Ocean Census - Bounty Trough - Sadie Mills Q & A

Learn more about the Bounty Trough Expedition and its voyage co-leader, Sadie Mills, Collection Manager at  NIWA.

Why did you want to be voyage leader for this trip?

SM: For me, it’s a natural progression for my career. I have been working on NIWA vessels for a long time and have slowly been working my way up to this role. From helping with sorting on deck, to leading the curation of specimens (another key role), to then shift leading and now a voyage leader for the first time. Biodiversity research is something I am passionate about and I enjoy learning more.

I’m really pleased I get to lead this expedition because it’s focused on biodiversity, which is right up my alley. Biodiversity research is something I am passionate about and I enjoy learning more.

When I initially interviewed for a fixed-term curatorial technician job at NIWA in 2006, the position was meant to be entirely lab-based so it was unlikely I would get the opportunity for fieldwork. But then research funding came to NIWA for Oceans Survey 20/20, a NZ Government initiative to provide New Zealand with better knowledge of its ocean territory, and I got the opportunity to go to sea for the first time. Suddenly they needed more people to go on voyages. And from then, I got the spark of excitement of work at sea.

In 2014, I was appointed Collections Manager, leading a team that is responsible for more than 300,000 preserved specimen lots. This voyage will contribute to that collection and ties together the work I do on land and at sea.

What is it about sea voyages that you enjoy?

SM: I really, really enjoy being out at sea! I love the thrill of discovering new things in unexplored areas. Being out at sea is actually pretty calming for me. It’s nice to sleep out there, with gentle rocking of the boat (not everyone agrees with that in stormy weather).

And for me in my role as Collection Manager at NIWA, I really like making the connection between what we collect out at sea in the wild, and what we see back in our collection being used for research and the resource that we look after for the future.

Why is this trip significant? 

SM: We have chosen a research area, the Bounty Trough, that is very under-sampled, where we don’t have many specimens in New Zealand collections and hence will likely yield many undescribed species. It’s the diversity of specimens that we will collect from different habitats that excites me. I know we don’t have a lot of meiofauna and macrofauna samples from this region. Meiofauna (microscopic animals that live between the sand grains) and Macrofauna (animals up to about a cm long) – the smaller bodied group of animals is really going to be the exciting stuff for new discoveries, but we will also discover larger fish and invertebrates that might be new species.

For my own interests, there is one unusual and probably new species of brittle star we have got previous collections of from this area, but all the specimens were damaged, so not in good condition for description and preserved in a way that is not suitable for genetic analysis. If we could get re-collect some of these specimens, that would be fantastic!

What is the responsibility of the voyage leader?

SM: Making sure everyone is happy with how the plan is going, making decisions about what gear to deploy next and where to go with ship next. Day to day I am enacting the voyage plan in consultation with the Ocean Census team. As with all good plans, there will be plenty of adjustments and challenges to solve, like bad weather, or if a piece of gear fails so we must deploy it again. I am also responsible for pastoral care of everyone onboard, making sure everyone is happy and healthy, and solving any problems so that everyone is working well on their shifts together.

I’m also responsible for pastoral care of everyone onboard, making sure everyone is happy and healthy, and solving any problems so that everyone is working well on their shifts together.

And finally, I will be looking after the paperwork, entering station records, reporting weekly to various authorities and writing up the final voyage report at the end of our expedition with help from our team.

You are sampling up to 5,000 metres? is this unusual for NIWA?

SM: This part is the most fascinating to us, and why we are going through so much effort to get there, because we rarely ever sample that deep. Only 0.4% of NIWA’s collection is comprised of species found between 4,000 – 6,000 metres. We have some great recent samples collected from abyssal and hadal depths from the bottom of the Kermadec Trench that are from far deeper (down to 10 kilometres), but sampling this deep elsewhere in the New Zealand region is very rare. It will be interesting to compare the infauna from the Bounty Trough from 5,000 metres with the specimen data we have from the Kermadec Trench at the same depths.

This is why we are going through so much effort to get there, because we rarely ever sample that deep. Only 0.4% of NIWA’s collection is comprised of species found between 4,000 – 6,000 metres.

At 5,000 metres on the abyssal plain is also where we think the end point (the terminal fan) of the Bounty channel is, where the nutrients that are being transporting down the channel finally run out. It’s not very visible on the map, but that’s where the geologists expect the terminal fan to be, so that’s why we need to multibeam map it on the way there and see if that really is the end of the channel and what lives down there.

Haven’t people been to the Bounty Trough before to do this research?

SM: Geologists have surveyed in this area in the past, but biologists have not. Several scientists have remarked that is a very interesting place because you have the influence of the Chatham Rise on one side and the Sub Antarctic Zone on the other. In this zone things get interesting in terms of biodiversity, you might have new species because of mixtures of communities and conditions they are living in.

There are a couple of sites we will visit on this survey that have been sampled for biology in the past, but these have been collected with different sampling equipment to the full suite we will use, or were done many years ago so the samples are not of molecular grade.

Why haven’t we been there if it shows so much promise?

