Five research organisations, six weeks, 23 scientists, 14 islands and reefs in the Southwest Pacific and hundreds of vital scientific samples and records. The Southwest Pacific marine expedition has come to an end but the different teams who took part have all returned with valuable scientific insights and vital additions for their marine reference collections.

The expedition team included scientists from Auckland Museum, Australian Museum, Massey University, Te Papa, Conservation International, along with ambassadors from the Sir Peter Blake Trust (on the first leg) and two underwater cameramen.

Auckland Museum’s Head of Natural Sciences Dr Tom Trnski, who led the six-week Southwest Pacific marine expedition, says the research trip was a great success allowing each of the teams to advance their scientific research and fill in a number of gaps in the records for this region.

“We got a lot done. We got really good representative samples everywhere we went and among those samples are some really exciting new discoveries.”

“We discovered fish and invertebrates that hadn’t been recorded at these islands before and, as we work through our findings, we are confident that some of our discoveries will be confirmed as new species that have never been recorded anywhere before.”

In terms of observations, Trnski says outside of the Kermadecs the team was surprised by how few large fish they recorded.

“For a lot of the expedition we weren’t seeing many sharks or large snapper or grouper. The reality is that’s a bellwether for what is happening around the world. There are very few places left where the impacts of fishing aren’t being seen in the marine communities. That’s what makes marine environments like Rangitahua, the Kermadec Islands, such an important baseline for comparison.”

Trnski says the expedition was ambitious given the two activity-packed legs and the number of different personnel, gear and research projects that were involved, but the teams were all incredibly productive and have returned with valuable data and samples.

“On the genetic side of things, we got a lot of new samples that will help us determine population connectivity between the islands, giving us an understanding of how closely related things are across the different islands.”

“These insights into population connectivity are of real interest globally. These islands have very rarely been visited and the marine life is largely unrecorded, so it has filled in a lot of holes.”

The Southwest Pacific expedition also marks the completion of a series of marine expeditions that the Auckland Museum began back in 2011, which has seen them lead scientific teams to the Kermadec Islands multiple times, as well as Three Kings, southern French Polynesia, Tonga and Niue. Many of the scientists, including researchers from Australian Museum and Te Papa, have taken part in multiple expeditions.

“There is always more to do but we are very happy with what we have achieved in terms of documenting the biodiversity in the South Pacific and building a picture of the biological connectivity across the region.”

Australian Museum’s Mark McGrouther and Sally Reader who were part of the wider ‘fish team’ have said the different researchers all worked well together to catch, identify, record, photograph, tissue-sample and preserve the fish specimens discovered during the expedition.

“We’re really pleased to have collected fishes in some very remote areas of the southwest Pacific. There were many first time records for the region and we were excited to see some we couldn’t recognise in the field, which may be new species.”

McGrouther says more work needs to be done to examine the specimens once they arrive at their respective museums (the specimens are shared between the marine collections of Auckland Museum and the Australian Museum), and they will call on assistance from world experts to help with identifications and determine whether there are new species among the records.

“Either way, the specimens housed at the museums comprise a valuable collection for study by the national and international ichthyological community, only made possible with collaborative expeditions like this one.”

Australian Museum collection manager Steve Keable, whose focus is marine invertebrates, says ahead of the Southwest Pacific marine expedition their collections contained comparatively few specimens from sites in the region.

"At times the diversity of invertebrates was overwhelming leading to some long processing hours to sort, catalogue and preserve. The Australian Museum invertebrate team members focused particularly on crustaceans (crabs, shrimp etc), marine worms and molluscs (snails, bivalves, octopus, nudibranchs etc) for research projects currently underway, as well as building the database of samples allowing future genetic study.”

“Among the crustaceans, highlights included a number of small mantis shrimp (Stomatopoda) that were collected using a suction pump from burrows on sediment flats at low-tide, the remote location and unusual collection method suggest these will be of particular interest to studies examining the distribution and relationships of these animals. A great variety of marine worms were apparent in many locations. Divers often had to compete with fish trying to eat these worms when rocks or rubble were turned to try and get specimen samples from the underside.”

