"I had been working in traditional chemistry and was bored and wanted to do something different. One of my lecturers said, ‘why don't you get interested in marine chemistry?' I hadn't even heard of it and no one was doing it - so it seemed obvious I should give it a go even though I knew nothing about it."
The young chemistry graduate wrote to Professor Peter Liss, then a newly-appointed lecturer at the University of East Anglia whose work appealed, and a singularly successful and rewarding career was set in motion.
"In hindsight, the best part about marine chemistry is that it is a relatively small field, so that I have come to know most of the main players personally, giving a strong sense of community to all."
It is more than likely that all the main players have come to know Keith Hunter. During a stellar career he has achieved high honours and prominence in his chosen field.
The Distinguished Research Medal comes on top of an already glittering CV. He is a Fellow of the Royal Society of New Zealand and a member of its Academy Council; he is a Fellow and past president of the New Zealand Institute of Chemistry; internationally he is the New Zealand delegate to the United Nations Scientific Committee on Oceanic Research, a member of the American Geophysical Union, and the American Society of Limnology and Oceanography.
He also serves on the editorial boards of five international science journals and is an associate editor of Marine Chemistry. He is at present head of Otago's Department of Chemistry.
Hunter graduated from the "hut" in his backyard where, as a schoolboy, he conducted his own chemistry experiments, to the University of Auckland where he earned his undergraduate degree and his master's, and was also awarded a Rutherford Scholarship. This entitled him to undertake his PhD at any university in the Commonwealth - which was when he latched onto the University of East Anglia and marine chemistry.
"The ocean is a fascinating part of the Earth system and I haven't lost my enthusiasm for this subject."
Following his PhD, Hunter took on a year's Royal Society European Exchange Postdoctoral Fellowship at the French Atomic Energy Commission. Then, in 1979, a job came up at the University of Otago, where he turned his attention to metals in seawater.
"We managed to get the money to build this ‘clean' lab - the first of its kind in New Zealand - and it's paid off 10 times over in the money from research contracts."
The resultant research, says Hunter, led to the realisation that "in major parts of the ocean, the productivity of phytoplankton is limited by the low availability of the trace element iron".
By a combination of happy accident and inspired intuition, while on sabbatical in the Department of Oceanography at the University of Washington in Seattle in 1990, and long before climate change seriously hit the scientific agenda, Hunter became interested in carbon dioxide and its absorption by the ocean.
The interest evolved into research projects at Otago.
"Our particular research here has involved tracking changes in CO2 partial pressure and pH in surface water across the Otago continental shelf. These measurements allow us to answer the question: to what extent have these waters achieved equilibrium with the increasing levels of CO2 in the atmosphere?"
Hunter explains that the work has become relevant to the issue of ocean acidification - the decrease in ocean pH that accompanies CO2 uptake by the ocean.
"While uptake by the ocean is a good thing for climate warming, it does have the potential to cause problems for calcifying organisms - under more acidic conditions the shells become soluble and likely to break."
Hunter sets great store by collaborative working methods. One such partnership is with NIWA plankton physiologist Dr Philip Boyd, with whom he has worked for 10 years. "Together we have been very productive - more productive than had we been working separately." Boyd was recently appointed as honorary professor in the Department of Chemistry.
In a similar vein, he is both humble and generous when it comes to the top award he has been honoured with this year.
"It is very flattering to have my research recognised by my peers at Otago, many of whom I admire greatly for their own research efforts. I also see it as an award that belongs to the many students and postdoctoral researchers who have worked in my group over the years."
Looking at his long list of academic and research commitments, it is almost impossible to imagine that Hunter has any spare time at all. But he still manages to find some.
He enjoys woodworking and cooking, and travelling around New Zealand with his wife, Wynsome. And the backyard chemistry experiments of his youth have been replaced by quite a different garden pastime - growing vegetables.
FUNDING
Foundation for Research, Science and Technology
National Institute for Water and Atmospheric Research
Marsden Fund
Community Trust of Otago
University of Otago