake and its consequences for the fisheries, the quota-holders, and the local community. We held permits granted by the Pāua Industry Council to collect samples, the processing was carried out in private accommodations and the pāua flesh was donated to the local iwi community: Te Runanga o Kaikoura.

Meeting the iwi, made me realise the impact of the research that has been done and will be done in Kaikoura post the earthquake and how important the outcomes are; which are clearly beyond pure academic research.

The aim of Te Korowai is to protect the sea and the coast by entitling locals to make management decisions about their environment with the advice of many New Zealand departments. I was one of the many researchers from different institutions and local fishery shareholders who attended the groups meeting in December 2019. The goal of this meeting was for researchers to share the preliminary results of their research involving the various effects of the earthquake on the environment with the local community of Kaikoura. This provided a chance for locals to find out about the recovery of the coastal environment and have open discussions about the best management decisions to make in the near future.

I am a strong believer that science should be used to improve people’s life in respect of their values and beliefs. In the science world, academics like me are instruments: we have the methods, but we need the knowledge of the local community to guide our work and that lies in their tradition, culture and history. I hope that, by the end of my PhD, these new learnings will also become part of my tradition, culture and personal history, regardless of the outcomes of my research.    

Giulia Trauzzi

PhD Candidate

 Victoria University of Wellington

Follow Giulia and the rest of the Moana Project team members and their progress here