2025 Hutton Medal: An inventory of all life in Aotearoa – past and present

Bryozoans are common marine invertebrate animals that form colonies with calcium carbonate on a variety of surfaces, including rocks, shells, and kelp—and vessel hulls. Dennis has described 758 new species, 182 new genera, and 34 new families of bryozoans, including fossils, from all over the world. He has also contributed to knowledge about bryozoan evolution, ecological niches, and potential to contribute to conservation, aquaculture, and marine products. Beyond bryozoans, he has also studied the taxonomy of hemichordates, a group of marine worm-like animals.

Dennis instigated, designed, and edited the New Zealand Inventory of Biodiversity, described as the most comprehensive review of its kind for any country. These three volumes list all known life in New Zealand, whether marine, freshwater, or terrestrial. The Inventory includes more than 56,000 living and 14,000 fossil species – from bacteria to blue whales. No category of organism was excluded, and the Inventory also included a ‘gap analysis’ on how many species are likely yet to be discovered. Dennis solicited and coordinated input from 237 other experts in 19 countries and authored or co-authored 16 of the 73 chapters.

“I am passionate about the natural environment, the species we share our planet with, and the evolution of biodiversity,” Dennis says.

He first became “captivated” by invertebrates while still at high school, thanks to a two-volume work titled Animals without Backbones.

“Subsequently, bryozoans engaged my interest, owing to their importance as marine-fouling organisms.”

“They are particularly abundant in the seas around our Zealandian continent, and in the fossil record, and there are lots of scientific applications.”

Beyond bryozoans, Dennis coordinated an ambitious project to inventory all our indigenous species.

“Owing to the relatively small population of Aotearoa New Zealand, and the very small workforce devoted to categorising and naming our biota, we are still very much in the discovery phase, especially in the sea and with our fossil biota.”

“Our taxonomists cannot keep up with the rate of discovery of new species. That means we cannot fully contextualise our biota relative to the rest of the world. Yet, from what we know to date, it is highly distinctive in a global context.”

The New Zealand Inventory of Biodiversity was a strategy to document and evaluate our entire living and fossil biodiversity at a point in time, making it easier to add to that body of knowledge, Dennis says.

He stresses the urgent need to train a new generation of taxonomists who can make use of new technologies, especially given that the rate of species loss is likely to accelerate.

“Negative impacts on our natural environment have not ceased and are likely to be exacerbated by climate change.”

“Currently the taxonomic skills-base in New Zealand is only one-person deep for many groups of organisms, or it doesn’t exist at all.”

Winning the Hutton Medal has special significance for Dennis:

“The very first inventory of New Zealand’s biodiversity (Animalia only) was achieved by F. W. Hutton in 1904 in his Index Faunae Novae Zealandiae. That work was an inspiration for the New Zealand Inventory of Biodiversity and its 2023 update of marine species.”

“I am grateful for my professorial teachers at the University of Auckland in the 1960s, especially John Morton and Valentine Chapman who inspired my career, and also for the wonderfully supportive and congenial research environment at NIWA over many decades.”

“My wife Brenda, and my family, have also been a rock in my life. I cannot thank them enough.”

Hutton Medal:
The Hutton Medal is for outstanding research in the earth, plant, or animal sciences. It was established in 1911 and is the Society’s oldest award.

Citation:
To Dennis Preston Gordon for extraordinary contributions to global taxonomy, as the world’s leading authority on bryozoa, and publication of the New Zealand Inventory of Biodiversity.