Cephalopod (think squid and octupus) expert Mandy Reid says she is eagerly awaiting the arrival of the specimens in Australia.

"Not many cephalopods were collected, so it makes those that were all the more precious. A couple were collected on scuba and others found out and about on a night walk at Minerva Reef during the second leg of the expedition."

"All were octopuses and these are notoriously difficult to identify without having preserved specimen in front of you, together with a lot of reference material to refer to. Those that were collected were quite small. There are a number of species that mature at small sizes so when they land in Australia we will have a better idea of whether they are mature or juveniles of previously known species. At the very least they will be new records from this part of the Pacific.”

Conservation International’s Mark Erdmann came away from the expedition with vital information for the organisation’s Lau Seascape Initiative, which will ultimately allow them to determine the best locations for marine reserves.

“Though it will still be several months before we have final tallies, we know for sure that we’ve added at least 63 new records to the overall Lau reef fish species list (which now stands at 786 species), as well as over 30 new records for Fiji reef fishes (now at 1119 species!). Included amongst our finds are several potential new species that we are keen to further examine in the laboratory and through genetic analysis.”

Community consultation is also vital to the Lau Seascape Initiative and Erdmann says the expedition team worked closely with the chiefs and communities in the Lao Group.

The team from Massey University (Adam Smith, Clinton Duffy, Odette Howarth, Emma Betty) spent their time deploying baited remote underwater video (BRUV) gear to find out which species of predatory fishes - particularly sharks – were in each of the locations visited during the Southwest Pacific marine expedition.

“Some places had an abundance of lethrinids (emperor fishes) and small grey reef sharks, some had larger species such as silvertip, various hammerheads, and tiger sharks, while others were surprisingly devoid of large fishes.”

Over the coming months, the videos will be analysed and converted to data to allow quantitative comparisons of locations and habitats. The data collected by the Massey team will also contribute to the Global FinPrint project , who supported their participation in the expedition.

“It was always a highlight when a very large shark payed our BRUVs a visit. The most impressive was the great white shark at the Kermadec Islands, who picked up our gear, swam with it to the surface, and dropped back to the sea floor. This happened not once, but three times before he lost interest. We also had some serious attempts at our bait canisters made by tiger sharks. The only successful attempt was by a large and very aggressive great hammerhead shark in Fiji, who managed to rip the canister right off the pole.”

Sir Peter Blake Ambassador Will McKay describes the expedition as ‘a highlight of my life’, and an experience that has given him greater clarity around what he wants to achieve with his marine research.
 
One of the experiences that stands out for him was the chance to take a small tissue sample from the dorsal fin of a Galapagos shark.
 
“I'm not sure I'll ever see the colours, species diversity and fish behaviours we were treated to. Having studied aspects of tropical reef ecology at university I was so lucky to further my understanding thanks to the very patient and enthusiastic human data bases of knowledge on board.”

A visual record of the Southwest Pacific

Specimens, tissue samples and scientific data aren’t the only records that have been captured on this expedition. Talented underwater videographer Kina Scollay and underwater photographer Richard Robinson have brought home incredible images and footage from the Southwest Pacific marine expedition.
 

Some of the content will be shared by New Zealand Geographic, some will be used in education resources being developed by the Sir Peter Blake Trust, and 100 high-quality still images and a series of 360-degree video experiences will be accessioned into Auckland Museum’s photographic collections.

Once these images and videos have been added to the collections we’ll make sure to share them and in coming months we’ll let you know when the scientists confirm any new species or other discoveries they have made as a result of the expedition - from one earlier marine expedition to the Kermadecs the team has confirmed 15 new species records.

“One thing that stands out from all the sampling and recording we have done is that there is still so much to discover. It is daunting to think of what we don’t know, but it’s exciting to think of the new discoveries we have made this time and how these will improve the understanding of these vital marine environments.”