PhD research on Samoa's treasured palolo and climate change

Palolo - scientific name eunice viridis for the South Pacific species- is a treasured sea delicacy in Samoa.

At a certain time each year, sometimes-twice-a-year, masses of spaghetti-like strands rise to the surface of the sea. 

Its late night to early morning arrival usually takes place on a moonlit night at a time usually predicted by those who follow the lunar calendar. Palolo's arrival marks the start of an anciently practiced fishing tradition, warmly welcomed with the celebratory sounds of Samoa, that traditionally saw people dressed and scented to signal something very special.

People wade into the sea, others paddle in canoes, to gather the sea delicacy, at certain coral reef locations on Samoa's islands, before palolo disappears, suddenly again, for another year. 

Over the last few decades, however, villagers have seen a decline in the palolo catch.  Now one of Samoa's scholars, a graduate of BYU-Hawaii and the University of the South Pacific, and a passionate climate change advocate, has taken up the challenge to find out why. 

Richard Crichton is a PHD candidate studying in Japan at the University of Tokyo's Graduate School of Frontier Science. The reproduction of palolo has been the subject of a two year research study from October 2015 to 2017, as part of his Masters degree in Sustainability Science at the university.

His central research question was: How do differences in the past palolo spawning patterns and the climate conditions compare, and what would this mean in a changing climate?

“The reason why interested in this is because it’s a significant marine species for the Pacific islands, especially for Samoa and being a Samoan; growing up and hearing stories of community members saying that there are significant changes that they’ve observed in the marine environment,” he says.

Palolo is listed as an endangered species under the IUCN (International Union for Conservation of Nature) Red-List and it's categorised as data deficient, meaning there's insufficient research on it, says the Samoan-born and bred academic who is the only Pacific Islands doctoral student on the university's sustainability science-global leadership programme.

Very little research exists in the Pacific marine areas, especially when it comes to specific marine species, he says, but there is a lot of research done on corals.

The earliest scientific publications on palolo date back to 1847 in a UK journal.  "Since then, a lot of other journals were focused on palolo itself, but again, these were mainly looking at the biological and ecological side of palolo," he says. 

"Not so much focused on climate change which is something that we're now looking into, says Mr Crichton, "and traditional knowledge...and seeing if there's any linkage with that, and seeing what it's going to mean in a changing climate."

“Secondly, I wanted to find out whether the palolo can be used as a proxy….to explain other marine species," he says. "One of the (research) aspects was to look at community surveys to validate what people were saying...whether marine life in general was on the decline.”

One of the research findings is that there is overall community consensus on this: that marine life has drastically declined over the past couple of decades. The majority of the community in Samoa are concerned about the state of the marine environment and the possibility of palolo extinction, he says.

“The question is why?,” he says. “Is it because of overfishing or other reasons? Particularly I was interested in palolo because traditional knowledge dictates that palolo spawning, or the quantity is influenced by weather conditions, or biological conditions as well. And that was the linkage with climate change.”

"I wanted to find out whether climate change will have impacts, or is impacting the quantity of palolo each year,” he says. “And we know that every year it varies. Some years it’s good, some years it’s weak, some it’s strong. “

Mr Crichton's research questions included: “What are the impacts of climate change on marine species and how does that affect communities? How does that affect society as a whole? " 

He conducted a correlation analysis to identify factors that influence the spawning of palolo and to validate traditional knowledge “which is sometimes not represented in scientific research today.”

Traditional knowledge, food security, social and economic impacts on the most vulnerable, people in the rural areas are key themes of the research. Using a multi-method research approach, Mr Crichton conducted community survey interviews in the villages of Salamumu, Falelatai, Lefaga, Siumu and Saanapu. He reviewed historical ecological data including journals, media reports and mapped out the observed variations in palolo spawning quantity annually.  Comparing that data with climate information, he created a statistical database to analyse the variations.


Mr Crichton's research showed that warmer ocean temperatures have a “significant influence on the quantity of palolo,"

" Heavy palolo rising is associated with weak Nino years and strong Nino events are typically characterised by a weak spawning," he says.

“There may be other factors that influence the quantity of palolo spawn but this case provides an important insight towards the sustainability of marine life, particularly societies that depend on coral reefs."

“Samoa’s climate data supports a changing climate and this will have a significant impact on marine life, especially coral reefs and marine biodiversity. The climate is changing and will likely impact fish reproduction.”

This study, says Mr Crichton, is an opportunity to “highlight some of the challenges that our community members, especially in the rural areas of Samoa, are facing...when it comes to depleting marine resources, and also the cultural practice of palolo.”

"...It would be very rewarding to see more Pacific Islanders involved in climate change research and to advocate for this," he says.

"We know that we, as a region, are very passionate about what is happening to our homes, and it would be great to see more people do scientific or social science research that will support our future in the Pacific."

"Climate change is real. As Pacific people, we are in the forefront of climate change impacts and so, for us, it's not a question of whether this is real. It's a question of: What can we do? ensure that we have a sustainable future," he says.

Mr Crichton's research was presented in New Zealand at last month’s Pacific Climate Change conference in Wellington. His PhD research is now extending its focus to other coral marine species.


Photo by Amoa Resort, Savaii.