This month, a fleet of sailing boats left the Bay of Islands to compete in the Island Cruising Pacific Rally. But 20 yachts will do more than race across the vast ocean passages between island nations. The sailors will tow cutting-edge miniaturised environmental DNA sampling kits as part of Citizens of the Sea, one of the world’s largest-scale ocean surveys, and return hundreds of samples to help map biodiversity in the southwest Pacific.
Seafarers are a natural fit for this task, says Cawthron Institute marine biologist Xavier Pochon, the founding scientist of the Citizens of the Sea charity. “They care deeply about the ocean because they spend a lot of time out there, and they want to be part of the solution and have embraced the opportunity to be citizen scientists.”
Each drop of seawater teems with genetic signatures of marine life, from invisible microbes and phytoplankton all the way to dolphins and whales that may have passed through as part of their migrations. While traditional oceanographic research relies on direct sightings or even physical capture of a species, fragments of DNA in seawater can be read like a species barcode, Pochon says, tracking the presence of animals without having to wait for observations.
This year’s rally is the second time the sailors have taken part. They returned more than 1000 eDNA samples last year and have already contributed to some remarkable discoveries, including the confirmation of multiple species of dolphins, slender snipe eels and a pygmy whale, which helped to refine knowledge of migratory paths.
“The elusive spurcheek lanternfish, a deep-sea organism famed for its epic bioluminescence, was also detected for the first time in the region through eDNA,” Pochon says.
The project has also tracked the presence of harmful bloom-forming algae, including species known to cause paralytic and amnesic shellfish poisoning.
“It was quite striking to see in our data that some of these very problematic species are already quite far south, getting much closer to New Zealand. Models show that in about 10 years, we will have many more occurrences of harmful algal blooms closer to the coastline, and this work provides critical early indicators for marine health and human safety.”
Apart from the sailors, the project has also engaged commercial vessels, fishing boats and even waka to tap “an enormous resource to help map ocean health”. Eventually, Pochon hopes to collect enough data to help governments and industries with interests in the health of the ocean to make informed decisions.
The project is built around collaborations with organisations in each island nation the rally visits, including Tonga, Fiji, Vanuatu and New Caledonia. Wherever the boats arrive, drop boxes are available to collect samples, which are then sent to Nelson for analysis at the Cawthron Institute.
Citizens of the Sea is supported by the Minderoo Foundation, whose quest is to bring different ocean initiatives together to make sure data collection is comparable and sharable.
“There’s an urgency to understand biodiversity and how climate change is affecting it around the ocean,” Pochon says. “We need to find processes to collect data in a format that will be useful for other research organisations, local communities, NGOs and governments.”
Citizens of the Sea data are placed with the Global Biodiversity Information Facility, which provides the International Union for Conservation of Nature (the keepers of the red list of threatened species) with eDNA information about the distribution of rare and endangered marine life.
While Pochon has spent a lot of time on research vessels, the Pacific Rally will be his first experience of embarking on a long ocean passage in a yacht, when he joins the rally on its return voyage from Fiji later this year.
He says he appreciates the start of the rally coinciding with David Attenborough’s latest documentary about the ocean, because he agrees with the veteran broadcaster’s sentiment: “If we save the sea, we save our world.”