SM: There just hasn’t been the funding available for a biodiversity-focused voyage like this recently, which makes the Ocean Census support now so significant. If we had more funding, we would find and be able to describe a lot more new species. It’s as simple as that. We get biologists out onto voyages as side projects on multi-disciplinary surveys, but true biodiversity trips like this are now few and far between. NZ government funded programmes like Ocean Survey 20/20, Biogenic Habitats, Seamounts, and Vulnerable Deep Sea Communities studies that focused on biodiversity, were more than 10 years ago now, so this is exciting.

If we had more funding, we would find and be able to describe a lot more new species. It’s as simple as that. True biodiversity trips like this are now few and far between.

18% of NIWA’s collection is between 1,001 – 6,000 metres, with only 0.4% comprised of species found between 4,001 – 6,000 metres. There have been very few expeditions in New Zealand in the last 135 years that have specifically focused on obtaining biological samples from abyssal depths (greater than 1,500 metres) in New Zealand waters. These included the visit of H.M.S. Challenger to New Zealand in 1874 as part of its round-the-world expedition. This visit can be regarded as one of the rare deep-water surveys in New Zealand.

This visit can be regarded as one of the rare deep-water surveys in New Zealand.

The taxonomic workshop – does this happen often?

SM: This doesn’t happen often. Having a workshop to identify and describe the species right after a voyage is pretty much unheard of for NIWA. Sometimes samples can go 10 years without being described. The voyage is only meaningful if it is also backed up by the identification and taxonomic description work onshore. Here, researchers estimate that the average shelf life between discovery and description of new species is 21 years.

A lot of the specimens we get throughout the year aren’t from biodiversity-focused research like this one. For example, there are samples collected by observers on fishing vessels. And there is often no follow-up funding to describe these if they are determined to be new.

On a biodiversity-focused voyage, it could typically be months before we actually get species sent out to researchers for identification. And, even then, there may not be funding to follow-up funding for species descriptions. The pool of funding for the actual taxonomic species description work is very minimal. Taxonomists have to pick which one small group of specimens they are going to describe each year because there is not enough funded time to complete all of the detailed work for descriptions for all of the specimens they know are still undescribed. The recent New Zealand Marine Biota NIWA Biodiversity Memoir outlines just how many species remain known yet undescribed. The Ocean Census workshop will be hosted at laboratory facilities at NIWA and Te Papa.

Why is this voyage so significant?

SM: We have amassed a whole lot of knowledge through collecting samples over the years in New Zealand waters. And now we are in a great position to see where the gaps are. We have amassed data from collections housed at all of our museums around the country, including NIWAs collection and the Museum of New Zealand Te Papa Tongarewa, and knowledge from experts in New Zealand and around the world and have inventoried this knowledge in the New Zealand Marine Biota NIWA Biodiversity Memoir.

We can now use this memoir as a starting to point to guide us to where and what to explore for in other areas. No one funds blue sky research like this, so that makes Ocean Census unique. To go where we think there are species to be found as the main mission, not something tacked onto the side of another mission.

We have amassed a whole lot of knowledge through collecting samples over the years in New Zealand waters. And now we are in a great position to see where the gaps are. No one funds blue sky research like this, so that makes Ocean Census unique.

Why is cooperation needed across NZ and the world?

SM: We are lucky at NIWA that we have taxonomists that are in-house that do a lot of publishing, but we also have a close connections with taxonomists at Te Papa and a lot of national and international collaborators that work on our collections. In NZ we don’t have taxonomists working on a lot of the invertebrate groups, so we rely on our international collaborators to do the description work of our fauna. If we all had access to more funding, we could train more people in taxonomy and a whole lot more species could be described and understood.

Globally, we have a problem. Experienced taxonomists are ageing and want to handover to the next generation, but there are just not the jobs and funding to support full-time taxonomists anymore. It’s more something people do as a part of their job, not the main function. Or for the love of it, and that’s not okay because people can’t sustain that forever.

Globally, we have a problem. Experienced taxonomists are ageing and want to handover to the next generation, but there are just not the jobs and funding to support full-time taxonomists anymore.

The expertise we are able to have on this voyage is unparalleled, and not just within NIWA, but organisations we work very closely with, such as Te Papa, Auckland University of Technology, and those we have just begun working with, like the Ocean Census team.

Discovering new species requires collaboration with partners across the world who lend their expertise in new techniques for describing species. We couldn’t achieve half the things we do without those strong global networks. On this voyage we have assembled a team who are well poised to do that.

Discovering new species requires collaboration with partners across the world who lend their expertise in new techniques for describing species. We couldn’t achieve half the things we do without those strong global networks.


Ocean Census is made possible as a result of a growing Alliance of the world’s leading marine science institutions, with the ambitious goal of discovering and protecting 100,000 new species across the global ocean over the next decade.Learn more here.

Ocean Census voyage - Bounty Trough voyage leaders: l-R: Alex Rogers from Ocean Census and Sadie Mills from NIWA.
Ocean Census voyage - Bounty Trough voyage co-leader Sadie Mills
Ocean Census voyage - Bounty Trough voyage Sadie Mills in the NIWA Invertebrate Collection